Shandong Gold Smelting Co.,Ltd.uses cyanidation and zinc powder replacement process to treat high copper and lead content gold concentrate,however,the gold replacement rate greatly decreases and replacement pipelines are seriously plugged in production.In view of these problems,analysis of influence factors of replacement and flowsheet investigation are carried out,determining the main reason to be excessive lead content,and correspondingly,lead removal test is carried out.Industrial application results show that Na2S precipitation of lead can effectively strip the pregnant solution of lead,ensuring replacement index; with Na2S added,the lead concentration in pregnant solution can be reduced to below 100 mg/L and the gold replacement rate increases from 70 % to 95 %.At the same time,the plugged replacement pipeline is effectively mitigated.