China Nonferrous Metallurgy

Silver separated slag is the remaining tailings of copper anode slime extracted major precious metals. Daye Non-ferrous Metals Co., Ltd. produces about 2000 tons of silver separated slag each year. In order to recover valuable metals, the company designed a segmented comprehensive recovery process. After the smelting, water crushing and leaching processes of silver separated slag were completed, the average direct yields of lead, bismuth, antimony, tin, gold, silver, platinum, palladium and tellurium were 93.65%, 95.42%, 95.28%, 90.66%, 99.07%, 98.39%, 96.15%, 90.13% and 95.65%. The average grade of crude calcium stannate was 12.03%, and the average direct yield of tin in the tin precipitation test was 97.01%.The refining test of tin showed that the average tin content in acid-washed calcium stannate was 15.97%, and the average direct yield in silver separated residue was 81.57%. The average antimony content of crude sodium antimony is 44.56%, and the average direct yield of antimony in the antimony precipitation test is 94.97%.The refining test of crude sodium antimony showed that the grade of sodium antimony was 51.3%, and the average direct yield of antimony in the silver separation slag was 82.63%. The direct yields of gold, silver, lead, bismuth, platinum and palladium in precious lead are 98.01%, 97.57%, 86%, 83.44%, 80% and 79.98%, respectively. The direct yield of tellurium in slag is 85.03%. Under this process condition, the whole production process was carried out in alkaline and reductive environment, and there was no harmful gas overflow in the smelting process. The benefit of CNY 40739.5 can be achieved by processing 1ton of silver separated slag.