Abstract: The main valuable element copper grade in a polymetallic copper ore in Xizang is 0.425%，and copper is mainly present in chalcopyrite in the form of independent minerals，with a distribu⁃ tion rate of 89.16%. The sulfur grade is 2.78%，mainly in pyrite，and the distribution rate is 84.23%. The associated rare precious metal Au grade is 0.20 g/t，Ag grade is 2.0 g/t. Based on the study of process miner⁃ alogy，the principle process of copper sulfur mixed flotation-regrinding-separation was adopted. In the cop⁃ per-sulfur mixed flotation stage，the combination of C3 and ammonium dibutyl dithiophosphate was used as the collector，and lime was used as the pH value regulator. The copper sulfur mixed concentrate was ob⁃ tained by one roughing，one cleaning and two scavenging. After regrinding the mixed concentrate to 90% of -0.043 mm，copper and sulfur were separated by one roughing，two cleaning and two scavenging with lime as pyrite inhibitor and C3 as copper collector. The copper concentrate with copper grade of 20.228% and re⁃ covery rate of 90.23% can be obtained by closed-circuit test. The associated Ag grade of copper concen⁃ trate is 53.1 g/t，and the associated Au grade is 4 g/t，both reaching the valuation grade，which significant⁃ ly improves the comprehensive value of copper concentrate. The research results is of great significance to promote the scientific development and sustainable utilization of copper resources in this area.

Key words: copper sulfur mixed flotation, copper sulfur separation, collector