Updated on 2024/02/26

写真a

 
TOKORO, Chiharu
 
Affiliation
Faculty of Science and Engineering, School of Creative Science and Engineering
Job title
Professor
Degree
Dr.Engineering ( 2003.03 The University of Tokyo )

Research Experience

  • 2023.11
    -
    Now

    株式会社トッパンフォトマスク   社外取締役

  • 2022.09
    -
    Now

    Waseda University

  • 2022.09
    -
    Now

    Waseda University

  • 2021.04
    -
    Now

    JX金属株式会社   社外取締役

  • 2021.04
    -
    Now

    The University of Tokyo   The Graduate School of Engineering

  • 2016.11
    -
    Now

    東京大学生産技術研究所   特任教授

  • 2015.04
    -
    Now

    Waseda University   Faculty of Science and Engineering

  • 2009.04
    -
    2015.03

    Waseda University   Faculty of Science and Engineering

  • 2007.04
    -
    2009.03

    Waseda University   Faculty of Science and Engineering

  • 2004.04
    -
    2007.03

    Waseda University   School of Science and Engineering

▼display all

Education Background

  • 1998.04
    -
    2003.03

    The University of Tokyo  

  • 1994.04
    -
    1998.03

    Waseda University   School of Science and Engineering  

Committee Memberships

  • 2015.02
    -
    2023.03

    経済産業省  中央鉱山保安協議会 委員

  • 2023.07
    -
    Now

    公益財団法人資源環境センター  理事

  • 2021.04
    -
    Now

    Scientific Reports  Editorial Board Member

  • 2020
    -
    Now

    資源・素材学会  粉体精製工学部門委員会 委員

  • 2020
    -
    Now

    環境資源工学会  編集委員長

  • 2020
    -
    Now

    環境資源工学会  常務理事

  • 2020
    -
    Now

    Minerals  Editor

  • 2019.06
    -
    Now

    公益社団法人日本工学アカデミー  正会員

  • 2019
    -
    Now

    エコデザイン推進機構  理事

  • 2015
    -
    Now

    環境資源工学会  理事

  • 2023.04
    -
    2025.03

    一般財団法人 ピースコミュニケーション財団  理事

  • 2021.06
    -
    2025.03

    国立研究開発法人科学技術振興機構  領域アドバイザー

  • 2019
    -
    2025.03

    粉体工学会  理事

  • 2022.12
    -
    2025.02

    文部科学省  科学技術・学術審議会専門委員

  • 2021.02
    -
    2025.01

    資源・素材学会  代議員

  • 2022.11
    -
    2024.10

    経済産業省  産業構造審議会 臨時委員/産業技術環境分科会廃棄物・リサイクル小委員会自動車リサイクルワーキンググループ指名

  • 2023.04
    -
    2024.04

    環境省 環境再生・資源循環局、経済産業省 資源エネルギー庁  「再生可能エネルギー発電設備の廃棄・リサイクルの在り方に関する検討会」委員

  • 2023.07
    -
    2024.03

    一般社団太陽光パネルリユース・リサイクル協会  招聘客員

  • 2023.04
    -
    2024.03

    国立研究開発法人日本原子力研究開発機構  深地層の研究施設計画検討委員会委員

  • 2023.03
    -
    2024.03

    公益財団法人廃棄物・3R研究財団  二酸化炭素排出抑制対策事業費等補助金(プラスチック資源・金属資源等のバリューチェーン脱炭素化のための高度化設備導入等促進事業)審査委員会 委員

  • 2023.01
    -
    2024.03

    東京工業大学科学技術創成研究院ゼロカーボンエネルギー研究所アドバイザリー委員会  委員

  • 2022.04
    -
    2024.03

    国立研究開発法人科学技術振興機構  輝く女性研究者賞選考委員会 委員

  • 2022.04
    -
    2024.03

    一般社団法人日本粉体工業技術協会  ふるい委員会 委員

  • 2020.04
    -
    2024.03

    日本粉体工業技術協会  分級ふるい分け分科会 副コーディネータ

  • 2018
    -
    2024.03

    公益財団法人ホソカワ粉体工学振興財団  選考委員

  • 2023.03
    -
    2024.02

    国立研究開発法人産業技術総合研究所  領域アドバイザリーボード 委員(材料・化学領域)

  • 2023.02
    -
    2024.02

    経済産業省  総合資源エネルギー調査会 臨時委員/資源・燃料分科会 委員

  • 2022.06
    -
    2024.02

    公益社団法人化学工学会/一般社団法人日本能率協会  INCHEM TOKYO 2023 展示委員会委員(コアメンバー)

  • 2022.02
    -
    2024.02

    東京都  使用済太陽光発電設備リサイクル検討会 委員

  • 2020
    -
    2023.09

    日本学術会議  広報委員会「学術の動向」編集分科会 編集委員長

  • 2017.10
    -
    2023.09

    日本学術会議  第三部会員

  • 2022.10
    -
    2023.06

    公益社団法人新化学技術推進協会  GSC賞二次選考委員

  • 2021.09
    -
    2023.06

    一般社団法人循環経済協会  招聘研究員

  • 2017.04
    -
    2023.06

    化学工学会  理事

  • 2023.01
    -
    2023.03

    三菱UFJリサーチ&コンサルティング株式会社(環境省委託)  マスバランス方式に関する研究会 委員

  • 2022.11
    -
    2023.03

    人事院  令和4年度人事院総裁賞選考委員会 委員

  • 2022.11
    -
    2023.03

    国立研究開発法人日本原子力研究開発機構  深地層の研究施設計画検討委員会 委員

  • 2022.07
    -
    2023.03

    一般社団法人低炭素投資促進機構(経済産業省補助事業)  無人自動運転等のCASE 対応に向けた実証・支援事業費補助金評価委員会 委員

  • 2022.06
    -
    2023.03

    BACE(Battery Circular Ecosystem)コンソーシアム2022  アドバイザー

  • 2022.05
    -
    2023.03

    有限責任監査法人トーマツ(環境省受託事業)  令和4年度脱炭素型金属リサイクルシステムの早期社会実装化に向けた実証事業評価審査委員会 委員

  • 2022.05
    -
    2023.03

    一般社団法人資源・素材学会  資源・素材教育センター実行委員

  • 2022.04
    -
    2023.03

    一般財団法人JCCP国際石油・ガス協力機関  令和4年度企画・執行委員会(PIC) 上席調査員

  • 2022.04
    -
    2023.03

    資源・素材学会  関東支部長

  • 2022.04
    -
    2023.03

    公益社団法人日本工学アカデミー  第16回日米先端工学シンポジウム(JAFOE) 運営委員長

  • 2021.05
    -
    2023.03

    国立研究開発法人新エネルギー・産業技術総合開発機構  技術委員

  • 2019.06
    -
    2023.03

    石油天然ガス・金属鉱物資源機構  海洋鉱物資源開発検討委員会選鉱・製錬ワーキンググループ 委員

  • 2019.03
    -
    2023.03

    粉体工学会  出版委員会 委員長

  • 2017.04
    -
    2023.03

    日本粉体工業技術協会  東京粉体工業展委員会 委員

  • 2011.03
    -
    2023.03

    粉体工学会  Advanced Powder Technology Editor

  • 2022.08
    -
    2023.02

    RSC Advances  Associate Editor

  • 2022.03
    -
    2023.02

    経済産業省  令和3年度基礎素材産業の低炭素化投資促進に向けた設計・実証事業補助金に係る外部審査委員会 委員

  • 2023.01
     
     

    有限責任監査法人トーマツ(内閣府科学技術・イノベーション推進事務局委託)  「グローバル・スタートアップ・キャンパス構想関連事前調査」有識者委員会 委員

  • 2022.01
    -
    2023.01

    経済産業省  蓄電池のサステナビリティに関する研究会 委員(委員長)

  • 2022.04
    -
    2022.12

    経産省(野村総研受託事業)蓄電池先端生産技術導入・開発促進事業審査委員会  審査委員

  • 2021.12
    -
    2022.12

    経済産業省 資源エネルギー庁  総合資源エネルギー調査会 臨時委員/資源・燃料分科会 委員

  • 2022.09
     
     

    MITテクノロジーレビュー「Innovators Under 35 Japan 2022」  審査委員

  • 2020.07
    -
    2022.06

    日本学術振興会  卓越研究員候補者選考委員会 委員

  • 2020.07
    -
    2022.06

    日本学術振興会  特別研究員等審査会 委員

  • 2021.12
    -
    2022.03

    国立研究開発法人科学技術振興機構  国際科学技術共同研究推進事業(戦略的国際共同プログラム)アドバイザー

  • 2021.10
    -
    2022.03

    株式会社価値総合研究所(環境省委託)  地球温暖化対策に係る技術実証事業管理・検討及び調査等事業委託業務 委員

  • 2021.09
    -
    2022.03

    石油天然ガス・金属鉱物資源機構  グリーンレメディエーション等研究委員会 委員

  • 2021.09
    -
    2022.03

    石油天然ガス・金属鉱物資源機構  基本方針検討ワーキンググループ 委員

  • 2021.07
    -
    2022.03

    一般財団法人JCCP国際石油・ガス協力機関  令和3年度女性活躍推進のためのUAE-日本合同調査プロジェクト 企画・執行委員会検討委員会 上席調査員

  • 2021.07
    -
    2022.03

    株式会社三菱総合研究所(国立研究開発法人新エネルギー産業技術総合開発機構委託事業)  3R技術ロードマップ作成に係る検討会 委員

  • 2021.05
    -
    2022.03

    一般社団法人低炭素投資促進機構  (経済産業省補助事業)電動車普及に伴い必要となる社会システムの整備に関する実証事業評価委員会 委員

  • 2021.05
    -
    2022.03

    有限責任監査法人トーマツ(環境省委託事業)  令和3年度脱炭素型金属リサイクルシステムの早期社会実装化に向けた実証事業評価審査委員会 委員

  • 2021.04
    -
    2022.03

    粉体工学情報センター  粉体工学情報センター学術奨励賞(IP奨励賞)審査委員・研究助成選考委員

  • 2021
    -
    2022.03

    国立研究開発法人科学技術振興機構  第3回輝く女性研究者賞(ジュン アシダ賞) 選考委員

  • 2020.07
    -
    2022.03

    石油天然ガス・金属鉱物資源機構  金属資源生産技術開発研究会 委員

  • 2020
    -
    2022.03

    資源・素材学会  関東支部幹事

  • 2017.09
    -
    2022.03

    経済産業省  産業構造審議会 産業技術環境分科会廃棄物・リサイクル小委員会自動車リサイクルWG 臨時委員

  • 2022
     
     

    EcoDesign2023国際会議  国内実行委員

  • 2021.12
    -
    2022.01

    公益財団法人本多記念会  第43回本多記念研究奨励賞受賞候補者選考委員会 委員

  • 2019.10
    -
    2021.12

    経済産業省  総合資源エネルギー調査会 臨時委員/資源・燃料分科会 委員

  • 2019.05
    -
    2021.09

    石油天然ガス・金属鉱物資源機構  パッシブトリートメント導入に向けた調査研究ワーキンググループ委員会 委員

  • 2018.10
    -
    2021.09

    日本学術振興会  「リソースロジスティクスに基づくサプライチェーンリスク戦略」に関する研究開発専門委員会 委員

  • 2018.05
    -
    2021.09

    石油天然ガス・金属鉱物資源機構  休廃止鉱山における坑排水処理の高度化調査研究委員会 委員

  • 2020.03
    -
    2021.04

    国際科学技術財団  日本国際賞審査部会 委員

  • 2020.10
    -
    2021.03

    Planning and Implementing Committee

  • 2020.10
    -
    2021.03

    ㈱ブルーアースセキュリティ(経済産業省受託事業)  マンガン酸化菌利用処理技術調査研究ワーキンググループ 委員

  • 2020.10
    -
    2021.03

    ㈱ブルーアースセキュリティ(経済産業省受託事業)  令和2年度休廃止鉱山におけるグリーン・レメディエーション(元山回帰)調査研究委員会 委員長

  • 2020
    -
    2021.03

    国立研究開発法人科学技術振興機構  第2回輝く女性研究者賞(ジュン アシダ賞) 選考委員

  • 2019.11
    -
    2021.03

    日本原子力研究開発機構  鉱山跡措置技術委員会坑水処理検討部会 委員

  • 2018
    -
    2021

    化学工学会  男女共同参画委員長

  • 2011.01
    -
    2020.12

    川崎市  環境局審議会 委員

  • 2018.07
    -
    2020.07

    東京都  使用済太陽光発電設備リサイクル検討会 委員

  • 2019.11
    -
    2020.03

    環境省  低炭素製品普及に向けた3R技術・システム動向調査革新的資源循環の実現に向けた社会システム基盤に関する検討会 委員

  • 2019.09
    -
    2020.03

    石油天然ガス・金属鉱物資源機構  休廃止鉱山におけるグリーン・レメディエーション(元山回帰)調査研究委員会 委員長

  • 2019.04
    -
    2020.03

    環境省  省CO2型リサイクル等設備技術実証事業評価審査委員会 委員

  • 2018.06
    -
    2020.03

    石油天然ガス・金属鉱物資源機構  休廃止鉱山における坑排水処理の高度化調査研究委員会地下水制御技術の調査研究ワーキンググループ委員会 委員

  • 2020
     
     

    化学工学会  女性賞 選考委員

  • 2020
     
     

    公益財団法人本多記念会  第42回本多記念研究奨励賞選考委員会 委員

  • 2018.04
    -
    2020

    日本学術会議  広報委員会「学術の動向」編集分科会 副委員長

  • 2010
    -
    2020

    資源・素材学会  編集委員

  • 2010
    -
    2020

    資源・素材学会  編集幹事

  • 2017.12
    -
    2019.11

    日本学術振興会  科学研究費委員会 専門委員

  • 2017.06
    -
    2019.06

    横浜市  環境影響評価審査会 委員

  • 2018.07
    -
    2019.03

    科学技術振興機構  国際科学技術共同研究推進事業(戦略的国際共同研究プログラム) アドバイザー

  • 2017.04
    -
    2019.03

    粉体工学会  ダイバーシティ委員会 委員

  • 2017.04
    -
    2019.03

    粉体工学会  国際粉工展 東京委員

  • 2017.03
    -
    2019.03

    粉体工学会  編集員会 委員

  • 2018.09
    -
    2019.03

    経済産業省  休廃止鉱山におけるグリーン・レメディエーション(元山回帰)調査研究委員会 委員

  • 2018.04
    -
    2019.03

    環境省  低炭素製品普及に向けた3R体制構築支援事業太陽光発電設備のリユース・リサイクル・適正処分推進に係るワーキンググループ 委員

  • 2018.04
    -
    2019.03

    環境省  省CO2型リサイクル等設備技術実証事業評価検討会 委員

  • 2016.12
    -
    2019.03

    石油天然ガス・金属鉱物資源機構  大谷鉱山鉱害防止技術委員会 委員

  • 2017.02
    -
    2019.02

    粉体工学会  評議員

  • 2019
    -
     

    APCOM2019  Session organizer

  • 2019
    -
     

    DEM8  Session organizer

  • 2019
    -
     

    ISSET2019  Organizer

  • 2019
    -
     

    EcoDesign2019  Organizer

  • 2019
    -
     

    APPChE2019  Organizer

  • 2015
    -
    2019

    資源・素材学会  粉体精製工学部門委員会 委員長

  • 2017
    -
    2018.06

    日本LCA学会  年会実行委員会 委員

  • 2018
    -
    2018.03

    日本原子力研究開発機構  任期付研究員採用試験研究業績評価委員会 委員

  • 2018.02
    -
    2018.03

    環境省  リサイクルシステム統合強化による循環資源利用高度化促進業務粉砕業者における自動車リサイクルの推進・質の向上に係る検討会 委員

  • 2017.12
    -
    2018.03

    環境省  低炭素製品普及に向けた3R体制構築支援事業太陽光発電パネルのリユース・リサイクル・適正処理に係る検討分科会 委員

  • 2017.11
    -
    2018.03

    経済産業省  植物利用型坑排水浄化技術等基礎調査事業会議体 委員

  • 2017.05
    -
    2018.03

    石油天然ガス・金属鉱物資源機構  休廃止鉱山における地下水制御・管理対策調査研究委員会 委員

  • 2018
     
     

    日本学術会議  広報委員会「学術の動向」編集分科会 委員

  • 2018
    -
     

    EcoDePS2018  実行委員長

  • 2018
    -
     

    ICCCI2018  Organizer

  • 2017
    -
    2018

    資源・素材学会  理事

  • 2015.10
    -
    2017.09

    日本学術会議  連携委員

  • 2017
    -
     

    EARTH2017  Organizer

  • 2015
    -
    2017

    化学工学会  関東支部第三企画委員長、男女共同参画委員

  • 2011
    -
    2017

    経済産業省  「アジアにおけるリサイクルビジネス展開可能性調査事業」の審査委員会 委員

  • 2016
    -
     

    Copper2016  Organizer

  • 2016
    -
     

    ICCCI2016  Organizer

  • 2012
    -
    2016

    石油天然ガス・金属鉱物資源機構  調査指導鉱害防止技術委員会 委員

  • 2011
    -
    2015

    環境資源工学会  評議員

  • 2011
    -
    2013

    日本工学教育協会  国際委員会委員

  • 2011
    -
    2013

    石油天然ガス・金属鉱物資源機構  鉱害防止技術適用可能性調査検討委員会 委員

  • 2009.10
    -
    2013.01

    経済産業省  休廃止鉱山鉱害防止対策研究会 委員

  • 2010.08
    -
    2012.02

    経済産業省  自治体間(茨城市-天津市)連携による濱海新区資源循環経済構築に関する調査事業委員会 委員

  • 2012
     
     

    経済産業省  先進型坑廃水処理技術開発評価検討会 委員

  • 2010.04
    -
    2011.03

    経済産業省  レアメタル抽出技術開発に係る事業評価(有識者)委員会 委員

  • 2011
     
     

    石油天然ガス・金属鉱物資源機構  パッシブトリートメント技術委員会 委員

  • 2009.08
    -
    2010.03

    経済産業省  新資源循環推進事業審査委員会 委員

  • 2009.04
    -
    2010.03

    石油天然ガス・金属鉱物資源機構  鉱物資源分野における国際人材育成プログラム開発検討委員会 委員

  • 2008.09
    -
    2010.03

    文部科学省  資源開発人材育成プログラムに係るプログラム調整企画委員

  • 2007
     
     

    経済産業省  今後の鉱害防止の在り方に関する研究会 委員

  • 2007
     
     

    経済産業省  鉱物資源供給対策調査研究会 委員

  • 2007
     
     

    日本学術会議  総合工学委員会持続可能なグローバル資源利活用 に係る検討分科会資源基礎調査小委員会 委員

▼display all

Professional Memberships

  • 2022.03
    -
    Now

    IEEE

  •  
    -
    2023.12

    日本エネルギー学会

  •  
     
     

    化学工学会

  •  
     
     

    粉体工学会

  •  
     
     

    環境資源工学会

  •  
     
     

    資源・素材学会

  •  
     
     

    日本化学会

  •  
     
     

    日本金属学会

  •  
     
     

    The American Ceramic Society

  •  
     
     

    日本工学アカデミー

  •  
     
     

    日本粉体工業技術協会

  •  
     
     

    エコデザイン推進機構

  •  
     
     

    日本LCA学会

  •  
     
     

    廃棄物資源循環学会

▼display all

Research Areas

  • Transport phenomena and unit operations / Metals production and resources production / Earth resource engineering, Energy sciences / Environmental materials and recycle technology / Environmental load reduction and remediation

Research Interests

  • 固液プロセッシング

  • シミュレーション工学

  • エネルギーシステム

  • エネルギー輸送・貯蔵

  • リサイクル技術

  • 環境保全技術

  • 有価物回収

  • 固固分離

  • Powder Simulation

  • Powder Processing

  • Enviromental Treatment

  • Recycling

  • Solid/Liquid Separation

  • Solid/Solid Separation

▼display all

Awards

  • Jubilee Global Diversity Award

    2024.01   The American Ceramic Society  

    Winner: Chiharu Tokoro

  • BP(Best Poster)賞

    2023.10   粉体工学会   乾式粉砕・分級プロセスを用いたリチウムイオン電池正極活物質粒子のダイレクトリサイクルの検討

    Winner: 泉健人, 髙谷雄太郎, 所千晴

  • 第10回ZAIKEN Festa 優秀賞

    2023.10   早稲田大学 各務記念材料技術研究所   海水浮選における海洋性鉄酸化細菌による黄鉄鉱親水化機構に関する考察

    Winner: 清水佑馬, 牧田寛子, 小山恵史, 三浦響, 所千晴, 淵田茂司

  • 最優秀学生発表賞

    2023.09   化学工学会   臭素系難燃剤を含む廃プラスチックを利用した製鋼ダストの鉛除去プロセスにおける焼成時のプラスチックの挙動の観察

    Winner: 高崎 裕二, 高谷 雄太郎, 所 千晴

  • 優秀ポスター発表賞

    2023.08   資源・素材学会   海洋性鉄酸化細菌の黄鉄鉱浮遊抑制効能力と海水浮選への利用可能性

    Winner: 清水佑馬, 牧田寛子, 小山恵史, 三浦響, 所千晴, 淵田茂司

  • Best Poster Student

    2023.08   The 62nd Annual Conference of Metallurgists   Establishment of an environmental-friendly recycling flow of waste photovoltaic panel for selective recovery of copper, silver, and tin

    Winner: Kento Izumi, Yutaro Takaya, Chiharu Tokoro

  • 学生特別賞

    2023.08   化学工学会   坑廃水処理における中和マンガン殿物の除去材としての活用と地球化学的機構解明

    Winner: 古郡 友輔, 小山 恵史, 所 千晴

  • 学生奨励賞

    2023.08   化学工学会   電気パルスによる集合粉砕および剥離を用いたCFRP積層板からの炭素繊維の分離の把握

    Winner: 佐藤 啓太, 小板 丈敏, 綱澤 有輝, 山口 晃司, 所 千晴

  • Award for Best Poster Presentation

    2023.07   The 2nd workshop of the Australia-Japan Collaborative Research Network   Application of Pulsed Discharge to Laminated CFRP for the Recycling of Carbon Fiber

    Winner: Keita Sato, Taketoshi Koita, Keishi Oyama, Koji Yamaguchi, Chiharu Tokoro

  • Best Oral Presentation Award

    2022.11   EARTH2022   Evaluation of the long-term chemical stability of adsorbed Hg on pyrite surfaces under various redox 3 and pH conditions

    Winner: Shun Ishii, Keishi Oyama, Shigeshi Fuchida, Chiharu Tokoro

  • 学生奨励賞

    2022.11   化学工学会   電気パルス法を用いた廃太陽光パネルからの有価金属選択分離・回収の検討

    Winner: 今泉 友斗, 高谷 雄太郎, 小板 丈敏, 浪平 隆男, 所 千晴

  • KONA Young Researcher Award

    2022.11   ICCCI 2022   Fundamental study of separation of different resin plates bonded by solvent using wire explosion by pulsed discharge

    Winner: Yoshiki Egawa, Taketoshi Koita, Soowon Lim, Takao Namihira, Chiharu Tokoro

  • 令和4年度リサイクル技術開発本多賞(第27回)

    2022.09   一般社団法人産業環境管理協会   新規電気パルス法によるリチウムイオン電池の高精度分離技術開発

    Winner: 所千晴, 浪平隆男, 菊池康紀

  • 第5回APT Outstanding International Contribution Award

    2022.05   粉体工学会  

    Winner: 所千晴

  • 2021年度優秀論文賞

    2022.05   公益社団法人化学工学会   シリカスケール生成抑制を目的としたMg, Al, Fe共存系におけるシリカ重合へのpHおよび温度影響の速度論的評価

    Winner: 石井 駿, 田嶋 翔太, 髙谷 雄太郎, 淵田 茂司, 所 千晴

  • 粉体精製工学部門委員会学生賞

    2022.03   資源・素材学会   バーネス鉱(δ-MnO2)吸着・共沈法による高Mn, Fe負荷酸性坑廃水処理の最適条件の検討

    Winner: 田嶋 翔太, 淵田 茂司, 所 千晴

  • 2021年度早稲田大学リサーチアワード(大型研究プロジェクト推進)

    2021.12   早稲田大学   製品ライフサイクル管理とそれを支える革新的解体技術開発による統合循環生産システムの構築

    Winner: 所 千晴

  • A finalist for the Falling Walls Science Breakthroughs of the Year 2021 in Engineering and Technology

    2021.07   Falling Walls  

    Winner: Chiharu Tokoro

  • 学生奨励賞

    2021.07   化学工学会   最終処分場における有害元素溶出挙動把握のための多硫化物の空気酸化と溶出に関する基礎的研究

    Winner: 石井 駿, 王 科人, 髙谷 雄太郎, 淵田 茂司, 所 千晴

  • 優秀学生賞

    2021.07   化学工学会   銅鉱石の浮選最適化を目指した黄鉄鉱表面酸化速度に基づくカルシウム抑制剤と親水化の関係評価

    Winner: 石田 紗菜, 薛 継峰, 淵田 茂司, 忰山 卓矢, 岸本 恭暢, 青木 悠二, 所 千晴

  • 2021年度論文賞

    2021.06   環境資源工学会   シリカスケール生成抑制を目的としたシリカ重合速度におけるpHおよび温度影響評価

    Winner: 田嶋 翔太, 淵田 茂司, 加藤 達也, 所 千晴

  • 学生優秀発表賞

    2021.03   日本LCA学会   新規電気パルス法を用いた新興技術リサイクルの環境影響評価:リチウムイオン電池および太陽光パネルにおけるケーススタディ

    Winner: 諏訪 出, 兵法 彩, 竇 毅, 所 千晴, 菊池 康紀

  • 粉体精製工学部門委員会学生賞

    2021.03   資源・素材学会   DEM-CFDシミュレーションによるプラスチック相互分離を目的とした水流比重選別装置の最適設計

    Winner: 新田 彩乃, 古作 吉宏, 土井 眞, 舩橋 悟, 綱澤 有輝, 所 千晴

  • 優秀学生賞

    2021.03   化学工学会   銅鉱石の浮選最適化を目的としたカルシウム溶液中における黄鉄鉱および黄銅鉱の酸化反応モデル構築

    Winner: 石田 紗菜, 薛 継峰, 淵田 茂司, 青木 悠二, 忰山 卓矢, 岸本 恭暢, 所 千晴

  • 2020年度早稲田大学リサーチアワード(国際研究発信力)

    2021.02   早稲田大学  

    Winner: 所 千晴

  • ポスター賞

    2020.11   エコデザイン推進機構   ライフサイクルシミュレーションを用いた循環生産システムのフロー制御

    Winner: 浅井 恵斗, 福重 真一, 髙田 祥三, 所 千晴

  • ベストプレゼンテーション賞

    2020.11   粉体工学会   DEM-CFD シミュレーションによるプラスチック高精度分離を目的とした水流型比重選別機の最適装置設計

    Winner: 新田 彩乃, 古作 吉宏, 舩橋 悟, 綱澤 有輝, 所 千晴

  • ベストプレゼンテーション賞

    2020.11   粉体工学会   電気パルス法を用いたハードディスクガラスプラッタからの白金族元素含有金属層剥離の検討

    Winner: 近藤 正隆, Lim Soowon, 小板 丈敏, 浪平 隆男, 所 千晴

  • 第32回IP奨励賞

    2020.08   粉体工学情報センター  

    Winner: 所 千晴

  • 学生奨励賞

    2020.05   粉体工学会   "プラスチック比重分離高精度化を目的としたDEM-CFDによる水流型比重選別機内の粒子挙動把握"

    Winner: 新田 彩乃, 舩橋 悟, 安藤 裕二, 木原 忠志, 張田 真, 綱澤 有輝, 所 千晴

  • 学生奨励賞

    2020.05   粉体工学会   "Evaluation of adsorption performance of zerovalent iron-magnetite nano-composite for Removal of As(Ⅲ) in artificially prepared wastewater"

    Winner: Zubair Yusuf Olalekan, Shigeshi Fuchida, Chiharu Tokoro

  • 若手ポスター発表賞

    2019.09   資源・素材学会   "メカノケミカル反応による風化残留型レアアース鉱物からのイットリウム浸出促進機構解明を目的としたEXAFS解析"

    Winner: 加藤 達也、所 千晴

  • 学生特別賞

    2019.08   化学工学会   "破壊モデルを組み込んだDEMによるHPGRのロール形状の粉砕性能評価"

    Winner: 長田 悠, 綱澤 有輝, 塚田 浩二, 矢口 裕一, 蛭子 陽介, 三觜 幸平, 所 千晴

  • 学生特別賞

    2019.08   化学工学会   "低結晶性酸化マグネシウムを用いた排水中の亜セレン酸およびセレン酸除去機構の解明"

    Winner: 土屋 宏典, 淵田 茂司, 鳥羽 裕一郎, 島村 祐司, 所 千晴

  • 平成31年度文部科学大臣表彰 科学技術賞

    2019.04   "非鉄金属資源循環分野の重要性や将来性の理解増進と普及啓発".

    Winner: 所 千晴

  • 学生賞

    2019   資源・素材学会   "MLAおよびDEMを用いたHPGRの単体分離促進効果に対する考察".

    Winner: 長田 悠, 塚田 浩二, 矢口 裕一, 蛭子 陽介, 三觜 幸平, 所 千晴

  • 優秀ポスター賞

    2019   環境資源工学会   "低結晶性酸化マグネシウムを用いた廃水中のフッ素除去機構の解明および定量モデル化".

    Winner: 土屋 宏典, 淵田 茂司, 鳥羽 裕一郎, 島村 祐司, 所 千晴

  • ポスター奨励賞

    2019   プラズマ分光分析研究会   "溶液中での黄鉄鉱表面酸化に対する酸化速度論構築"

    Winner: 石田 紗菜, 土屋 宏典, 加藤 達也, 淵田 茂司, 黒岩 樹人, 青木 悠二, 所 千晴

  • 優秀学生賞

    2018   化学工学会   "鉱物の粉砕に伴うメカノケミカル反応発生機構のDEMシミュレーションによる考察".

    Winner: 皆川 真也, 久富 渉生, 加藤 達也, Granata Giuseppe, 所 千晴

  • 最優秀学生賞

    2018   化学工学会   "化学反応を考慮した地圏流体解析を用いた人形峠鉱さいたい積場内の鉄・ヒ素の自然浄化機構の再現".

    Winner: 川崎 遥平, 八木澤 真, Granata Giuseppe, 所 千晴, 小原 義之

  • 学生賞

    2018   資源・素材学会   "層状復水酸化物であるGreen Rustを用いた4価および6価セレン除去機構の比較検討".

    Winner: 小野口 愛奈, 余 哲邦, Mamun Abdullah AI, Granata Giuseppe, 所 千晴

  • ベストプレゼンテーション賞

    2018   粉体工学会   "遊星ボールミル粉砕によるレアアース浸出促進に適した鉱石中のレアアース鉱物の形態制御".

    Winner: 加藤 達也, グラナタ ジュセッペ, 所 千晴, 綱澤 有輝, 高木 哲一

  • 優秀ポスター賞

    2018   環境資源工学会   "共沈法と吸着法におけるδ-MnO2によるCd除去機構の比較".

    Winner: 鈴木 滉平, 川﨑 遥平, 加藤 達也, G. Giuseppe, G. Mariusz, 所 千晴

  • Student Poster Award

    2018   日本粉体工業技術協会   "The enhancement mechanism investigation of rare earth elements dissolution from weathered residual rare earth ores by planetary ball milling with addition of solid sodium hydroxide ".

    Winner: T. Kato, G. Granata, C. Tokoro, Y. Tsunazawa, T. Takagi

  • 学生奨励賞

    2018   化学工学会   "ナノ粒子の分散に適したビーズミル設計へのDEMシミュレーションの適用".

    Winner: 長田 悠, 皆川 真也, 関根 靖由, グラナタ ジュセッペ, 所 千晴

  • 最優秀学生発表賞

    2018   化学工学会   "δ-MnO2を用いてCd除去機構の解明及び表面錯体モデルの構築".

    Winner: 鈴木 滉平, 川﨑 遥平, 加藤 達也, Giuseppe Granata, Mariusz Grabada, 所 千晴

  • ベストポスター賞

    2018   エコデザイン推進機構   "未利用資源からの希土類元素回収に向けた高分子吸着剤の開発".

    Winner: 篠崎 智博, 尾形 剛志, 成田 弘一, 所 千晴, 田中 幹也

  • Award for Oral Presentation

    2017   環境資源工学会   "Geo-fluid analysis of the natural purification mechanism of Yotsugi mill tailings pond".

