Abstract: In order to recover copper and cobalt from the leaching solution of sulfuric acid slag containing valuable metals such as iron and copper and cobalt,a hydrolysis precipitation method was proposed to remove iron from the leaching solution with high concentration of iron ions. The effects of the amount of oxidizing agent H2O2,oxidation time,titration temperature,pH value of titration end point and stirring time on the iron removal rate and the loss rate of copper and cobalt were systematically studied. The results showed that the optimal conditions for iron precipitation are H2O2 dosage of 5 mL,oxidation time of 2 h,titration temperature of 70 ℃ ,titration end pH value of 3. 0,stirring time of 1. 0 h. At this time,the removal rate of iron in the leaching solution is 91. 97%,and the loss rate of copper and cobalt are 12. 20% and 12. 04%,respectively. SEM-EDS and XRD analysis results showed that the calcium carbonate iron precipitation residue has a single phase,and the surface of the product is smooth with rod shape and irregular sheet. The main substances of the product are calcium sulfate dihydrate and goethite. In the process of iron removal,a small amount of Cu and Co are adsorbed by the precipitate,resulting in the loss of Cu and Co.

Key words: leaching solution containing copper and cobalt,hydrolysis precipitation method,iron removal,loss rate of copper and cobalt