Abstract: Aimed at the problems that the former beneficiation process can not adapt the nature of the ore and cyanide addition in the process for a lead-zinc-silver mine in Sichuan, another flotation test on this ore was made.The results showed that: under the grinding fineness of -0.074 mm 85%, and with lime as adjusting agent, zinc sulfate+sodium sulfite as inhibitor, diethyldithioc butyl xanthate as collector to concentrate zinc, lead concentrate with grade of 51.80% and lead recovery of 64.75% and zinc concentrate with grade of 53.55% and recovery of 91.83% were obtained separately.The total recovery of silver in lead and zinc concentrates reached 83.75%.The tests realized higher recovery of lead, zinc and silver and adopted cyanide-free process, comparing with the on-site process.

Key words: Lead-zinc-silver sulfide, Lead-zinc sequential flotation, Zinc sulfate sodium sulfite combined depressants, Cyanide-free process