China Nonferrous Metallurgy

The Pb-Ag residue resulted from hydrometallurgical zinc leaching was studied to recover lead, zinc, carbon, silver, iron and other valuable metals through the combined process of metallurgy-ore beneficiation. The results showed that the direct volatilization yields of lead and zinc were 98.85% and 97.60% respectively when the reductive roasting temperature was 1200℃, the duration was 60minutes, the proportion of coke powder reductant was 40% and the proportion of added lime was 4%; the grades of carbon concentrate, silver concentrate and iron concentrate reached 71.58%, 548.10g/t and 70.55% respectively, and the recovery rates of carbon, silver and iron reached 95.29%, 91.2% and 40.71% respectively by adopting the process comprising carbon roughing-carbon cleaning, silver roughing-silver cleaning, and magnetic separation of iron of the modified roasting slag; and the resource recovery and utilization of lead, zinc, iron, silver in Pb-Ag residue and carbon in harmless-treated tailings was realized through this process.