    Winner: Y. Kawasaki, M. Yagisawa, G. Granata, C. Tokoro, Y. Ohara

  • 学生賞

    2017   資源・素材学会   "高分子吸着剤の細孔制御による希土類元素の吸着特性向上".

    Winner: 篠崎智博, 尾形剛志, 柿沼遼, 成田弘一, 所千晴, 田中幹也

  • 学生奨励賞

    2017   化学工学会   "離散要素法を用いたパン型ペレタイザにおける湿式造粒過程のモデリング".

    Winner: 所 拓磨, G. Granata, 所 千晴, 綱澤 有輝

  • 優秀学生賞

    2017   化学工学会   "低結晶性酸化マグネシウムを用いた廃水中のホウ素除去機構の解明".

    Winner: 福田 宏樹, 帆保 駿吾, G. Granata, 所 千晴, 鳥羽 裕一郎, 江口 正浩

  • 学生奨励賞

    2017   化学工学会   高純度グリーンラストを用いた六価セレン除去の基礎的検討

    Winner: 小野口 愛奈, 内田 丈博, A. A. Mamun, G. Granata, 所 千晴

  • 優秀学生賞

    2017   化学工学会   鉄共存下における亜鉛の塩化揮発特性に関する検討

    Winner: 劉 暢之, 松岡 光昭, 所 千晴, 川上 智

  • BEST PRESENTATION AWARD

    2016.07   3rd AJ-BCEP Geo-Resources World Forum 2016 (Jul. 28, Bangkok, Thailand). 2016, 3.   "Application of DEM simulation for investigation of the effect of agitator shape on the grinding mechanism in agitation mill"

    Winner: T. Tokoro, S. Fukui, N. Kawabe, Y. Tsunazawa, C. Tokoro

  • 優秀学生賞

    2016   化学工学会   "高濃度H2SiF6含有廃液からのF回収を目的としたCaF2およびSiO2の析出挙動の把握".

    Winner: 森田 将夫, 所 千晴

  • e-Teaching Good Practice

    2016   早稲田大学 大学総合研究センター  

    Winner: 所 千晴

  • 優秀ポスター賞

    2016   環境資源工学会   "温度保持による銅製錬スラグ中のマグネタイト結晶促進および磁選による回収".

    Winner: 劉 暢之, 堀内 健吾, 松岡 光昭, 大蔵 隆彦, 所 千晴

  • Oral Presentation Award

    2016   環境資源工学会   "The Crystal Growth Promotion of Magnetite in Copper Smelting Slag by Temperature Retention and Recovery by Physical Separation".

    Winner: C. Liu, K. Horiuchi, M. Matsuoka, C. Tokoro

  • 粒子・流体プロセス部会 シンポジウム賞(プレゼンテーション賞)

    2016   化学工学会   "液架橋モデルを組み込んだDEMシミュレーションによる湿潤微粒子の挙動解析".

    Winner: 所 拓磨, 河辺 夏希, 福井 将, 松岡 光昭, 所 千晴, 綱澤 有輝, 酒井 幹夫

  • 平成27年度 論文賞

    2016   廃棄物資源循環学会   "Ship Breaking and the Steel Industry in Bangladesh: A Material Flow Perspective".

    Winner: M. Sujauddin, R. Koide, T. Komatsu, M. M. Hossain, C. Tokoro, S. Murakami

  • 特別賞

    2016   化学工学会   "高濃度H2SiF6廃液処理汚泥からのCaF2回収を目的としたアルカリ洗浄によるSi成分除去".

    Winner: 森田 将夫, 松岡 光昭, 所 千晴

  • 金賞

    2016   化学工学会   "Fe(Ⅲ)担持イオン交換樹脂を用いた廃水中のAs(Ⅴ)除去機構の把握".

    Winner: 内田 丈博, 森田 将夫, 松岡 光昭, 所 千晴

  • 奨励賞

    2016   化学工学会   "DEMシミュレーションを用いたボールミルにおける表面粉砕特性の予測".

    Winner: 福井 将, 綱澤 有輝, 松岡 光昭, 所 千晴

  • 優秀賞

    2016   エコデザイン推進機構   "DEMシミュレーションを用いた破砕による廃小型家電からの基板回収挙動の予測".

    Winner: 福井 将, 綱澤 有輝, 松岡 光昭, 所 千晴, 村上 進亮

  • Oral Presentation Award

    2016  

  • Oral Presentation Award

    2016  

  • Oral Presentation Award

    2016  

  • Oral Presentation Award

    2016   環境資源工学会   Powder synthesis for battery application by one-step mechanical method

    Winner: M. Matsuoka, C. Tokoro, A. Kondo, T. Kozawa, M. Naito

  • Oral Presentation Award

    2016  

  • 第40回 論文賞

    2015   資源・素材学会   "Characteristic Sorption of H3BO3/B(OH)4- on Magnesium Oxide".

    Winner: 笹木 圭子, 邱心泓, 森山 紗好, 所 千晴, 出田 圭子, 宮脇 仁

  • ベストプレゼンテーション賞

    2015   粉体工学会   "ボールミルを用いた黄銅鉱からの銅浸出の促進".

    Winner: 三谷 友梧, 所 千晴

  • 特別賞

    2015   化学工学会   "廃リチウムイオン電池からコバルト回収を目的とした最適加熱条件の検討".

    Winner: 堀内 健吾, 所 千晴, 大和田 秀二, 薄井 正治郎

  • 銅賞

    2015   化学工学会   "エトリンガイトによるホウ素除去の実用化を目的とした温度および共存元素の影響".

    Winner: 武藤 研一, 前田 素生, 帆保 駿吾, 所 千晴, 田中 善之

  • 金賞

    2015   化学工学会   "溶媒抽出法による塩酸溶液からのPt(Ⅳ)/Fe(Ⅲ)相互分離の高度化".

    Winner: 前田 素生, 成田 弘一, 所 千晴, 田中 幹也

  • Research World Excellent Paper Award

    2015   Research World International Conference   "Clarification For Hg(Ⅱ) Removal Mechanism in Ferrihydrite Co-Precipitation Process by XAFS Analysis".

    Winner: T. Kato, T. Uchida, C. Liu, C. Tokoro

  • Best Paper Award

    2015   Journal of Material Cycles and Waste Management   "Characterization of ship breaking industry in Bangladesh".

    Winner: M. Sujauddin, R. Koide, T. Komatsu, M. M. Hossain, C. Tokoro, S. Murakami

  • 特別賞

    2015   化学工学会   アルミナ製造時の廃棄物「赤泥」の硫酸中和とバイポーラ膜電気透析による改質プロセスの構築

    Winner: 岸田 真悠子, 原戸 卓雄, 所 千晴, 大和田 秀二

  • 銅賞

    2015   化学工学会   Fe(Ⅲ)担持樹脂カラムによるAs(Ⅴ)含有排水の処理

    Winner: 二見文也, 所千晴

  • 第39回論文賞

    2014   資源・素材学会   "表面沈殿モデルを用いた希薄As(Ⅴ)廃水の水酸化第二鉄共沈処理に対する定量モデル化".

    Winner: 原口 大輔, 所 千晴, 大和田 秀二, 井澤 彩

  • 学生賞特別賞

    2014   化学工学会   "物理選別による銅製錬スラグからのMo濃縮を目的としたSEM-EDSによるMo結晶化への加熱/冷却条件の影響評価".

    Winner: 須藤 俊佑, 戸井 龍太郎, 岡田 慎太郎, 所 千晴, 大藏 隆彦

  • 奨励賞

    2014   エコデザイン推進機構   "銅精錬スラグからの有用金属の回収を目的とした徐冷処理がスラグ中成分の結晶成長に及ぼす影響".

    Winner: 戸井 龍太郎, 所 千晴, 大藏 隆彦

  • ポスター賞

    2014   環境資源工学会   "濾過砂のリサイクルにおける表面粉砕の有効性の検討".

    Winner: 岡田 慎太郎, 藤橋 大輝, 綱 澤有輝, 所 千晴

  • 銅賞

    2014   化学工学会   "付着力を考慮した新規接触モデルを組み込んだDEMシミュレーションによるパン型ペレタイザ内における湿潤粒子の挙動解析".

    Winner: 藤橋 大輝, 綱澤 有輝, Gytis Basinkas, 酒井 幹夫, 所 千晴

  • 奨励賞

    2014   化学工学会   "物理選別による銅精錬スラグからの有用金属回収を目的とした除冷処理がスラグ中成分に及ぼす影響".

    Winner: 戸井 龍太郎, 所 千晴, 大藏 隆彦

  • ポスター優秀賞

    2014   日本溶媒抽出学会   "アミド含有第3級アミンによる塩化白金アニオンの抽出分離".

    Winner: 前田 素生, 成田 弘一, 所 千晴, 田中 幹也, 元川 竜平, 塩飽 秀啓, 矢坂 毅

  • 奨励賞

    2014   化学工学会   水酸化アルミニウム共沈法による希薄Si含有排水からのシリカ除去の定量モデル化

    Winner: 鈴木慎哉, 所千晴, 榊原泰佑

  • 奨励賞

    2013   資源・素材学会   "環境浄化・資源循環に寄与する分離技術のモデル化およびシミュレーションの適用".

    Winner: 所 千晴

  • Excellent Poster Presentation Award

    2013   環境資源工学会   "Mechanism of As(Ⅴ) removal in wastewater treatment using ion exchange resins supported by Fe(Ⅲ)".

    Winner: F. Futami, C. Tokoro, S. Owada, H. Kubota

  • 若手優秀ポスター賞

    2013   資源・素材学会   "DEMシミュレーションによるパン型ペレタイザにおける造粒機構の基礎的検討".

    Winner: 藤橋 大輝, 綱澤 有輝, 田原 一輝, 所 千晴, 大和田 秀二

  • Advanced Power Technology Excellence in Reviewing

    2013   Advanced Power Technology  

    Winner: C. Tokoro

  • 優秀賞

    2012   日本鉄鋼協会   "バングラデシュにおける船舶解体産業と鉄鋼産業(マテリアルフローから見た分析)".

    Winner: 小出 瑠, 所 千晴, 村上 進亮, モハマド スジャウディン

  • 論文賞

    2012   環境資源工学会   "Application of DEM Simulation to an Intensive Mixer".

    Winner: 所 千晴, 山下 達也, 久保田 英敏, 大和田 秀二

  • ポスター賞 (2位)

    2012   化学工学会   "高効率フェントン法によるCO2還元メタノール・エタノール化".

    Winner: 山岸 史弥, 原口 大輔, 所 千晴, 村田 逞詮

  • 若手優秀ポスター賞

    2012   資源・素材学会   "水酸化物による廃水中有害元素の共沈除去に対する定量モデル化".

    Winner: 原口 大輔, 井澤 彩, 所 千晴, 大和田 秀二

  • 優秀ポスター賞

    2012   資源・素材学会   過酸化水素を用いた黄銅鉱リーチングの高速化に関する基礎的研究

    Winner: 鈴木 慎哉, 須藤 俊佑, 山岸 史弥, 所 千晴, 大藏 隆彦

  • 学生賞銅賞

    2011   化学工学会   "DEMシミュレーションによる基板からの部品剥離機構の検討に関する基礎的研究".

    Winner: 綱澤 有輝, 所 千晴, 大和田 秀二, 酒井 幹夫, 村上 進亮

  • 学生賞奨励賞

    2011   化学工学会   "分光学的手法を用いた水中のフッ素の水酸化物沈殿への共沈機構解析".

    Winner: 原口 大輔, 所 千晴, 大和田 秀二

  • 若手ポスター賞

    2010   資源・素材学会   "廃携帯電話からのレアメタル濃縮における部品選別の有効性-人工鉱床(RtoS)構想の一環として-".

    Winner: 古賀 千香子, 後藤 昌也, 大和田 秀二, 所 千晴, 白鳥 寿一, 湯本 徹也

  • 若手ポスター賞

    2007   資源・素材学会   "酸性坑廃水の中和・共沈処理を目的とした赤泥のヒ素吸着特性の解明".

    Winner: 中津川 香世, 大槻 晶, 所 千晴, 大和田 秀二

▼display all

Media Coverage

  • 超DXサミット リアルとデジタルが一体化した時代を生きる 全セッション見逃し配信スタート!

    Newspaper, magazine

    日本経済新聞  

    全面広告  

    2023.09

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    生産性新聞  

    6面  

    2023.08

  • 超 DXサミット リアルとデジタルが一体化した時代を生きる

    Newspaper, magazine

    日本経済新聞  

    全面広告  

    2023.08

  • リケンテクノスと早稲田大学 PVCの有効活用法開発に着手

    Newspaper, magazine

    ゴムタイムス  

    電子版  

    2023.06

  • リケンテクノス-早大、廃塩ビで有用金属回収

    Newspaper, magazine

    化学工業日報  

    2023.06

  • EV電池 CO2排出開示 車体購入補助の要件追加

    Newspaper, magazine

    日本経済新聞  

    1面  

    2023.05

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    Newspaper, magazine

    北海道新聞  

    28面  

    2023.04

  • 思考ガチャ!早回ししたくなるワケ

    TV or radio program

    NHK   Eテレ  

    2023.03

  • 太陽光パネル廃棄 回収の仕組みづくりを急げ

    TV or radio program

    BSテレ東   日経モーニングプラスFT  

    2023.01

  • 循環経済へリサイクルを見直そう

    Newspaper, magazine

    Author: Myself  

    日本経済新聞  

    電子版  

    2022.12

  • 捨てない経済へ~循環型社会が未来を変える~

    TV or radio program

    NHK Eテレ   TVシンポジウム  

    2022.12

  • レーザー欄「内側に寄せる」

    Newspaper, magazine

    日刊工業新聞  

    24面  

    2022.08

  • コバルト・ニッケル リチウム電池から回収

    Newspaper, magazine

    日刊工業新聞  

    24面  

    2022.06

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    Newspaper, magazine

    鉄鋼新聞  

    4  

    2021.08

  • 粉体工学情報センター IP奨励賞に早大・所教授 日清製粉グループ本社も支援

    Newspaper, magazine

    Author: Other  

    食糧醸界新聞  

    2020.09

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Papers

  • Chemical stability of Hg-adsorbed pyrite under different pH and redox conditions: A fundamental study for stable management of Hg-bearing wastes

    Keishi Oyama, Shun Ishii, Shigeshi Fuchida, Chiharu Tokoro

    Journal of Environmental Chemical Engineering    2024.01  [Refereed]

    DOI

    Scopus

  • Evaluating the grinding performance of cutter-type disk mills using DEM-CFD simulations with a breakage model

    Ryuto Kamo, Yuki Tsunazawa, Taketoshi Koita, Kyoko Okuyama, Motonori Iwamoto, Yasuyoshi Sekine, Chiharu Tokoro

    Advanced Powder Technology   35   104303  2024.01  [Refereed]

    Authorship:Corresponding author

  • Improving Flotation Separation of Mg(OH)2-Depressed Chalcopyrite and Pyrite by EDTA Modification: A Promising Method for Sustainable Cu Production

    Jifeng Xue, Keishi Oyama, Shigeshi Fuchida, Chiharu Tokoro

    Journal of Sustainable Metallurgy    2023.10  [Refereed]

    Authorship:Corresponding author

    DOI

    Scopus

  • 接着接合の易解体における浸漬前処理の有効性評価【受理】

    佐藤啓太, 小山恵史, 小板丈俊, 久保田明紀子, 所千晴

    環境資源工学会誌   70 ( 2 ) 65 - 72  2023.10  [Refereed]

    Authorship:Corresponding author

  • 酸性触媒廃液からの硫化物法によるNi回収プロセスと硫化沈殿物の化学特性【受理】

    岩井 久典, 石井 駿, 小山 恵史, 淵田 茂司, 横田 尚樹, 高橋 優子, 所 千晴

    粉体工学会   60 ( 10 ) 600 - 606  2023.10  [Refereed]

    DOI

    Scopus

  • 衝撃試験とDEMシミュレーションによる電子スクラップの単体分離機構の考察【受理】

    辰本 拓也, 綱澤 有輝, 小板 丈敏, 高谷 雄太郎, 小山 恵史, 所 千晴

    Journal of MMIJ    2023.09  [Refereed]

    Authorship:Corresponding author

  • 空気分級における比重選別の影響を考慮した分級評価方法―太陽光パネルセルシートを例とした考察―【受理】

    泉 健人, 高谷 雄太郎, 所 千晴

    化学工学論文集    2023.09  [Refereed]

    Authorship:Corresponding author

  • Chemical speciation changes of an all-solid-state lithium-ion battery caused by roasting determined by sequential acid leaching

    Yutaro Takaya, Syuichi Kuwaba, Yusaku Tsujimura, Katsunori Yamaguchi, Chiharu Tokoro

    Waste Management   166   122 - 132  2023.07  [Refereed]

    DOI

    Scopus

  • Extraction of Se(iv) and Se(vi) from aqueous HCl solution by using a diamide-containing tertiary amine

    Hirokazu Narita, Motoki Maeda, Chiharu Tokoro, Tomoya Suzuki, Mikiya Tanaka, Hideaki Shiwaku, Tsuyoshi Yaita

    RSC Advances   13 ( 25 ) 17001 - 17007  2023.06  [Refereed]

     View Summary

    A protonated diamide containing tertiary amine (EHBAA) can extract Se(iv) and Se(vi) from HCl via solvation and anion-exchange reactions, respectively.

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Simple and efficient selective extraction of lithium from spent ternary lithium-ion batteries via oxidation/de-lithiation using NaClO

    Yanhui Kong, Yutaro Takaya, Mauricio Córdova-Udaeta, Chiharu Tokoro

    Separation and Purification Technology     124280 - 124280  2023.06  [Refereed]

    Authorship:Corresponding author

    DOI

    Scopus

    2
    Citation
    (Scopus)
  • Applicability of Gravity Separation to Recycling Biodegradable Plastics

    Yuki Tsunazawaa, Chiharu Tokoro, Yuji Andod, Tomoki Nakamurad, Ryosuke Tsukimie, Nobuo Miyatake

    Journal of Chemical Engineering of Japan   56 ( 1 ) 2215269 - 2215269  2023.05  [Refereed]

    DOI

  • Prospective life cycle assessment of recycling systems for spent photovoltaic panels by combined application of physical separation technologies

    Aya Heiho, Izuru Suwa, Yi Dou, Soowon Lim, Takao Namihira, Taketoshi Koita, Kazuhiro Mochidzuki, Shinsuke Murakami, Ichiro Daigo, Chiharu Tokoro, Yasunori Kikuchi

    Resources, Conservation and Recycling   192 ( 5 ) 106922 - 106922  2023.05  [Refereed]

    DOI

    Scopus

  • Waste-Based Ceramsite for the Efficient Removal of Ciprofloxacin in Aqueous Solutions

    Juan Qin, Yeting Fang, Jian Shi, Chiharu Tokoro, Mauricio Córdova-Udaeta, Keishi Oyama, Juncheng Zhang

    International Journal of Environmental Research and Public Health   20 ( 6 ) 5042 - 5042  2023.03

     View Summary

    Ciprofloxacin (CIP), a compound with bioaccumulation toxicity and antibiotic resistance, is frequently detected in water at alarming concentrations, which is becoming an increasing concern. In this study, a low-cost ceramsite was developed from industrial solid wastes through sintering to remove CIP from wastewater. The effects of adsorbent dosage, initial pH, contact time, initial CIP concentration, and temperature were explored. More than 99% of CIP (20–60 mg/L) was removed at around pH 2–4 by the ceramsite. The kinetic data fitted well with the pseudo-second-order model, revealing that chemisorption was the main rate-determining step. The isotherm data was better described by the Freundlich model, suggesting that CIP was removed by the formation of multiple layers on the heterogeneous surface. Moreover, the removal efficiency was practically higher than 95% during five regeneration cycles, when different regeneration methods were used, including calcination, HCl, and NaOH washing, indicating that the ceramsite exhibited outstanding reusability in removing CIP. The primary mechanism of CIP removal by the ceramsite was found to be the synergism of adsorption and flocculation, both of which depended on the release of Ca2+ from the ceramsite. In addition, strong Ca-CIP complexes could be formed through surface complexation and metal cation bridging between Ca2+ and different functional groups in CIP.

    DOI

    Scopus

  • A coarse grain model with parameter scaling of adhesion forces from liquid bridge forces and JKR theory in the discrete element method

    Yoshihiro Kosaku, Yuki Tsunazawa, Chiharu Tokoro

    Chemical Engineering Science   268   118428 - 118428  2023.03  [Refereed]

    Authorship:Corresponding author

    DOI

    Scopus

    6
    Citation
    (Scopus)
  • Highly Efficient Cd2+ Removal Using Tobermorite with pH Self-Adjustment Ability from Aqueous Solution

    Juan Qin, Sujuan Yuan, Mauricio Córdova-Udaeta, Keishi Oyama, Chiharu Tokoro

    Materials   16 ( 3 ) 1314 - 1314  2023.02  [Refereed]

    Authorship:Corresponding author

     View Summary

    Cadmium (Cd), as a type of heavy metal, can increase the incidence of many diseases, even in low concentrations. In this study, tobermorite was hydrothermally synthesized and then applied to adsorb Cd2+ from an aqueous solution. The physicochemical characteristics of the synthesized tobermorite were detected, and the results indicated that the well-crystallized tobermorite had a lot of mesopores and a large specific surface area of 140.92 m2/g. It acquired a pH self-adjustment ability via spontaneously releasing Ca2+ and OH- into the aqueous solution. The effects of different factors on Cd2+ removal were investigated. For Cd2+, the removal efficiency could reach 99.71% and the maximum adsorption capacity was 39.18 mg/g using tobermorite. The adsorption data was best fitted with the pseudo-second-order kinetic and Langmuir isotherm models. In addition, there was no strict limit on the solution pH in Cd2+ adsorption because the tobermorite could adjust the solution pH to an alkaline atmosphere spontaneously. The efficient removal of Cd2+ using tobermorite was a result of surface complexation and ion exchange.

    DOI

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    2
    Citation
    (Scopus)
  • Separation of Different Resin Plates Bonded by Solvent through a Wire Explosion Induced by Pulsed Discharge

    Yoshiki Egawa, Taketoshi Koita, Soowon Lim, Takao Namihira, Chiharu Tokoro

    IEEE Transactions on Dielectrics and Electrical Insulation     Early access available - 1  2023.02  [Refereed]

    Authorship:Corresponding author

    DOI

  • Geochemical Modeling of Heavy Metal Removal from Acid Mine Drainage in an Ethanol-Supplemented Sulfate-Reducing Column Test

    Keishi Oyama, Kentaro Hayashi, Yusei Masaki, Takaya Hamai, Shigeshi Fuchida, Yutaro Takaya, Chiharu Tokoro

    Materials   16 ( 3 ) 928 - 928  2023.01  [Refereed]

     View Summary

    A passive treatment process using sulfate-reducing bacteria (SRB) is known to be effective in removing heavy metals from acid mine drainage (AMD), though there has been little discussion of the mechanism involved to date. In this work, a sulfate-reducing column test was carried out using supplementary ethanol as an electron donor for microorganisms, and the reaction mechanism was examined using geochemical modeling and X-ray absorption fine structure (XAFS) analysis. The results showed that Cu was readily removed from the AMD on the top surface of the column (0–0.2 m), while Zn and Cd depletion was initiated in the middle of the column (0.2–0.4 m), where sulfide formation by SRB became noticeable. Calculations by a developed geochemical model suggested that ethanol decomposition by aerobic microbes contributed to the reduction of Cu, while sulfide produced by SRB was the major cause of Zn and Cd removal. XAFS analysis of column residue detected ZnS, ZnSO4 (ZnS oxidized by atmospheric exposure during the drying process), and CuCO3, thus confirming the validity of the developed geochemical model. Based on these results, the application of the constructed geochemical model to AMD treatment with SRB could be a useful approach in predicting the behavior of heavy metal removal.

    DOI

    Scopus

  • Electrical properties of adhesives designed for smart debonding by a pulsed discharge method

    Manabu Inutsuka, Masataka Kondo, Taketoshi Koita, Soowon Lim, Keisuke Ota, Tomoki Honda, Ryo Ogawa, Takao Namihira, Chiharu Tokoro

    The Journal of Adhesion     1 - 15  2023.01

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Role of Resource Circularity in Carbon Neutrality

    Shinsuke Murakami, Kotaro Shimizu, Chiharu Tokoro, Takashi Nakamura

    sustainability   14 ( 24 ) Article number - 16408  2022.12  [Refereed]

  • Adsorption and Microscopic Analysis of Arsenate Uptake by Magnetic Fe Nanoparticles: a Detailed Study on Coexisting Anions Effects

    Yusuf O. Zubair, Shigeshi Fuchida, Chiharu Tokoro

    Water, Air, & Soil Pollution   233 ( 12 )  2022.12  [Refereed]

    Authorship:Corresponding author

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • Synthesis and selenate removal of magnesium–aluminum-layered double hydroxide particle using magnesium oxide

    Kosuke Tsuchiya, Shigeshi Fuchida, Chiharu Tokoro

    International Journal of Environmental Science and Technology   20   9481 - 9494  2022.11  [Refereed]

    Authorship:Corresponding author

    DOI

    Scopus

  • Study of the Metal Sphere Explosion Driven by Pulsed Discharge for Separating Adherends

    Masataka Kondo, Taketoshi Koita, Soowon Lim, Takao Namihira, Chiharu Tokoro

    IEEE Transactions on Plasma Science   50 ( 11 ) - 4649  2022.11  [Refereed]

    Authorship:Corresponding author

    DOI

  • Influence of Agitator Shape on Characteristics and Grinding Efficiency of Attritor Mill

    Chenzuo Ye, Yutaro Takaya, Yuki Tsunazawa, Kazuhiro Mochidzuki, Chiharu Tokoro

    International Journal of Automation Technology   16 ( 6 ) 756 - 765  2022.11  [Refereed]

    Authorship:Last author, Corresponding author

  • Coprecipitation mechanisms of Zn by birnessite formation and its mineralogy under neutral pH conditions

    Shota Tajima, Shigeshi Fuchida, Chiharu Tokoro

    Journal of Environmental Sciences   121   136 - 147  2022.11  [Refereed]

    DOI

    Scopus

    5
    Citation
    (Scopus)
  • Comparison of Positive Electrode Separation by Electrical Pulsed Discharge in Underwater and Air Environments

    Soowon Lim, Kaito Teruya, Fuki Mizumoto, Minori Asao, Taketoshi Koita, Takao Namihira, Chiharu Tokoro

    IEEE Transactions on Plasma Science   50 ( 10 ) 3625 - 3634  2022.10  [Refereed]

     View Summary

    This study presents a novel method to separate positive electrode active materials (PEAMs) and aluminum (Al) foil from positive electrodes (PEs) to enable more effective recycling processes. A pulsed current was applied to a PE sample that was prepared by manual dismantlement of spent lithium-ion batteries (LiBs). Joule heating caused the temperature of the Al foil to increase to be above the melting points of adhesion included in the PEAMs. The influence of the surrounding medium of the PE sample on the delamination phenomenon was investigated. PEAMs were peeled from the Al foil in water and air environments. High-speed visible imaging was employed to discuss separation processes. Differences in the size of the separated PEAMs and the amount of residual PEAM on the surface of the Al foil occurred due to the influence of the medium filled in the voids inside the PEAM layer.

    DOI

  • Investigation of Optimum Scale-up of Media Stirred Mill Using the Discrete Element Method

    Yoshihiro Kosaku, Yuki Tsunazawa, Kyoko Okuyama, Motonori Iwamoto, Yasuyoshi Sekine, Chiharu Tokoro

    Materials Transactions   63 ( 10 ) 1501 - 1509  2022.10  [Refereed]

    Authorship:Last author, Corresponding author

  • Chemokine expression in human 3-dimensional cultured epidermis exposed to PM2.5 collected by cyclonic separation

    Maori Kono, Tomoaki Okuda, Nami Ishihara, Hiroyuki Hagino, Yuto Tani, Hiroshi Okochi, Chiharu Tokoro, Masayuki Takaishi, Hidefumi Ikeda, Yasuhiro Ishihara

    Toxicological Research    2022.07  [Refereed]

    DOI

    Scopus

    5
    Citation
    (Scopus)
  • Quantitative Evaluation of the Effect of High-Pressure Grinding Roll on the Promotion of the Mineral Liberation of Copper Ore

    Yuki TSUNAZAWA, Yoshihiro KOSAKU, Yoshitaka SAKAIRI, Koji TSUKADA, Tamaki SAITO, Yosuke EBISU, Kohei MITSUHASHI, Youqing CHEN, Chiharu TOKORO

    Journal of MMIJ   138 ( 6 ) 95 - 102  2022.06  [Refereed]

    Authorship:Corresponding author

    DOI

  • Involvement of polycyclic aromatic hydrocarbons and endotoxin in macrophage expression of interleukin-33 induced by exposure to particulate matter

    Nami Ishihara, Tomoaki Okuda, Hiroyuki Hagino, Ami Oguro, Yuto Tani, Hiroshi Okochi, Chiharu Tokoro, Yoshiaki Fujii-Kuriyama, Kouichi Itoh, Christoph, F.A. Vogel, Yasuhiro Ishihara

    Journal of Toxicological Sciences   47 ( 5 ) 201 - 210  2022.05  [Refereed]

    DOI

    Scopus

    10
    Citation
    (Scopus)
  • Kinetic Investigation of Initial Oxidative Dissolution of Pyrite in Alkaline Media (pH 9–12) and Influence of Ca and Mg: A Fundamental Study for Pyrite Depression in Froth Flotation

    Shigeshi Fuchida, Jifeng Xue, Sana Ishida, Chiharu Tokoro

    Journal of Sustainable Metallurgy   8 ( 2 ) 732 - 741  2022.04  [Refereed]

    Authorship:Last author

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Mechanochemical degradation treatment of TBBPA: A kinetic approach for predicting the degradation rate constant

    Yutaro Takaya, Yiyun Xiao, Yuki Tsunazawa, Mauricio Córdova, Chiharu Tokoro

    Advanced Powder Technology   33 ( 3 ) 103469 - 103469  2022.03  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • Derivation of Flotation Kinetic Model Combining Surface Property Analysis and Kinetics

    Hidekazu MATSUOKA, Kohei MITSUHASHI, Masanobu KAWATA, Yutaro TAKAYA, Chiharu TOKORO

    Journal of MMIJ   138 ( 2 ) 12 - 18  2022.02

    Authorship:Last author, Corresponding author

    DOI

  • Utilization of underwater electrical pulses in separation process for recycling of positive electrode materials in lithium-ion batteries: Role of sample size

    Kaito Teruya, Soowon Lim, Kazuhiro Mochidzuki, Taketoshi Koita, Fuki Mizunoto, Minori Asao, Takao Namihira, Chiharu Tokoro

    International Journal of Plasma Environmental Science and Technology   16 ( 1 ) e01003  2022.02  [Refereed]

    Authorship:Corresponding author

     View Summary

    The amount of generated waste of lithium-ion batteries (LiBs) that are used in automobiles is expected to increase because of increases in EV usage. Thus, it is required to recover strategic elements, such as lithium, cobalt, nickel, and manganese in the positive electrodes (PEs) found within LiB. In recent years, a direct application of electrical pulsed power to PEs has been reported to separate the active material layer from the aluminum foil in PEs. The electrical pulsed-discharge treatment enables the separation of the active materials from the aluminum foil without changing in a significant manner the chemical composition of the materials. In this study, we investigated the influence of length of rolled PE samples on the separation of active material from the aluminum foil of PE via the electrical pulsed-discharge treatment. Calculated energy and charging voltage for specific sample sizes were applied to PE samples installed in discharging electrodes in water. After the electrical pulsed-discharge treatment, up to 98.8% cobalt and 6.7% aluminum were recovered from liberated particles of 8 mm or less. For a longer length of PE sample, the separation efficiency of cobalt for aluminum was higher, and the aluminum contamination for active material particles was lower. The internal circuit resistance should be reduced as much as possible to reduce the circuit energy consumption. In terms of energy efficiency, a longer, narrower, and thinner aluminum foil had positive effects in the separation of the positive electrode by the electrical pulsed-discharge treatment.

