Separation and recovery of Cu and As during purification of copper electrolyte

Cu, As, Sb and Bi in copper electrolyte could be efficiently removed by reducing with SO2 followed by evaporative crystallization. As2O3 and CuSO4·5H2O were obtained after crystallized product was treated by dissolution, oxidation, neutralization, sedimentation, filtration and evaporative crystallization. The removal rates of Cu, As, Sb and Bi are 87.1%, 83.9%, 21.0% and 84.7%, respectively, when As (V) in copper electrolyte is fully reduced to As (III) by SO2, and the H2SO4 in concentrated copper electrolyte is 645 g/L. The removal rate of As is 92.81% when 65 g crystallized product is dissolved in 200 mL water at 30°C. The CuSO4·5H2O content is 98.8% when the filtrate is purified under the conditions that n(Fe):n(As) is 1.2, the dosage of H2O2 is 19 times the stoichiometric needed, temperature is 45°C, time is 40 min, pH is 3.7, and then is evaporation crystallized.