Abstract: The content of pyrite in a lead-zinc ore from Inner Mongolia increased with the deep of mining, of which the sulfur was close to 30%. There for, on the basis of technological mineralogy study of newly mining raw ore, the processing test was carried out, to provide technical basis for determination of the rational processing flow in the processing plant. The results showed that the major elements of the ore are lead, zinc and sulfur with 7.56% Pb and 23.35% Zn. Lead and zinc are mainly in form of sulfide ores and the main useful minerals such as galena, sphalerite and pyrite are coarse-grained. With the grinding fineness of -0.074 mm 70%, using ZnSO₄ as inhibitor, ethyl xanthate as collector and 730A as frother, iso-flotation of lead-zinc-sulfur by one roughing, two scavenging process. Zinc concentrate 1 was got from iso-flotation tailings using CuSO₄ as activator, butyl xanthate as collector and 730A as frother via one roughing, one cleaning and one scavenging process. Lead concentrate was got from iso-flotation concentrate using CaO as inhibitor, sodium diethyl dithiocarbamate as collector via one roughing three cleaning and one scavenging process. Zinc concentrate 2 and sulfur concentrate were got from lead tailings using CuSO₄ as activator, butyl xanthate as collector and 730A as frother with one roughing, one cleaning and one scavenging process. Zinc concentrate 1 and zinc concentrate 2 were mixed as zinc concentrate. Finally lead concentrate with 59.26% Pb and recovery of 88.73%; zinc concentrate 52.21% Zn and recovery of 94.95%; sulfur concentrate with 48.71% S and recovery of 48.93% was finally obtained. The test results can provide technical basis for exploring and utilization of the high sulfur Pb-Zn ore in the deep ore body.

Key words: High sulfur Pb-Zn ore, Galena, Sphalerite, Iso-flotation process