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • 開放型石灰路-アルカリ路による酸性坑廃水の処理予測とパッシブトリートメント導入に向けた示唆

    髙谷 雄太郎, 淵田 茂司, 濱井 昂弥, 堀内 健吾, 正木 悠聖, 所 千晴

    Journal of MMIJ   138 ( 2 ) 19 - 27  2022.02  [Refereed]

  • Investigation of Cerium Reduction Efficiency by Grinding with Microwave Irradiation in Mechanochemical Processing

    Tatsuya Kato, Motonori Iwamoto, Chiharu Tokoro

    Minerals   12 ( 2 ) 189 - 189  2022.01  [Refereed]

     View Summary

    This study evaluated the efficiency of cerium reduction by grinding with microwave irradiation in mechanochemical processing. Grinding experiments with microwave irradiation were conducted using an agitating mixer. Since the structure of the ground samples was amorphous and the cerium concentration was much lower than those of other elements, the valence change and structural change of cerium after grinding with microwave irradiation were investigated using X-ray absorption fine structure (XAFS) analysis in the cerium K-edge. The X-ray absorption near-edge structure (XANES) analysis revealed that a portion of tetravalent cerium was reduced to trivalent cerium by grinding with microwave irradiation. In addition, it was confirmed by extended X-ray absorption fine structure (EXAFS) analysis that oxygen vacancies were produced as a result of the cerium reduction reaction. To evaluate the efficiency of cerium reduction efficiency, the percentage reduction by grinding with microwave irradiation was compared to that by planetary ball milling and microwave irradiation. As a result, it was revealed that the efficiency of cerium reduction via grinding with microwave irradiation was higher than that via microwave irradiation and the same as that via planetary ball milling. Moreover, a larger amount of tetravalent cerium could be reduced to trivalent cerium by grinding with microwave irradiation than when using planetary ball milling and microwave irradiation.

    DOI

    Scopus

    2
    Citation
    (Scopus)
  • Insight on Exogenous Calcium/Magnesium in Weakening Pyrite Floatability with Prolonged Pre-Oxidation: Localized and Concomitant Secondary Minerals and Their Depression Characteristics

    Jifeng Xue, Shigeshi Fuchida, Sana Ishida, Chiharu Tokoro

    Minerals   12 ( 2 ) 115 - 115  2022.01

     View Summary

    In this study, we investigated the localized and concomitant precipitation of calcium (Ca)/magnesium (Mg)-bearing species and iron oxides/oxyhydroxides, and their depression characteristics to the pyrite floatability in flotation process at pH 9 and pH 10.5 with prolonged pre-oxidation. Contrary to the depression characteristics at pH 9, the incipient (within aeration times of 30 min) depression of pyrite floatability in Ca/Mg-bearing solutions was more obvious at pH 10.5, while the subsequent decline was only slightly when the pre-oxidation time was expanded to 120 min and 360 min. The competitive adsorption among Ca/Mg-bearing species and potassium amyl xanthate (PAX, C6H11OS2K, collector) at specific sites onto the pyrite surface was demonstrated by the regularly decreased zeta potential of the pyrite surface pretreated in Ca/Mg-bearing solutions. Further scanning electron microscopy-energy dispersive spectrometry demonstrated the concomitant secondary Ca/Mg/Fe-bearing precipitates on the pyrite surface. X-Ray photoelectron spectroscopy suggested strong reprecipitation of iron oxides/oxyhydroxides on the pyrite surface via acid–base complexation among Ca/Mg hydroxy species and iron hydroxy species. Incipient occupation efficiency of specific reaction sites by Ca/Mg-bearing species, which were mainly controlled by the metastable distribution of Ca/Mg hydroxy species and their electrostatic affinity with pyrite surface, was the crucial factor that influenced the competitive adsorption of xanthate and pyrite floatability. More obvious incipient depression at pH 10.5 rather than at pH 9 contributed to more effective Ca/Mg-bearing species and their higher affinity to pyrite surface at pH 10.5. The localized and concomitant precipitation of secondary Ca/Mg/Fe-bearing species leads to a slightly increased hydrophilic coverage upon the pyrite surface, thus a slowly decreased pyrite floatability with increasing pre-oxidation time.

    DOI

    Scopus

    4
    Citation
    (Scopus)
  • Kinetic Modeling and Mechanisms of Manganese Removal from Alkaline Mine Water Using a Pilot Scale Column Reactor

    Shigeshi Fuchida, Shota Tajima, Takuro Nishimura, Chiharu Tokoro

    Minerals   12 ( 1 ) 99 - 99  2022.01

     View Summary

    Manganese (Mn) is a major element in various aqueous and soil environments that is sometimes highly concentrated in mine water and other mineral processing wastewater. In this study, we investigated Mn removal from alkaline mine water (pH > 9) with an Mn-coated silica sand packed into a pilot-scale column reactor and examined the specific reaction mechanism using X-ray absorption near-edge structure (XANES) analysis and geochemical kinetic modeling. The kinetic effect of dissolved Mn(II) removal by birnessite (δ-Mn(IV)O2) at pH 6 and 8 was evaluated at different Mn(II)/Mn(IV) molar ratios of 0.1–10. Our results confirmed the positive effect of the presence of δ-MnO2 on the short-term removal (60 min) of dissolved Mn. XANES analysis results revealed that δ-MnO2 was more abundant than Mn(III)OOH in the reactor, which may have accumulated during a long-term reaction (4 months) after the reactor was turned on. A gradual decrease in dissolved Mn(II) concentration with depth was observed in the reactor, and comparison with the kinetic modeling result confirmed that δ-MnO2 interaction was the dominant Mn removal mechanism. Our results show that δ-MnO2 contents could play a significant role in controlling Mn removability from mine water in the reactor.

    DOI

    Scopus

    7
    Citation
    (Scopus)
  • Application of CAPE Tools into Prospective Life Cycle Assessment: A Case Study in Recycling Systems Design of Lithium-Ion Battery

    Yasunori Kikuchi, Aya Heiho, Yi Dou, Izuru Suwa, Chiharu Tokoro

    Computer Aided Chemical Engineering   51   1585 - 1590  2022

    DOI

  • Elution of Sulfuric Compounds from Na-sulfide Waste for Stable Management at a Disposal Site: an Experimental Investigation

    Shun Ishii, Shigeshi Fuchida, Takaya Yutaro, Chiharu Tokoro

    Water, Air, & Soil Pollution   233 ( 1 ) 28 - 28  2022.01  [Refereed]

    DOI

    Scopus

  • Prediction of Acid Mine Drainage Quality for the Next Decades by a Tank Model and Multiple Regression Analysis

    Shigeshi FUCHIDA, Masakazu KADOKURA, Chiharu TOKORO

    Journal of MMIJ   137 ( 12 ) 116 - 122  2021.12  [Refereed]

    DOI

  • Application of electrical pulsed discharge to metal layer exfoliation from glass substrate of hard-disk platter

    Masataka Kondo, Soowon Lim, Taketoshi, Koita, Takao Namihira, Chiharu Tokoro

    Results in Engineering   12 ( 100306 ) 100306 - 100306  2021.12  [Refereed]

    Authorship:Corresponding author

    DOI

    Scopus

    4
    Citation
    (Scopus)
  • Kinetic Evaluation of pH and Temperature Effects on Silica Polymerization in the Presence of Mg, Al and Fe

    Shun Ishii, Shota Tajima, Yutaro Takaya, Shigeshi Fuchida, Chiharu Tokoro

    KAGAKU KOGAKU RONBUNSHU   47 ( 6 ) 237 - 244  2021.11

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Investigation on Removal Performance of Multi-Element Using Layered Double Hydroxide Produced from Magnesium Oxide and Ferrous Iron

    Kosuke Tsuchiya, Shigeshi Fuchida, Chiharu Tokoro

    KAGAKU KOGAKU RONBUNSHU   47 ( 6 ) 224 - 230  2021.11

    DOI

    Scopus

  • Mechanism of gold and palladium adsorption on thermoacidophilic red alga Galdieria sulphuraria

    Eri Adams, Kazuki Maeda, Tatsuya Kato, Chiharu Tokoro

    Algal Research   60   102549 - 102549  2021.11  [Refereed]

    Authorship:Corresponding author

    DOI

    Scopus

    9
    Citation
    (Scopus)
  • Removal Mechanisms of Arsenite by Coprecipitation with Ferrihydrite

    Yutaro Takaya, Masakazu Kadokura, Tatsuya Kato, Chiharu Tokoro

    Journal of Environmental Chemical Engineering   9 ( 5 ) 105819 - 105819  2021.10  [Refereed]

    Authorship:Last author

    DOI

    Scopus

    17
    Citation
    (Scopus)
  • Projecting future changes in element concentrations of approximately 100 untreated discharges from legacy mines in Japan by a hierarchical log-linear model

    Yuichi Iwasaki, Keiichi Fukaya, Shigeshi Fuchida, Shinji Matsumoto, Daisuke Araoka, Chiharu Tokoro, Tetsuo Yasutaka

    Science of the Total Environment   786   147500  2021.09  [Refereed]

     View Summary

    Understanding future changes in the concentrations of elements such as Cd in mine drainages, which can cause severe environmental impacts, is crucial to strategically optimize the treatment and management of such drainages. In this study, on the basis of 17-year data (2003–2019) for 99 untreated drainages from legacy mines in Japan, we developed a Bayesian hierarchical log-linear model that can capture temporal changes in the concentrations of seven elements including six metals (Cd, Pb, As, Cu, Zn, Fe, and Mn) in individual mine drainages. We also projected future changes to understand the prospective trends nationwide. The modeling results showed that, during 2003–2019, although overall decreasing trends were observed for most elements across all the drainages evaluated, decreases in the concentrations of these elements were not evident in many mine drainages (5%–28% of drainages for individual elements); in addition, any rise in the number of mine drainages with element concentrations below nationwide drainage standards over the next 100 years will likely be limited (e.g., approximately 10 drainages for Zn and Fe at median estimates). These results have significant implications for future strategies to manage mine drainages: it is probably too optimistic to assume that the element concentrations of mine drainages will always decrease, or that these drainages will satisfy drainage standards (permits) in the not so distant future.

    DOI

    Scopus

    9
    Citation
    (Scopus)
  • Investigation of Separation of Metal Layers Including Platinum Group Metals from Glass Substrates by Pulsed Power

    近藤正隆, Lim Soowon, 小板丈敏, 浪平隆男, 所千晴, 所千晴

    粉体工学会誌   58 ( 9 ) 474 - 480  2021.09

    J-GLOBAL

  • Investigating the upper limit for applying the coarse grain model in a discrete element method examining mixing processes in a rolling drum

    Yoshihiro Kosaku, Yuki Tsunazawa, Chiharu Tokoro

    Advanced Powder Technology   32 ( 11 ) 3980 - 3989  2021.09  [Refereed]

  • Recovery of silver from waste crystalline silicon photovoltaic cells by wire explosion

    Lim Soowon, Imaizumi Yuto, Mochidzuki, Kazuhiro, Koita Taketoshi, Namihira Takao, Tokoro Chiharu

    IEEE Transactions on Plasma Science   49 ( 9 ) 2857 - 2865  2021.09  [Refereed]

    Authorship:Corresponding author

    DOI

  • Separation of cathode particles and aluminum current foil in lithium-ion battery by high-voltage pulsed discharge Part II: Prospective life cycle assessment based on experimental data

    Yasunori Kikuchi, Izuru Suwa, Aya Heiho, Yi Dou, Soowon Lim, Takao Namihira, Kazuhiro Mochidzuki, Taketoshi Koita, Chiharu Tokoro

    Waste Management   132   86 - 95  2021.08  [Refereed]

    DOI

    Scopus

    12
    Citation
    (Scopus)
  • Arsenate Removal by Resin-Supported Ferric Ions: Mechanism, Modeling, and Column Study

    Chiharu Tokoro, Tatsuya Kato

    Advanced Powder Technology   32 ( 6 ) 1943 - 1950  2021.06  [Refereed]

    Authorship:Lead author, Corresponding author

  • Separation of Cathode Particles and Aluminum Current Foil in Lithium-Ion Battery byHigh-voltage Pulsed Discharge Part I: Experimental Investigation

    Chiharu Tokoro, Soowon Lim, Kaito Teruya, Masataka Kondo, Kazuhiro Mochidzuki, Takao Namihira, Yasunori Kikuchi

    Waste Management   125   58 - 66  2021.04  [Refereed]

    Authorship:Lead author

    DOI

    Scopus

    28
    Citation
    (Scopus)
  • Selenite and selenate adsorption on low-crystalline magnesium oxide under alkaline conditions

    Shigeshi Fuchida, Kosuke Tsuchiya, Chiharu Tokoro

    Water, Air, & Soil Pollution   232 ( 4 ) 160  2021.04  [Refereed]

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • DEM-CFDによるプラスチック高精度分離を目的とした水流型比重選別機における粒子供給速度の影響評価

    新田彩乃, 綱澤有輝, 所千晴

    粉体工学会誌   58 ( 3 ) 100 - 110  2021.03  [Refereed]

    Authorship:Last author, Corresponding author

  • Selective grinding of glass to remove resin for silicon-based photovoltaic panel recycling

    Chiharu Tokoro, Maiko Nishi, Yuki Tsunazawa

    Advanced Powder Technology   32 ( 3 ) 841 - 849  2021.03  [Refereed]

    Authorship:Lead author

  • Optimum design of agitator geometry for a dry stirred media mill by the discrete element method

    Chiharu Tokoro, Yuki Ishii, Yuki Tsunazawa, Xin Jiang, Kyoko Okuyama, Motonori Iwamoto, Yasuyoshi Sekine

    Advanced Powder Technology   32 ( 3 ) 850 - 859  2021.03  [Refereed]

    Authorship:Lead author

  • Numerical investigation of segregation behavior of multi-sized particles during pharmaceutical mini-tablet die filling

    Zhibin Xu, Shinji Yoshinaga, Yuki Tsunazawa, Chiharu Tokoro

    Journal of Drug Delivery Science and Technology   61   102301 - 102301  2021.02  [Refereed]

    Authorship:Corresponding author

    DOI

    Scopus

    5
    Citation
    (Scopus)
  • Purification of Calcium Fluoride (CaF2) Sludge by Selective Carbonation of Gypsum

    Yutaro Takaya, Shota Inoue, Tatsuya Kato, Shigeshi Fuchida, Susumu Tsujimoto, Chiharu Tokoro

    Journal of Environmental Chemical Engineering   9 ( 1 ) 104510 - 104510  2021.02  [Refereed]

    DOI

    Scopus

    7
    Citation
    (Scopus)
  • Visualization of Behavior of Microbubble Attached to Solid Wall Loaded by Underwater Shock Wave Induced by Electrical Discharge

    KOITA Taketoshi, LIM Soowon, NAMIHIRA Takao, TOKORO Chiharu

    The Proceedings of Mechanical Engineering Congress, Japan   2021   J022-06  2021

     View Summary

    This paper reports on the visualization results of the phenomena of interaction of underwater shock wave induced by the electrical pulsed discharge with microbubbles attached to the solid wall and the behavior of bubbles collapse caused by the shock wave loading. The effect of microbubble diameter on the behavior was investigated. The time histories of microbubble diameter which was constricted by the underwater shock wave loading was also researched by analyzing the visualized images. The images and analysis results quantitatively clarified that the time of microbubble collapse induced by the shock wave interaction was increased as the increased of that diameter.

    DOI

  • Control of the discharge path in adhesive for separation of the bonding structure

    Masataka Kondo, Taketoshi Koita, Soowon Lim, Takao Namihira, Chiharu Tokoro

    IEEE International Pulsed Power Conference   2021-December  2021

     View Summary

    Recently, the easy disassembly of bonding structures used in lightweight automobile bodies is needed. This is because these bonding structures are difficult to separate efficiently as there are joints using chemicals with a high adhesive strength and are commonly separated manually. In this study, we applied a pulsed discharge for the separation of bonding structures consisting of two adherends bonded by epoxy adhesive. The separation was carried out by controlling the discharge path inside the adhesive with a notch punched on the adherend and peeling the adhesive by the explosive force caused by the discharge. The discharge path in the adhesive was generated by the concentration of electric field at the tip of the notch. The effect of notch geometry on the electric field strength was studied by simulation with the AC/DC module of COMSOL Multiphysics. Simulation results indicated that the notch height affected the electric field concentration, and likewise, that the electric field strength at the notch was higher than the one at the edge of the adhered material. The discharge path of the bonding structure with the notch was visualized using the shadowgraph method. The fracture surfaces of structure without and with the notch after the pulsed discharge were also observed to confirm the discharge crater. The visualized images indicated that the discharge path occurred inside the adhesive from the tip of the notch and that the structure was separated by the expansion of gasified adhesive caused by the discharge when the notch was punched to the structure. A discharge crater was observed in the adhesive surface near the notch. In the case of the structure without a notch, the discharge luminescence appeared not in the adhesive but at the edge of the adherend because of the electric field concentration at the edge, resulting in non-separation due to surface discharge in the structure. These results indicated that the notch was responsible for controlling the discharge path inside the adhesive and caused the separation of the bonding structure.

    DOI

    Scopus

  • Application of simple notch to selective separation of adherend bonded with resin adhesive by pulsed discharge in air

    Taketoshi Koita, Masataka Kondo, Soowon Lim, Manabu Inutsuka, Takao Namihira, Satoshi Oyama, Chiharu Tokoro

    IEEE Transactions on Plasma Science   49 ( 12 ) 3860 - 3872  2021  [Refereed]

    Authorship:Last author, Corresponding author

    DOI

  • マンガンオキシ水酸化物(γ-MnOOH)に対するカドミウム表面錯体モデルの構築と酸性坑廃水中和モデルへの応用

    淵田 茂司, 田嶋 翔太, 所 千晴

    環境資源工学   67 ( 3 ) 117 - 121  2021  [Refereed]

  • シリカスケール生成抑制を目的としたMg, Al, Fe共存系におけるシリカ重合へのpHおよび温度影響の速度論的評価

    石井 駿, 田嶋 翔太, 髙谷 雄太郎, 淵田 茂司, 所 千晴

    化学工学論文集   47 ( 6 ) 1 - 8  2021  [Refereed]

    Authorship:Last author, Corresponding author

  • 酸化マグネシウムおよび第一鉄を用いた層状複水酸化物による多元素含有排水の除去性能の検討

    土屋 宏典, 淵田 茂司, 所 千晴

    化学工学論文集   47 ( 6 ) 1 - 7  2021  [Refereed]

  • Understanding the biogeochemical mechanisms of metal removal from acid mine drainage with a subsurface limestone bed at the Motokura Mine, Japan

    Shigeshi Fuchida, Kohei Suzuki, Tatsuya Kato, Masakazu Kadokura, Chiharu Tokoro

    Scientific Reports   10 ( 1 ) 20889  2020.12  [Refereed]

    Authorship:Last author

     View Summary

    Abstract

    Subsurface limestone beds (SLBs) are used as a passive treatment technique to remove toxic metals from acid mine drainage (AMD). In this study, we investigated the mechanisms and thermodynamics of metal (manganese, copper, zinc, cadmium, and lead) precipitation in the SLB installed at the Motokura Mine. Field surveys in 2017 and 2018 showed that the pH of the SLB influent (initially 5–6) increased to approximately 8 in the drain between 24 and 45 m from the inlet. This increase was caused by limestone dissolution and resulted in the precipitation of hydroxides and/or carbonates of copper, zinc, and lead, as expected from theoretical calculations. Manganese and cadmium were removed within a pH range of approximately 7–8, which was lower than the pH at which they normally precipitate as hydroxides (pH 9–10). X-ray absorption near-edge structure analysis of the sediment indicated that δ-MnO2, which has a high cation-exchange capacity, was the predominant tetravalent manganese compound in the SLB rather than trivalent compound (MnOOH). Biological analysis indicates that microorganism activity of the manganese-oxidizing bacteria in the SLB provided an opportunity for δ-MnO2 formation, after which cadmium was removed by surface complexation with MnO2 (≡ MnOH0 + Cd2+  ⇄  ≡ MnOCd+  +  H+). These findings show that biological agents contributed to the precipitation of manganese and cadmium in the SLB, and suggest that their utilization could enhance the removal performance of the SLB.

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  • Derivation of Flotation Kinetic Model for Activated and Depressed Copper Sulfide Minerals

    Hidekazu Matsuoka, Kohei Mitsuhashi, Masanobu Kawata, Chiharu Tokoro

    Minerals   10 ( 11 ) 1027 - 1027  2020.11  [Refereed]

    Authorship:Last author, Corresponding author

     View Summary

    The wettability and floatability of oxidized chalcocite, bornite, and chalcopyrite with the conditions of sodium hydrosulfide (NaHS) dosages and pHs were studied by contact angle measurements, and single and mixture mineral flotation tests. To evaluate the results of the flotation, the flotation kinetic model for copper sulfide minerals treated by NaHS was derived. In this study, we focused on the activation and depression by NaHS, a well-known activator and depressant of copper minerals. The flotation results showed that there can be a threshold NaHS dosage to activate the mineral surfaces, as evidenced by the depression of the minerals and reduction of recoveries at higher dosages of NaHS. Chalcocite recoveries increased with an increase of NaHS dosage. Bornite recoveries tended to be depressed with a smaller amount of NaHS as pH increased. The recoveries of chalcopyrite increased as pH increased at an optimum NaHS dosage. Moreover, the flotation kinetic model that includes the surface properties and the reaction rate constant between the copper sulfide minerals and NaHS was derived. The trends of the flotation rate constants and mass fractions with NaHS dosages and pHs could quantitatively well-explain the flotation results.

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  • Copper/Silver Recovery from Photovoltaic Panel Sheet by Electrical Dismantling Method

    Chiharu Tokoro, Soowon Lim, Yukihiro Sawamura, Masataka Kondo, Kazuhiro Mochidzuki, Taketoshi Koita, Takao Namihira, Yasunori Kikuchi

    International Journal of Automation Technology   14 ( 6 ) 966 - 974  2020.11  [Refereed]

    Authorship:Lead author

     View Summary

    The volume of spent photovoltaic (PV) panels is expected to grow exponentially in future decades. Substantial material resources such as silver (Ag), copper (Cu), aluminum (Al), silicon (Si), and glass can potentially be recovered from silicon-based PV panels. In this paper, we targeted the recovery of Cu and Ag from a cell sheet separated to a glass panel from a spent PV panel. The technical feasibility of a novel electrical dismantling method was experimentally studied. This method employed a pulsed power technology that releases high energy in a short time. It allowed a selective separation of the Cu/Ag wires from the sheet once per discharge in water. The experimental results indicated that 95.6% of the total Cu and 17.2% of the total Ag in the sample were successfully separated from the cell sheet using a 3.5-kJ capacitor bank circuit. Moreover, 3.66% of the total Si in the sample was contaminated by the separated Cu/Ag particles from the cell sheet, mainly by shockwaves generated by plasma expansion, and some of them formed a compound with Cu and Ag by eutectic melting, resulting in low liberation. At the lower energy of 3.5 kJ, eutectic melting of Cu and Ag with Si was more suppressed than 4.6 kJ, and 94.3% of Cu and 77.5% of Ag in the separated particles were liberated, which would be acceptable for further wet gravity and/or shape separation of Cu and Ag.

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  • Defining Requirements on Technology Systems Assessment from Life Cycle Perspectives: Cases on Recycling of Photovoltaic and Secondary Batteries

    Yasunori Kikuchi, Aya Heiho, Yi Dou, Izuru Suwa, I-Ching Chen, Yasuhiro Fukushima, Chiharu Tokoro

    International Journal of Automation Technology   14 ( 6 ) 890 - 908  2020.11  [Refereed]

    Authorship:Last author

     View Summary

    Since the enactment of the “Feed-in Tariff” scheme in 2012, the solar power generation capacity in Japan has been steadily growing. Therefore, in the near future, the demand for the mass processing of spent photovoltaic (PV) panels is expected to increase. Secondary batteries, especially lithium-ion batteries (LiBs), have become important products for vehicles and mobile devices. The production of LiBs is also expected to significantly increase in the near future. In this study, we address the design of recycling systems for such emerging technologies. From life cycle perspectives, the requirements for the assessment of these technology systems are carefully defined through a bibliometric analysis of technology assessments, critical reviews of current research and developments in the recycling of PV panels and LiBs, and analysis of the intensities of life cycle impacts (such as greenhouse gas emissions and resource use). The necessities for life cycle assessments, material flow analyses, and other assessment methods are clarified, along with the conditions to be examined using these assessment methods.

    DOI CiNii

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  • Insight into the Mechanism of Arsenic(III/V) Uptake on Mesoporous Zerovalent Iron–Magnetite Nanocomposites: Adsorption and Microscopic Studies

    Yusuf O. Zubair, Shigeshi Fuchida, Chiharu Tokoro

    ACS Applied Materials & Interfaces   12 ( 44 ) 49755 - 49767  2020.10  [Refereed]  [International journal]

    Authorship:Last author

     View Summary

    Mesoporous zerovalent iron-magnetite nanocomposites (ZVI-MNCs) were developed to circumvent the limitations of magnetite, such as its susceptibility to phase transition in air-water interfaces. High-resolution transmission electron microscopy images revealed the presence of Fe0 and Fe3O4 in the as-prepared adsorbent. High-resolution X-ray photoelectron spectroscopy (HR-XPS) Fe 2p deconvoluted spectra showed that electron transfer between Fe0 and Fe3O4 controlled the magnetite transformation. The isotherm equilibrium data for As(III) and As(V) are described by the Sips model, which suggests single- and multilayer formation onto a heterogeneous surface with different binding sites, whereas adsorption is controlled by a pseudo-second-order kinetic model, which indicates chemisorption. The maximum sorption capacities (qm) for As(III) and As(V) are 632.6 and 1000 μmol g-1, respectively, which are larger than the qm of similar adsorbents. The greater qm for As(V) is attributed to a higher multilayer formation and a stronger bonding force compared with As(III). The arsenic uptake capacity showed that the as-prepared adsorbent was effective over a wide pH range, and an optimal uptake capacity was recorded between pH 5.0 and 9.0 for As(III) and 3.0 and 7.0 for As(V). The adsorbent exhibited a remarkable regeneration performance for As(III) and As(V) uptake. Several microscopic analytical tools, including Fourier transform infrared spectroscopy, HR-XPS, and X-ray absorption near-edge structure together with zeta potential, confirmed that the binding mode of As(III) and As(V) on ZVI-MNCs was predominantly inner-sphere coordination. Partial redox transformation occurred for As(III) and As(V) on nearly 10 nm of the adsorbent, which indicates that a surface redox mechanism contributed partially to arsenic uptake on the near surface of the ZVI-MNCs. Extended X-ray absorption fine structure spectral analysis proposed that a corner-sharing monodentate mononuclear (1V) complex occurred for As(III) with a small portion of a corner-sharing bidentate binuclear (2C) complex, whereas As(V) formed a corner-sharing bidentate binuclear (2C) complex with octahedral Fe bonding.

    DOI PubMed

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  • Rapid boron removal from wastewater using low-crystalline magnesium oxide

    Hiroki Fukuda, Kosuke Tsuchiya, Yuichiro Toba, Masahiro Eguchi, Chiharu Tokoro

    Journal of Environmental Chemical Engineering   8 ( 5 ) 104171 - 104171  2020.10  [Refereed]

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  • Surface properties of copper-sulfide minerals with sodium-hydrosulfide activation

    Hidekazu Matsuoka, Kohei Mitsuhashi, Masanobu Kawata, Tatsuya Kato, Chiharu Tokoro, Kazutoshi Haga, Atsushi Shibayama

    Minerals Engineering   156   106530 - 106530  2020.09  [Refereed]

     View Summary

    The surface properties of slightly oxidized chalcocite, bornite, and chalcopyrite with sodium hydrosulfide (NaHS) treatment were investigated by solid analyses of X-ray photoelectron spectroscopy, solution analyses, and zeta potential measurements. NaHS is known as a flotation activator for copper-oxide minerals by sulfurizing their surfaces. This study focused on the surface properties before/after sulfurization by the NaHS at several NaHS dosages and alkaline pHs. Iron leaching and precipitates of copper–iron-sulfide minerals have also been investigated. The analysis results showed that NaHS sulfurized the oxidized copper species, CuO and CuSO4, to copper sulfide, but oxidized iron species, Fe2O3 and Fe(OH)3, were not sulfurized by NaHS. These oxidized iron species dissolved into solutions as complex ion, Fe(HS)20, then Fe(HS)20 was decomposed by dissolved oxygen and reprecipitated as Fe2O3. The results of chalcocite showed that Cu2S was generated on the surfaces with NaHS treatment at any pH. The bornite and chalcopyrite results indicated that Fe2O3 was produced on bornite surfaces with an increase in pH, whereas the chalcopyrite surfaces were covered as the pH decreased. A flotation test was conducted using a Chilean copper ore that contained chalcocite, bornite, and chalcopyrite, and the flotation recovery of each mineral was consistent with the surface sulfurization at several NaHS dosages and pHs.

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  • Removal mechanisms of cadmium by δ-MnO2 in adsorption and coprecipitation processes at pH 6

    Kohei Suzuki, Tatsuya Kato, Shigeshi Fuchida, Chiharu Tokoro

    Chemical Geology   550   119744 - 119744  2020.09  [Refereed]

     View Summary

    We elucidate the removal mechanism of Cd by birnessite (delta-MnO2) in adsorption and coprecipitation processes in the context of acid mine drainage (AMD) treatments. The removal mechanism was studied through batch removal experiments at different initial Cd/Mn molar ratios (0-2) by zeta potential measurements, X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), and X-ray absorption fine structure (XAFS) analysis. The sorption isotherm and zeta potential measurements suggest that surface complex formation is the dominant mechanism, and that surface precipitation and/or intercalation also occur in the coprecipitation process when the initial Cd/Mn molar ratio is high (1-2). Increasing the initial Cd/Mn molar ratio to above 0.5 decreased the particle size of delta-MnO2 and shifted its (001) XRD peak to lower angles, suggesting that the delta-MnO2 interlayer ((001) and (002) planes) was expanded and the growth of delta-MnO2 crystals was inhibited in the coprecipitation process. The results of XAFS analysis revealed the production of Mn(III) precipitates and surface complex formation with Cd at high Cd/Mn molar ratio condition ( < 1). No significant changes in the crystalline structures of delta-MnO2 over the entire range of initial Cd/Mn molar ratios were observed in the adsorption process, confirming that Cd could be adsorbed by triple-corner-sharing at neutral pH.

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  • Experimental Investigation of Boron Removal Mechanism from Wastewater by Calcined Ettringite

    Shigeshi Fuchida, Shungo Hobo, Kosuke Tsuchiya, Yoshiyuki Tanaka, Takeshi Nakamura, Chiharu Tokoro

    Water, Air, & Soil Pollution   231 ( 7 ) 344  2020.07  [Refereed]

     View Summary

    The development of efficient and inexpensive boron removal techniques is required to treat wastewater from many industrial processes. We investigated the removal mechanism of boron from wastewater by calcinated ettringite, a concrete sludge, and compared the advantage of this method to coprecipitation with ettringite. The amount of boron remaining in solution decreased slightly from an initial concentration of 2.3 mmol/dm(3) to 1.3-1.4 mmol/dm(3) after reaction for 60 min with ettringites calcinated at 55 and 65 degrees C. The boron removal efficiency increased greatly, with only 0.30 mmol/dm(3) remaining in solution after treatment for 60 min with samples calcinated at 75 degrees C, but samples calcinated at 95 and 175 degrees C removed slightly less boron than those calcinated at 75 degrees C. This enhancement of boron removal performance is due to the amorphization of the ettringite structure by calcination. However, excess heating inhibits ion exchange between the sulfate ions in the ettringite and the borate ions in the solution. The coprecipitation method also achieved efficient boron removal at high Al/B molar ratio (0.44 mmol/dm(3) boron remaining after 60 min). However, uptake by a different amorphous precipitant became the dominant removal mechanism. Large amounts of sludge are generated by this method. Adsorption using calcinated ettringite is therefore the optimal method for the efficient and inexpensive removal of boron from wastewater.

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    3
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  • Forecast of AMD quantity by a series tank model in three stages: Case studies in two closed Japanese mines

    Chiharu Tokoro, Kenichiro Fukaki, Masakazu Kadokura, Shigeshi Fuchida

    Minerals   10 ( 5 ) 430  2020.05  [Refereed]

     View Summary

    © 2020 by the authors. Licensee MDPI, Basel, Switzerland. There are about 100 sites of acid mine drainage (AMD) from abandoned/closed mines in Japan. For their sustainable treatment, future prediction of AMD quantity is crucial. In this study, AMD quantity was predicted for two closed mines in Japan based on a series tank model in three stages. The tank model parameters were determined from the relationship between the observed AMD quantity and the inflow of rainfall and snowmelt by using the Kalman filter and particle swarm optimization methods. The Automated Meteorological Data Acquisition System (AMeDAS) data of rainfall were corrected for elevation and by the statistical daily fluctuation model. The snowmelt was estimated from the AMeDAS data of rainfall, temperature, and sunshine duration by using mass and heat balance of snow. Fitting with one year of daily data was sufficient to obtain the AMD quantity model. Future AMD quantity was predicted by the constructed model using the forecast data of rainfall and temperature proposed by the Max Planck Institute–Earth System Model (MPI–ESM), based on the Intergovernmental Panel on Climate Change (IPCC) representative concentration pathway (RCP) 2.6 and RCP8.5 scenarios. The results showed that global warming causes an increase in the quantity and fluctuation of AMD, especially for large reservoirs and residence time of AMD. There is a concern that for mines with large AMD quantities, AMD treatment will be unstable due to future global warming.

