Abstract: For a Pb-Zn-Ag polymetallic sulfide ore of Jiangxi, lead mainly occurs in galenite, zinc mainly occurs in sphalerite, silver mainly exists in the forms of affonite, argentite and pyrargyrite and is closely associated with galenite.In order to rationally explore the mineral resources, the beneficiation researches were made.The results showed that under grinding fineness of -0.074 mm 78%, and alkaline conditions of pH=11 when lime formed, with diethyldithiocarbamate + ammonium dibuyldithiophosphate as the combined collector for lead-silver minerals, ZnSO₄ + Na₂SO₄ as inhibitor for zinc mineral to preferentially concentrate lead and the associated silver minerals, copper sulfate as activator for lead-silver tailings flotation, and butyl xanthate as collector for sphalerite flotation, lead concentrate with grade of 57.05% and recovery of 88.11%, and zinc concentrate with grade of 48.31% and recovery of 86.29% were obtained respectively.Total silver recovery reached 87.99% from lead and zinc concentrates.

Key words: Pb-Zn-Ag sulfide ore, Lead-zinc sequential flotation, Diethyldithiocarbamate+ammonium dibuyldithiophosphate combined collector, Zinc sulfate sodium sulfite combined depressants