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 Cu2+ concentration on the extraction of copper and iron are investigated. The effect of initial Cu2+ 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 °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.