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  • Mechanism of arsenate coprecipitation at the solid/liquid interface of ferrihydrite: A perspective review

    Chiharu Tokoro, Masakazu Kadokura, Tatsuya Kato

    Advanced Powder Technology   31 ( 2 ) 859 - 866  2020.02  [Refereed]

  • Experimental study and surface complexation modeling of fluoride removal by magnesium hydroxide in adsorption and coprecipitation processes

    Kosuke Tsuchiya, Shigeshi Fuchida, Chiharu Tokoro

    Journal of Environmental Chemical Engineering   8 ( 6 ) 104514  2020  [Refereed]

     View Summary

    © 2020 Elsevier Ltd. High contaminated levels of fluoride (F) in groundwater and drinking water are of significant concern for human health in many countries. This study examined adsorption and coprecipitation for effective F- removal from high F-containing water using inexpensive magnesium hydroxide, Mg(OH)2. Fluoride solutions were reacted with Mg2+-or Mg(OH)2-containing solution at different F/Mg molar ratios of 0.05-2, and the F- removal performance and mechanisms were investigated in both processes. As a result, the residual amount of F- in the solution decreased with an increase in Mg2+ concentrations for both processes, and the sorption isotherms followed the Langmuir type. Mg(OH)2 was precipitated only after F- removal, which suggests that adsorption to Mg(OH)2 was the main removal mechanism in both processes. However, the saturated adsorption capacity in the coprecipitation process was two times higher than that in the adsorption process. The chemical equilibrium calculation results implied that the surface complexation of MgF° and MgOH2F° was the dominant mechanism in the adsorption process whereas multiple complexations of Mg-MgF3° and Mg-MgF4- occurred in the coprecipitation process. This complex formation improves F- removal; hence, coprecipitation with Mg(OH)2 exhibited better potential as an efficient process for the treatment of industrial wastewater that contains F-.

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  • Kinetic modelling of chalcopyrite leaching assisted by iodine in ferric sulfate media

    Ronny Winarko, David B.Dreisinger, Akira Miura, Chiharu Tokoro, Wenying Liu

    Hydrometallurgy   197   105481  2020  [Refereed]

  • 腐葉土を充填したカラムを用いた亜鉛含有坑廃水連続処理の定量モデル化

    加藤 達也, 福島 諒, 佐藤 康市, 山縣 三郎, 所 千晴

    Journal of MMIJ   136 ( 12 ) 151 - 158  2020  [Refereed]

  • Application of nano‐scale zero‐valent iron adsorbed on magnetite nanoparticles for removal of carbon tetrachloride: Products and degradation pathway

    Xiaofan Lv, Widyawanto Prastistho, Qi Yang, Chiharu Tokoro

    Applied Organometallic Chemistry   34 ( 5 ) 5592  2020  [Refereed]

  • Effect of the roll stud diameter on the capacity of a high-pressure grinding roll using the discrete element method

    Yu Nagata, Yuki Tsunazawa, Kouji Tsukada, Yuichi Yaguchi, Yosuke Ebisu, Kohei Mitsuhashi, Chiharu Tokoro

    Minerals Engineering   154   106412  2020  [Refereed]

  • Effect of Cellulose Nanocrystals Extracted from Oil Palm Empty Fruit Bunch as Green Admixture for Mortar

    Dianah Mazlan, Santhana Krishnan, Mohd Fadhil Md Din, Chiharu Tokoro, Nur Hafizah, Abd Khalid, Izni Syahrizal Ibrahim, Hideki Takahashi, Daisuke Komori

    SCIENTIFIC REPORTS   10 ( 1 ) 6512  2020  [Refereed]

     View Summary

    This paper aims to examine the effect of cellulose nanocrystals (CNCs) derived from oil palm empty fruit bunch fiber (EFB) incorporating cement mortar on its structural performances. Cellulose nanocrystals (CNCs) were extracted from alpha -cellulose extracted from EFB using an acid hydrolysis process with a concentration of acid used was 64% w/v under the temperature of 45 degrees C for 60minutes. The Cellulose nanocrystals (CNCs) were mixed into the cement mortar ranging from 0 to 0.8% w/w and its mechanical properties were determined. The developed CNCs mortar was characterized for their compressive and flexural properties as well as microstructure. The influence of CNCs concentration, curing method, dispersion of CNCs on mortar's mechanical performance was thoroughly examined to find out the optimum condition. Overall results revealed that an addition of 0.4% cellulose nanocrystals has shown to increase the compressive and flexural strength to 46% and 20%, respectively cured under the wrapping method. The hydration of cementitious composites also improved significantly with the addition of CNCs by the formation of highly crystalline of portlandite observed under the XRD test. This present work demonstrates the importance of palm oil empty fruit bunch waste as a sustainable resource of cellulose nanocrystals admixture to achieve structural strength of cement mortar and promotes green technologies in construction.

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  • Application of GETFLOWS Coupled with Chemical Reactions to Arsenic Removal through Ferrihydrite Coprecipitation in an Artificial Wetland of a Japanese Closed Mine

    Tatsuya Kato, Yohei Kawasaki, Masakazu Kadokura, Kohei Suzuki, Yasuhiro Tawara, Yoshiyuki Ohara, Chiharu Tokoro

    Minerals   10 ( 5 ) 475  2020  [Refereed]

  • 坑廃水処理における水酸化物への共沈機構

    所千晴, 加藤達也

    地球化学   54   5 - 14  2020  [Refereed]

  • Mechanochemical activation of chalcopyrite: Relationship between activation mechanism and leaching enhancement

    G. Granata, K. Takahashi, T. Kato, C. Tokoro

    Minerals Engineering   131   280 - 285  2019  [Refereed]

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    22
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  • Mechanism and kinetics of enhancement of cerium dissolution from weathered residual rare earth ore by planetary ball milling

    Tatsuya Kato, Giuseppe Granata, Yuki Tsunazawa, Tetsuichi Takagi, Chiharu Tokoro

    Minerals Engineering   134   365 - 371  2019  [Refereed]

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    18
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  • 表面錯体形成を考慮した腐葉土による亜鉛除去の定量モデル化

    加藤 達也, 福島 諒, グラナタ ジュセッペ, 佐藤 康市, 山縣 三郎, 所 千晴

    粉体工学会誌   56 ( 3 ) 136 - 141  2019  [Refereed]

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  • 粉砕により機械的に活性化させた風化残留型希土類鉱石からの軽希土類浸出への酸の影響評価

    加藤 達也, グラナタ ジュセッペ, 所 千晴

    粉体工学会誌   56 ( 4 ) 174 - 180  2019  [Refereed]

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    3
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  • Iodide-assisted leaching of chalcopyrite in acidic ferric sulfate media

    G.Granata, A.Miura, W.Liu,F.Pagnanelli, C.Tokoro

    Hydrometallurgy   186   244 - 251  2019  [Refereed]

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    15
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  • Investigation of optimum design for nanoparticle dispersion in centrifugal bead mill using DEM-CFD simulation

    Yu Nagata, Masaya Minagawa, Shosei Hisatomi, Yuki Tsunazawa, Kyoko Okuyama, Motonori Iwamoto, Yasuyoshi Sekine, Chiharu Tokoro

    Advanced Powder Technology   30   1034 - 1042  2019  [Refereed]

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    15
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  • Kinetics and mechanism of selenate and selenite removal in solution by green rust-sulfate

    Aina Onoguchi, Giuseppe Granata, Daisuke Haraguchi, Hiroshi Hayashi, Chiharu Tokoro

    ROYAL SOCIETY OPEN SCIENCE   6  2019  [Refereed]

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  • Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-Ray Absorption Fine Structure

    Tatsuya Kato, Yuki Tsunazawa, Wenying Liu, Chiharu Tokoro

    minerals   9   267 - 278  2019  [Refereed]

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    9
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  • Direct recovery of copper nanoparticles from leach pad drainage by surfactant-assisted cementation with iron powder

    Giuseppe Granataa, Uuganzaya Tsendorjb, Wenying Liuc, Chiharu Tokoro

    Colloids and Surfaces   580   267 - 278  2019  [Refereed]

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    12
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  • Preparation of copper nanoparticles for metal-metal bonding by aqueous reduction with D-glucose and PVP

    Giuseppe Granata, Aina Onoguchi, Chiharu Tokoro

    Chemical Engineering Science    2019  [Refereed]

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  • Life cycle assessment of resource recovery from waste electrical and electronic equipment: A case study of Tantalum recovery by chain-using drum-typed impact mill

    A. Heiho, Y. Kanematsu, M. Nagase, S. Murakami, C. Tokoro, Y. Kikuchi

    化学工学論文集   45 ( 6 ) 244 - 252  2019  [Refereed]

     View Summary

    The recovery of metal resources from urban mines such as waste electrical and electronic equipment (WEEE) has become an emerging issue. The establishment of technology and social systems for recycling rare metals is of especially high priority due to their worldwide shortage. This study tackles the recycling of rare metals, especially tantalum, by applying a chain-using drum-type impact mill (CDIM) for pulverization of WEEE in the intermediate treatment for physical separation of components contained in plastic routers. A life-cycle assessment (LCA) was conducted based on actual process inventories of the CDIM, segregation and concentration of electronic parts. Climate change and resource depletion were adopted as the impact category indicated by life-cycle greenhouse gas emission (LC-GHG) and characterized resource consumption in this LCA. Although the tantalum contained in WEEE is input into the copper smelting and cannot be separated from other metals in conventional recycling systems, it was demonstrated that the CDIM intermediate treatment could selectively concentrate the tantalum capacitors. The tantalum capacitors can be converted into sintered tantalum, substitutes for Ta2O5, which can reduce resource consumption potentials at the expense of additional energy consumption. Most of the LC-GHG was derived from energy, especially public electricity. Decarbonization in the power grid can reduce the LC-GHG attributable to the recycling system. Rare metals other than tantalum should also be recoverable from WEEE. Physical and chemical treatment processes for metal recovery should be developed, demonstrated, and implemented in line with the recycling systems for various products.

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    4
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  • Applying analysis of mineral surfaces to predict flotation behavior

    H. Matsuoka, R. Kawarabuki, K. Mitsuhashi, M. Kawata, C. Tokoro, K. Haga, A. Shibayama

    IMPC 2018 - 29th International Mineral Processing Congress     1481 - 1488  2019

     View Summary

    The mineral surface characteristic is important for the flotation because it affects the flotation behavior of the mineral. Conventionally, in the flotation process for Cu sulphide ores, the degree of ore floatabilities varies depending on the mineral phase such as chalcopyrite, bornite, or chalcocite. Therefore, mineral surfaces are treated with activators and depressants to control the floatability of target minerals and obtain high recovery performance. There are lots of flotation reagents which have many effects on ores depending on ore characteristics and conditioning methods. For example, sodium hydrosulphide (NaHS) as activator is known to have the effect of re-sulfurizing and activating oxidized surface of chalcocite and bornite. On the other hand, NaHS is reported to depress chalcopyrite floatability. In this study, the evaluation of mineral surfaces was conducted to predict flotation behavior. Activation of Cu minerals (chalcocite, bornite, and chalcopyrite) by NaHS was experimented. The three Cu minerals were treated in two steps. Firstly, they were oxidized in the drying oven. Secondly, they were treated with NaHS solution. After each treatment step, each mineral was measured by contact angle apparatus then analyzed by X-ray photoelectron spectroscopy (XPS). The results of surface characteristics after oxidation and NaHS treatment were utilized to accomplish the study's objective.

  • Investigation and evaluation of the detachment of printed circuit boards from waste appliances for effective recycling

    Yuki Tsunazawa, Shosei Hisatomi, Shinsuke Murakami, Chiharu Tokoro

    Waste Management   78   474 - 482  2018.08  [Refereed]

     View Summary

    To establish an effective recycling process for waste appliances, the process of recovering printed circuit boards (PCBs) containing valuable elements in comminution was investigated and evaluated. The present study performed comminution tests using three different types of waste appliances: smartphones, microwave ovens and electrical rice cookers. Comminution tests showed that a drum-type agitation mill operated at a mid-range rotation speed could achieve a relatively high recovery ratio of PCBs and inhibit excessive breakage of PCBs. Following these experiments, simulations using the discrete element method with a particle-based rigid-body model were conducted to evaluate the comminution performance of the drum-type agitation mill. Experimental and simulation results confirm that the processes of detachment of PCBs from waste appliances and subsequent breakage can be expressed by kinetic equations related to collision energy. It is concluded from these results that the kinetic equations obtained in experiments and simulations can be used to evaluate the recovery process of PCBs from waste appliances.

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  • Enhancement of copper dissolution by mechanochemical activation of copper ores: Correlation between leaching experiments and DEM simulations

    Masaya Minagawa, Shosei Hisatomi, Tatsuya Kato, Giuseppe Granata, Chiharu Tokoro

    Advanced Powder Technology   29 ( 3 ) 471 - 478  2018.03  [Refereed]

     View Summary

    In this work we investigated the influence of planetary ball milling and vertical stirred ball milling on the leaching of a copper ore containing copper sulfate and covellite. We used a mixed experimental-simulation approach to correlate the kinetic parameters of leaching to the collision energy during grinding. The effect of milling was studied by scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS). Results showed that both high-intensity grinding techniques resulted into a dramatic decrease of particle size. Furthermore, under specific grinding conditions, the planetary ball milling determined also the partial amorphization of covellite. The collision energies corresponding to specific grinding conditions in terms of rotational speed and number of grinding media were assessed by DEM simulations and were related to the specific surface area after grinding. The specific surface area of grinded samples was found to be directly proportional to the collision energy in grinding. The leaching of the ore occurred through three subsequent steps: (i) dissolution of copper sulfate, (ii) dissolution of amorphousized covellite and (iii) dissolution of residual crystalline covellite. The results of kinetic fitting highlighted an increase of the rate constants for the leaching of amorphous and crystalline covellite by intensifying the milling conditions. By correlating the collision energies from DEM simulation with the leaching rate constants, we confirmed that the rate constants for the leaching of covellite increased due to an occurred mechanochemical reaction. The mechanochemical reaction that determined the partial amorphization of covellite occurred above 0.25 J/s · g. On the other hand, the rate constants for the leaching of the residual crystalline covellite constantly and progressively increased with the collision energy, thus highlighting an improvement of leaching due to an increase of surface area.

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    25
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  • Effect of agitator shaft direction on grinding performance in media stirred mill: Investigation using DEM simulation

    Sho Fukui, Yuki Tsunazawa, Shosei Hisatomi, Giuseppe Granata, Chiharu Tokoro, Kyoko Okuyama, Motonori Iwamoto, Yasuyoshi Sekine

    Materials Transactions   59 ( 3 ) 488 - 493  2018  [Refereed]

     View Summary

    Recently, the discrete element method (DEM) has been widely applied to investigate the influence of operating and design parameters on grinding performances. However, while most studies investigated the effects of such parameters on the fineness of milling products, the relationship between them and the size dispersion of milling products has not been elucidated yet. In this study, we investigated the influence that the direction of the agitator shaft has on grinding performance in a media stirring mill. First, we proved by milling experiments that the media stirring mill with the horizontal direction of the agitator shaft can provide better grinding performances. Then, we further elucidated this experimental evidence by applying DEM simulations to a media stirring milling process in a vertical and a horizontal stirred mill. According to the simulations, in the vertical shaft configuration, the motion of the grinding media in the lower section through the vertical direction was inhibited by a too low velocity. On the other hand, the grinding media in the horizontal stirred mill moved more uniformly but with a lower collision energy. Furthermore, the grinding media in the low sections actively mixed with the grinding media in the upper sections, thereby resulting in a more uniform energy transfer and in a better grinding process. Accordingly, this study demonstrated that not only the collision energy but also the uniformity of the movement of the medium particles should be evaluated in order to investigate the grinding performance in a media stirred mill by DEM simulation.

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    12
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  • Recovery of calcium fluoride from highly contaminated fluoric/hexafluorosilicic acid wastewater

    Masao Morita, Giuseppe Granata, Chiharu Tokoro

    Materials Transactions   59 ( 2 ) 290 - 296  2018  [Refereed]

     View Summary

    We investigated the recovery of calcium fluoride (CaF2) from highly concentrated hexafluorosilicic acid wastewater by neutralization- purification. Neutralization was achieved by dosing calcium hydroxide, whereas purification was carried out by alkaline leaching with sodium hydroxide. X-ray diffraction, X-ray absorption fine structure, mineral liberation analyzer, Fourier transform infrared spectroscopy and Inductively-coupled plasma atomic emission spectroscopy were used to quantify the neutralization and leaching performance and to elucidate their mechanisms. The precipitation behavior was strongly dependent on the calcium (Ca)/silicon (Si) molar ratio. For a Ca/Si ratio of 1.12, approximately 25% of the total fluorine was precipitated selectively as CaF2. By increasing the Ca/Si ratio to 3.91, the recovery yield increased to 100% because of the precipitation of CaSiF6 and the hydrolytic decomposition of hexafluorosilicate ion (SiF6 2-) to CaF2. The hydrolytic decomposition of SiF6 2- resulted in the precipitation of silicon dioxide on the surface of the previously formed CaF2. Alkaline leaching by sodium hydroxide at 70°C resulted in an efficient removal of the silicon phase from the neutralized sludge with the formation of a CaF2 product with a grade above 90%. Leaching parameters, such as the kinetic constant and the activation energy, were determined by assuming first-order kinetics. The residual silicon phase in the final product could not be dissolved because of the formation of non-leachable SiO3 2-.

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    7
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  • Crystal formation and growth by slow cooling for recovery of magnetite particles from copper smelting slag

    Y. Tsunazawa, C. Liu, R. Toi, T. Okura, C. Tokoro

    Mineral Processing and Extractive Metallurgy   128 ( 4 ) 248 - 255  2018  [Refereed]

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    9
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  • Removal of chromate from tannery wastewater: the applicability of sulfate-green rust in real coprecipitaion processes

    A. Mamun, M. M. Khin, G. Granata, C. Tokoro

    環境資源工学   65 ( 3 ) 67 - 73  2018  [Refereed]

  • Role of pH in green rust preparation and chromate removal from water

    Abdullah Al Mamun, Aina Onoguchi, Giuseppe Granata, Chiharu Tokoro

    Applied Clay Science   165   205 - 213  2018  [Refereed]

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    20
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  • Preparation of Polymeric Adsorbents Bearing Diglycolamic Acid Ligands for Rare Earth Elements

    T. Shinozaki, T. Ogata, R. Kakinuma, H. Narita, C. Tokoro, M. Tanaka

    Industrial & Engineering Chemistry Research   57 ( 33 ) 11424 - 11430  2018  [Refereed]

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    19
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  • Comparison of the Extractabilities of Tetrachloro- and Tetrabromo-palladate(II) Ions with a Thiodiglycolamide Compound

    Hirokazu Narita, Motoki Maeda, Chiharu Tokoro, Tomoya Suzuki, Mikiya Tanaka, Ryuhei Motokawa, Hideaki Shiwaku, Tsuyoshi Yaita

    ANALYTICAL SCIENCES   33 ( 11 ) 1305 - 1309  2017.11  [Refereed]

     View Summary

    Using N,N,N',N'-tetra-2-ethylhexyl-thiodiglycolamide (TEHTDGA) in n-dodecane as the extractant, we compared the percentages of Pd(II) extracted from HCl and HBr solutions, and analyzed the structures of the Pd(II)-extractant complexes. For comparison, similar experiments were performed with di-n-hexyl sulfide (DHS), a well-known sulfide-type extractant. TEHTDGA extracted Pd(II) from both HCl and HBr solutions much faster than DHS. The Pd(II)/(TEHTDGA or DHS) stoichiometry in the organic phase was 1:2. For TEHTDGA, the extractability of Pd(II) from HBr solution was inferior to that from HCl solution, whereas the opposite was true for DHS. However, FT-IR spectroscopy and EXAFS measurements indicated that the inner-sphere structure of Pd(II) in the TEHTDGA complex was almost the same as that in the DHS system: in both cases, two of the halide ions in the tetrachloro- or tetrabromopalladate(II) ion were replaced by the sulfur atoms of two extractant molecules.

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    11
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  • In situ remediation of bauxite residue by sulfuric acid leaching and bipolar-membrane electrodialysis

    Mayuko Kishida, Takuo Harato, Chiharu Tokoro, Shuji Owada

    HYDROMETALLURGY   170   58 - 67  2017.07  [Refereed]

     View Summary

    In situ remediation of a bauxite residue by integrating a storage area with CSIRO's soda recovery process was evaluated. The process consisted of the following steps: bauxite residue is neutralized with sulfuric acid; the slurry is separated into a neutralized residue and a leachate. The, residue is sent to a storage area -and washed with rainfall. The leachate and drainage/runoff from the storage area are collected and purified; sodium sulfate in the solution is then split into sodium hydroxide and sulfuric acid using bipolar-membrane electrodialysis. Finally, the sodium hydroxide is used in a Bayer refinery and the sulfuric acid is used for neutralization of bauxite residue. This study investigated the optimum conditions and remediation of the bauxite residue. pH rebounding was observed after sulfuric acid neutralization of bauxite residue. Considering this rebound, the most suitable pH was set at 4.5. Washing remediated the residue to accomplish the goals for bauxite residue rehabilitation. Furthermore, sodium hydroxide and sulfuric acid were recovered by bipolar -membrane electrodialysis. Cost -benefit analysis for an assumed one million tons refinery showed 10% return on investment. Evaluation of the advantages of neutralized residue and technical improvements are expected to make this process feasible for remediation of bauxite residue. (C) 2016 Elsevier B.V. All rights reserved.

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    34
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  • Sorption mechanisms of chromate with coprecipitated ferrihydrite in aqueous solution

    Abdullah Al Mamun, Masao Morita, Mitsuaki Matsuoka, Chiharu Tokoro

    JOURNAL OF HAZARDOUS MATERIALS   334   142 - 149  2017.07  [Refereed]

     View Summary

    Hexavalent chromium (Cr(VI)) attracted researchers' interest for its toxicity, natural availability and removal difficulty. Nevertheless, its sorption mechanism is not clearly understood yet. In this work, we elucidated the sorption mechanism of the co-precipitation of chromates with ferrihydrite through quantitative analysis. The influence of Cr/Fe molar ratio on sorption was investigated by zeta potential measurements, X-ray diffraction (XRD) and X-ray adsorption fine-structure analysis (XAFS). Coprecipitation at pH 5 showed almost twice the sorption density of adsorption at pH 5. In co-precipitation, a shift of the XRD peak due to inner-sphere sorption of chromate was observed at Cr/Fe molar ratio 0.5. For adsorption, the same peak shift was confirmed at Cr/Fe molar ratio of 1. Zeta potential at pH 5 suggested that the sorption mechanism changed at Cr/Fe molar ratio 0.25 for coprecipitation and at Cr/Fe molar ratio of 1 for adsorption. Fitting of Cr and Fe K-edge extended X-ray adsorption fine-structure suggested that ferrihydrite immobilized Cr(VI) via outer sphere surface complexation for lower Cr/Fe ratios and via inner-sphere surface complexation for higher molar ratios. At higher molar ratios, bidentate binuclear Cr Fe bonds were well established, thus resulting in the expansion of the ferrihydrite structure. (C) 2017 Elsevier B.V. All rights reserved.

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    58
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  • Selective extraction of Pt(IV) over Fe(III) from HCl with an amide-containing tertiary amine compound

    Motoki Maeda, Hirokazu Narita, Chiharu Tokoro, Mikiya Tanaka, Ryuhei Motokawa, Hideaki Shiwaku, Tsuyoshi Yaita

    SEPARATION AND PURIFICATION TECHNOLOGY   177   176 - 181  2017.04  [Refereed]

     View Summary

    The separation properties of Pt(IV) over Fe(III) in HCl solutions using N-2-ethylhexyl-bis(N-di-2-ethylhexyl-ethylamide)amine (EHBAA) were investigated and then compared with those using the conventional extractant tri-n-octylamine (TOA). Also, the structural analyses of Pt(IV) in both of the aqueous (HCl solution) and organic (EHBAA in n-dodecane-2-ethylhexanol solution) phases were performed with EXAFS spectroscopy. The extractability of Pt(IV) was much higher with EHBAA than with TOA in the studied HCI concentration range (0.2-8 M HCl); additionally, EHBAA selectively extracted Pt(IV) over Fe(III) under the condition of [EHBAA] &lt;= 0.1 M and [HCI] &lt;= 1 M. The Pt(IV) loading capacity of 0.1 M EHBAA was about 9.2 (about 0.05 M). Most of the Pt(IV) extracted with 0.1 M EHBAA from 1 M HCI was stripped with 0.1 M NaOH; the co-extracted Fe(III) was selectively scrubbed with distilled water. The structural studies indicated that the Pt(IV) extracted with EHBAA from 1 M HCl formed an ion-pair complex, [PtCl6].(EHBAA.H)(2). (C) 2017 Elsevier B.V. All rights reserved.

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    24
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  • Ship Breaking and the Steel Industry in Bangladesh A Material Flow Perspective

    Mohammad Sujauddin, Ryu Koide, Takahiro Komatsu, Mohammad Mosharraf Hossain, Chiharu Tokoro, Shinsuke Murakami

    JOURNAL OF INDUSTRIAL ECOLOGY   21 ( 1 ) 191 - 203  2017.02  [Refereed]

     View Summary

    Bangladesh has emerged as a leading ship breaking nation. We conducted a material flow analysis of steel in Bangladesh with an emphasis on the ship breaking industry (SBI). The total aggregate domestic steel consumption in fiscal year (FY) 2010 was 2,930,000 tonnes (t) in Bangladesh; SBI met approximately 51% of the demand for raw materials and 37% of the demand for finished steel products. Rolling industries output in FY2010 was 1,451,000 t; 23% of the input for this production was from ship breaking sources. Dismantled ships also generate high-quality reusable steel scraps. SBI was found to be the sole source of scraps for small rerolling industries in Bangladesh, and their output in 2008 more than doubled as compared to 2005. Larger rolling industries fulfilled their input needs for steel scraps by using both SBI and imported materials. We found a sharp increase in input imports during the global ship breaking recession in 2003-2007 and when Bangladesh's SBI faced a temporary ban in 2010. Induction furnaces in Bangladesh in FY2010 produced a total of 787,000 t of billets; more than 40% was from ship-sourced scraps. In 2008, the country's steel consumption was 3,220,000 t, that is, 22 kilograms per person, and the intensity of steel use was 40 grams per U.S. dollar, which was much higher than that of other developing countries with a similar per capita gross domestic product (GDP). The country exhibited a high level of steel consumption relative to its GDP, which is indicative of the contribution of SBI.

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    29
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  • Design for Separating Performance of Grinding Media in Bead Mill by DEM Simulation

    Hisatomi Shosei, Fukui Sho, Matsuoka Mitsuaki, Tsunazawa Yuki, Tokoro Chiharu, Okuyama Kyoko, Iwamoto Motonori, Sekine Yasuyoshi

    Journal of the Society of Powder Technology, Japan   54 ( 6 ) 377 - 383  2017  [Refereed]

     View Summary

    <p>Smaller grinding media beads in bead mills are well known for determining high grinding performances. However, the post-grinding separation between beads and slurry might be a difficult task, especially in bead mills with centrifugal bead separation, where the separating performances are strongly affected by the shape of the rotors in the mill. Aiming to study and design grinding operations, the discrete element method (DEM) is a powerful tool which allows for predicting the grinding and separating performances in the mill. In this study, by using DEM simulations, we examined the slurry-beads separation in a bead mill and we investigated the influence of the rotor shape on the separating performances. We compared the performances of two kinds of rotors, one with conventional shape and one with outside projections for the activation of the media beads. Results of DEM simulation were in good agreement with experimental results.</p>

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  • 磁選による使用済みリチウムイオン電池からのコバルト回収に適した加熱条件の検討

    堀内 健吾, 松岡 光昭, 所 千晴, 大和田 秀二, 薄井 正治郎

    化学工学論文集   43 ( 4 ) 213 - 218  2017  [Refereed]

  • 表面錯体形成を考慮した酸性坑廃水処理の定量モデル化

    加藤 達也, 八木澤 真, 松岡 光昭, 所 千晴, 榊原 泰佑, 林 健太郎

    化学工学論文集   43 ( 4 ) 207 - 212  2017  [Refereed]

  • Contact force model including the liquid-bridge force for wet-particle simulation using the discrete element method

    Yuki Tsunazawa, Daiki Fujihashi, Sho Fukui, Mikio Sakai, Chiharu Tokoro

    ADVANCED POWDER TECHNOLOGY   27 ( 2 ) 652 - 660  2016.03  [Refereed]

     View Summary

    The handling of wet particles in chemical engineering is often difficult because cohesive forces acting on wet particles cause particulate aggregation and the adherence of devices, unlike what occurs under a dry condition. The liquid-bridge force is introduced to the discrete element method in the investigation of the behavior of wet particles. However, existing numerical modeling has problems from the viewpoint of the effect of cohesion in contact states. Specifically, the cohesive force is treated as a constant value for contact states. This means the effect of the cohesive force is not only dependent on the spring constant in the discrete element simulation but is also frequently overestimated. To solve this problem, the present study developed a numerical contact model considering quantitatively the effect of the cohesive force in contact states and validated the model for a pan pelletizer. The behaviors and cascading angles of wet particles in simulation and experiments were in good agreement and the validity of the contact model was thus demonstrated. The present numerical contact model is thus a promising model for the numerical simulation of wet particles. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

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  • Ship Recycling Industry in Chittagong, Bangladesh

    小出 瑠, モハマド スジャウディン, 小松 孝裕, モハマド ムシャラフ ホセイン, 東田 啓作, 所 千晴, 村上 進亮

    廃棄物資源循環学会論文誌   27   161 - 175  2016  [Refereed]

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  • Investigation of Part Detachment Process from Printed Circuit Boards for Effective Recycling Using Particle-Based Simulation

    Yuki Tsunazawa, Chiharu Tokoro, Mitsuaki Matsuoka, Shuji Owada, Hiroyuki Tokuichi, Masamichi Oida, Hirobumi Ohta

    MATERIALS TRANSACTIONS   57 ( 12 ) 2146 - 2152  2016  [Refereed]

     View Summary

    For the establishment of appropriate recycling process, the delamination of electric components from printed circuit boards (PCBs), which are major components of c-waste, is expected, because some of useful critical metals are concentrated in specific components. However, the knowledge about the mechanism of the delamination process in a drum typed agitation mill is still limited and uncertain. To better comprehend the mechanism, in this study, the particle-based simulation and comminution tests using handmade PCBs were conducted. The behavior of PCBs and the air flow in the mill having flexible chains was simulated by the discrete element method (DEM) coupled with computational fluid dynamics (CFD). To model the shape of PCBs, the particle based rigid body model was introduced into the DEM. Since this model could not directly simulate the breakage phenomena, collision energy was calculated to qualitatively evaluate the comminution performance. In addition, the simulation results were compared with the experimental comminution tests, This study demonstrated the behavior of PCBs and the air flow in the mill, and the effect of the air to comminution process in the mill. It was also shown that the collision energy related to parts collision was better correlated with the experimental results and this correlation can be assumed using first order rate equation, which suggested part detachment was mainly brought by direct collision to parts in the mill.

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    13
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  • Numerical simulation of industrial die filling using the discrete element method

    Yuki Tsunazawa, Yusuke Shigeto, Chiharu Tokoro, Mikio Sakai

    CHEMICAL ENGINEERING SCIENCE   138   791 - 809  2015.12  [Refereed]

     View Summary

    Die filling is an important aspect of powder molding in chemical engineering. The discrete element method (DEM) has been applied to simulations of die filling systems in the literature. In these simulations, the die has been modeled by simple shapes such as cylinders and cuboids. However, industries require modeling of complex die shapes in the computations. In addition, the existing DEM is problematic from the viewpoint of industrial applications, since complexly shaped dies might not be modeled by existing technologies. To solve this problem, the signed distance function (SDF) model is applied to the DEM simulation (DEM/SDF) and the DEM/SDF approach is validated for arbitrarily shaped dies. Focusing on macroscopic powder flow, simulation results are compared with experimental results, and good agreement is confirmed for the spatial distribution of velocity, the projection areas of the shoe, and the final mass of filling particles. Therefore, the adequacy of the DEM/SDF model is newly demonstrated in the die filling system; i.e., the DEM/SDF method is shown to be an effective method for the numerical simulation of particle flow into arbitrarily shaped dies. (C) 2015 Elsevier Ltd. All rights reserved.

