Abstract: Main valuable elements of a polymetallic sulphide ore in Southwest China is mainly copper, tin and sulphur with grade of 1.05%, 0.28% and 7.19%, respectively, associated silver grade is 13.20 g/t. Copper mainly exists in form of copper sulfide, accounted for 93.60%. Copper and sulphur bulk flotation-copper and sulphur separation, tin concentration from tailings of flotation by shaking table was used by on-site process, all of copper, sulfur, silver and tin were comprehensively recovered (silver went with copper). The process comes with large consumption of lime, high alkalinity, low recovery of copper and silver. In order to find the possibility of effective recover copper and silver with low alkalinity, compound new type ZA collector for copper mineral flotation collector were studied The results show that: copper-sulphur rough concentrate can be obtained at the grinding fineness of 75% passing 0.074 mm, with copper sulfate as activator, butyl xanthate as collector, via one roughing, two cleaning, two scavenging copper-sulphur bulk flotation. After reground the rough concentrate to 85% -0.043 mm, using compound collector ZA as copper collector, lime as inhibitor, with low alkalinity conditions of pH=10.5 through one roughing, three cleaning, three scavenging copper and sulphur separation process, copper concentrate assaying 25.16% Cu and 212.2 g/t Ag at the recoveries of 91.75% and 61.18%, respectively; and the sulphur concentrate containing 35.32% S and recovery of 79.06% can be obtained. The results realize the separation and enrichment recovery of copper, sulphur and silver in the ore, especially intensify beneficiation enrichment of free silver. The test results can provide technique basis for beneficiation of minerals associated precious metals.

Key words: Copper-tin-silver-sulfur mine, Low alkalinity, High selective collector ZA of silver and copper , Copper and sulphur separation