Abstract: In view of high content of organic carbon even existing in aphanitic form and fine dissemination size of lead-zinc sulfide ore，beneficiation tests on the ore is carried out by the process of pre-flotation decarbonization after grinding-Pb-Zn-S sequential flotation-regrinding of lead and zinc coarse concentrate for cleaning concentration，and adding high efficient inhibitor of carbon called iron-chromium lignosulfonate in the lead cleaning process. Through the process above，lead concentrate with Pb grade of 53.67 % and Pb recovery of 56.93%，zinc concentrate with Zn grade of 44.64% and zinc recovery of 83.19%，and sulfur concentrate with S grade of 36.89% and sulfur recovery of 59.11% was obtained separately，thus providing a basis for the development of the ore.

Key words: Carbon-bearing low-grade lead-zinc sulfide ore, Pre-decarbonization, Lead-zinc-sulfur sequential flotation, Regrinding of coarse concentrate, Ferri-chrome lignosulfonate