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  • Mechanism investigation and surface complexation modeling of zinc sorption on aluminum hydroxide in adsorption/coprecipitation processes

    Chiharu Tokoro, Taisuke Sakakibara, Shinya Suzuki

    CHEMICAL ENGINEERING JOURNAL   279   86 - 92  2015.11  [Refereed]

     View Summary

    The sorption mechanism of dilute Zn [initial Zn(II) concentration up to 40 mg dm(-3)] on aluminum hydroxide was investigated. Adsorption and coprecipitation at pH 7 were compared. The adsorption process gave a Langmuir-type isotherm and the zeta potential of Zn(II)-adsorbed aluminum hydroxide decreased linearly with increasing sorption density of Zn on aluminum hydroxide. The adsorption mechanism is therefore mainly surface complexation. In contrast, in the coprecipitation process, a Brunauer-Emmett-Teller like isotherm was obtained; the slope of the zeta potential versus Zn(II) sorption density decreased when the initial Zn/Al molar ratio was greater than 0.5. The X-ray diffraction pattern of Zn(II)-coprecipitated aluminum hydroxide changed from that of poorly crystalline gibbsite to a Zn-Al layered double-hydroxide (LDH) when the initial Zn/Al molar ratio was greater than 0.5, showing that surface complexation was the main sorption mechanism, but surface precipitation of Zn-Al LDH was also involved when the initial Zn/Al molar ratio in the coprecipitation process was greater than 0.5. A quantitative diffuse-layer model was constructed. The aluminum hydroxide exchange capacity was set at 0.61 mol mol-Al-1, based on the experimentally determined surface area, 340 m(2) g(-1). Surface complexation coefficients for H+, OH-, and Zn(II) adsorption on aluminum hydroxide were determined by fitting to the experimental adsorption results. The obtained parameters were in excellent agreement with those previously reported for a database of gibbsite adsorption equilibrium constants. The pH edge for Zn(II) removal by aluminum hydroxide was successfully reproduced by the constructed model. (C) 2015 Elsevier B.V. All rights reserved.

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  • Removal Mechanism in Anionic Co-precipitation with Hydroxides in Acid Mine Drainage Treatment

    C. Tokoro

    Resources Processing   62 ( 1 ) 3 - 9  2015  [Refereed]

     View Summary

    Acid mine drainage from approximately 80 abandoned or closed Japanese mines has been treated by neutralization over the last forty years. A more efficient and cost-effective treatment process is required, as the national government spends billions of yen each year to protect the environment from acid mine drainage discharge. Surface complexation at the interface between hydroxides such as ferrihydrite or aluminum hydroxide and wastewater is the most important mechanism for the removal of dilute toxic ions. We have categorized the immobilization mechanism of inorganic toxic elements at the hydroxide solid/liquid interface into surface complexation and surface precipitation. We have introduced this concept using experimental methods to understand their mechanism, for example arsenate co-precipitation with ferrihydrite, fluorine co-precipitation with aluminum hydroxide, and boron co-precipitation with magnesium hydroxide. From detailed investigations using isotherm formation, X-ray diffractometry, and Fourier-transform infrared spectroscopy analysis, we found that co-precipitation achieved a more efficient removal of toxic anions than simple adsorption, because of surface precipitation or surface complexation of multiple complexes.

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  • Enhancement of Copper Leaching from Chalcopyrite Using Wet-type Ball Mill

    Yugo Mitani, Yuki Tsunazawa, Takahiko Okura, Chiharu Tokoro

    Journal of the Society of Powder Technology, Japan   52   723 - 729  2015  [Refereed]

    DOI

  • Characterization of ship breaking industry in Bangladesh

    Mohammad Sujauddin, Ryu Koide, Takahiro Komatsu, Mohammad Mosharraf Hossain, Chiharu Tokoro, Shinsuke Murakami

    JOURNAL OF MATERIAL CYCLES AND WASTE MANAGEMENT   17 ( 1 ) 72 - 83  2015.01  [Refereed]

     View Summary

    Dismantling (or "breaking") of ships invigorates global shipping by replacing older ships and recycling or reusing as much as 95 % of their materials. Recently, Bangladesh is dominating global ship breaking. Here, we aimed basically at expounding the inflows of the ship breaking industry (SBI) in Bangladesh from the perspectives of origin, types, and lifespan of dismantled ships in order to develop a better understanding of this industry. The inflows in SBI have been increasing and the tonnage dismantled rose to a record high of 2,308,525 LDT (light displacement tonnage) in 2009. Interestingly, ships dismantled in Bangladesh were relatively younger having the mean age of 27 years. Of the outflows from ships dismantled, reusable/recyclable steel comprised 85 % of the total weight of ships; the rest were machinery, hardware, fittings, and consumable items. The major hurdle we faced was the unwillingness of stakeholders in disclosing available but relevant information due to widespread suspicion. We suggest that keeping organized records and their disclosure is critical to developing a comprehensive understanding of this industry. We are hopeful that this research will pave the path for continued objective scientific investigations into the contributions, both positive and negative, as well as the evolution of SBI in Bangladesh.

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    35
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  • Silicate Removal in Aluminum Hydroxide Co-Precipitation Process

    Chiharu Tokoro, Shinya Suzuki, Daisuke Haraguchi, Sayaka Izawa

    MATERIALS   7 ( 2 ) 1084 - 1096  2014.02  [Refereed]

     View Summary

    The removal mechanisms of silicate using an aluminum hydroxide co-precipitation process was investigated and compared with an adsorption process, in order to establish an effective and validated method for silicate removal from wastewater. Adsorption isotherms, XRD and FT-IR analyses showed that silicate uptake occurred by adsorption to boehmite for initial Si/Al molar ratios smaller than two, but by precipitation of poorly crystalline kaolinite for the ratios larger than two, in both co-precipitation and adsorption processes. Silicate was removed by two steps: (i) an initial rapid uptake in a few seconds; and (ii) a slow uptake over several hours in both processes. The uptake rate in the first step was higher in the co-precipitation process than in adsorption process, presumably due to increased silicate adsorption to boehmite and rapid precipitation of kaolinite. These results suggest that silicate removal using aluminum salts could be effectively achieved if the pH adjustment and aluminum concentration are strictly controlled.

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    34
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  • DEMシミュレーションによる湿式媒体撹拌型ミルの最適化設計

    HAYASHI Kentaro, TSUNAZAWA Yuki, TOKORO Chiharu, OWADA Shuji, IITSUKA Hideaki, ISHIKAWA Osamu

    Shigen-to-Sozai   130 ( 2,3 ) 53 - 59  2014  [Refereed]

     View Summary

    The discrete element method (DEM) coupled with fluid analysis was applied to describe the basic characteristics of media beads in a wet-type media agitation grinding mill, which is expected for ultrafine particles grinding or dispersion. Three types of agitator were compared by both of simulation and experimental investigation to know which one is suitable for ultrafine particles grinding and how the shape of agitator affects grinding performance. In the simulation, the collision energy and collision number between beads or bead and wall were calculated from kinetic energy at the instant of impact, separately in normal and tangential direction. On the other hand, the grinding rate and minimum ground size were obtained from experimental grinding results using calcium carbonate particles. The grinding rate had positive correlation to the average value of the collision energy between bead and wall, and the minimum ground size was correlated to the ratio of the collision energy in tangential direction to total collision energy between beads. This means that these two values obtained from DEM simulation are useful for a optimization design of a wet-type agitation mill. We also investigated the correlation between the collision energy for bead and wall calculated from DEM simulation results and the degree of abrasion in the wall observed in experimental grinding tests. At the part in which remarkable abrasion of wall was observed inside the mill, larger value of the collision energy between bead and wall was obtained from DEM simulation.

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  • Mechanism of As(V) Removal in Wastewater Treatment Using Fe(Ⅲ)-Supported Exchange Resins

    F. Futami, C. Tokoro, S. Izawa, S. Owada

    Resources Processing   61 ( 1 ) 3 - 9  2014  [Refereed]

    DOI

  • Investigation for Mechanism of Part Detachment and Board Breakage in Chain-using Drum-typed Mill by DEM Simulation

    Kazuki Tahara, Yuki Tsunazawa, Chiharu Tokoro, Shuji Owada

    粉体工学会誌   51 ( 4 ) 240 - 249  2014  [Refereed]

    DOI

  • Sorption Mechanism of Boron to Magnesium Hydroxide using Co-precipitation Process in Aqueous Solution

    Sayaka IZAWA, Motoki MAEDA, Chiharu TOKORO, Keiko SASAKI

    Journal of MMIJ   130 ( 5 ) 155 - 161  2014  [Refereed]

     View Summary

    We investigated co-precipitation using magnesium (Mg) salt as a cost efficient method of removing B from wastewater. To clarify the mechanism of co-precipitation and the effect of precipitation rate against B sorption mechanism, we conducted co-precipitation experiments changing reaction time at different temperatures. For these experiments, we carried out sorption isotherm formation and XRD analysis to clarify how co-precipitation of B with magnesium hydroxide (Mg (OH) 2) occurred. The sorption isotherm of co-precipitation was a BET type, while the XRD peak shift occurred as the initial B/Mg molar ratio increased. These results suggested that the mechanism of B uptake was a combination of surface precipitation and surface complexation, and the later mechanism became more apparent as the initial B/Mg molar ratio increased. XRD spectrum of co-precipitated residues was relatively similar to that of hydromagnesite, which indicated that structure of surface precipitation is similar to that of hydromagnesite. Co-precipitation experiments for 6 hours revealed that Mg precipitation rate was faster at the higher temperature, while sorption density became worse as the temperature increased. At 40<tt>℃</tt> and 60<tt>℃</tt>, XRD peak shift did not occur when the initial B/Mg molar ratio was0.063, which suggests that fast precipitation rate disturbed production of surface precipitation. In addition, the initial B/Mg molar ratio in which B sorption mechanism changed from formation of surface compexation to production of surface precipitation became larger as Mg precipitation rate increased.

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  • Performance Comparison between Chain-using and Agitator-using Drum-typed Impact Mill for Parts Detachment from PCBs

    Yuki Tsunazawa, Kazuki Tahara, Kousuke Hosoda, Chiharu Tokoro, Shuji Owada

    粉体工学会誌   51 ( 6 ) 415 - 423  2014  [Refereed]

    DOI

  • Effect of Precipitates Form in Reduction of Carbon Dioxide to Alcohol Using Cyclic Fenton Reaction

    Fumiya YAMAGISHI, Daisuke HARAGUCHI, Chiharu TOKORO, Toshiaki MURATA

    Journal of MMIJ   130 ( 7 ) 385 - 390  2014  [Refereed]

     View Summary

    Fenton reaction has been focused as an option of CO2 reduction to organic compounds such as alcohol. We investigated the effect of morphology of precipitates during Fenton reaction to CO2 reduction in order to establish effective and validated process. Precipitates during/after reactions were analyzed by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). Morphology of precipitates was gradually changed from ferrihydrite to schwertmannite when the reaction time and pH were increased. The chemical thermodynamics equilibrium calculation suggested that schwertmannite was the main precipitate in Fenton reaction. In the actual experiments, ferrihydrite was also formed because schwertmannite is hardly precipitated under pH sharp fluctuation associated with Fenton reaction. Reactivity between hydrogen peroxide and artificial sludge (ferrihydrite or schwertmannite) was measured by Absorptiometer using the Mutarotase-GOD method. Ferrihydrite consumed more hydrogen peroxide than schwertmannite, which suggested that hydroxyl radical was produced by the reaction between hydrogen peroxide and the surface of ferrihydrite. All experimental results showed that more CO2 was reduced to organic compounds when more ferrihydrite was formed in precipitates. These results suggested that ferrihydrite was more largely contributed to Fenton reaction than schwertmannite.

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  • Immobilization Mechanism of Toxic Elements at Solid/liquid Interface in Wastewater Treatment Using Hydroxide Coprecipitation

    C. Tokoro

    Journal of the Society of Powder Technology, Japan   51 ( 11 ) 765 - 771  2014  [Refereed]

    DOI

  • DEM Simulation of Particle Behavior in Pan-type Pelletizer Considering the Effect of the Capillary Force

    Daiki Fujihashi, Yuki Tsunazawa, Chiharu Tokoro, Mikio Sakai

    Journal of the Society of Powder Technology, Japan   51 ( 12 ) 828 - 836  2014  [Refereed]

    DOI

  • A Predictive Model forthe Future Treatment of Acid Mine Drainage with Regression Analysis and Geochemical Modeling

    OTSUKA Hiroshi, MURAKAMI Shinsuke, YAMATOMI Jiro, KOIDE Ryu, TOKORO Chiharu

    Shigen-to-Sozai   130 ( 10 ) 488 - 493  2014

     View Summary

    Acid Mine Drainage (AMD), high acid water containing heavy metals discharged from mines, not only from the operating ones but also from the already abandoned ones, has been recognized as major cause of mine pollution. In Japan, the government spends billions of yen every year to prevent pollution caused by AMD in about 80 abandoned mines. It is widely believed that the treatment will continue for decades or an even century,but it is difficult to predict how long it will be and how much it will cost.Therefore, a predictive model is quite helpful. In our previous work, a two-steps predictive model for solution composition and neutralization chemical requirements of AMD in future was constructed based on the regression analysis and geochemical modeling. The model requires the past historical water quality data from AMD monitoring, such as metal concentration and pH in the solution, instead of the sample rocks as other conventional prediction methods. In this paper, two more case studies were carried out for Japanese abandoned mines. In each case study, future solution composition, neutralizer dosage and sludge generation were estimated. Then, the time when the water quality satisfies Japanese effluent standard was estimated. The results of this study demonstrate the effectiveness of our model for the prediction of AMD quality and chemical requirements of neutralization treatment after mine closing. These results were analyzed in the context of TMR (Total Material Requirement) and the environmental burden of this neutralization process is relatively small comparing to the burden of operations and the long time span of neutralization seems more serious concern. Comparing the result of this paper with that of our previous works, it is revealed that we have to carry out more case studies in order to obtain the general idea of future AMD treatment.

    DOI CiNii

  • Acid Mine Drainage (AMD), high acid water containing heavy metals discharged from mines, not only from the operating ones but also from the already abandoned ones, has been recognized as major cause of mine pollution. In Japan, the government spends billi

    Hiroshi Otsuka, Shinsuke Murakami, Jiro Yamatomi, Ryu Koide, Chiharu Tokoro   130 ( 10_11 ) 488 - 493  2014  [Refereed]

     View Summary

    Acid Mine Drainage (AMD), high acid water containing heavy metals discharged from mines, not only from the operating ones but also from the already abandoned ones, has been recognized as major cause of mine pollution. In Japan, the government spends billions of yen every year to prevent pollution caused by AMD in about 80 abandoned mines. It is widely believed that the treatment will continue for decades or an even century,but it is difficult to predict how long it will be and how much it will cost.Therefore, a predictive model is quite helpful. In our previous work, a two-steps predictive model for solution composition and neutralization chemical requirements of AMD in future was constructed based on the regression analysis and geochemical modeling. The model requires the past historical water quality data from AMD monitoring, such as metal concentration and pH in the solution, instead of the sample rocks as other conventional prediction methods. In this paper, two more case studies were carried out for Japanese abandoned mines. In each case study, future solution composition, neutralizer dosage and sludge generation were estimated. Then, the time when the water quality satisfies Japanese effluent standard was estimated. The results of this study demonstrate the effectiveness of our model for the prediction of AMD quality and chemical requirements of neutralization treatment after mine closing. These results were analyzed in the context of TMR (Total Material Requirement) and the environmental burden of this neutralization process is relatively small comparing to the burden of operations and the long time span of neutralization seems more serious concern. Comparing the result of this paper with that of our previous works, it is revealed that we have to carry out more case studies in order to obtain the general idea of future AMD treatment.

  • Effect of Ion Water Washing of Neutralized Sludge Contaminated by High Concentrations of Chloride

    Chiharu Tokoro, Yuji Oda, Shuji Owada, Hiroshi Hayashi

    MATERIALS TRANSACTIONS   54 ( 7 ) 1176 - 1181  2013.07  [Refereed]

     View Summary

    The effects of NO3- and SO42- ions on chloride ion removal from neutralized sludge were investigated to determine if removal of chloride ions enabled the use of sludge for cement production. An artificial sludge prepared from iron, calcium and chloride that primarily consisted of two-line ferrihydrite was prepared. Chloride ions in the sludge were easily washed out by distilled water, NO3- water or SO42- water to levels below those specified in the standard for Eco-cement production (1,000 mg/kg), but the washed sludges did not meet the standard for ordinary Portland cement (350 mg/kg). Conversely, artificial sludge prepared from aluminum, calcium and chloride mainly consisted of low crystalline boehmite with other minor components. Chloride ions in this sludge were only reduced to below those specified in the standard for the ordinary cement production if SO42 water was used to wash the sludge. The filtration rate during washing using SO42 water was faster than when distilled water or NO3- water was used because SO42 ions were adsorbed onto the sludge particles and the absolute value of the zeta potential of the sludge particles decreased. Overall, sludge washing using SO42-water was the best process for chloride ion removal and efficient filtration.

    DOI

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    2
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  • Sorption Mechanisms of Arsenate in Aqueous Solution during Coprecipitation with Aluminum Hydroxide

    Daisuke Haraguchi, Chiharu Tokoro, Yuji Oda, Shuji Owada

    JOURNAL OF CHEMICAL ENGINEERING OF JAPAN   46 ( 2 ) 173 - 180  2013  [Refereed]

     View Summary

    This study investigates the removal mechanism of arsenate, i.e., As(V), by coprecipitation with aluminum hydroxide in solution at pH 5. Both the filtrates and precipitates were analyzed. The removal mechanisms of As(V) were investigated by constructing sorption isotherms and by analyses of X-ray diffraction (XRD) patterns, zeta potentials, and Fourier-transform infrared (FT-IR) spectra. The sorption isotherms showed Brunauer-Emmett-Teller (BET) behavior. The sorption densities showed a rapid uniform increase when the initial As/Al solution molar ratio was more than 1.5. This suggests two sorption mechanisms of As(V), namely surface complexation and three-dimensional uptake, which were dependent on the initial As/Al molar ratio. It is important to note that the As(V) and Al(III) concentrations were unable to reach the thermodynamic solubility product of aluminum arsenate in the bulk solution. The three-dimensional uptake was therefore estimated to be not bulk precipitation but surface precipitation of aluminum arsenate. Surface precipitation, generation of a new surface phase, is known to be derived from surface complexes. XRD, zeta potential, and FT-IR analyses of the precipitates for each As/Al molar ratio confirmed that As(V) was predominantly removed by the adsorption of the As(V) oxyanions to the aluminum hydroxide surface when the initial As/Al molar ratio was less than 1.5. At an initial As/Al molar ratio greater than 1.5 at pH 5, As(V) was removed mostly by surface precipitation, evidently by poorly crystalline aluminum arsenate on the surface. This sorption as surface precipitation is a phenomenon specific to the coprecipitation process.

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    16
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  • Fundamental Study on the Reduction of Carbon Dioxide to Methanol/Ethanol Using a Cyclic Fenton Reaction

    Fumiya Yamagishi, Chiharu Tokoro, Daisuke Haraguchi, Toshiaki Murata

    Resources Processing   60 ( 1 ) 22 - 27  2013  [Refereed]

     View Summary

    Conversion of carbon dioxide to useful chemicals or fuels has become an active area of research. However, most methods used in these studies need expensive or precious reagents, such as hydrogen or rare metals. The objective of this study is the reduction of carbon dioxide to organic compounds using a cyclic Fenton reaction that uses only inexpensive reagents. We achieved carbon dioxide reduction to methanol and ethanol using this reaction at ambient temperatures and pressures. The Fenton reaction was promoted by the repetitive addition of H2O2 and Fe(II) salts, resulting in the synthesis of methanol/ethanol and formic/acetic acids from carbon dioxide saturated water. In addition, it was found that H2O2 and Fe(II) in a molar ratio of 1 or 2 is optimal for the reaction as this increase the generation of OH. The catalytic effects of magnetite, pyrite, sodium hypophosphite and copper sulfate were also investigated in the reduction of carbon dioxide to acetic acid. All reagents acted as a catalyst, and the concentration of TOC and acetic acid was increased. The highest concentration of acetic acid was achieved with the addition of copper sulfate. This enhanced the generation of H or H− as Cu(II) forms more stable complexes with oxalic acid than Fe(II)/Fe(III), meaning more free Fe(II)/Fe(III) ions were present in the solution. © 2013, The Resources Processing Society of Japan. All rights reserved.

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  • MgOを中和剤とする層状複水酸化物の生成反応とフッ素廃水処理法への応用

    二瓶智也, 林浩志, 山崎淳志, 所千晴

    Journal of MMIJ   129 ( 4 ) 132 - 137  2013  [Refereed]

     View Summary

    Removal of fluorine in effluent with low concentration is difficult technique and an effective method has not been established. This paper describes a novel fluorine-removal process that composed the following processes, addition of Al(III) source to feed water, conditioning of the slurry with magnesium oxide (MgO), neutralizing reaction, returning the settled slurry, and gravitational settling of the solids. This process allows the formation of a mixed Mg(II)-Al(III) hydroxide precipitate, which gradually develops into Layered Double Hydroxides (LDH) compound. MgO, which serves as both the neutralizer and the Mg(II) source, contributes to both the excellent settling and dewatering characteristics of the resulting solids. The sludge returning technique, well-known as High Density Sludge (HDS) method, is employed to prolong the sludge retention time to dissolve as much MgO as possible. Repeated batch-wise fluorine-removal tests showed that the residual fluorine concentration gradually decreased according as the number of batch test increased. Optimum fluorine removal ratio reached 96 %, where initial fluorine concentration 20 mg/L decreased below the national environmental standard, 0.8 mg/L. Powder X-ray diffraction analysis indicated the presence of both LDH phase and Periclase phase in the formed solids. Considering the good settling and dewatering characteristics of solids, the proposed process served as alternative treatment technique for low concentrated fluorine-containing effluents.

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  • 表面沈殿モデルを用いた希薄As(V)廃水の水酸化第二鉄共沈処理に対する定量モデル化

    原口大輔, 所千晴, 大和田秀二, 井澤彩

    Journal of MMIJ   129 ( 5 ) 158 - 164  2013  [Refereed]

     View Summary

    Construction and calculation using surface precipitation model were attempted for As(V) coprecipitaiton treatment with ferrihydride. Surface precipitation model was defined as extended surface complexation model. Original surface complexation model with parameter values reported by Dzombak and Morel was validated to adsorption experimental results for As(V) removal using ferrihydrite. The surface complexation model could represent experimental As(V) removal and isotherm quantitatively. In surface precipitation model, precipitation was described by the formation of solid compound between ferric hydroxide and ferric arsenate. Activity of these precipitates was determined by surface precipitation ratio of FeAsO4(s) obtained experimentally from XANES analyses. Solubility products of surface precipitation of FeAsO4(s) (KspAsO4(suf. ) were determined by fitting to sorption densities and surface precipitation ratio in each condition. The values of KspAsO4(suf.) were determined 10<tt></tt>7.7 at pH5 and 10<tt></tt>10.2 at pH7, respectively. These values were reasonably relative to the literatures and previous studies. Based on the obtained KspAsO4(suf.) value, As(V) removal and isotherm were calculated for As(V) coprecipitation treatment using surface precipitation model. Good agreement between experimental and calculated values was observed. For both of observed and calculated data, the sorption isotherms in coprecipitation treatment indicated saturated shapes because the species of surface precipitation was FeAsO4(s) and surface precipitation rate largely increased when As/Fe molar ratio is relatively low. These results were suggested that the quantitative prediction of As(V) coprecipitation treatment was possible if KspAsO4(suf.) value was estimated experimentally.

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  • Characteristic Sorption of H3BO3/B(OH)(4)(-) on Magnesium Oxide

    Keiko Sasaki, Xinhong Qiu, Sayo Moriyama, Chiharu Tokoro, Keiko Ideta, Jin Miyawaki

    MATERIALS TRANSACTIONS   54 ( 9 ) 1809 - 1817  2013  [Refereed]

     View Summary

    The reaction mechanism of H3BO3/B(OH)(4)(-) with MgO in aqueous phase was investigated using sorption isotherm, XRD, B-11-NMR and FTIR. Release of Mg2+ was observed soon after contact of MgO with H3BO3 and maximum released Mg2+ was proportional to the initial boron concentration, suggesting ligand-promoted dissolution of MgO by H3BO3. The molecular form of H3BO3 was more reactive with MgO in releasing Mg2+ ions than B(OH)(4)(-). B-11-NMR results indicated that trigonal B (B-[3]) was predominant over tetrahedral B (B-[4]) in solid residues after sorption of H3BO3. The molar ratio of B-[4]/B-[3] increased with H3BO3 sorption density. XRD patterns for the solid residues were assigned to Mg(OH)(2) and peaks broadened with increasing H3BO3 sorption density, except for (hk0) planes due to c-axis lattice strain induced by incorporation of H3BO3 between layers. These results indicated that H3BO3 interfered in the c-axis stacking of in Mg(OH)(2). Molecular H3BO3 acted as a trigger when reacting with the MgO surface, releasing Mg2+ to produce an unstable complex leading to the precipitation formation of Mg(OH)(2), which is a sink for the immobilization of H3BO3/B(OH)(4)(-).

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    35
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  • A Model for Prediction of Neutralizer Usage and Sludge Generation in the Treatment of Acid Mine Drainage from Abandoned Mines: Case Studies in Japan

    Ryu Koide, Chiharu Tokoro, Shinsuke Murakami, Tsuyoshi Adachi, Akihiro Takahashi

    MINE WATER AND THE ENVIRONMENT   31 ( 4 ) 287 - 296  2012.12  [Refereed]

     View Summary

    Acid mine drainage (AMD) from about 80 abandoned or closed mines in Japan are actively treated by neutralization; the government spends billions of yen every year to protect the environment from these discharges, and treatment will have to continue for many years. However, it is difficult to predict the future AMD chemistry, neutralizer requirements, and volume of sludge to establish future costs, chemical inputs, and wastes. The water monitoring data or source rock samples for conventional predictive methods are not available. In this study, a predictive model for AMD composition and the neutralization process was constructed based on geochemical modeling, assuming first order kinetics for the dissolution of several minerals. The solution composition, neutralizer requirements, and sludge generation were estimated for case studies at two abandoned mines in Japan: a sulfur mine, and a copper and iron mine. The model effectively predicted AMD composition after termination of mining and was also useful for estimating future neutralizer requirements and sludge volumes. This research will increase understanding of the lifecycle environmental costs in the mining industry.

    DOI

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    14
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  • Quantitative Evaluation of the Abrasion Rate in Attrition Washing on Lead Contaminated Soil from Shooting Ranges

    Chiharu Tokoro, Yutaro Yamaoka, Sei Yuki, Tomohiro Shiozawa, Shuji Owada

    MATERIALS TRANSACTIONS   53 ( 11 ) 1997 - 2003  2012.11  [Refereed]

     View Summary

    The effects of attrition on sandy and silty Pb-contaminated soil from shooting ranges were quantitatively investigated. The abrasion rate could be quantitatively evaluated using a population balance model from the size distribution of soil particles before and after attrition in an intensive mixer. The maximum abrasion rate was 0.047 mu m/s in the first stage of attrition (1 mm of grinding), and then declined between 2 and 4 min of grinding. The two samples had similar maximum abrasion rates, but the decline in the abrasion rate was larger in the silty soil, which would have a thinner soft layer on the surface of the soil particles, than the sandy soil. The incremental change in the mass fraction of Pb in the &lt;20 mu m particle size fraction increased proportionally with the abrasion thickness from the surface of the soil particles. Although the Japanese regulatory standard for the Pb concentration in soil (150 mg/kg) was not met for either sample, the Japanese regulatory standard for the concentration of leached Pb (0.01 mg/L) was met for silty soil after attrition. Sequential extraction using Tessier's procedure for the &gt;20 mu m size fraction before and after attrition showed the attrition was more effective for the oxides or organic-bound species and carbonate species of Pb chemical forms. [doi:10.2320/matertrans. M2012240]

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    1
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  • Investigation and DEM Simulation for Part Detachment Process of Printed Circuit Board in a Drum-type Impact Mill

    TSUNAZAWA Yuki, TOKORO Chiharu, OWADA Shuji, SAKAI Mikio, MURAKAMI Shinsuke

    粉体工学会誌   49 ( 3 ) 201 - 209  2012  [Refereed]

    DOI CiNii

  • Fundamental Study of Parts Detachment Mechanism from Wasted Printed Circuit Boards in Agitation Mill

    Chiharu Tokoro, Yuki Tsunazawa, Nozomi Tsusaka, Kazuki Tahara, Shuji Owada

    Resources Processing   59 ( 1 ) 27 - 32  2012  [Refereed]

     View Summary

    Recycling of printed circuit boards (PCBs) is an important subject not only from the treatment of waste but also from the recovery of valuable materials including rare metals. We have tried a special and selective grinding such as parts detachment from the board using drum typed agitation mill to concentrate a part of “rare metals”. The objective of this study is revealing the mechanism of parts detachment process from PCBs. A simulant PCBs on which nine capacitors were solder-mounted were used for the communition test using the agitation mill. Effects of rotation speed and the number of boards for parts detachment or board breakage were investigated. Both of parts detachment rate and board breakage rate were increased as rotation speed increased. On the other hand, as the number of boards increased, parts detachment rate was increased while board breakage rate was slightly increased. DEM simulation with and without particle breakage model was conducted. DEM simulation with spherical particle model (without particle breakage model) showed that board breakage was strongly affected by collision of PCBs to the wall in the normal direction while parts detachment was affected by both of collision of PCBs to the wall in the tangential direction and interaction between PCBs. To investigate the mechanism of parts detachment process more directly, DEM simulation with particle breakage model was also conducted. Simulation results obtained from DEM with particle breakage model corresponded to these experimental trends successfully. © 2012, The Resources Processing Society of Japan. All rights reserved.

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  • Concentration of Rare Metals from Wasted Cellular Phones by Combining Novel Comminution and Device/Powder Separation

    OWADA Shuji, KOGA Chikako, KAGEYAMA Sou, TOKORO Chiharu, SHIRATORI Toshikazu, YUMOTO Tetsuya

    Journal of MMIJ   128 ( 12 ) 626 - 632  2012  [Refereed]

     View Summary

    This paper describes the possibility of concentrating minor rare metals contained in cellular phones by applying a novel comminution and the combination of physical separation technologies, which were followed by metallurgical processes to extract them. We compared two kinds of comminution processes, conventional and novel, from the viewpoint of compositional separation and combined two kinds of physical separation categories, &amp;ldquo;Device Separation&amp;rdquo; and &amp;ldquo;Powder Separation&amp;rdquo; to achieve an effective concentration of rare metals. It was demonstrated that the novel comminution process could separate printed circuit board (PCB) from the body in the first stage and detach the installed electronic devices from the board in the second stage and that several kinds of rare metals could be concentrated by combining the novel comminution and &amp;ldquo;Device/Powder Separation&amp;rdquo;. The &amp;ldquo;Device&amp;rdquo; and &amp;ldquo;Powder&amp;rdquo; products concentrated are expected to be further treated by hydrometallurgical processes to extract rare metals and/or stocked as &amp;ldquo;Artificial Deposits&amp;rdquo; in accordance with the concept of &amp;ldquo;RtoS (Reserve to Stock)&amp;rdquo;.

