Abstract: The Cu， Pb， Zn， Au， Ag， and S grades of a copper-lead-zinc polymetallic sulfide ores in Gansu are 0.75%， 2.50%， 5.30%， 2.80 g/t， 120 g/t， and 14.20%， respectively， which are worthy to recycle. However， the effective separation of copper and lead-zinc had not progressed in the early study. In this paper， experimental study of focusing on the effective separation of copper and lead-zinc without affecting the separation and recovery of other elements was carried out. The results showed that the principle process of full mixed flotation-mixed concentrate desulfurization， multi-stage grinding and the separation of copper and lead-zinc was carried out. Cu， Pb， Zn grade and Cu recovery rate in the copper concentrate were 21.42%， 3.61%， 4.28%， 71.69% respectively. Pb， Zn， Cu grade and Pb， Zn recovery rate in the mixed lead-zinc concentrate were 13.46%， 28.52%， 1.01%， 93.04%， and 92.98%， respectively. The key to achieve effective separation of copper and lead-zinc was the combination of lead-zinc inhibitor sodium sulfite + sulfurous acid + FY and the fine-grinding deep-concentrating process.

Key words: Polymetallic sulfide ores, Mixed flotation, Separation