Abstract: College of Resources and Civil Engineering, Northeastern University The properties of Cu-Pb-Zn polymetallic ore with high sulfur from Inner Mongolia are complex, in which metal minerals are associated with each other closely.The study on mineral processing techniques was conducted by the flowsheets of Cu-Pb bulk flotation-separation of Cu amd Pb-sulfur depression Znic flotation.The results show that Cu-Pb bulk flotation with once roughing flotation, four times cleaning flotation and once scavenging flotation, Cu-Pb separation with once roughing flotation, once cleaning flotation and once scavenging flotation, and the flowsheets of sulfur depression and Zn flotation with once roughing flotation, four times cleaning flotation and once scavenging flotation,middlings urderly returm,can obtain  the high quality productions as Cu concentrate, Pb concentrate, Zn concentrate and sulfur concentrate, in which contents of impurity elements are low.

Key words: Polymetallic sulphide ore, Cu-Pb bulk flotation, Cu-Pb flotation separation, Sulfur-depression and Zn flotation