Pressure oxidative leaching of lead-containing copper matte

The pressure oxidative leaching of lead-containing copper matte is studied systematically. The effects of leaching time, oxygen partial pressure, leaching temperature, agitation speed, acid addition and initial Cu(2+) concentration on the extraction of copper and iron are investigated. The effect of initial Cu(2+) concentration is insignificant compared to the other reaction parameters. The best found conditions are: leaching time 2 h, oxygen partial pressure 0.8 MPa, acid addition 80% of matte mass, temperature 150 +/- 5 degrees C and agitation speed 600 rpm. Under these conditions, >95% Cu is extracted with the concentration of iron in solution <5 g/L and the yield of sulfur is 20-30% of total sulfur mass. The leach residue is about 30% of the initial mass and the recovery of lead and silver is close to 100% and 98% respectively. (C) 2008 Elsevier B.V. All rights reserved.