資源・素材2021（札幌）
2021年9月14日〜9月16日オンライン開催
資源・素材2021（札幌）
2021年9月14日〜9月16日オンライン開催
[1K0501-05-05]Application of microencapsulation technique for improving flotation separation of chalcopyrite and molybdenite
○Ilhwan - Park1、Seunggwan Hong1、Dai Uchida1、Sanghee Jeon1、Mayumi Ito1、Naoki Hiroyoshi1(1. Hokkaido University)
司会：橋本 晃一（JOGMEC）
キーワード：
Flotation、Microencapsulation、Chalcopyrite、Molybdenite
Porphyry Cu-Mo deposits are the most important sources of copper and molybdenum, and they are separately recovered by flotation. For the separation of Cu and Mo minerals (mostly chalcopyrite and molybdenite), the strategy of floating molybdenite while depressing chalcopyrite has been widely adopted by using chalcopyrite depressants, such as NaHS, Na2S, and Nokes reagent. However, the conventionally used depressants can emit toxic H2S gas when pulp pH decreased to < 9. In this study, thus, the application of microencapsulation (ME) technique using ferrous (Fe2+) and phosphate (H2PO4–) ions to selectively depress the floatability of chalcopyrite by forming hydrophilic FePO4 coating was investigated.
The results of ME treatments showed that FePO4 coating was favorably formed on the surface of chalcopyrite compared to that of molybdenite due to the difference in their electrical resistivities. The electrical resistivity of chalcopyrite is by far lower than that of molybdenite, so the oxidation of Fe2+ to Fe3+ followed by FePO4 precipitation occurred more actively on the surface of chalcopyrite than molybdenite. However, the results of single mineral flotation indicated that ME treatment depressed not only chalcopyrite (from ~70% to ~15%) but also molybdenite (from ~45% to ~6%). Although ME treatment also reduced the floatability of molybdenite, ~92% Mo could be recovered by utilizing emulsified kerosene. Flotation of chalcopyrite/molybdenite mixture confirmed that ME treatment improved the separation efficiency from 10.9% to 66.8%, indicating that ME treatment can be employed as a conditioning process for Cu-Mo flotation separation.
The results of ME treatments showed that FePO4 coating was favorably formed on the surface of chalcopyrite compared to that of molybdenite due to the difference in their electrical resistivities. The electrical resistivity of chalcopyrite is by far lower than that of molybdenite, so the oxidation of Fe2+ to Fe3+ followed by FePO4 precipitation occurred more actively on the surface of chalcopyrite than molybdenite. However, the results of single mineral flotation indicated that ME treatment depressed not only chalcopyrite (from ~70% to ~15%) but also molybdenite (from ~45% to ~6%). Although ME treatment also reduced the floatability of molybdenite, ~92% Mo could be recovered by utilizing emulsified kerosene. Flotation of chalcopyrite/molybdenite mixture confirmed that ME treatment improved the separation efficiency from 10.9% to 66.8%, indicating that ME treatment can be employed as a conditioning process for Cu-Mo flotation separation.