Research on Comprehensive Recovery and Harmless Treatment Process of Copper Smelting Slag

Taking copper smelting slag as raw material, and anthracite and quartzite as additives, the research on comprehensive recovery and harmless treatment of copper smelting slag is carried out by using a 120 kW submerged arc furnace. Theoretical analysis shows that when the temperature is increased from 1200 to 1450 °C, the slag viscosity decreases from 0.283 Pa s to 0.033 Pa s. In the range of 1300–1450 °C, selective reduction can be used to comprehensively recover Cu, Pb, Zn, Sb and other valuable metals in the slag and deeply remove arsenic(As) from the slag. The reduction ability of C is better than that of CO. The results show that addition of quartz can effectively reduce the copper content in the final slag. Under the conditions of holding temperature, quartz content, anthracite content and holding time, 1450 °C, 5%, 10% and 120 min, respectively, Zn volatilizes and gets oxidized, in the same time Cu settles and gets enriched in matte, and the contents of Cu, Pb, Zn, Sb and As in the final slag are reduced to 0.31, 0.043, 0.12, 0.0045 and 0.0014%, respectively. The copper in the final slag mainly exists as sulphide droplets, and arsenic in copper matte is mainly distributed in the region where metallic iron exists.