Abstract: The nature of a copper-lead-zinc polymetallic sulfide ore in Inner Mongolia is complex，and it is difficult to achieve the effective separation of copper，lead and zinc. Some factors that affecting the separation of copper，lead and zinc are studied. The results show that the combination of T-16 and zinc sulfate is a efficient pulp regulator to highly effective realize the separation of copper，lead and zinc，which owns the role of inhibiting zinc，activating copper and eliminating the sticky pulp foam. The pre-dewatering and thickening of the mixed copper and lead concentrate build the foundation for the next reagent removal with activated carbon，which is the precondition to achieve the efficient separation of copper and lead. Then，the optimized process is applied to the laboratory closed-circuit tests and field production separately,obtain the desired expectation on effective separation of copper，lead and zinc，and significantly the quality of copper concentrate improve and lead concentrate. In on-site production，the Cu grade of copper concentrate is increased from 23.15 % to 28.18%，and its recovery increased from 64.53% to 79.51%. Pb grade of lead concentrate is increased from 44.59% to 57.07%，and its the recovery increased from 59.61% to 89.68%.

Key words: Cu-Pb mixed flotation, Separation of copper and lead, Regulator T-16, Dewatering and thickening, Reagent removal