METHOD OF PROCESSING LEAD-ZINC WASTES CONTAINING TIN AND COPPER Russian patent published in 1999 - IPC

FIELD: recovery of lead from fine dusts, cakes and drosses containing zinc, tin and copper. SUBSTANCE: method includes charging and smelting of initial material with carbonic reducing agent in the presence of salts of alkali and alkali-earth metals at temperature of 880-1160 C for 2-4 h, withdrawal of lead alloys, cooling and trapping of zinc sublimates. In this case, reducing agent-total amount of main metals weight ratio is maintained equal to (0.3-0.6): 1 and carbonate melt-charged wastes weight ratio is (7.5-20): 1. To provide for maximum recovery of tin and copper into lead alloy, content of carbon in reducing agent shall be at least 0.4 and not above 0.6 of total content of main metals in wastes. To provide for maximum recovery of zinc into sublimates, melt temperature is maintained within 1100-1160 C. EFFECT: higher degree of recovery of lead and zinc, simplified process due to reduction of a number of stages. 4 cl, 1 tbl