Pressure leaching technique of smelter dust with high-copper and high-arsenic

The application of pressure leaching technology in the treatment of high-copper and high-arsenic dust was studied. The pressure leaching technique was determined as follows: the liquid to solid ratio (mL/g) of 5:1, the leaching temperature of 453 K, the retention time of 2 h, the initial sulfuric acid concentration of 0.74 mol/L, the oxygen partial pressure of 0.7 MPa, and the agitation speed of 500 r/min. Under these conditions, 95% of copper and 99% of zinc and only 6% of iron in the dust were leached, while about 20% of arsenic was also leached. The leaching technique was optimized further to restrain the leaching of arsenic by adding a small quantity of ferrous iron into the leaching system (c(Fe2+)=0.036 mol/L). Copper and zinc can be effectively separated from arsenic and iron in the leach. The optimal pressure leaching technique of high-copper and high-arsenic smelter dust is proved to be effective.