Abstract:The smelting slag produced in the process of copper smelting contains more copper, cobalt and other valuable metals, and recovering these valuable metals from smelting slag has important economic value and environmental protection significance. Cobalt-rich copper smelting slag with Cu content of 8.260% and Co content of 1.515% was taken as raw material and treated by pre-leaching-oxygen pressure leaching process. The effects of acid-ore ratio, reaction temperature, reaction time, oxygen partial pressure and liquid-solid ratio on leaching rate of Co, Cu and Fe were studied systematically. The leaching rate of Co, Cu and Fe is 98.38%, 95.34% and 2.07%, respectively under the optimum process conditions including liquid-solid volume mass ratio of 3, reaction temperature of 230 ℃, reaction time of 1.5 h, acid-ore ratio of 350 kg/t, 75% of grinding fineness —0.074 mm, and oxygen partial pressure of 0.2 MPa. Compared with the atmospheric pressure leaching, this process can effectively reduce the acid consumption and the concentration of ferric ions in the leaching solution.