Sustainable Mining and Metallurgy

The content of manganese, lead and silver in zinc electrolysis anode slime of zinc smelting system is high, which has high recovery value. The indium extraction waste liquid of the indium recovery system is generally discharged after the sewage treatment process reaches the standard. The heavy metal ions such as iron, manganese and zinc enter the gypsum slag through the sewage treatment process and occupy a large amount of land resources. Based on the reducibility of Fe²⁺ ions, this paper proposed to use Fe²⁺ ions in the indium extraction waste liquid to react with manganese in the anode mud of zinc electrolysis to comprehensively recover manganese, lead and silver in the anode mud, and then used fresh wet copper slag and copper sulfate to dechlorinate, and used aluminum sulfate and calcium hydroxide to defluorinate, comprehensively recycle the indium extraction waste liquid and save the treatment cost of the indium extraction waste liquid. The experimental results show that the recovery rate of manganese can reach more than 98% under the conditions of temperature 80℃, leaching reaction time 3h, anode mud addition amount 0.8 times of the theoretical amount. The wet copper slag and copper sulfate were stirred at 60℃ for 2h to dechlorinate, and the dechlorination rate reached 91.86%. Appropriate amount of aluminum sulfate and calcium hydroxide were added to the dechlorination solution. Under the conditions of filtrate pH 5.2~5.4, temperature 60℃ and reaction time 45min, the defluorination rate reached 93.44%. The dechlorination and dechlorination solution met the process requirements of zinc hydrometallurgy electrolysis process.