A novel copper depressant for selective flotation of chalcopyrite and molybdenite

In this work, the effect of Na 2 S 2 O 3 and the mixture of Na 2 S 2 O 3 and Cu 2+ on the selective flotation performances of chalcopyrite and molybdenite were investigated through single and mixed mineral flotation tests. The depression mechanisms were studied in detail through Zeta potential, contact angle, XPS and Raman measurement. The results indicated that Na 2 S 2 O 3 had more powerful depression effect on chalcopyrite than that on molybdenite. The depression could be greatly enhanced with the addition of Cu 2+ without losing selectivity. XPS and Raman measurement revealed that Na 2 S 2 O 3 and Cu 2+ chemically adsorbed on chalcopyrite surface, formation of CuS which was responsible for the depression. On the other hand, the surface of molybdenite was slightly affected after the treatment in the mixed solution of Na 2 S 2 O 3 and Cu 2+ . This new depressant had the advantage of low cost and environment friendly over conventional depressant, which could be utilized as an alternative depressant for the selective flotation separation of chalcopyrite and molybdenite.