Abstract: Based on investigation of natural flotation of chalcopyrite and pyrite，effects of lime (adjusting slurry pH value)，sodium hydrogen bisulfite，copper ion on floatability of chalcopyrite and pyrite，effects of citric acid on floatability of Cu²⁺  activated pyrite and chalcopyrite，and effects of combining inhibitor of citrate acid-sodium hydrogen bisulfite-lime on floatability of Cu²⁺  activated pyrite and chalcopyrite，the combining citrate acid-sodium hydrogen bisulfite-lime is used as inhibitor to make the flotation separation of artificially mixed ores of pyrite and chalcopyrite activated by Cu²⁺ Then，copper concentrate grading at 24.12% with an 88.48% Cu recovery and Sulfur concentrate grading at 49.69% with a 72.51% S recovery were obtained. It demonstrates that this combining inhibitor can realize selective inhibit effect on Cu²⁺ activated pyrite.

Key words: Pyrite, Chalcopyrite, Flotation separation, Combining depressor of citric acid-sodium hydrogen sulfite-lime