Selective recovery of silver from an acidic solution by cementation with copper

Abstract

An acidic solution containing 280 mg/l silver and others was treated. In order to selectively recover silver without losing other metallic elements from the solution, cementation was adopted with metallic copper. The kinetics of cementation reaction and copper dissolution and mechanism of copper consumption were studied. The results indicated that the rate of cementation reaction and copper consumption were markedly increased with the increase of temperature. For the same cementation recovery of silver, copper consumption at elevated temperature was much higher than that at ambient temperature. Cementation rate and copper consumption rate also increased with the increase of stirring velocity, while copper consumption at different stirring velocity for the same recovery of silver was almost not different. Studies on the chemical mechanism of copper consumption showed that Fe³⁺ and residual leaching additive RH in the solution were the main factors that caused extra copper consumption in acidic solutions.