Abstract: In order to develop and utilize the sulfur-oxygen mixed lead-zinc ore in Burma， the mineral processing experiment was carried out based on the study of process mineralogy. The results showed that the raw ore contains lead 4.70%， zinc 5.51%，and silver 150.66 g/t， and the major impurity is SiO₂ with the content of 30.45%， followed by CaO and MgO. The oxidation rate of lead mineral and zinc mineral are about 22% and 17%， respectively. Lead mainly exists in the form of galena， followed by cerusite and zinc mainly exists in the form of sphalerite， followed by smithsonite. One roughing-one scavenging-two cleaning process was adopted to select lead preferentially and one roughing-one scavenging-three cleaning was adopted to select zinc. With the grinding fineness of -0.074 mm accounting for 80%， silver-rich lead concentrate with lead grade of 61.25%， silver grade of 1 791.53 g/t， lead recovery rate of 91.24%， silver recovery rate of 82.94%， zinc content of 4.43% and zinc recovery rate of 5.63% was obtained. Meanwhile， zinc concentrate with zinc grade of 50.86%， silver content of 174.25 g/t， zinc recovery rate of 88.68%， silver recovery rate of 11.07%， lead content of 2.39% and lead recovery rate of 4.88% was obtained， which indicated better separating indexes.

Key words: Sulfur-oxide mixed lead-zinc ore, Preferential flotation, Vulcanization-xanthate