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  • Keeping gallium metal to liquid state under the freezing point by using silica nanoparticles

    Lingfei Cao, Hyunseo Park, Gjergj Dodbiba, Kenji Ono, Chiharu Tokoro, Toyohisa Fujita

    APPLIED PHYSICS LETTERS   99 ( 14 )  2011.10  [Refereed]

     View Summary

    Gallium metal under the freezing point was observed to maintain its liquid state by dispersing silica nanoparticles of a given particle size and concentration. Though the freezing point of pure gallium is 302.9 K, the liquid gallium maintained its supercooling state at 276-277 K for more than 400 days by dispersing 1.0 wt. % of silica nanoparticles (10 nm in size). Extended x-ray absorption fine structure analysis shows that the supercooled gallium liquid has a beta-Ga-like feature, and the nearest neighboring atom distance is 0.1 angstrom larger than that of pure liquid gallium. This method opens the way to use liquid gallium as a promising fluid carrier in energy conversion devices. (C) 2011 American Institute of Physics. [doi:10.1063/1.3645596]

    DOI CiNii

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  • Comparison between Aluminum Hydroxide Coprecipitation and Adsorption for Removal of Dilute As (V) from Wastewater

    HARAGUCHI Daisuke, ODA Yuji, TOKORO Chiharu, OWADA Shuji

    Journal of MMIJ   127 ( 2 ) 82 - 87  2011  [Refereed]

     View Summary

    The mechanism for removal of dilute As (V) by coprecipitation with aluminum hydroxide was investigated using sorption isotherms, X-ray diffraction (XRD) patterns, and zeta potential analysis. The results from the coprecipitation experiments were compared with those from simple adsorption experiments. &lt;BR&gt;During simple adsorption of As (V) on aluminum hydroxide, the sorption density obeyed a Langmuir-type isotherm. XRD patterns of the adsorbed As (V) were independent of the mass adsorbed. The relationship between zeta potential and sorption density was linear. These results suggest that As (V) was removed mainly by surface complexation.&lt;BR&gt;In comparison, during As (V) co-precipitation with aluminum hydroxide, the sorption density followed a BET-type isotherm at pH 5 and 7, and there was a steep increase in sorption density at a transition point. XRD patterns and zeta potential analysis also supported the existence of a transition point during As (V) co-precipitation. The transition was from surface complexation to precipitation, and occurred when the initial molar ratio was As/Al=1.5. These results suggest that during coprecipitation As (V) is removed by surface complexation at molar ratios of As/Al &amp;le; 1.5, and by the formation of amorphous aluminum arsenate at As/Al &amp;ge; 1.5.

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  • Comparison between Aluminum Hydroxide Coprecipitation and Adsorption for Removal of Fluoride from Wastewater

    HARAGUCHI Daisuke, TOKORO Chiharu, OWADA Shuji

    Journal of MMIJ   127 ( 1 ) 26 - 31  2011  [Refereed]

     View Summary

    Comparison of removal characteristics between coprecipitation and adsorption method of aluminum hydroxide for wastewater containing F (-I) was attempted by sorption isotherms, X-ray diffraction (XRD) patterns, and zeta potential analysis. &lt;BR&gt;When F (-I) was coprecipitated with aluminum hydroxide, the sorption density was higher at pH 7 than at pH 5. The sorption density at both pH values followed a BET-type isotherm. High sorption density was obtained when the initial F/Al molar ratio was high, and some of the aluminum hydroxide dissolved. The sorption density in adsorption treatment was slightly lower than that in coprecipitation treatment. These results suggest that the mechanism of F&lt;SUP&gt;&amp;mdash;&lt;/SUP&gt; coprecipitation was not simply surface complexation of F&lt;SUP&gt;&amp;mdash;&lt;/SUP&gt;.&lt;BR&gt;At pH 7, the XRD patterns for F (-I) coprecipitates and aluminum hydroxide were identical. The slope between zeta potential and sorption density changed when the initial molar ratio was F/Al=3 in both coprecipitation and adsorption experiments. This F/Al=3 transition point corresponded to the point where the sorption density increased abruptly in the sorption isotherm. These results reveal that F (-I) was primarily adsorbed as a surface complex to aluminum hydroxide when the initial molar ratio was F/Al&amp;lsaquo;3. In contrast, when the initial molar ratio was F/Al&amp;rsaquo;3, amorphous compounds of F&lt;SUP&gt;&amp;mdash;&lt;/SUP&gt; and Al (III) formed or F-Al complexes such as AlF&lt;SUP&gt;2-&lt;/SUP&gt;, AlF&lt;SUB&gt;2&lt;/SUB&gt;&lt;SUP&gt;+&lt;/SUP&gt;, AlF&lt;SUB&gt;3&lt;/SUB&gt;&lt;SUP&gt;0&lt;/SUP&gt; and AlF&lt;SUB&gt;4&lt;/SUB&gt;&lt;SUP&gt;-&lt;/SUP&gt; were adsorbed.

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  • Real Option Analysis for Deep-sea Mineral Resources Development in Japanese Waters

    Kohama Makoto, Adachi Tsuyoshi, Tokoro Chiharu

    Journal of Real Options and Strategy   4 ( 1 ) 101 - 116  2011  [Refereed]

     View Summary

    Deep-sea minerals extraction has been attracted as domestic resources of Japan from the viewpoint of resources security. This study investigates feasibility evaluation with uncertainties for deep-sea mineral resources development project using real option analysis. Resources development has a lot of unique uncertainties. We propose multi-investments (compound option) model considering volatility of metal prices and ore deposit scale. Results from this model imply high option value at a case study of Sunrise ore deposit in Japanese EEZ, and show marginal investment prices and marginal cost to abandon the project by comparative statics. Furthermore, considering historical trend of metal prices, different types of stochastic process i.e. mean reverting process and geometric brownian motion are compared.

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  • DEM回転抵抗モデルの改良

    山田 祥徳, 酒井 幹夫, 水谷 慎, 村上 進亮, 所 千晴, 土屋 将夫, 藤川 隆男

    粉体工学会誌   48 ( 10 ) 692 - 700  2011  [Refereed]

  • Sorption mechanism of As(V) to ferrihydrite in coprecipitation treatment

    Tokoro Chiharu

    Abstracts of Annual Meeting of the Geochemical Society of Japan   58   302 - 302  2011

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  • XAFS Investigation for As(V) Co-Precipitation Mechanism with Ferrihydrite

    Chiharu TOKORO, Hajime KOGA, Yuji ODA, Shuji OWADA, Yoshio TAKAHASHI

    Journal of MMIJ   127 ( 4/5 ) 213 - 218  2011  [Refereed]

     View Summary

    XRD/XAFS analysis were conducted to investigate the As(V) co-precipitation mechanism with ferrihydrite (γ-FeOOH). In As(V) co-precipitation with ferrihydrite, XRD results showed that As(V) complexation to the surface of ferrihydrite was dominant when the initial molar ratio of As/Fe was less than 0.25, whereas surface precipitation of amorphous ferric arsenate was formed when the initial molar ratio of As/Fe was more than 0.5.<BR>Both of XANES and EXAFS analysis on K-edge of As showed As(V) co-precipitates with ferrihydrite was the mixture of As(V) adsorbed ferrihydrite and amorphous ferric arsenate. Molar ratio of amorphous ferric arsenate in As(V) co-precipitates was estimated to be more than 0.5 when the initial molar ratio of As/Fe was more than 0.5. These results are in good agreement with the XRD results. EXAFS analysis assuming one surface complex for As-Fe bond showed the coordination number of As to Fe in As(V) co-precipitates increased with increasing the initial molar ratio of As/Fe. Moreover, EXAFS analysis assuming three kinds of surface complexes for As-Fe bond showed the coordination number for 2.85 Å of the atomic distance of As-Fe increased and it for 3.24 Å of the atomic distance of As-Fe decreased with increasing the initial As/Fe molar ratio. All experimental data obtained in this study showed As(V) co-precipitation mechanism shifted gradually from As(V) complexation to the surface of ferrihydrite toward amorphous ferric arsenate with increase in the initial molar ratio of As/Fe.

    DOI CiNii

  • Sorption Mechanisms of Arsenate during Coprecipitation with Ferrihydrite in Aqueous Solution

    Chiharu Tokoro, Yohei Yatsugi, Hajime Koga, Shuji Owada

    ENVIRONMENTAL SCIENCE & TECHNOLOGY   44 ( 2 ) 638 - 643  2010.01  [Refereed]

     View Summary

    Dilute arsenate (As(V)) coprecipitation by ferrihydrite was investigated to determine if treatment of acid mine drainage containing dilute As(V) using coprecipitation is feasible. The sorption density obtained at pH 5 and 7 was nearly identical when As(V) was coprecipitated with ferrihydrite, while it was higher at pH 5 when As(V) was adsorbed on the ferrihydrite. The high sorption density of As(V) to ferrihydrite in coprecipitation with 1-h reaction time suggested that coprecipitation Occurs via both adsorption and precipitation. Furthermore, the relationship between residual As(V) and sorption density revealed a BET-type isotherm, with a transition point from a low residual As(V) concentration to a high residual As(V) concentration being observed for all initial As(V) concentrations between 0.15 and 0.44 mmol/dm(3) when the initial molar ratio was 0.56 at pH 5 and 7 X-ray diffraction and the xi potential revealed that the transition point from surface complexation to precipitation was obtained when the initial As/Fe ratio was 0.4 or 0.5. When dilute As(V) was coprecipitated with ferrihydrite at pH 5 and 7, it was primarily adsorbed as a surface complex when the initial molar ratio was As/Fe &lt; 0.4, while a ferric arsenate and surface complex was formed when this ratio was &gt;= 0.4.

    DOI PubMed CiNii

    Scopus

    91
    Citation
    (Scopus)
  • Sorption Mechanisms of Arsenic Coprecipitation with Ferric or Aluminum Hydroxides in Aqueous Solution

    C.Tokoro, D.Haraguchi, S.Owada

    Research Advances in Environment Science and Technology   1   1 - 14  2010  [Refereed]

  • Selective removal of arsenic from acid mine drainage containing ferrous ion using sulfide precipitation method

    Tokoro C, Sunada K, Dai D, Dodbiba G, Fujita T, Onishi A, Nagasawa S, Asano H, Hashimoto K

    XXV International Mineral Processing Congress 2010, IMPC 2010   5   3965 - 3973  2010  [Refereed]

  • Application of DEM Simulation to an Intensive Mixer

    Chiharu TOKORO, Tatsuya YAMASHITA, Hidetoshi KUBOTA, Shuji OWADA

    Resources Processing   56 ( 3 ) 113 - 119  2009  [Refereed]

     View Summary

    The discrete element method (DEM) was applied to describe the basic characteristics of particles in an intensive mixer that is expected to grind only the surfaces of particles with a particular agitator and is applied in many industries. Surface grinding experiments using a sample of bauxite particles were also conducted to compare with the simulation. The roles of the pan and agitator were estimated from the DEM simulations and it was revealed that employing only agitator rotation increases the particle mobility in the vertical direction, while employing both pan and agitator rotation increases the mobility in the horizontal direction and stably maintains large mobility in the vertical direction.<br> We also investigated the correlation between the rates of energy dissipation during interparticle contact calculated from DEM simulation results and the abrasion rate estimated from experimental results. The abrasion rate was estimated from the particle size distribution obtained from the surface grinding experiments using an intensive mixer charged with bauxite particles and a population balance model in which two mechanisms of attrition—abrasion and fracture—are considered. The results show that the abrasion rate decreased with an increase in energy dissipation due to friction, which suggests that the energy dissipation of the friction obtained from the DEM simulation results could be used to estimate the abrasion rate in the surface grinding process. <br>

    DOI CiNii

  • A Quantitative Modeling of Co-precipitation Phenomena in Wastewater Containing Dilute Anions with Ferrihydrite using a Surface Complexation Model

    C.Tokoro, Y.Yatsugi, H.Sasaki, S.Owada

    RESOURCES PROCESSING   55 ( 1 ) 3 - 8  2008  [Refereed]

     View Summary

    Although numerous qualitative studies have been published on removal characteristics from wastewater of dilute anions by co-precipitation treatment with Fe(III) or Al salts, detailed mechanisms or quantitative characteristics are not well understood. In this study, a quantitative modeling of co-precipitation phenomena in wastewater containing dilute As(V), Se(VI), Cr(VI) or F with ferrihydrite was tried using a diffuse layer model (DLM), which is one of the most popular and simplest of surface complexation models. Co-precipitation experimental results from wastewater containing 2 mg/dm3 of Se(VI), 2 mg/dm3 of Cr(VI), or 15 mg/dm3 of F with ferrihydrite could be predicted quantitatively by the DLM with a existing set of parameters. However, results from wastewater containing 10 mg/dm3 of As(V) with ferrihydrite could not be predicted quantitatively but only qualitatively by the model. It was confirmed from the comparison of co-precipitation experimental results and simple adsorption ones that this quantitative difference between experimental and calculation data resulted from the procedure difference between co-precipitation and simple adsorption; in short, the precipitation of ferrihydrite and adsorption of As(V) develop simultaneously in the former system, and only As(V) adsorbs onto prepared ferrihydrite in the latter system.<br>

    DOI CiNii

  • Classification of submicron Ni particles by heterocoagulation

    Toyohisa Fujita, Ryoji Ito, Chiharu Tokoro, Jun Sadaki, Gjergj Dodbiba, Ryosuke Tsukamoto, Hiroshi Okuda, Hiroshi Yamane

    POWDER TECHNOLOGY   173 ( 1 ) 19 - 28  2007.04  [Refereed]

     View Summary

    In this work, the size classification of a mixture of submicron and micron size Ni particles dispersed in aqueous solution was investigated. The suspension of Ni particles was allowed to flow, under laminar condition, through a burette filled with an adhesion medium (i.e. substrate). The difference between zeta potentials of larger particles and adhesion medium created a base for the heterocoagulation. Thus, the larger particles move towards the medium assisted by the Saffman lift force and are attracted to its surface. The finer particles, on the other hand, flow off the burette and were collected as a separate fraction. This phenomenon was then explained by numerical simulating the particle's motion and showing that a stronger Saffman lift force will act in the direction of the substrate only for large particles, leaving the smaller ones unaffected as they sediment out. (c) 2006 Elsevier B.V All rights reserved.

    DOI

    Scopus

    9
    Citation
    (Scopus)
  • Effects of Co-existing Ions on the Ferrite Formation at Ambient Temperature in the Treatment of Acid Mine Drainage Containing Iron : An Application of Ferrite Formation at Ambient Temperature to the Treatment of Acid Mine Drainage Containing Iron (Part 2)

    C.Tokoro, H.Miyazawa, T.Takada, D.Takao, G.C.Badulis, H.Sasaki

    Shigen-to-Sozai   123 ( 3 ) 103 - 109  2007  [Refereed]

     View Summary

    The feasibility of making ferrite at ambient temperature from aqueous solutions of simulated acid mine drainage was investigated following our previous report. In this paper, qualitative and quantitative effects of coexisting ions such as Mn(II), Zn(II), Al(III) and Si(IV), on ferrite formation were investigated.&lt;BR&gt;As the first step, influences of several coexisting ions on the settling volume of the precipitates were investigated. In the case of Mn(II) or Zn(II) coexisting system, which are well known to have the capacity to substitute to the part of the lattice of ferrite, the settling volume increased a little, but in the case of Al(III) or Si(IV) coexisting system, which are known to impede ferrite formation, the settling volume considerably increased. However, the interference of Al(III) or Si(IV) to ferrite formation was weakened in the sludge recycling system.&lt;BR&gt;Secondly, their influences on the yield of magnetite or ferrite, which are calculated by the total oxygen consumption in the aerial oxidation reaction test, were investigated. The yield of magnetite decreases with an increase of Al(III) or Si(IV), but their interferences on ferrite formation were weakened in the presence of restored magnetite seed.&lt;BR&gt;Thirdly, their influences on the reaction rate in the aging process were also examined by solid-solid reaction test in which Fe(OH)&lt;SUB&gt;2&lt;/SUB&gt;, FeOOH and coexisting ions reacted directly in reduction atmosphere and at a fixed pH. The reaction coefficient considerably decreased not only by Al(III) or Si(IV), but also by Mn(II) or Zn(II), which are estimated not to impede ferrite formation.

    DOI CiNii

  • Quantitative Evaluation of Ferrite Formation at Ambient Temperature in Acid Mine Drainage Containing Iron : An Application of Ferrite Formation at Ambient Temperature to the Treatment of Acid Mine Drainage Containing Iron (Part 1)

    C.Tokoro, D.Takao, H.Sasaki

    Journal of MMIJ   122 ( 4,5 ) 155 - 162  2006  [Refereed]

     View Summary

    The removal of iron and various heavy-metal ions in waste water into stable ferrite-type precipitates at ambient temperature is a promising alternative to clean up large volumes of polluted effluents. In this study, quantitative evaluation of ferrite formation method from aqueous solutions containing iron and sulfate at ambient temperature was considered, toward future application of this method to the treatment of acid mine drainage containing iron. In order to evaluate suitable conditions of Fe&lt;SUB&gt;3&lt;/SUB&gt;O&lt;SUB&gt;4&lt;/SUB&gt; formation quantitatively, these formation process was considered to be divided into two processes, i.e. oxidation process and aging process.&lt;BR&gt;The reaction rate in the oxidation process was examined by aerial oxidation reaction test. The results showed that the oxidation rate of ferrous iron was determined by the mass transfer of oxygen from atmosphere to solution, so the yield of Fe&lt;SUB&gt;3&lt;/SUB&gt;O&lt;SUB&gt;4&lt;/SUB&gt; in precipitation could be evaluated quantitatively by the total oxygen consumption which could be estimated from the oxygen transfer coefficient and the oxidation time.&lt;BR&gt;The reaction rate in the aging process was also examined by solid-solid reaction test in which Fe(OH)&lt;SUB&gt;2&lt;/SUB&gt; and FeOOH reacted directly in reduction atmosphere and at a fixed pH. At the initial stage of the reaction, the concentration change of FeOOH followed the first-order reaction concerning with FeOOH concentration. Surface complexation model which Fe(II) adsorbed to Fe(III) oxide could describe this phenomenon qualitatively.&lt;BR&gt;Relation between quantitative indexes which investigated in this study and several reaction conditions such as pH, Fe concentration and stirring intensity agrees with the results of Fe&lt;SUB&gt;3&lt;/SUB&gt;O&lt;SUB&gt;4&lt;/SUB&gt; forming reaction from aqueous solutions at 25 &amp;deg;c which have been investigated by us or other researchers. These quantitative indexes are useful to understand suitable conditions or mechanisms of ferrite formation.

    DOI CiNii

  • Sludge Generation in the Treatment of Acid Mine Drainage (AMD) by High-Density Sludge (HDS) Recycling Method

    G.C.Badulis, C.Tokoro, H.Sasaki

    Journal of MMIJ   122 ( 8 ) 406 - 414  2006  [Refereed]

     View Summary

    Calcium hydroxide (Ca(OH)&lt;SUB&gt;2&lt;/SUB&gt;), a combination of calcium carbonate (CaCO&lt;SUB&gt;3&lt;/SUB&gt;) and Ca(OH)&lt;SUB&gt;2&lt;/SUB&gt; (two step) and magnesium oxide (MgO) were used as a neutralizer in the treatment of synthetic Horobetsu Acid Mine Drainage (AMD) by High-Density Sludge (HDS) recycling method to obtain the appropriate guidelines of optimum AMD treatment. The result during the initial neutralization demonstrated that at pH 7, arsenic, either As(III) or As(V) in solution, could be removed by adsorption to the sludge with a concentration in the supernatant solution below the Japanese regulated environmental effluent standard. The sludge generated in HDS recycling method with Ca(OH)&lt;SUB&gt;2&lt;/SUB&gt; neutralization was composed of Fe(III) hydroxide combined with a high amount of gypsum (CaSO&lt;SUB&gt;4&lt;/SUB&gt;&amp;middot;2H&lt;SUB&gt;2&lt;/SUB&gt;O), the same as in the two step neutralization in which undissolved CaCO&lt;SUB&gt;3&lt;/SUB&gt; was included. The sludge generated in HDS recycling with MgO neutralization was composed of basic ferric sulphate combined with a low content of undissolved MgO. The sludge-settling rate generally decreased as the recycling process proceeded. The settling rate of the sludge from MgO neutralization was faster than that of the sludge from the Ca(OH)&lt;SUB&gt;2&lt;/SUB&gt; and two step neutralization. The Fe density of the sludge by MgO neutralization was highest compared to the other neutralization.

    DOI CiNii

  • Application of Surface Complexation Model for Dilute As Removal in Wastewater by Fe(III) or Al(III) Salts : A Fundamental Study for Efficient Treatment of Wastewater Containing Dilute Arsenic (Part 2)

    C.Tokoro, Y.Maruyama, G.C.Badulis, H.Sasaki

    資源と素材   121 ( 8 ) 399 - 406  2005  [Refereed]

     View Summary

    The diffuse layer model (DLM) of surface complexation modeling (SCM) was applied to discuss in the removal of dilute arsenic in wastewater. The equilibrium constants for complexation reactions of arsenic to ferric/aluminum hydroxide were based on several reference values and the total site capacity of ferric/aluminum hydroxide was determined by fitting to experimental results, since it is difficult to obtain surface area of amorphous hydroxide in wastewater system directly by experiment. The fitting results turns out that the total site capacity ratio becomes smaller as the concentration of ferric or aluminum hydroxide precipitates in wastewater increases. The experimental approximation formula between the total site capacity and the concentration of ferric or aluminum hydroxide precipitates was obtained. The model gave a quantitative correct description of experimental results for As(V) removal by ferric or aluminum hydroxide.&lt;BR&gt;The above-mentioned examination was also applied to As(V) removal in waste water with SO&lt;SUB&gt;4&lt;/SUB&gt;. In Fe(III) salts, the total site capacities in wastewater with SO&lt;SUB&gt;4&lt;/SUB&gt; became a little smaller than them in wastewater without SO&lt;SUB&gt;4&lt;/SUB&gt;, but in Al(III) salts, they are almost same value regardless of coexistence of SO&lt;SUB&gt;4&lt;/SUB&gt;. The removal of As(V) by ferric hydroxide at pH6 were predicted quantitatively by the model, also when SO&lt;SUB&gt;4&lt;/SUB&gt; is contained.

    DOI CiNii

  • As(V) Removal by Fe(III), Al or Pb salts and Rapid Solid/Liquid Separation in Waste Water Containing Dilute Arsenic

    TOKORO Chiharu, SHIMIZU Tomonori, HIRAI Kenji, BADULIS G. C., SASAKI Hiroshi

    Shigen-to-Sozai   121 ( 8 ) 399 - 406  2005  [Refereed]

     View Summary

    The removal of As(V) from wastewater containing low concentration of As(V) was investigated by addition of Fe(III), Al or Pb salts. Results show wastewater that contains 5 mg/dm3 As(V) is reduced below the regulated concentration of Japanese effluent standard (0.1 mg/dm3) when treated at pH 4.5&sim;7.5 with the addition of 50 mg/dm3 Fe(III) salts and at pH 6&sim;8 with the addition of 20 mg/dm3 Al salts. Successful removal of 3.75 mg/dm3 As(V) in wastewater is also possible when treated at pH 7&sim;11 with the addition of 20.7 mg/dm3 Pb salts, subsequently reducing Pb concentration below the regulated concentration of Japanese effluent standard (0.1 mg/dm3).<BR>Chemical equilibrium calculation which considering the formation of arsenic salts with Fe(III), Al or Pb hardly explains the experimental results. Furthermore, as the concentration of As(V) increases, the isoelectric point (IEP) of precipitations after the removal of As(V) by Fe(III), Al or Pb shifted to acidic pH. It is surmised that As(V) is removed by adsorption on the surface of ferric, aluminum or lead hydroxide.<BR>Solid/liquid separation from these As(V) removal experiments using a column bed method packed with fibrous ferro-nickel slag was also investigated. Ferric, aluminum or lead hydroxide particles adsorbing dilute As(V) that have several hundred nm in sizes, are thinly dispersed and can perform rapid solid/liquid separation (2.5mm/sec).

    DOI CiNii

  • A Fundamental Study of Dry Gravity Concentration Method Using Fluidized Bed

    C.Tokoro, K.Okaya, J.Sadak, A.Shibayama, K.Liu, T.Fujita

    資源と素材   120 ( 6,7 ) 388 - 394  2004  [Refereed]

     View Summary

    Dry gravity concentration method using a fluidized bed is being investigated. We employ polystyrene (PS) balls and glass beads (GB) as a fluidizing medium. Pieces of corrugated cardboard, paulownia wood, polypropylene (PP), polyvinyl chloride (PVC) and Al are employed as test materials. The separation efficiency is experimented and vertical position of separated materials in the fluidization bed is simulated, by changing the superficial velocity. It is found by experiment that high recovery (&gt;90%) of sink products and float products is achieved, even if the density difference between them is slight. These high recoveries are achievable when the superficial velocity is slightly higher than the minimum fluidization velocity.&lt;BR&gt;The recovery of float products is found to be sensitive to the superficial velocity: i.e., the recovery is low when the superficial velocity is either too high or too low. In order to examine the influence of the superficial velocity on the recovery of float products in detail, we employ two-dimensional simulation based on the discrete element method (DEM). The grater the superficial velocity is, the wider the vertical positioning of float materials becomes. It is found by DEM simulation that the recovery of float products tends to be low when the superficial velocity is too high, because the lowest vertical position during separation test is lower than that when the superficial velocity is optimal.&lt;BR&gt;It is found from these series of experiments and simulation in this study that high efficient separation by dry gravity concentration using a fluidized bed is possible.

    DOI CiNii

  • Fast Algorithm of Distinct Element Method with Contact Force Prediction Method

    C.Tokoro, K.Okaya, J.Sadaki

    粉体工学会誌   40 ( 4 ) 236 - 245  2003  [Refereed]

     View Summary

    Distinct element method (DEM) requires enormous computation time because it needs small time increments that are sufficient to follow high frequency fluctuations in contact dynamic model. In general, the equations of motion of particles are solved by the second order Adams-Bashforth method, which estimates the contact force for the next time step by linear extrapolation, or by multistep methods such as predictor-corrector method. In order to overcome the deficit of conventional methods, we propose a Contact Force Prediction Method that allows us to use larger time increments. The method incorporates the contact force at every contact point obtained as the exact solutions or numerical solutions of differential equations that describe two particle contacts. It is confirmed that the proposed method gives the simulation results for packing and discharge of particles which are consistent with the experimental data, while accelerating DEM computation by 3 to 8 times.

    DOI CiNii

  • Boundary conditions for column flotation - A study by transfer function representation of an axial diffusion model

    C Tokoro, Y Okano

    MINERALS ENGINEERING   14 ( 1 ) 49 - 64  2001.01  [Refereed]

     View Summary

    The boundary conditions for an axial diffusion model were overviewed and then modified concerning the pulp layer boundaries in a flotation column. It has been confirmed through the transfer function representation that the four general boundary conditions for an axial diffusion model correspond to the particular cases of Wehner and Wilhelm's, which considers not only the reaction section itself but also those of its top and bottom sides.
    Various mathematical models have been proposed for the pulp layer in a flotation column and the most popular one may be an axial diffusion with first order reaction model of one stage. They are, however, unable to estimate the behaviors of free particles which have not attached to bubbles at the pulp-froth interface.
    In this study, therefore, the authors, represented the transportation of free particles in the pulp layer of a flotation column by the two-stage axial diffusion with first order reaction model. The Wehner and Wilhelm's, as well as Danckwerts' boundary conditions have been partly modified and then applied to the feed point, the pulp-froth interface and the tailing discharge point of the flotation column. The proposed models and their boundary conditions made it possible to estimate the behaviors of free particles at the pulp-froth interface. (C) 2000 Elsevier Science Ltd. All rights reserved.

    DOI CiNii

    Scopus

    7
    Citation
    (Scopus)
  • Coagulation Kinetics of Monodispersed Polystyrene Latex Particles by Dynamic Light Scattering Method

    TOKORO Chiharu, OKANO Yasuhiko, SASAKI Hiroshi

    Journal of MMIJ   116 ( 3 ) 193 - 197  2000  [Refereed]

     View Summary

    The experimental collision frequency factors of monodispersed polystyrene latex (PSL) particles in KCl solutions were measured by the use of the dynamic light scattering method. This method determines the cluster-size distribution by counting the number of different clusters during the coagulation process and therefore permits the determination of the rough collision frequency factors by the fitting curves for the data. The fitting curves were calculated on the assumption that the coagulation between two same-fold particles is dominant. <br> Numerous studies have revealed significant discrepancies between the theoretical collision frequency factors that can be calculated from Smoluchowski and Fuchs formulation and the experimental results, especially in the slow coagulation region. In this paper's results, good qualitative agreement was found for the theoretical collision factors in the rapid coagulation, but in the slow coagulation, significant discrepancies were confirmed both qualitatively and quantitatively, especially for high-fold particles.<br>

    DOI CiNii

  • Boundary Conditions for Column Flotation-A study by transfer function representation of an axial diffusion model-

    C.Tokoro, Y.Okano

    資源と素材   116 ( 8 ) 663 - 668  2000  [Refereed]

     View Summary

    The boundary conditions for an axial diffusion model are overviewed and modified concerning the pulp layer in a column flotation cell. It is confirmed by the transfer function representation that the four general boundary conditions for an axial diffusion model correspond to the particular cases of Wehner and Wilhelm&#039;s, which considers not only the reaction section itself but also its fore and after ones. &lt;br&gt; Various mathematical models for the pulp layer in a column flotation cell have been proposed and the most popular one of them is an axial diffusion with first order reaction model of one stage. However, they can&#039;t estimate the behaviors of non-adhesive particles at the pulp level. &lt;br&gt; In this paper, the authors, therefore, represented the transportation of non-adhesive particles in the pulp layer of a column flotation cell by the two-stage axial diffusion with first order reaction model. The Wehner and Wilhelm&#039;s as well as Danckwerts&#039; boundary conditions have been partly modified and then applied to the feed point, the pulp level and the tailing point of the column flotation. The proposed models with their appropriate boundary conditions make it possible to estimate the behaviors of non-adhesive particles at the pulp level.&lt;br&gt;

    DOI CiNii

  • Performance Analysis of a Flotation Column in Operation - Study by a two-stage axial diffusion model -

    C.Tokoro, K.Okaya, Y.Okano

    資源と素材   116 ( 12 ) 994 - 998  2000  [Refereed]

     View Summary

    The authors proposed the mathematical model for the pulp layer in a flotation column by the two-stage axial diffusion with first order reaction model in the former paper. The &lt;i&gt;Wehner&lt;/i&gt; and &lt;i&gt;Wilhelm&lt;/i&gt;&#039;s as well as &lt;i&gt;Danckwerts&lt;/i&gt;&#039; boundary conditions have been partly modified and then applied to the feed point, the pulp level and the tailing point of the column. This model makes it possible to estimate the behaviors of particles that haven&#039;t yet attached (free particles) at the pulp level. &lt;br&gt; The proposed model has three unknown parameters, that is, the Peclet &amp;middot; Bodenstein number, the collection rate constant and the concentration of drainage particles from the froth layer. From the sensitivity analysis, it was found that the proposed model has little sensitivity to the Peclet &amp;middot; Bodenstein number, but some sensitivity to other parameters, especially to the concentration of drainage particles. In this study, the Peclet &amp;middot; Bodenstein number was assumed from the empirical expression derived by &lt;i&gt;Mankosa&lt;/i&gt; et al.(1992), and the collection rate constant and the concentration of drainage particles were estimated by a least squares regression fit to the data sampled from an industrial operation, concerning the superficial concentration of attached particles as well as free particles. It is estimated by investigation of those parameters that the cleaning effect prevails exclusively not in the pulp layer but in the froth layer.&lt;br&gt;

    DOI CiNii

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Books and Other Publications

  • EV用電池の安全性向上、高容量化と劣化抑制技術

    所 千晴( Part: Contributor, 第9章第1節リチウムイオン電池リサイクルの現状と課題,pp. 431-436)

    技術情報協会  2023.11 ISBN: 9784861049927

  • CFRPリサイクル・再利用の最新動向

    所 千晴( Part: Contributor, 第2章第3節 電気パルスを用いたCFRPの解体および炭素繊維の回収,pp. 61-66)

    エヌ・ティー・エス  2023.11 ISBN: 9784860438463

  • 車載用リチウムイオン電池リサイクル:技術・ビジネス・法制度

    所 千晴( Part: Contributor, 第7章 リチウムイオン電池からの金属回収のためのミネラルプロセッシング技術,pp.98-112)

    株式会社シーエムシー・リサーチ  2023.06 ISBN: 9784910581415

  • 蛍雪時代. 2023, 4月臨時増刊

    所 千晴( Part: Contributor, 工学部系統◇資源工学 何を学ぶ?資源工学, pp. 619-620)

    旺文社  2023.04

  • 旧松尾鉱山新中和処理施設40年史

    所 千晴( Part: Contributor, 40周年記念シンポジウム 北上川から環境新時代を考える ~明るい未来へとつながる、SDGs・カーボンニュートラルの時代へ~, pp. 12-21)

    独立行政法人 エネルギー・金属鉱物資源機構  2023.03

  • 資源循環論から考えるSDGs

    所 千晴( Part: Sole author)

    エネルギーフォーラム  2022.11 ISBN: 9784885555299

  • リチウムイオン電池リサイクル・リユースの最新の動向・法規制と分離・回収技術・EV電池における今後の展望

    佐藤 登, 安部 浩司, 鹿島 理, 所 千晴, 星野 毅, 田畑 奨太, 上杉 諒平, 大河内 章宏, 福代 和宏, 喜多川 和典, 福家 正剛, 繁田 徳彦( Part: Contributor, 第2章第1節:リチウムイオン電池リサイクルのための物理的分離濃縮技術)

    株式会社AndTech  2022.10 ISBN: 9784909118479

  • 接着界面解析と次世代接着接合技術

    所 千晴( Part: Contributor, 第Ⅱ編第2章第4節 外部刺激による接着解体技術の開発, pp.251-258.)

