Abstract:A very low-grade lead-zinc silver mine in Gansu Province has lead grade of 0.96%, lead oxidation rate of 37.50%, zinc grade of 0.76%, zinc oxidation rate of 32.88%, and silver grade of 207.66g/t. Silver mainly exists in the form of Silver-Antimony-Copper and coexists with galena. According to the properties of the ore, lead concentrate is produced by preferential flotation, lead-zinc concentrate by mixed flotation, and silver is enriched in lead concentrate and lead-zinc concentrate .The new collector GH is used to select lead through closed-circuit text .Lead concentrated with lead grade of 55.71%, recovery rate of 20.73%, silver grade of 7476.81g/t and recovery rate of 14.39% was obtained by closed-circuit test. In closed-circuit mixed flotation，Lead-zinc concentrate was also abtained . Lead-zinc concentrate with lead grade of 17.61%, recovery rate of 37.47%, zinc grade of 23.64%, recovery rate of 65.67%, silver grade of 5593.42g/t and recovery rate of 59.49% was also abtained by closed-circuit test. The lead grade of lead-zinc concentrate is 17.61%, the recovery is 37.47%, the zinc grade is 23.64%, the recovery is 65.67%, the silver grade is 5593.42g/t, the recovery is 59.49%. Good flotation index has been obtained in this experiment, and the associated silver was also recovered. Associated silver minerals was enriched, and low-grade minerals were also recycled efficiently.