Abstract:Purification-replacement process was applied to treat chlorination leachate of Pb-Ag residue to extract silver and lead. Technological influence conditions of replacement of silver with lead powder and replacement of lead with iron powder were studied. The results show that Fe3+ is easy hydrolysis and iron is removed by neutralization. Iron can be completely removed by adjusting pH value of solution to 4.0 with lime. Replacement rate of silver is 98% above with residual silver concentration in solution of 1 mg/L below under the conditions including dosage of lead powder of 6 g/L, pH value of 1.5-2.5, temperature of 60 ℃, and replacement time of 40-60 min. Lead in solution can be replaced by two-stage countercurrent process. The comprehensive replacement rate of lead is 87.08%, and lead content in final replacement product is 90% above, which meets requirements of refining.