Abstract:Conventional pyrometallurgical processes can directly reduce PbO2 directly to lead, however, this requires high temperature conditions and is easy to cause problems such as lead volatilization. Although hydrometallurgy can efficiently reduce PbO2 to divalent lead compounds at low temperatures, it requires the consumption of strong acids and reduction reagents. A green conversion method of PbO2 was proposed, which utilized (NH4)2SO4 decompose into NH4HSO4 at low temperatures to reduce PbO2 to PbSO4. The results indicate that the reaction process between NH4HSO4 and PbO2 will generate the intermediate product Pb(NH4)2(SO4)2. The reduction rate of PbO2 is 96.64%, and PbSO4 content of the roasting product is 96.38% under the optimum conditions for the reaction of spent lead paste with (NH4)2SO4 including molar ratio of n(SO42-)/n(TPb)=1, roasting temperature of 340 ℃, and roasting time of 1.5 h.