Kosei Aikawa

The purpose of this study is to propose the flotation procedure of seafloor massive sulfide (SMS) ores to separate chalcopyrite and galena as froth and sphalerite, pyrite, and other gangue minerals as tailings, which is currently facing difficulties due to the presence of water-soluble compounds. The obtained SMS ore sample contains CuFeS2, ZnS, FeS2, SiO2, and BaSO4 in addition to PbS and PbSO4 as Pb minerals. Soluble compounds releasing Pb, Zn2+, Pb2+, and Fe2+/3+ are also contained. When angl

The presence of anglesite (PbSO4) in complex sulfide ores negatively affects the separation of Cu-Pb sulfides and sphalerite (ZnS) due to lead activation, and PbSO4 rejected to tailings dams contaminates the surrounding environment with lead. To address these problems, this study investigated the application of ethylene diamine tetra acetic acid (EDTA) pretreatment extracting PbSO4 to ZnS flotation and the recovery of the extracted Pb2+ as zero-valent Pb by cementation using zero-valent iron (ZV

Porphyry copper deposits are important sources of copper and typically processed by flotation to produce copper concentrates. As mining areas become deeper, the amounts of impurities, such as sphalerite, can be increased in copper ores, so the appropriate depression of sphalerite floatability should be achieved to obtain saleable copper concentrates. In this study, the flotation behaviors of chalcopyrite and sphalerite in model samples mimicking copper ores with high Cu/Zn ratios (i.e., the rati

Iron oxides (hematite, Fe2O3, and magnetite, Fe3O4), previously used as electron mediators in the galvanic system with zero-valent aluminum (ZVAl), have been shown to recover Au upon cementation in Au–Cu ammoniacal thiosulfate media selectively, and this warrants further investigation. This research is focused on investigating the role of the semiconductive properties of metal oxides by performing a cementation experiment by mixing 0.15 g of electron mediators (Fe3O4, Fe2O3, TiO2 (anatase and ru

循環経済（サーキュラーエコノミー）の実現に向けて，天然金属資源の効率的な利用や都市鉱山開発（リサイクル）による資源循環は，ますます重要になっている。金属生産における製錬前処理工程において，物理選別では鉱石中の有用鉱物や廃製品中の有用金属を一次濃縮（固体原料化）する。筆者はこれまで，物理選別技術の一種である浮選を用いた鉱石中の有用鉱物の選別に関する研究に取り組んできた。本稿では，筆者がこれまでに検討してきた天然鉱山開発における浮選プロセスの改善事例を紹介するとともに，都市鉱山開発への浮選適用の課題について考察する。