Separation of As and Bi and enrichment of As, Cu, and Zn from copper dust using an oxidation-leaching approach

[Display omitted] Copper dust with high arsenic content is a hazardous waste that should be treated properly. Herein, the copper dust is oxidized, leached, and separated at room temperature and atmospheric pressure. To separate As and Bi, part of As(III) in copper dust is oxidized to As(V), so that most of the As, Cu, and Zn elements enter the solution and the Bi remains in the leaching residue. Also, the influence of several factors, such as H2SO4 dosage, H2O2 dosage, liquid–solid ratio, leaching temperature and leaching time, on the leaching percentage of As, Bi, Cu, and Zn is systematically investigated. The optimal conditions are obtained as follows: liquid–solid ratio of 3:1, H2O2 dosage of 10 ml/50 g (dust), H2SO4 dosage of 4.5 ml/50 g (dust), leaching temperature of 85 °C, and leaching time of 3 h. Under these conditions, the leaching percentage of As, Cu, Zn, and Bi is found to be 97.39%, 96.11%, 97.32%, and 2.40%, respectively. For further recovery of As from the leaching solution, the one-step recycle leaching of the leaching solution is performed to increase the concentration of As in the recycled leaching solution. The concentration of arsenic in the recycling leaching solution is found to be 79.63 g·L–1, which is beneficial for the study on further recovery of As2O3.