Research On New Technology For Comprehensive Recovery Of Valuable Metals From Copper Anodes

2016 domestic copper accounted for 21.0%of the total output of electrolytic copper,compared with 2010 decreased by 16.5%.As the domestic scrap copper and electrolytic copper difference narrowed,scrap copper in the smelting enterprises to reduce the cost advantage.Compared with ordinary copper anodic mud,the content of Pb,Sn,Cu and Ag in the main metal is relatively high,but it does not contain the rare element Se,Te.So the comprehensive recovery of valuable metals which have a very important significance,while enabling enterprises to produce better economic benefits.In this paper,the combination of fire method and hydrometallurgical process is used to treat miscellaneous copper anode slime.Firstly,the thermodynamic analysis of carbothermal reduction,vacuum evaporation and sulfuric acid leaching is analyzed theoretically.The theoretical analysis shows the feasibility of carbothermal reduction,vacuum evaporation and sulfuric acid leaching.The experimental study on the preparation of copper,such as sodium pyrolysis,vacuum evaporation,atmospheric sulfuric acid leaching,and sodium thiosulfate were carried out.(1)Pb and Sn were mainly PbSO4 and SnO2 in the raw materials.The dried miscellaneous copper anode mud and reductive carbon were mixed evenly and pressed at a pressure of 3 MPa of a tablet press.The tablets were placed in a graphite crucible in a muffle furnace,with a carbon content of 12.7%,a reduction time of 60 min and a reduction temperature of 1200℃.Pb reduction rate can reach 85.26%;Sn reduction rate can reach 85.35%;Cu reduction rate can reach 82.84%;Ag content can reach 9.78%,enrichment 2.22 times;Au content can reach 420g/t,enrichment of 2.23 Times.(2)Carbothermal reduction products in the volatile temperature of 1050℃,the evaporation time 75min under the conditions of vacuum evaporation.Pb volatilization rate can reach 95.46%;SnS volatilization rate can reach 91.7%;Cu residual rate can reach 98.57%;The Ag content in the residue was enriched from 9.78%to 25.94%,the enrichment rate was 2.65 times,which was 5.88 times higher than that of the raw material.Au content from 420g/t enrichment to 1100g/t,enrichment rate of 2.62 times,compared with the raw material enrichment 5.85 times.(3)During the leaching process,the leaching rate of Cu was up to 5 times when the amount of sodium chlorate was 5 times,the concentration of sulfuric acid was 3mol/L,the stirring speed was 300r/min and the liquid-solid ratio was 5,80℃ for 2h 94.4%.(4)Sodium thiosulfate in the process of copper,the amount of sodium thiosulfate for the theoretical amount of 6 times,leaching temperature of 80 ℃,leaching time 2h,stirring speed 300r/min,Cu removal rate can reach 99.3%.