Abstract: In order to solve the cyclic utilization problems on waste water in a lead zinc plant in Gansu，effect of natural purification treatment was explored，and the influences of different flocculants on the treatment efficiency of waste water are contrasted.Further study on the process parameters of activated carbon reprocessing was conducted based on the optimum process parameters using PAM，finally，the product index of treatment using wastewater both before and after purification and the tap water was compared.The results show that ①water quality improvement significantly by using PAM flocculation + activated carbon adsorption to treat wastewater，the reduction of solid suspended solids was 81.43%;the CODCr reducing rate is 74.56%；the Cu2+ reducing rate is 90.16% and Pb2+，Zn2+，Fe3+ removal rate was up to 93%；②treatment of ore by using purified wastewater，the indexes of lead concentrate and zinc concentrate were better than those of untreated wastewater，with the use of tap water production indicators have small differences.So，the purified wastewater return to production is completely feasible.

Key words: Bulk Lead-zinc ore, Dressing waste water, PAM Coagulating sedimentation, Activated carbon adsorb