High-valued and deep utilization technology of copper slag

In order to achieve single recovery of Fe, Cu and Si in copper slag and deep removal of impurities in products, the activated reduction combining directional oxidation are adopted to improve the separation limit of target components, which mineral constituent as well as chemical composition at different stages are investigated through XRD and chemical analysis. Finally, a process of high-valued and deep utilization of copper slag is put forward. The fayalite in copper slag transforms into metallic iron and sodium silicate salt in the activated reduction process, after the following water-leaching and magnetic separation, about 76% of silicon dissolves into the leaching solution and the metallic iron powders with a recovery rate higher than 90% is obtained. The sodium silicate in leaching solution converts into amorphous silicic acid during carbonation process, and pure silicon dioxide is acquired through further acid leaching. Copper and arsenic enrich in metallic iron in the reduction process, and the impurities of carbon, sulfur and arsenic in iron can be deeply removed through directional oxidation by hematite. At the same time, copper is inert in coexistence with hematite and remains metallic state, which can be separated from iron through gravity separation. Finally, clean iron oxide, metallic copper and pure silicon dioxide can be obtained from copper slag.