Abstract: When iso-flotation process is adopted for the flotation of lead-zinc sulphide ore in Guangxi,large amount of collectors are adhered to the surface of lead-zinc bulk concentrate.Zinc ore are hard to be depressed when its surface adhered by collectors in the followed lead-zinc separation process.In order to improve the separation effect of lead and zinc,remove collectors adhered to the surface of zinc minerals was conducted.The lead-zinc separation effects by the separated reagent removal and combinative reagent removal of sodium sulfide,activated carbon and mechanical grinding was studied.The results show that the sodium sulfide is the best reagent while the activated carbon is the worst.In the combinative reagent removal,the combination of sodium sulfide and activated carbon is the best one.When the dosage of sodium sulfide and activated carbon is 5 000 g/t and 400 g/t respectively,the lead rough concentrate with the grade of lead is 25.47% and the recovery rate of lead is 90.18%,the grade of zinc is 5.13% and the recovery rate of zinc is 9.61% was obtained.Therefore,a proper combination mode can improve the effect of reagent removal and promote the separation of iso-flotation lead and zinc bulk concentrate.

Key words: Lead-zinc sulfide ore, Sodium sulfide, Activated carbon, Mechanical grinding, Reagent removal