Abstract:The properties and flotation tests of a mixed lead-zinc ore with high weathering sandstone containing 0.88% lead and 4.61% zinc were carried out. Among them, lead minerals are distributed in pyrite, sphalerite and quartz spaces with extremely fine grains, which are difficult to concentrate and recover. The KM collector with strong collecting ability and conventional flotation reagent with no toxicity and little environmental pollution is adopted,Optimizes the way to add, The separation of zinc closed circuit flow through two coarse and three precision three scavenging processes, The beneficiation indexes of zinc concentrate yield 8.26%, grade 45.78% and recovery rate 83.27% were obtained.