Abstract:Gallium concentrate obtained from zinc hydrometallurgy is an important intermediate product for the preparation of gallium metal, and the efficient leaching of gallium concentrate with sodium hydroxide for the preparation of electrowinning precursor is a key production link for the preparation of high quality gallium metal. The effects of various technological parameters on leaching rate of Ga and Al and the filtration performance of leachate were analyzed through studying the kinds of additives, amount of additives, concentration of sodium hydroxide, ratio of liquid to solid (L/S), reaction temperature and leaching time during the leaching process of gallium concentrate.The results show that under the optimum conditions including 15% CaO as additive, NaOH concentration of 3 mol/L, L/S=10, leaching temperature of 80 ℃ and leaching time of 120 min, the leaching rate of Ga and Al is 98.15% and 53.01% respectively, and the filtration rate of leachate is 108.88 mL/min. The calcium aluminate produced by additive CaO in the reaction process is used as the supporting skeleton of filter cake, which effectively improves the filtration performance of leachate