钙盐脱铝-树脂吸附法从镓电积贫液中选择性分离镓铝OA

Gallium,as a strategic rare metal,is often associated with elements such as zinc and aluminum.In the oxygen-pressure zinc hydrometallurgical system,gallium is typically recovered through a leaching-enrichment-extraction-electrowinning process.The gallium concentration of the depleted solution after electrowinning is generally 5～10 g/L.The aluminum concentration can reach as high as 25 g/L,and the accumulation of recycled aluminum increases the burden of gallium electrowinning and reduces gallium quality.For this reason,this study designed a calcium oxide de-alumina-resin(ZGD887)adsorption of gallium de-alumina/gallium-rich double-effect process,with the gallium electrowinning depleted solution provided by an enterprise as the raw material,to explore the optimal conditions of calcium oxide de-alumina,and examined the effect of adsorption conditions on the gallium performance of the resin adsorption of de-alumina solution after the performance of gallium.The results showed that calcium oxide could induce the conversion of aluminum to calcium aluminate hexahydrate in the electro-gallium depleted solution,thereby achieving aluminum removal.Under conditions of a temperature of 90℃,a reaction time of 120 min,and twice the theoretical mass of calcium oxide,the precipitation efficiency of aluminum reached 92.44%and the loss efficiency of gallium was only 12.60%.Then,under adsorption conditions of 30℃,resin dosage of 0.1 g/mL,and oscillation rate of 250 r/min,the total recovery efficiency of gallium reached 83.05%after four adsorption cycles.By applying the calcium salt de-aluminized resin adsorption method,the aluminum removal rate was 92.44%and the comprehensive gallium recovery rate was 72.59%,achieving open-circuit of aluminum in the electro-gallium lean solution and efficient enrichment of low-concentration gallium.