Abstract: The wet zinc smelting process produces a large amount of copper and cadmium slag， which is harmful to resources， environment and society. Taking copper and cadmium slag produced by a wet zinc Purification process in Guizhou as research object， the leaching conditions were studied by oxidizing acid leaching method. The results show that at the grinding fineness of 80% -0.075 mm， the mass ratio amount of hydrogen peroxide is 15% of copper cadmium， the ratio of liquid to solid is 4m L/g， the concentration of sulfuric acid is 20%， the leaching temperature is 75 ℃， and the leaching time is 4 h. Under the conditions， the leaching rates of valuable metals Cu， Zn and Cd in copper cadmium slag can reach 86.42%， 97.65% and 94.86%， respectively. The test results can provide reference for the comprehensive recovery of copper， zinc and cadmium from copper cadmium slag.

Key words: Copper and cadmium slag, Oxidation acid leaching, Valuable metals, Leaching rate