Study On Flotation-Metallurgy Process Of Copper Anode Slime With High-Lead

The copper anode slime contains abundant valuable metals, such as gold and silver. Recovering the valuable metals has already been a hot area of research. However, the conventional treatment processes of copper anode slime are backward and need to enhance, due to the low recovery of valuable metals and the great environmental damage. This paper applied the flotation-metallurgy process to treat the copper anode slime with high-lead. The composition of raw material and acid leaching slag were tested and the process conditions of extracting copper and selenium were studied. And then the best conditions of subsequent flotation process were studied. In order to advance the recovery rate of precious metal, the wet dilution process of flotation tailings was also conducted by using the sodium chlorate and thiourea.Technological mineralogy studies shows that the major elements of copper anode slime are gold, silver, copper, selenium and lead, and their content were0.17%,7.73%,13.38%,2.61%,11.18%, respectively. The major mineral constituents are CUSO4·3H2O, BaSO4, PbSO4, Ag2Se. After the pretreatment processes of removing selenium by roasting and acid-leaching copper, the copper and selenium in the leaching slag were reduced from13.38%to0.32%and from2.61%to0.007%, respectively. And the grade of gold and silver were concentrated from0.17%to0.38%and from7.73%to14.56%, respectively. The major mineral constituents of acid leaching slag were AgCl, PbSO4and BaSO4.From the research of flotation process, the optimized conditions are obtained as followed, pH value of slurry was6, the dosage of xanthate was2.86kg·t-1, the dosage of sodium hexametaphosphate was5kg·-1, the time of flotation was2.5min, slurry density was25%. The recovery of gold and silver were89.74%and97.09%, respectively.After the dilution process of flotation tailings with the sodium chlorate and hydrochloric acid leaching, the recovery of gold was91.86%. And its recovery rate turned to95%with the sodium chlorate and sodium chloride leaching the tailing. And using the thiurea to leach the tailing, the recovery of gold was93.86%. After the flotation-metallurgy process of copper anode slime, the recovery of copper, gold, selenium were99.98%,97.49%and91.34%respectively.