Abstract:Composition of waste lead paste is complex, in which PbO2 is relatively stable and difficult to recycle. Sulfuric acid and oxalic acid were used to leach waste lead paste simultaneously. Effects of sulfuric acid concentration, oxalic acid addition and reaction time on sulfation of waste lead paste were investigated. The results show that 5 g waste lead paste is fully reacted under the conditions including 25 mL of 85% sulfuric acid, 1.5 g oxalic acid, and 2.0 h reaction time, respectively. Contents of PbO2 and PbSO4 in acid leaching lead paste are 1.39% and 95.76% respectively. Most of waste lead paste is converted into PbSO4 during simultaneous reduction and sulfation, which will shorten waste lead paste recovery process and reduce energy consumption. The subsequent desulfurization process can be more simple and efficient with this method. The obtained acid leaching lead paste can be recovered in form of lead oxide products by further desulfurization and low temperature roasting.