    株式会社エヌ・ティー・エス  2022.10 ISBN: 9784860437961

  • 資源循環のための分離シミュレーション

    所, 千晴, 林, 秀原, 小板, 丈敏, 綱澤, 有輝, 淵田, 茂司, 高谷, 雄太郎( Part: Contributor)

    近代科学社Digital (発行),株式会社近代科学社 (販売)  2022.08 ISBN: 9784764960442

  • 車載用LiBのリユース/リサイクル技術と規制動向

    第2章第3節第5項LiB からの高効率元素回収のための分離濃縮技術( Part: Contributor, pp.112-121)

    株式会社情報機構  2022.03 ISBN: 9784865022339

  • EV用リチウムイオン電池のリユース・リサイクル2021 菅原秀一(執筆・調査)

    所 千晴(特別寄稿)"第10章リチウムイオン電池のリサイクル技術開発動向"( Part: Other, pp.217-226)

    株式会社シーエムシー・リサーチ  2021.06

  • バリューチェーンと単位操作から見たリサイクル (最近の化学工学69)

    所千晴, 中村崇(監修)

    化学工学会関東支部  2021.01

  • 学術会議叢書27持続可能な社会への道-環境科学から目指すゴール- 大政謙次, 阿尻雅文, 北川尚美, 青野光子 編

    所千晴, 後藤雅宏( Part: Contributor, 第4章 資源循環技術の進歩と課題 持続可能な社会のための金属資源循環)

    公益財団法人日本学術協力財団  2020.10

  • 分離プロセスの最適化とスケールアップの進め方

    所千晴, 綱澤有輝( Part: Contributor, 第2章第4節 "粉粒体シミュレーションを用いた分離操作の設計, pp.84-92)

    技術情報協会  2019.01

  • 車載用リチウムイオン電池の高安全・評価技術 吉野彰, 佐藤登(監修)

    所千晴, 大和田秀二, 薄井正治郎( Part: Contributor, 第23章 リチウムイオン電池のリサイクル技術)

    シーエムシー出版  2017.04 ISBN: 9784781312422

  • 初心者のためのPHREEQCによる反応解析入門.

    所 千晴

    R&D支援センター  2016 ISBN: 9784905507123

     View Summary

    https://www.rdsc.co.jp/book/bk0014

  • 粉体・ナノ粒子の創製と製造・処理技術 基礎物性からプロセス設計の実務・トラブル処理まで 小波盛佳, 松本幹治(監修)

    所千晴( Part: Contributor, 第7章 第4節 粉砕・破砕に関するシミュレーションと設計)

    テクノシステム  2014 ISBN: 9784924728721

  • 粉体精製と湿式処理 ―基礎と応用―.

    小林 幹男, 大木 達也, 中澤 廣, 日下 英史, 藤田 豊久, 大和田 秀二, 古谷仲 茂樹, 新苗 正和, 芝田 隼次, 所 千晴, 田中 幹也, 小山 和也

    環境資源工学会  2012 ISBN: 9784879746672

  • Electrical Phenomena at Interfaces and Biointerfaces.

    Hiroyuki Oshima (Editor, H. Sasaski, C. Tokoro, H. Hayashi(Chapter 17 "Colloidal Particle Processing Using Heterocoagulation".)

    A john wiley & Sons, Inc.  2012 ISBN: 9780470582558

  • 濾過プロセスの最適選定と効率改善

    所千晴, 砂田和也( Part: Contributor, 第2節 : レアメタルの濾過, 回収)

    情報機構  2010

  • 土壌, 地下水汚染の浄化および修復技術

    所千晴, 大和田秀二( Part: Contributor, 表面粉砕による射撃場鉛汚染浄化処理)

    NTS  2008

▼display all

Presentations

  • 所千晴研究室HPに掲載 http://www.tokoro.env.waseda.ac.jp/gyouseki.html, http://www.tokoro.env.waseda.ac.jp/lecture.html

Research Projects

  • 製品ライフサイクル管理とそれを支える革新的解体技術開発による統合循環生産システムの構築

    JST  未来社会創造事業

    Project Year :

    2019.12
    -
    2024.03
     

    所 千晴

  • 忌避物質のマテリアルフロー分析と資源循環高効率化の余地の定量化

    日本学術振興会  科学研究費助成事業 基盤研究(B)

    Project Year :

    2019.04
    -
    2022.03
     

    村上 進亮, 醍醐 市朗, 山口 勉功, 所 千晴

  • 製品ライフサイクル管理とそれを支える革新的解体技術開発による統合循環生産システムの構築

    JST  未来社会創造事業

    Project Year :

    2017.04
    -
    2019.11
     

    所 千晴

  • Construction of magnetite recovery process from slag based on process mineralogy

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    Project Year :

    2015.04
    -
    2017.03
     

    Tokoro Chiharu

     View Summary

    As one of the new applications of copper smelting slag, we aimed to construct a process of slowly cooling for the slag, crystallizing magnetite, and separating by physical separation. Focusing on the magnetite expected as both iron resources and a carrier of many other useful metals, the influence on the production amount and grain size of magnetite by process conditions such as slow cooling rate and temperature retention was systematically examined using both the simulated and the actual slag. It was confirmed that grain size that is enough for physical separation can be obtained by slow cooling rate under 3 K / min. After slow cooling, by grinding and high gradient wet magnetic separation, it was confirmed that magnetic products with equivalent iron grade without copper contamination could be obtained.

  • 都市鉱山からの希少元素の回収・再生技術の高度化による元素循環の実現

    文部科学省  希少元素高効率抽出技術領域

    Project Year :

    2012
    -
    2017
     

  • XAFS investigation for inhomogeneous and irreversible reaction mechanism in hydroxide/sulfide coprecipitation treatment

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    Project Year :

    2012.04
    -
    2015.03
     

    TOKORO Chiharu, NUMAKO Chiya

     View Summary

    Immobilization mechanism of As(V), F, Si(IV), Zn(II) to ferrihydrite and aluminum hydroxide in co-precipitation process was revealed using several solid analysis and basic chemical engineering method, toward construction of efficient treatment process for acid mine drainage. Based on the knowledge obtained from these investigation, a quantitative model was constructed for immobilization of several toxic elements to in wastewater treatment, using chemical equilibrium calculation coupled by surface complexation model between each toxic element and ferrihydrite/aluminum hydroxide and reaction rate model of precipitation. Obtained model could represent experimental neutralization results using real acid mine drainage.

  • Preparation of Alcohol by CO2 reduction and carbon-carbon bond formation using high efficiency Fenton reaction

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    Project Year :

    2012.04
    -
    2014.03
     

    OWADA Shuji, TOKORO Chiharu

     View Summary

    CO2 could be transformed to methanol and ethanol using high efficiency Fenton reaction in which radical generation could be promoted by the repetitive supply of ferrous sulfate, hydrogen peroxide and pH regulator to CO2 saturated sulfate solution. Formic acid, acetic acid, oxalic acid, formaldehyde, acetaldehyde were also formed as intermediate products. Alcohol yield was increased by usage of several catalysts and optimization of process conditions. Furthermore, component of resulting sludge by Fenton reaction was combination of ferrihydrite and schwertmannite, and alcohol yield was increased by control of process conditions such that the ratio of ferrihydrite was maximum in the sludge.

  • ナノジオサイエンスに基づく環境材料の探索と創出

    JSPS  基盤研究(A)

    Project Year :

    2010
    -
    2013
     

  • E-Wasteからのレアメタルリサイクリングに関するセパレーションプロセス最適化に関する研究

    環境省  循環型社会形成推進科学研究費補助金

    Project Year :

    2010
    -
    2012
     

  • 海洋性微細藻類及び貝類をバイオリアクターとした無機ヒ素含有廃水処理および無害化

    JSPS  挑戦的萌芽研究

    Project Year :

    2010
    -
    2012
     

    所 千晴

  • 酸性坑廃水処理への赤泥の適用に関する研究

    JSPS  若手研究(B)

    Project Year :

    2008
    -
    2010
     

    所 千晴

  • 固液界面特性を利用したリサイクル技術の開発

    Project Year :

    2007
    -
     
     

  • 希薄廃水からの有害元素の選択除去法の確立を目的とした動的シミュレータの開発

    JSPS  若手研究(B)

    Project Year :

    2005
    -
    2007
     

    所 千晴

  • 廃水処理・土壌汚染浄化技術の効率化

    Project Year :

    2004
    -
     
     

  • 粉砕・分級技術への離散要素法の適用

    Project Year :

    2003
    -
     
     

▼display all

Misc

  • 持続可能な資源循環型社会構築のための分離技術開発の重要性

    所千晴

    静電気学会誌   47 ( 5 ) 174 - 179  2023.10

    Article, review, commentary, editorial, etc. (scientific journal)  

  • 新規電気パルス法によるリチウムイオン電池の高精度分離技術

    小板文敏, 所千晴

    月刊 車載テクノロジー   9   20 - 25  2023.09

    Authorship:Last author

    Article, review, commentary, editorial, etc. (scientific journal)  

  • サーキュラー・エコノミーの実現に向けた、資源循環のための分離技術

    所 千晴

    大学×SDGs     33  2023.09

  • 【特集】二次電池・燃料電池関連技術の動向>粉体プロセス技術の高度化による資源循環

    所 千晴

    JETI(Japan Energy & Technology Intelligence)   71 ( 66 ) 9 - 15  2023.06

    Rapid communication, short report, research note, etc. (scientific journal)  

  • 硫化物を含む廃棄物の安定管理を目的とした硫黄化合物の溶出挙動に関する基礎研究

    石井 駿, 淵田 茂司, 髙谷 雄太郎, 所 千晴

    硫酸と工業   76 ( 4 ) 51 - 61  2023.04

    Article, review, commentary, editorial, etc. (scientific journal)  

  • カーボンニュートラルを支えるデバイスの資源循環に資する分離濃縮技術

    所 千晴

    化学装置   1月号 ( 66 ) 34 - 41  2023.01

    Authorship:Lead author, Corresponding author

  • 新規電気パルス法によるリチウムイオン電池の高精度分離技術開発

    所 千晴, 浪平 隆男, 菊池 康紀

    環境管理   58 ( 12 ) 20 - 25  2022.12  [Invited]

    Authorship:Lead author

  • カーボンニュートラルで加速するサーキュラーエコノミーの現状とそのための分離技術高度化の重要性

    所 千晴

    鉱山   75 ( 7 ) 8 - 15  2022.10

  • 蓄電池のリユース・リサイクルの現状と資源循環構築のための技術開発

    所千晴

    研究開発リーダー   19 ( 4 ) 58 - 62  2022.07

    Authorship:Lead author

  • ハイテク産業に欠かせない物質所要量急増で需給を懸念

    所 千晴

    エネルギーフォーラム   ( 811 ) 89 - 90  2022.07

    Authorship:Lead author

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

  • 早稲田大学におけるダイバーシティ推進の取組み

    所 千晴

    大学マネジメント   18 ( 3 ) 20 - 25  2022.06

    Authorship:Lead author

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

  • 電気パルスによる分離技術が拓く未来の資源循環

    所 千晴

    化学工業   73 ( 6 ) 376 - 381  2022.06

    Authorship:Lead author

  • 使用済みリチウムイオン電池からの資源分離回収技術

    所千晴

    廃棄物資源循環学会誌   33 ( 3 ) 181 - 187  2022.05

    Authorship:Lead author

    Article, review, commentary, editorial, etc. (scientific journal)  

  • 特集大学のSDGs 早稲田大学のダイバーシティ推進

    所千晴

    早稲田大学広報キャンパスナウ   243   12 - 13  2022.04

    Other  

  • 水酸化第二鉄へのヒ素の共沈機構

    所 千晴

    あいちシンクロトロン光センター2020年度年次報告     15 - 19  2022.02

    Authorship:Lead author

  • 金属資源循環とサーキュラーエコノミー

    所千晴

    化学工学   86 ( 2 ) 61 - 64  2022.02

    Authorship:Lead author

  • 生分解性プラスチック、特にPHBHのマテリアルリサイクルへの影響

    所 千晴, 高谷 雄太郎, 安藤 裕二, 中村 友紀, 千葉 健, 宮武 信雄

    環境資源工学   68 ( 3 ) 143 - 149  2022.02  [Refereed]

    Authorship:Lead author

  • リチウムイオン電池リサイクルのための分離技術の現状と課題

    所 千晴

    分離技術   52 ( 4 ) 186 - 193  2022

    Article, review, commentary, editorial, etc. (scientific journal)  

  • 粉体プロセス技術の高度化による資源循環

    所 千晴

    The Micromeritics   66   13 - 20  2022

    Article, review, commentary, editorial, etc. (bulletin of university, research institution)  

  • 工学におけるジェンダーの視点

    所 千晴

    GRL Studies   ( 4 ) 55 - 59  2022

    Authorship:Lead author

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

  • Study of Shock Wave and Separation of Different Resin Plates Bonded by Solvent Induced by Wire Explosion Using Pulsed Discharge

    小板丈敏, 江川世士輝, LIM Soowon, 浪平隆男, 所千晴, 所千晴

    衝撃波シンポジウム講演論文集(CD-ROM)   2021  2022

    J-GLOBAL

  • 新規電気パルス法による分離技術が拓く資源循環の未来

    所 千晴

    2021年度MDB技術予測レポート(環境・資源・エネルギー分野)     1 - 13  2022.01

    Authorship:Lead author

    Internal/External technical report, pre-print, etc.  

  • 電気パルス分離技術が拓く未来の資源循環

    所千晴

    クリーンテクノロジー   32 ( 1 ) 1 - 4  2022.01

    Article, review, commentary, editorial, etc. (scientific journal)  

  • シリコン系太陽光パネルリサイクルを目的としたガラスからの樹脂除去のための選択的粉砕

    所 千晴, 西 麻依子, 綱澤 有輝

    粉体工学会誌   59 ( 1 ) 25 - 25  2022.01

    Authorship:Lead author

    Other  

  • <協会創立50周年記念特集企画特別座談会2>協会活動と粉体技術の未来について大いに語る

    所 千晴

    粉体技術   13 ( 11 ) 926 - 940  2021.11

    Authorship:Lead author

    Other  

  • パン型ペレタイザの離散要素シミュレーションの応用

    所 千晴, 綱澤 有輝

    粉体技術   13 ( 10 ) 775 - 780  2021.10  [Refereed]

    Authorship:Lead author

    Article, review, commentary, editorial, etc. (scientific journal)  

  • 持続可能な社会に向けた新リサイクル技術の開発

    所千晴

    工業材料   69 ( 10 ) 20 - 24  2021.10  [Invited]

    Authorship:Lead author

    Article, review, commentary, editorial, etc. (other)  

  • 太陽光パネルのリサイクルプロセス

    所千晴

    材料の科学と工学   58 ( 4 ) 130 - 133  2021.08

    Article, review, commentary, editorial, etc. (scientific journal)  

  • 第86年会女性技術者フォーラム報告

    所 千晴, 室井 桂, 吉宗美紀

    化学工学   85 ( 6 ) 361 - 362  2021.06

    Meeting report  

  • Investigation of generation energy of shock wave induced by wire explosion for application of the explosion by electrical pulse method to selective separation

    小板丈敏, 江川世士輝, LIM Soowon, 浪平隆男, 所千晴

    資源・素材学会春季大会(Web)   2021  2021

    J-GLOBAL

  • Investigation of metal thin film exfoliation from hard disk glass platters for recovery of platinum group metals by electric pulse method

    近藤正隆, LIM Soowon, 小板丈敏, 浪平隆男, 所千晴

    資源・素材学会春季大会(Web)   2021  2021

    J-GLOBAL

  • Investigation of the effect of metal sphere in adhesive on the separation of adhesive bonding by pulsed discharge

    近藤正隆, 小板丈敏, LIM Soowon, 浪平隆男, 所千晴, 所千晴

    資源・素材(Web)   2021  2021

    J-GLOBAL

  • Observation of Separation Process of Positive Electrode Active Material of Lithium-ion Battery using Electrical Pulse Discharge in Water

    照屋海人, LIM Soowon, 小板丈敏, 浪平隆男, 所千晴, 所千晴

    資源・素材(Web)   2021  2021

    J-GLOBAL

  • Investigation of silver recovery from spent crystalline silicon solar cells by fine wire explosion method using high voltage pulse discharge

    今泉友斗, LIM Soowon, 望月和博, 小板丈敏, 浪平隆男, 所千晴, 所千晴

    電気学会基礎・材料・共通部門大会(Web)   2021  2021

    J-GLOBAL

  • 粒子破壊モデルを組み込んだ離散要素法による粉砕プロセスのシミュレーション―High Pressure Grinding Rollへの適用―

    所 千晴

    環境資源工学   68 ( 3 ) 137 - 142  2021  [Refereed]

    Authorship:Lead author

  • リチウムイオン電池リサイクルに寄与する物理的分離濃縮技術

    所千晴

    車載テクノロジー   8 ( 4 ) 37 - 40  2021.01

    Authorship:Lead author

    Article, review, commentary, editorial, etc. (scientific journal)  

  • スマートエネルギーを支える資源循環の現状と課題

    所千晴

    金属   91 ( 1 ) 61 - 66  2021.01

    Authorship:Lead author

    Article, review, commentary, editorial, etc. (scientific journal)  

  • 新規電気パルス法を用いたリサイクルプロセスのライフサイクル評価

    諏訪出, 兵法彩, 竇毅, 所千晴, 菊池康紀, 菊池康紀

    化学工学会年会研究発表講演要旨集(CD-ROM)   85th  2020

    J-GLOBAL

  • 新規電気パルス法を用いたリサイクルプロセスのライフサイクル評価

    諏訪出, 兵法彩, 竇毅, 所千晴, 菊池康紀, 菊池康紀

    化学工学会秋季大会研究発表講演要旨集(CD-ROM)   51st  2020

    J-GLOBAL

  • A modeling study of AMD treatment process by sulfate-reducing bacteria adding ethanol

    林健太郎, 正木悠聖, 濱井昂弥, 加藤達也, 淵田茂司, 所千晴

    資源・素材学会春季大会(Web)   2020  2020

    J-GLOBAL

  • 水酸化マグネシウムを用いた廃水中のフッ素除去機構の解明および定量モデル化

    土屋宏典, 淵田茂司, 所千晴

    化学工学会年会研究発表講演要旨集(CD-ROM)   85th  2020

    J-GLOBAL

  • Mn酸化物を利用したCdおよびZn除去の高効率化

    田嶋翔太, 加藤達也, 淵田茂司, 西村拓朗, 所千晴

    化学工学会秋季大会研究発表講演要旨集(CD-ROM)   51st  2020

    J-GLOBAL

  • Kinetic investigation on initial oxidative dissolution of pyrite at alkaline conditions

    淵田茂司, XUE Jifeng, 石田紗菜, 所千晴

    日本地球化学会年会要旨集(Web)   67th  2020

    J-GLOBAL

  • Geochemical study of AMD generation mechanism from a VMS deposit in Japan

    門倉正和, 淵田茂司, 高谷雄太郎, 石橋純一郎, 島田和彦, 所千晴

    日本地球化学会年会要旨集(Web)   67th  2020

    J-GLOBAL

  • リチウムイオン電池のリサイクルプロセスと今後の展望

    所千晴

    化学装置   9   65 - 70  2020

  • 経済と資源循環型社会の両立に向け、都市鉱山に眠る有用資源を活用 上

    所千晴

    科学機器   7   12 - 19  2020

    Article, review, commentary, editorial, etc. (other)  

  • 経済と資源循環型社会の両立に向け、都市鉱山に眠る有用資源を活用 下

    所千晴

    科学機器   8   20 - 27  2020

    Article, review, commentary, editorial, etc. (other)  

  • リチウムイオン電池正極材リサイクルを目的とした電気パルスによる選択的解体

    丸山修平, 澤村幸宏, 近藤正隆, LIM Soowon, 浪平隆男, 大和田秀二, 所千晴

    静電気学会講演論文集   2019  2019

    J-GLOBAL

  • Selective Dismantlement of Lithium-ion Battery Positive Electrode Material by Electrical Discharge for Recycling

    MARUYAMA Shuhei, LIM Soowon, NISHI Maiko, SAWAMURA Yukihiro, NAMIHIRA Takao, TOKORO Chiharu

    Eco Design   2019 (CD-ROM)  2019

    J-GLOBAL

  • A Novel Electrical Disintegration Method for Cu/Ag Recovery from Photovoltaic Panel

    SAWAMURA Yukihiro, LIM Soowon, NISHI Maiko, MARUYAMA Shuhei, NAMIHIRA Takao, TOKORO Chiharu

    Eco Design   2019 (CD-ROM)  2019

    J-GLOBAL

  • リチウムイオン電池の高度リサイクルを目的とした破砕・粉砕法

    所千晴, 丸山修平, LIM Soowon

    粉体工学会・日本粉体工業技術協会技術討論会・テキスト   54th  2019

    J-GLOBAL

  • 坑廃水処理へのパッシブトリートメント適用条件の検討

    鈴木滉平, 門倉正和, 林健太郎, 淵田茂司, 所千晴

    化学工学会大会(Web)   2019  2019

    J-GLOBAL

  • 低結晶性酸化マグネシウムを用いた廃水中の亜セレン酸およびセレン酸除去機構の解明

    土屋宏典, 淵田茂司, 鳥羽裕一郎, 島村祐司, 所千晴

    化学工学会大会(Web)   2019  2019

    J-GLOBAL

  • JOGMECプロセスの定量モデル構築の取り組み

    林健太郎, 正木悠聖, 濱井昂弥, 門倉正和, 加藤達也, 淵田茂司, 所千晴

    資源・素材(Web)   2019  2019

    J-GLOBAL

  • 酸性坑廃水を対象とした鉄酸化槽における鉄酸化および沈殿挙動の機構解明および定量モデル化

    門倉正和, 鈴木滉平, 加藤達也, 淵田茂司, PRASTISTHO Widyawanto, 正木悠聖, 林健太郎, 濱井昂弥, 所千晴

    資源・素材(Web)   2019  2019

    J-GLOBAL

  • パッシブトリートメントを用いた坑廃水処理における水質予測モデルの構築

    加藤達也, 門倉正和, 鈴木滉平, 淵田茂司, PRASTISTHO Widyawanto, 正木悠聖, 林健太郎, 濱井昂弥, 所千晴

    資源・素材(Web)   2019  2019

    J-GLOBAL

  • 統計解析による休廃止鉱山における酸性坑廃水の将来予測

    門倉正和, 鈴木滉平, 加藤達也, 淵田茂司, PRASTISTHO Widyawanto, 所千晴

    資源・素材(Web)   2019  2019

    J-GLOBAL

  • X線吸収微細構造による水酸化第二鉄界面における有害陰イオン除去機構の考察

    所千晴, 加藤達也

    Journal of Society of Inorganic Materials, Japan   26   156 - 165  2019

  • 循環型社会におけるリチウムイオン電池リサイクルのこれから

    所千晴

    クリーンテクノロジー   29 ( 9 ) 22 - 25  2019

  • 蓄電池リサイクル高度化のための物理的分離技術の進展

    所千晴

    工業材料   67 ( 11 ) 75 - 79  2019

  • 機械的処理による黄銅鉱からの銅浸出の促進

    所千晴, 加藤達也

    硫酸と工業   72 ( 12 ) 145 - 153  2019

  • 研究室紹介 早稲田大学 創造理工学部 環境資源工学科 環境資源処理工学研究室(所千晴研究室)

    所千晴

    Journal of Life Cycle Assessment,Japan   15 ( 1 ) 1 - 3  2019

  • セクシャルマイノリティの取組み事例

    所千晴, 篤田美穂

    IDE 現代の高等教育   614 ( 10 ) 57 - 62  2019

  • 【研究室紹介】早稲田大学 創造理工学部 環境資源工学科 所千晴研究室

    所千晴

    粉体技術   11 ( 12 ) 54 - 55  2019

  • 都市鉱山のリユース/リサイクルを支える解体技術

    所千晴

    化学工学   82 ( 8 ) 418 - 420  2018

  • 特集 進化する環境保全-わが国の水処理技術 わが国における休廃止鉱山廃水処理の現状と展望

    所千晴

    化学装置   60 ( 8 ) 17 - 22  2018

  • フリー地球化学コード「PHREEQC」で解析できること

    所千晴

    土木学会誌   102 ( 2 ) 42 - 43  2017

  • 使用済み小型家電からのレアメタル回収に適した中間処理技術

    所千晴, 大和田秀二

    金属   87 ( 8 ) 11 - 17  2017

  • 資源循環における固体分離濃縮技術の概要

    所千晴

    材料の科学と工学   54 ( 2 ) 6 - 9  2017

  • 中堅女性研究者の現状

    所千晴

    化学工学   81 ( 6 ) 323  2017

  • 島尻安伊子大臣との意見交換会に参加して

    所千晴

    学術の動向   6   120 - 121  2016

  • The development for waste-water recycles process by using RO membranes in MSW incineration plant

    YAMAMOTO Hiroshi, TOMIDA Yohei, SUZUKI Yasuo, SUZUKI Shin-ya, TOKORO Chiharu

    Symposium on Environmental Engineering   24   66 - 68  2014

     View Summary

    The recycle system for wastewater in Municipal Solid Waste incineration plant was investigated. In this study, RO membrane devices were able to attach for conventional water process in MSW incineration plant. To achieve the high availability and to avoid the fouling on RO membranes, it was important to optimize the operating parameter "permeation flux". In additional, to avoid the fouling by silicate, an effective method for silicate removal from wastewater in MSW incineration plant was investigated. In the case of using an aluminum hydroxide, the co-precipitation process showed high removal rate compared with an adsorption process.

    CiNii

  • 安全で効率のよい鉱山廃水の処理

    所千晴

    化学と教育   62 ( 4 ) 190 - 191  2014

  • 希少金属回収のための粉砕シミュレーション

    所千晴, 大和田秀二

    粉体技術   6 ( 6 ) 607 - 611  2014

  • プロセスミネラロジーで環境資源問題の解決に挑む

    所千晴

    大学ジャーナル   113 ( 12 ) 3  2014

  • 衝撃式破砕機における固気連成シミュレーション

    綱澤 有輝, 所 千晴

    ホソカワ財団年報   22 ( 0 ) 108 - 110  2014

    DOI CiNii

  • Introduction of Tokoro Lab., Waseda University

      44 ( 176 ) 248 - 250  2013

    CiNii

  • 欧州 E-Scrap 事情視察報告

    白鳥 寿一, 須藤 孝一, 大和田 秀二, 所 千晴, 柴田 悦郎, 中村 崇

    Journal of MMIJ : journal of the Mining and Materials Processing Institute of Japan   128 ( 8 ) 531 - 536  2012.08

    CiNii

  • 都市鉱山の有効利用に適した破砕・粉砕方法 (特集 都市鉱山の有効利用のための方法論)

    所 千晴, 大和田 秀二

    金属   82 ( 7 ) 594 - 599  2012.07

    CiNii

  • フィンランドの鉱区活用および休廃止鉱区環境対策 : IAGS2011エクスカーションに参加して

    笹木 圭子, 所 千晴

    Journal of MMIJ : journal of the Mining and Materials Processing Institute of Japan   127 ( 12 ) 724 - 728  2011.11

    CiNii

  • Improvement of the DEM Rotational Resistance Model

    YAMADA Yoshinori, SAKAI Mikio, MIZUTANI Shin, MURAKAMI Shinsuke, TOKORO Chiharu, TSUCHIYA Masao, FUJIKAWA Takao

    Journal of the Society of Powder Technology,Japan   48 ( 10 ) 692 - 700  2011.10

    DOI CiNii J-GLOBAL

  • 私とピアノ

    所 千晴

    化学と工業 = Chemistry and chemical industry   64 ( 8 ) 637 - 637  2011.08

    CiNii

  • 廃携帯電話・廃通信基板中の各種レアメタル濃縮挙動の総括

    古賀千香子, 大和田秀二, 所千晴, 白鳥寿一, 湯本徹也

    資源・素材学会春季大会講演集   2011 (CD-ROM)   ROMBUNNO.1120  2011

    J-GLOBAL

  • 廃通信基板からのレアメタル濃縮に及ぼす粉砕手法の影響

    菊谷英生, 小室隆将, 大和田秀二, 所千晴, 白鳥寿一, 湯本徹也

    資源・素材学会春季大会講演集   2011 (CD-ROM)   ROMBUNNO.1119  2011

    J-GLOBAL

  • レアメタル回収を目的としたDEMシミュレーションによる廃電子基板からの部品剥離機構の解明

    綱澤有輝, 鳥越謙一郎, 菊谷英生, 所千晴, 大和田秀二, 白鳥寿一, 湯本徹也

    粉体工学会研究発表会講演論文集   2010   3 - 4  2010.11

    J-GLOBAL

  • Pb recycling from contaminated soil using thiosulfuric acid

    所 千晴, 山岡 祐太郎, 大和田 秀二

    Sulphuric acid and industry.   Vol.63 ( No.11 ) 1 - 7  2010.11

    CiNii

  • 廃小型家電品からのレアメタル回収技術 (特集 資源回収とリサイクル技術)

    大和田 秀二, 所 千晴

    ケミカルエンジニヤリング   55 ( 10 ) 729 - 734  2010.10

    CiNii

  • 第7回「資源・素材・環境」技術と研究の交流会報告

    所 千晴

    Journal of MMIJ : journal of the Mining and Materials Processing Institute of Japan   126 ( 10 ) 627 - 628  2010.09

    CiNii

  • 311 Visualization of nano-fiber sedimentation by resistance computed tomography

