Hydrometallurgical Pretreatment Process for the Recovery of Valuable Metals from the Lead Anode Slime

Abstract

After stacking pre-oxidation treatment, lead anode slime was leached in sulfuric acid added with sodium chloride and oxidant of sodium chlorate. The leaching rates of As, Te, Sb, Bi and Cu are more than 98% with potential controlled at 500mV. And noble metals are left in the residue, which are separated from the base metals effectively. Through cooling and crystallizing out arsenate, the solution is reduced with potential controlled. According to reducing slag, the recovery rate of Te is 96.52%. Sb is recovered by neutralizing hydrolysis and the recovery rate is 95.2%. By the effect of iron powder, As, Bi and Cu are entirely reduced with the recovery rates of Bi and Cu to be 91.56% and 83.49%, respectively. The total recovery of As from the crystalline product and reducing slag achieves 91.56%.