Abstract: Aimig at the low leaching rate of the traditional ammonium leaching process,the oxidizing ammonium leaching process of extracting cadmium,zinc,and copper from copper-cadmium slag is adopted.The effect of copper-cadmium slag was studied by orthogonal tests in laboratory in order to find out the optimum ammonia leaching conditions with oxidants.The optimum conditions obtained are as follows:ammonia concentration 3.7 mol/L,ammonium ion concentration 5.0 mol/L,(NH₄)₂S₂O₈ concentration 30 g/L,and liquid to solid ratio 6∶1.Under the optimum conditions,the leaching rate of Cd and Cu can reach 99%,and at the same time the leaching rate of Zn and Cd can reach 96%.The leaching rate of the oxidizing ammonium leaching process is obviously higher than that of the traditional ammonium leaching process.

Key words: copper-cadmium slag, oxidizing ammonium leaching, cadmium, zinc, copper