China Nonferrous Metallurgy

In the process of zinc hydrometallurgy, iron powder replacement method is often used to remove copper and arsenic from acid solution containing copper arsenic.However, this method requiresn n_Cu∶n_As≥3∶1 in the solution to ensure the complete settlement of As. In the normal zinc hydrometallurgy,n_Cu∶n_As≥3∶1 in acidic solution containing copper and arsenic, the As deposition is not complete, and it is easy to produce toxic and harmful gases of hydrogen arsenide. A smelting enterprise produces copper residuum as by-product, containing 55%~60% copper, in the zinc smelting process. A method of adding copper residuum in the iron powder replacement process was proposed and verified by experiments. The results show that when the excess coefficient of iron powder is 1.5 times, without adding copper residuum, the removal rate of copper and arsenic is only 57.14% and 26.73% resp. The removal rate of copper and arsenic can reach 92.35% and 89.85% by adding 2g/L copper residuum. Under the conditions of better process parameters, reaction time 1h, temperature 80℃, copper residuum addition 2g/L, iron powder excess coefficient 1.5 times, the removal rate of copper and arsenic can reach more than 90%. This method can reduce the consumption of iron powder and reduce the production cost, which provides a reference for zinc smelting enterprises to deal with acidic solution containing copper and arsenic.