Research and prospect of gallium recovery technology in zinc smelting

Gallium is an important dispersive metal with widespread applications in high-tech fields such as semiconductor materials, optoelectronics, and radio technology. Recently, the market demand for gallium metal has grown, given the continuous progress of science and technology. Gallium is primarily recovered as a by-product of aluminum and zinc metallurgy, accounting for approximately 90% and 10% of the total gallium production. The relatively low production share derived from zinc metallurgy is because of the high recovery difficulty. In this study, various technological routes for gallium extraction from zinc metallurgy are summarized with detailed analyses based on technological and economic perspectives. During closed blast furnace zinc smelting, >95% of Ga is enriched in water-quenched slag with an average mass fraction of 0.025%–0.031%. Several methods for extracting Ga from the slag are proposed, including reduction evaporation, chlorination volatilization, sulfuric acid leaching, caustic fusion–leaching,