Study on copper extraction from refining slag of copper smelting anode furnace

The combination of pyrometallurgy and hydrometallurgy processes, including oxidation leaching by waste acid, CaO roasting leaching slag and oxidation leaching product of roasting by waste acid, were applied to extract copper from the refining slag of copper smelting anode furnace. Detailed studies were conducted on the effects of leaching temperature, liquid-solid ratio, leaching time, and air flow on the leaching rates of Cu, Fe, As, as well as the calcination temperature, time, and mass ratio of leaching slag to CaO (m(slag)/m(CaO)) on the leaching rates of Cu, Fe, As, when waste acide is directly oxidized to leach refining slag. The results show that during the direct oxidation leaching of waste acid, the leaching rates of Cu, Fe and As are respectively 85.32%, 68.41%, and 44.97%, under the conditions of a leaching temperature of 90 ℃, liquid-solid ratio of 9 mL/g, time of 4 h, and air flow per liter of solution of 200 mL/min. After being mixed with CaO, the leaching slag is baked at temperature of 800 ℃, time of 4 h, and the mass ratio of leaching slag and CaO of 5.1. The resulting baked sand is leached by waste acide oxidation, and the total leaching rates of Cu, Fe and As can reach 98.10%, 69.60% and 50.48%, respectively.