    SAWADA Yousuke, TOKORO Chiharu, SCOTT David, TAKEI Masahiro

    Symposium on Environmental Engineering   2010 ( 20 ) 202 - 203  2010.06

    CiNii

  • 廃電子基板/実装部品の分離を目的とした粉砕手法のDEMシミュレーションによる比較

    鳥越謙一郎, 綱澤有輝, 山下達也, 所千晴, 大和田秀二, 白鳥寿一, 湯本徹也

    資源・素材学会春季大会講演集   ( 2 ) 67 - 68  2010.03

    J-GLOBAL

  • 廃電子基板/実装部品の分離を目的とした粉砕手法の実験的比較

    菊谷英生, 古賀千香子, 松永恵里, 後藤昌也, 大和田秀二, 所千晴, 白鳥寿一, 湯本徹也

    資源・素材学会春季大会講演集   ( 2 ) 69 - 70  2010.03

    J-GLOBAL

  • 部品選別・粉砕物選別による廃携帯電話・通信基板中のレアメタル濃縮―人工鉱床(RtoS)構想の一環として―

    古賀千香子, 菊谷英生, 後藤昌也, 松永恵里, 大和田秀二, 所千晴, 白鳥寿一, 湯本敏也

    資源・素材学会春季大会講演集   ( 2 ) 71 - 72  2010.03

    J-GLOBAL

  • 廃通信基板/実装部品の剥離性に関する各種粉砕手法の比較

    菊谷英生, 大和田秀二, 所千晴, 白鳥寿一, 湯本徹也

    資源・素材   2010   91  2010

    J-GLOBAL

  • 廃携帯電話からのレアメタル濃縮における部品選別の有効性―人工鉱床(RtoS)構想の一環として―

    古賀千香子, 後藤昌也, 大和田秀二, 所千晴, 白鳥寿一, 湯本徹也

    資源・素材   2010   49  2010

    J-GLOBAL

  • 廃電子基板からの実装部品剥離機構の解明を目的とした離散要素シミュレーションの開発

    鳥越謙一郎, 綱澤有輝, 所千晴, 大和田秀二, 白鳥寿一, 湯本徹也

    資源・素材   2010   50  2010

    J-GLOBAL

  • レアメタルの濾過・回収

    所千晴, 砂田和也

    濾過プロセスの最適選定と効率改善(情報機構)     154 - 162  2010

  • 部品選別の適用による廃携帯電話中のレアメタル濃縮‐人工鉱床(RtoS)プロジェクトの一環として‐

    古賀千香子, 影山創, 大和田秀二, 大槻晶, 所千晴, 白鳥寿一, 湯本徹也

    資源・素材学会春季大会講演集   ( 2 ) 101 - 102  2009.03

    J-GLOBAL

  • 粉砕物選別の適用による廃携帯電話中のレアメタル濃縮―人工鉱床(RtoS)プロジェクトの一環として―

    影山創, 古賀千香子, 大和田秀二, 大槻晶, 所千晴, 白鳥寿一, 湯本徹也

    資源・素材学会春季大会講演集   ( 2 ) 99 - 100  2009.03

    J-GLOBAL

  • 部品選別による廃携帯電話中のレアメタル濃縮―人工鉱床(RtoS)プロジェクトの一環として―

    古賀千香子, 後藤昌也, 大和田秀二, 所千晴, 白鳥寿一, 湯本徹也

    資源・素材   2009   68  2009

    J-GLOBAL

  • 表面粉砕による射撃場鉛汚染浄化処理

    所千晴, 大和田秀二

    土壌・地下水汚染の浄化および修復技術(企画・編集:ブッカーズ、NTS)     285 - 291  2008

  • 表面粉砕による射撃場鉛汚染土壌処理の可能性

    大和田 秀二, 所 千晴, 塩澤 友浩, 結城 晴

    春季大会講演集. I, 資源編   19 ( 1 ) "企画 - 87"-"企画-88"  2007.03

    CiNii

  • 磁選とエアテーブルを組み合わせた廃蛍光管端部の成分分離

    大和田 秀二, 所 千晴, 川俣 大和

    春季大会講演集. I, 資源編   19 ( 2 ) 33 - 34  2007.03

    CiNii

  • 離散粒子破壊モデルを用いた焼結鉱の破壊シミュレーション

    所 千晴, 遠藤 優, 大和田 秀二

    春季大会講演集. I, 資源編   19 ( 2 ) 35 - 36  2007.03

    CiNii

  • 表面錯体モデルを用いた希薄陰イオンを含む廃水処理における共沈メカニズムの解明

    所 千晴, 矢次 洋平, 大和田 秀二, 佐々木 弘

    春季大会講演集. I, 資源編   19 ( 2 ) 129 - 130  2007.03

    CiNii

  • 赤泥を用いたヒ素含有酸性坑廃水の中和・共沈処理

    所 千晴, 大和田 秀二, 中津川 香世

    春季大会講演集. I, 資源編   19 ( 2 ) 131 - 132  2007.03

    CiNii

  • 粉体層の圧縮・せん断破壊試験を用いた二成分系粉砕機構の解明(その2)

    藤原 直太, 大宮 隆之, 大和田 秀二, 所 千晴

    春季大会講演集. I, 資源編   19 ( 2 ) 147 - 148  2007.03

    CiNii

  • ピンミルおよびボールミルによる解体系廃石膏ボード中の石膏・紙両成分高度分離および選択粉砕機構の解明

    大和田 秀二, 原 隆人, 所 千晴

    春季大会講演集. I, 資源編   19 ( 2 ) 149 - 150  2007.03

    CiNii

  • 陰イオン性-陽イオン性界面活性剤混合系でのプラスチックの浮遊性と溶液特性との関係

    大和田 秀二, 所 千晴, 山本 佳子

    春季大会講演集. I, 資源編   19 ( 2 ) 159 - 160  2007.03

    CiNii

  • アルミドロス有効利用のための最適処理フローの構築 : G水素モデル社会構築のための水素製造技術の一環として

    大和田 秀二, 所 千晴, 前田 英律, 山田 真一郎

    春季大会講演集. I, 資源編   19 ( 2 ) 165 - 166  2007.03

    CiNii

  • 第23回国際選鉱会議(IMPC2006)に参加して

    所 千晴

    資源と素材 : 資源・素材学会誌   122 ( 10 ) 549 - 550  2006.11

    CiNii

  • 第3回「資源・素材・環境」技術と研究の交流会

    所 千晴

    資源と素材 : 資源・素材学会誌   122 ( 9 ) 468 - 469  2006.10

    CiNii

  • 離散要素法による揺動ふるいの最適運転条件に関する基礎的検討

    所 千晴, 大和田 秀二, 松山 拓

    春季大会講演集. I, 資源編   18 ( 2 ) 53 - 54  2006.03

    CiNii

  • 鉄鉱石焼結鉱の粉砕工程における粉砕機構に関する基礎研究

    大和田 秀二, 所 千晴, 松山 拓

    春季大会講演集. I, 資源編   18 ( 2 ) 57 - 58  2006.03

    CiNii

  • スラグウールを付着担体としたバイオリアクターによる希薄有害イオン廃水の処理

    本多 幸太, 山田 貴子, 林 浩志, 所 千晴, 佐々木 弘

    春季大会講演集. I, 資源編   18 ( 2 ) 193 - 194  2006.03

    CiNii

  • 未利用植物バイオマスを微生物付着担体及び炭素源とした硝酸汚染水の処理

    須藤 隆一, 吉本 正和, 所 千晴, 佐々木 弘

    春季大会講演集. I, 資源編   18 ( 2 ) 195 - 196  2006.03

    CiNii

  • 希薄有害イオンを含む廃水の鉄およびアルミニウム塩による共沈除去の定量モデル化

    所 千晴, 行田 明子, BADULIS G. C, 佐々木 弘

    春季大会講演集. I, 資源編   18 ( 2 ) 203 - 204  2006.03

    CiNii

  • 表面改質した繊維状捕捉材による希薄Cd(II)及びSe(VI)の迅速除去

    酒井 哲, 梅野 快世, 林 浩志, 所 千晴, 佐々木 弘

    春季大会講演集. I, 資源編   18 ( 2 ) 209 - 210  2006.03

    CiNii

  • 電極法の廃水処理への応用に関する基礎的研究

    中本 慶介, 所 千晴, 佐々木 弘

    春季大会講演集. I, 資源編   18 ( 2 ) 211 - 212  2006.03

    CiNii

  • 苫小牧・リサイクルコース : (株)R&E・白老ポロト湖・北海道エコリサイクルシステムズ(株)

    所 千晴

    資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan   121 ( 10 ) 551 - 552  2005.11

    CiNii

  • 非球形粒子の充填率に関する研究

    中川 剛直, 溝呂木 茂, 所 千晴, 岡屋 克則, 定木 淳

    春季大会講演集. I, 資源編   17 ( 2 ) "企画 - 45"-"企画-46"  2005.03

    CiNii

  • 非球形粒子の充填率に関する研究

    中川 剛直, 溝呂木 茂, 所 千晴, 岡屋 克則, 定木 淳

    春季大会講演集. I, 資源編   17 ( 1 ) "企画 - 45"-"企画-46"  2005.03

    CiNii

  • 界面特性を利用した固定化バクテリアを用いる希薄鉛およびカドミウムの除去

    生木 大志, 勝賀瀬 暢一, 林 浩志, 二瓶 智也, 山田 貴子, 所 千晴, 佐々木 弘

    春季大会講演集. I, 資源編   17 ( 1 ) "企画 - 19"-"企画-22"  2005.03

    CiNii

  • 界面特性を利用した固定化バクテリアを用いる希薄ヒ素およびセレンの除去

    白鳥 寿一, 林 浩志, 河合 真知子, 中島 信裕, 本多 幸太, 所 千晴, 佐々木 弘

    春季大会講演集. I, 資源編   17 ( 1 ) "企画 - 23"-"企画-26"  2005.03

    CiNii

  • 希薄ヒ素の界面特性を利用した迅速分離

    平井 健二, 清水 伴紀, 小出 康夫, BADULIS Geronimo, 中本 慶介, 所 千晴, 佐々木 弘

    春季大会講演集. I, 資源編   17 ( 1 ) "企画 - 27"-"企画-30"  2005.03

    CiNii

  • 表面改質した繊維状スラグによる希薄カドミウムイオンの迅速分離

    山崎 武志, 桜井 敦, 高村 豊, 酒井 哲, 所 千晴, 佐々木 弘

    春季大会講演集. I, 資源編   17 ( 1 ) "企画 - 31"-"企画-34"  2005.03

    CiNii

  • 表面改質した繊維状スラグによる希薄セレンの迅速除去

    宮澤 寛, 高尾 大, 林 浩志, 小林 明浩, 梅野 快世, 所 千晴, 佐々木 弘

    春季大会講演集. I, 資源編   17 ( 1 ) "企画 - 35"-"企画-38"  2005.03

    CiNii

  • 汚染マトリックスとしての土壌

    佐々木 弘, 所 千晴

    春季大会講演集. I, 資源編   17 ( 1 ) "企画 - 97"-"企画-100"  2005.03

    CiNii

  • 金属水酸化物による希薄ヒ素の除去機構に関する考察

    所 千晴, BADULIS G. C, 佐々木 弘

    春季大会講演集. I, 資源編   17 ( 2 ) 159 - 160  2005.03

    CiNii

  • A fast algorithm for the discrete element method by contact force prediction

    Chiharu Tokoro, Katsunori Okaya, Jun Sadaki

    KONA Powder and Particle Journal   23 ( March ) 182 - 193  2005

     View Summary

    The discrete element method (DEM) takes enormous calculation time because it requires a very small time step, one small enough to represent the large frequency in the contact dynamic model. In general, the equations of motion of particles are solved using the second-order Adams-Bashforth method, which estimates the values of contact force in the following calculation time by linear extrapolation, or by multi-step methods such as the predictor-corrector method. Inspired by these two conventional methods, we propose a Contact Force Prediction Method that makes a larger time step possible. Our method uses the predicted values of contact force at every contact point, which are exact solutions or numerical solutions of differential equations that represent two particle contacts. It has been confirmed experimentally that the proposed method gives reasonable results of packing and discharge simulations, and accelerates DEM calculation 3-8 times.

    DOI

  • A fast algorithm for the discrete element method by contact force prediction

    Chiharu Tokoro, Katsunori Okaya, Jun Sadaki

    KONA Powder and Particle Journal   23 ( March ) 182 - 193  2005

     View Summary

    The discrete element method (DEM) takes enormous calculation time because it requires a very small time step, one small enough to represent the large frequency in the contact dynamic model. In general, the equations of motion of particles are solved using the second-order Adams-Bashforth method, which estimates the values of contact force in the following calculation time by linear extrapolation, or by multi-step methods such as the predictor-corrector method. Inspired by these two conventional methods, we propose a Contact Force Prediction Method that makes a larger time step possible. Our method uses the predicted values of contact force at every contact point, which are exact solutions or numerical solutions of differential equations that represent two particle contacts. It has been confirmed experimentally that the proposed method gives reasonable results of packing and discharge simulations, and accelerates DEM calculation 3-8 times.

    DOI

  • 乾式流動層選別の基礎的研究

    所 千晴, 柴山 敦, 岡屋 克則, 定木 淳, 藤田 豊久

    春季大会講演集. I, 資源編   16 ( 1 ) "企画 - 55"-"企画-58"  2004.03

    CiNii

  • NGH輸送・貯蔵システムに関する基礎的研究

    所 千晴, 溝呂木 茂, 伊藤 賢志, 松尾 誠治, 岡屋 克則, 定木 淳

    春季大会講演集. I, 資源編   16 ( 1 ) 137 - 138  2004.03

    CiNii

  • 天然ガスハイドレート輸送・貯蔵システムへの離散要素法の応用に関する研究

    所 千晴

    粉体工学会誌 = Journal of the Society of Powder Technology, Japan   40 ( 10 ) 757 - 758  2003.10

    DOI CiNii

  • 離散要素法によるNGHペレット充填・排出特性の解析

    所 千晴, 岡屋 克則, 定木 淳

    春季大会講演集. I, 資源編   15 ( 1 ) 170 - 171  2003.03

    CiNii

  • DEMの高速化に向けて

    所 千晴, 岡屋 克則, 定木 淳

    春季大会講演集. I, 資源編   14 ( 1 ) 302 - 302  2002.03

    CiNii

  • カラム浮選機のフロス層モデル

    徳田 吉範, 所 千晴, 岡屋 克則, 定木 淳

    一般発表(研究・業績発表)講演要旨集   2001 ( 2 ) 163 - 164  2001.03

    CiNii

  • カラム浮選機におけるパルプ液位変動のモデル化

    所 千晴, 徳田 吉範, 岡屋 克則, 定木 淳

    一般発表(研究・業績発表)講演要旨集   2001 ( 2 ) 165 - 166  2001.03

    CiNii

  • 粒度測定法によるコロイド粒子の凝集分散の速度に関する研究

    小林 昭一, 前北 高志, 所 千晴, 佐々木 弘

    一般発表(研究・業績発表)講演要旨集   2001 ( 2 ) 175 - 176  2001.03

    CiNii

  • Coagulation Kinetics of Monodispersed Polystyrene Latex Particles by Dynamic Light Scattering Method

    TOKORO Chiharu, OKANO Yasuhiko, SASAKI Hiroshi

    Shigen-to-Sozai   116 ( 3 ) 193 - 197  2000.03

     View Summary

    The experimental collision frequency factors of monodispersed polystyrene latex (PSL) particles in KCl solutions were measured by the use of the dynamic light scattering method. This method determines the cluster-size distribution by counting the number of different clusters during the coagulation process and therefore permits the determination of the rough collision frequency factors by the fitting curves for the data. The fitting curves were calculated on the assumption that the coagulation between two same-fold particles is dominant. &lt;br&gt; Numerous studies have revealed significant discrepancies between the theoretical collision frequency factors that can be calculated from Smoluchowski and Fuchs formulation and the experimental results, especially in the slow coagulation region. In this paper&#039;s results, good qualitative agreement was found for the theoretical collision factors in the rapid coagulation, but in the slow coagulation, significant discrepancies were confirmed both qualitatively and quantitatively, especially for high-fold particles.&lt;br&gt;

    DOI CiNii J-GLOBAL

  • 動的光散乱法による粒径測定及び臨界凝集測定

    小林 昭一, 前北 高志, 所 千晴, 佐々木 弘

    一般発表(研究・業績発表)講演要旨集   2000 ( 2 ) 39 - 40  2000.03

    CiNii

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Industrial Property Rights

  • 坑廃水の処理方法

    洪承官, 所千晴, 小山恵史, 古郡友輔

    Patent

  • 易解体方法および易解体可能な構造体

    所千晴, 林秀原, 小板丈敏, 近藤正隆, 浪平隆男

    Patent

  • 水処理方法および水処理装置

    土屋宏典, 所千晴, 淵田茂司, 島村祐司

    Patent

  • 接着層の接着強度を低下させる方法

    所千晴, 犬束学, 林秀原, 小板丈敏, 近藤正隆, 小川亮, 太田啓介

    Patent

  • ニッケルの回収方法

    Patent

  • 金属の回収方法

    特許7130278

    アダムス英里, 前田和輝, 所千晴, 加藤達也

    Rights holder: 株式会社ガルデリア

    Patent

  • 対象物の解体方法及び部材の再生方法

    所千晴, 林秀原, 浪平隆男

    Patent

  • 選鉱方法

    所千晴, 淵田茂司, 青木悠二, 忰山卓矢, 岸本恭暢, 島田啓正

    Patent

  • ホウ素含有水の処理方法

    特許6950893

    所千晴, 帆保駿吾, 中村壮志, 田中善之

    Patent

  • 水処理方法および水処理装置

    土屋宏典, 所千晴, 島村祐司

    Patent

  • 電気パルス分解方法、複合材、複合材分解方法

    小山哲史, 岸本直輝, 所千晴, イムスウォン, 小板丈敏, 近藤正隆, 浪平隆男

    Patent

     View Summary

    US17/676,841、2022年2月22日、公開番号: US2022/0323967
    CN202210162203.5、2022年2月22日

  • 積層体の解体方法およびそのための装置

    所千晴, 林秀原, 浪平隆男, 浦田泰裕

    Patent

  • 選鉱方法

    所千晴, 淵田茂司, 青木悠二, 忰山卓矢, 岸本恭暢

    Patent

  • ホウ素含有水の処理方法

    特許第6599153号

    所 千晴, 武藤 研一, 加藤 達也, 鈴木 慎哉, 田中 善之

    Patent

  • 非晶質エトリンガイトの製造方法

    特許第6591343号

    所 千晴, 武藤 研一, 帆保 駿吾, 田中 善之, 中村 壮志

    Patent

  • リチウムイオン電池の処理方法

    特許第6587861号

    大和田 秀二, 所 千晴, 薄井 正治郎

    Patent

  • ホウ素含有水の処理方法

    特許6840354

    所 千晴, 帆保 駿吾, 田中 善之, 中村 壮志

    Patent

  • 砒素吸着装置及び砒素吸着方法

    特許6376536

    所 千晴, 二見 文也, 久保田 裕久

    Patent

  • フッ素含有水処理方法およびフッ素含有水処理システム

    大里 彩, 冨田 洋平, 所 千晴, 森田 将夫, 宇田川 悟

    Patent

  • 水処理方法及び水処理装置

    特許7116395

    島村祐司, 鳥羽裕一郎, 都司雅人, 所千晴, 福田宏樹, 福島諒

    Patent

  • コバルトの分離方法

    西村 建二, 川崎 始, 林 浩志, 所 千春, 岡田 慎太郎

    Patent

  • 硫化モリブデンの製造方法

    所 千晴, 須藤 俊佑, 大藏 隆彦

    Patent

  • 電気パルス解体方法

    特許6857363

    所 千晴, 浪平 隆男

    Patent

  • 太陽光パネルの選択的解体方法および解体装置

    所 千晴, 浪平 隆男, 土居 大亮, 浪越 悠介

    Patent

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Syllabus

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Sub-affiliation

  • Affiliated organization   Global Education Center

  • Faculty of Science and Engineering   Graduate School of Creative Science and Engineering

Research Institute

  • 2022
    -
    2024

    Waseda Research Institute for Science and Engineering   Concurrent Researcher

  • 2022
    -
    2024

    Research Organization for Open Innovation Strategy   Concurrent Researcher

Internal Special Research Projects

  • ⾼度に活性化した酸化マグネシウム材を⽤いたホウ素等有害元素処理

    2019  

     View Summary

    本研究では,粒子表面を活性化させた酸化マグネシウム(MgO)材を用いて,廃水中のホウ素等有害元素を処理する技術開発を試みた。塩基性炭酸マグネシウムおよび水酸化マグネシウムを400~1000℃で1時間焼成することで低結晶性かつ比表面積の大きい酸化マグネシウムが得られる。これらを用いて模擬廃水中のホウ素除去実験を実施した結果,通常の高結晶MgOと比べて約4倍程度の速度でホウ素が除去されることが明らかとなった。とくに,塩基性炭酸マグネシウムを600℃で焼成したMgOを用いた場合ホウ素の除去速度が最大となった。なお,上記ホウ素除去に有効であったMgOを用い,フッ素やセレンの除去も試みたところ,F(-I)やSe(IV)に良好な除去特性を確認した。

  • 難処理無機元素除去プロセス確立のためのナノMgO合成および表面錯体モデル構築

    2017  

     View Summary

    本研究では、比表面積の大きいMgO粉末の合成によって、迅速に高効率なホウ素除去剤の開発を試みた。塩基性炭酸マグネシウムを、電気炉を用いて400~1000℃で1時間焼成し、脱水もしくは脱炭酸した結果、400~450℃、900~1000℃で焼成合成したMgO&nbsp;のBET比表面積は100m2/gを下回った(最低値:20.78 m2/g)のに対し、500~800℃で焼成合成したMgOのBET比表面積は、100m2/gを超えており(最高値:168.98 m2/g)、比表面積を約8倍以上向上させることに成功した。初期濃度500mg/dm3のホウ酸模擬廃水に対して、上記で合成したMgOを添加し、除去実験を行ったところ、500~800℃で焼成合成した比表面積の高いMgOを用いた場合、非常に速い速度でホウ素を除去するという結果が得られた。

  • 加熱・徐冷プロセスを利用した銅製錬スラグからのモリブデン回収に関する新規法の提案

    2013  

     View Summary

    本研究では,銅製錬スラグからモリブデンを回収することを目的として,スラグを加熱しさまざまな条件で冷却して,モリブデンを特定の相に濃縮,結晶化させ,その後粉砕・物理選別により回収することを試みた。手法としては①:モリブデンの硫化・徐冷によるMolybdenite(硫化Mo)の結晶化および浮選によるMolybdeniteの回収,②:徐冷によるモリブデンのスピネル化および磁選によるモリブデンを含むスピネルの回収を検討した。まず粉末Fe,Fe2O3,非晶質SiO2を混合し,るつぼに入れ電気炉で1300℃で溶融したものを水砕し,不純物を含まない模擬スラグを作製した。これは,不純物によるモリブデンの硫化反応が阻害される可能性を取り除くためである。これにMoO3試薬を添加し,スラグのモリブデン品位を1.25,1.50,1.75%となるようにしたのち,それぞれのスラグにPyrite(モリブデン1molに対して硫黄が5mol)を添加し,電気炉によりAr雰囲気,1300℃にて1時間30分加熱したのちに3℃/minで冷却した試験を実施し,Molybdeniteの生成を試みた。分析にはXRD(リガク,RINT UltimaIII)および,SEM-EDS / MLA(FEI,Quanta 250G)を用いた。その結果,XRDによりモリブデン品位1.50%および1.75%のスラグではMolybdeniteの生成が確認できたものの,1.25%のスラグではMolybdeniteが生成しなかった。実際のスラグはモリブデン品位が1.0%未満であるため,Molybdeniteとしての回収は難しいことが示唆された。また,モリブデンはMolybdenite以外の形態として,モリブデンの多くが磁性を持つスピネルフェライトとして存在していることがSEM-EDS/MLAの結果より確認された。このため,製錬所スラグにおいて,磁性を持つスピネルフェライトを回収することを目的として硫化を伴わない加熱・徐冷実験をMo品位0.2%,1.0%のスラグで実施した。特に冷却速度のスピネル結晶サイズへの影響をみるため,冷却速度を3℃/min,10℃/minと変化させて行った。分析には光学顕微鏡(キーエンス, VHX-500F)を使用した。冷却速度が速いほうが,生成したスピネルの粒度は小さいことが確認された。湿式磁選は少なくとも数十μm以上のサイズを必要とするため,磁選に用いるには冷却速度を遅く,好ましくは3℃/min程度とする必要があると確認された。また,Mo品位が高いほうがスピネルのグレインサイズも大きくなる傾向があることが示された。そこで本実験でもっともスピネルのグレインサイズが大きかったMo1%,冷却速度3℃/minのスラグの湿式磁選を実施した。2Lの手付きビーカーに水を1L,ヘキサメタリン酸ナトリウムを0.5g,-38μmに粉砕したスラグ5g入れ,スターラーと攪拌棒を用いて良く攪拌・混合した。これを金属製のバットに移し,1000Gのハンドマグネットを用いて磁選した。この結果,Mo品位3.2%の磁着物が得られ,Moの回収率は70.6%であった。スラグ中のMoを硫化物として結晶化するためには一定のMo品位が必要であることが確認されたため,Mo品位1%以下のスラグ中のMoを硫化物として浮選で回収するのは困難であるとみられた。しかしながら,Moは結晶化により大部分がSpinel化して存在することがわかり,これは磁選により回収が可能であった。Spinelのグレインサイズは冷却速度を遅くすることで大きくなることが確認されたため,スラグの冷却速度を制御することで磁選での回収率が良くなる可能性が示唆された。

  • 水酸化物・硫化物処理法における不均一・不可逆反応機構の解明

    2011  

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    ヒ素(As(V))を対象として、水酸化第二鉄または水酸化アルミニウム共沈法における不可逆、不均一機構の解明をすべく、収着等温線作成、ゼータ電位測定、XRDおよびXAFS解析を行った。As(V)を10ppm含有するpH5の溶液に対して、共沈法と吸着法による処理特性を比較したところ、水酸化第二鉄、水酸化アルミニウムの双方において、共沈法では吸着法よりも高い処理特性が得られた。収着等温線の形状を比較すると、吸着法では通常のラングミュア型であったのに対し、共沈法ではBET型が得られたことから、共沈法では吸着以上の機構によるAs(V)の水酸化物への取り込みが生じていることがわかった。また、ゼータ電位と収着密度の関係をプロットすると、共沈法の場合には、初期As/FeまたはAlモル比が小さい範囲では収着密度の増加に応じてゼータ電位が低下するのに対し、初期As/FeまたはAlモル比が大きい範囲では収着密度が増加してもゼータ電位がさほど変化しないという傾向が得られた。その境界値は、水酸化第二鉄では初期As/Feモル比0.4程度、水酸化アルミニウムでは初期As/Alモル比が1.5程度であった。このことから、共沈法を用いた場合、初期As/FeまたはAl比が大きい範囲では、As(V)は水酸化物と溶解度積は満たしていないにもかかわらず表面沈殿を生成していることが確認された。この表面沈殿生成は、XRDおよびXAFS測定からも裏付けされた。すなわち、XRDパターンを比較すると、As/Fe=0.4以上では、別途参照物質として作成した非晶質ヒ酸鉄に似たパターンが得られ、As/Al=1.5以上では、やはり別途参照物質として作成した非晶質ヒ酸アルミニウムに似たパターンが得られた。また、XANESスペクトルにおいても同様の傾向が得られた。共沈法において得られたXANESスペクトルに対し、As(V)を吸着した水酸化物のスペクトルと非晶質ヒ酸鉄または非晶質ヒ酸アルミニウムを参照物質としてその割合をパターンフィッティングにより求めたところ、非晶質ヒ酸鉄または非晶質ヒ酸アルミニウムの割合が50%を超えるのは、これまでの他の実験結果と同様にAs/Fe=0.4またはAs/Al=1.5以上であることが確認された。

  • 硫化物法による自然水・工業廃水からの重金属の浄化処理および資源回収

    2010  

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    本研究は、硫化物法によって廃水からのNi選択回収を試みるものである。高濃度Ni含有めっき廃水に硫化物法を適用すると、硫化ニッケルを主とするスラッジが得られる。この硫化ニッケルを再溶解させることによって、高純度のNi溶液を得ることができ、電解採取等によってNiの資源回収が可能である。しかし、硫化ニッケルは溶解度が低く、水や酸によって溶解させることができない。一方、硫化ニッケルを酸化させ、硫酸ニッケルとすることによって、水にある程度を溶解させることが可能である。本研究では、XAFS法により、Ni含有廃水から得られた硫化ニッケルに対し、空気酸化による硫酸ニッケルへの酸化機構を検討した。測定試料として、模擬廃水または実廃水((株)みすず工業より提供)に硫化剤を添加して得られた硫化物スラッジを用いた。スラッジは含水率を制御した容器ないで空気酸化を行い、定期的に分取してXAFS測定に供した。KEK-PFで行ったXAFS測定より、熟成時間が短い場合には、S(-2)に由来すると考えられる低エネルギー側でのピークが確認されたが、そのピークは時間の経過と共に消滅することがわかった。また、SO3(-2)に由来すると考えられるピークは、熟成時間6時間において既に認められており、時間の経過と共にピーク強度はそれほど変化していなkった。一方、SO4(-2)に由来すると考えられるピークは、熟成時間6時間において既に認められ、時間の経過と共にピーク強度が大きくなっている様子が確認できた。以上より、硫化ニッケルは、亜硫酸ニッケルを経て、硫酸ニッケルまで酸化すると考えられた。XAFSの結果を裏付けるために、得られた沈殿物を熟成時間毎に水または酸に溶解させる実験を行った。ニッケルは水、酸ともに不溶、亜硫酸ニッケル水に不溶であるが酸に可溶、硫酸ニッケルは水、酸ともに可溶であるという性質が知られている。これを利用して、各溶出率からスラッジ中の硫化ニッケル、亜硫酸ニッケル、硫酸ニッケルの量を算出した。その結果、硫化ニッケルは初期では70%ほどを占めていたが、40日間熟成を行なうと、10%まで減少しており、酸化が進行するにつれて急激に減少することが判明した。一方で亜硫酸ニッケルは10日間を境にゆっくりと割合が減少することがわかった。このことから、硫化ニッケルから亜硫酸ニッケルへの酸化よりも、亜硫酸ニッケルから硫酸ニッケルへの酸化の方が速度が遅いと推察される。

  • 種々の連続抽出法の比較による鉛汚染土壌における汚染形態分析法の確立

    2007  

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    発生源の異なる2種の鉛汚染土壌(建設工場跡、化学工場跡)に関し、それぞれの土壌の基礎物性、土壌からの酸による溶出特性、Tessierらによる連続抽出法、さらにはSpositoらによる土壌表面のイオン交換能および表面錯体容量を実験的に把握し、それぞれの土壌のキャラクタリゼーションを行った。粒度分布に関しては、建設工場跡では20μm以下の細粒が多く、化学工場跡ではそれ以上の中粒が多いことがわかった。また、塩酸や王水を用いた溶出量では、建設工場跡では1.18mm~の粗粒で溶出量が多く、化学工場跡では20μm以下の細粒で溶出量が多い結果となった。また、建設工場跡の土壌は王水分解によって鉛の全体量の40%しか溶出しないことから、ケイ酸塩鉱物を代表とする鉱物が多い、反応性に富まない土壌であることがわかった。一方、化学工場跡では王水分解によって鉛の全体量の70%が溶出した。これらの結果と、Tessierの連続抽出法の結果とを比較すると、建設工場跡では、炭酸塩態、酸化物態、および残渣(ケイ酸塩鉱物や非分解性物質)中の鉛が多いことが分かった。特に、残渣分が半分以上を占めており、前述の酸溶出特性と同様の傾向が得られた。また、化学工場跡では、炭酸塩態、有機物態、酸化物態中の鉛がほぼ同程度存在しており、一般の汚染土壌に比べて有機物態の割合が高いことがわかった。これは、化学工場由来の有機物に起因していると考えられる。さらに、Spositoらの方法により、土壌中のイオン交換能と表面錯体容量を実験的に検討したところ、両者の土壌において、イオン交換能が2~7mmol/kgであったのに対し、表面錯体容量は20~35mmol/kgであった。Tessierの連続抽出法の結果においても、両者の土壌ではイオン交換態の鉛が少なく、鉄・マンガン酸化物中の鉛が比較的多かったことから、鉛分は鉄・マンガン酸化物中に表面錯体として取り込まれているものが多いと考えられる。以上の結果より、複数の分析法を組み合わせることによって、土壌の詳細なキャラクタリゼーションが可能であることが確認された。

  • 界面特性を利用した超微粒子希薄懸濁液の迅速固液分離に関するシミュレーション的考察

    2004  

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     コロイド次元の微粒子を含有する希薄懸濁液の迅速固液分離法として、繊維状のスラグウールを捕捉材に吸着除去する方法に関するシミュレーションを行なうにあたり、その基礎となる水溶液中の化学平衡計算に関する考察を行った。化学平衡計算によって、平衡状態にある溶液のpHや沈殿生成状況を把握するためには、系内に存在する全ての成分の影響を考慮する必要があり、化学種の数が多くなると計算がきわめて繁雑になるため、幾つかの工夫を行なった。 特に希薄ヒ素の除去機構をシミュレーションにより考察したところ、希薄ヒ素はそれ自身が微粒子を形成してスラグウールに吸着しているのではなく、共存あるいは添加した鉄(III)またはアルミニウム塩が形成した水酸化鉄または水酸化アルミニウムの微粒子表面へヒ素が吸着し、ヒ素を吸着した水酸化鉄またはアルミニウムがスラグウールに吸着されることによって迅速分離されていることがわかった。 更に本研究では、ヒ素の除去に関する共存イオンの影響に関する定量的考察も行った。ヒ素は陰イオンの形態で水溶液中に存在するため、共存イオンの中でも特に陰イオンはヒ素の除去を妨害する可能性がある。本研究では、陰イオンの中でも酸性坑廃水中に最も一般的に存在する硫酸イオンに注目し、その共存による影響を計算と実験の両面から検討した。硫酸イオンの影響は、水酸化鉄または水酸化アルミニウムへのヒ素および硫酸イオンの吸着を考慮した計算により、実験結果を良好に再現することが確認された。また、硫酸イオンはヒ素の水酸化鉄あるいは水酸化アルミニウムへの吸着を妨害し、その影響はヒ素(V)イオンよりヒ素(III)イオンの方が大きく、アルミニウム塩より鉄(III)塩の方が大きいことが確認された。

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