Decopperization mechanism of copper anode slime enhanced by ozone

Abstract

Ozone with outstanding oxidation capacity has tremendous potential to leach metals from anode slime. The leaching behavior of copper from copper anode slime under ozone was investigated under different conditions and compared with that under oxygen. The optimum leaching conditions are: the flowrate of ozone is 200 L/h, the H2SO4 concentration is 150 g/L, the temperature is 25 °C, the time is 100 min, the stirring speed is 500 rpm, the liquid-to-solid ratio is 3:1. Meanwhile, the leaching mechanism of copper from anode slime under ozone is proposed based on the form and the phase composition of the raw material and the leaching residue. All forms of copper in the raw materials are converted into CuSO4, Te2− into H2TeO4 and Se2− into SeO32− under ozone. Compared with oxygen, the leaching method under ozone significantly reduced the leaching temperature, the leaching time and consumption of sulfuric acid concentration. Therefore, the leaching under ozone has a promising application prospect in the treatment of copper anode slime and refractory leaching minerals.