α-PbO Recovery from Spent Lead Paste by Coalesced Reduction and Sulfur Fixation

Recycling end-of-life lead acid batteries is essential for the recovery of lead oxide (active material of new laboratory assembly) from spent lead paste. In this approach, a low-temperature coalesced reduction and sulfur fixation process was introduced for the extraction of lead oxide from spent lead paste followed by wet chemical conversion and immobilized sulfur which usually coincide with the release of sulfur oxides and lead particulates by using traditional recycling techniques. This technique offers a facile green lead extraction alternative for end-of-life lead acid batteries that is economical and environmentally benign. Herein, the phase conversion technique for PbO2/PbSO4 components and impurity contents of spent lead paste were studied. Furthermore, the CH3OH/KOH reaction system for the reduction/desulfurization of PbO2/PbSO4 was also explored briefly. Moreover, the metal impurities were efficiently removed, and 99/99.9% of the reduction/desulfurization efficiency of PbO2/PbSO4 was achieved. As compared to pyrometallurgy and conventional hydrometallurgy, this novel technique significantly shortens flow, reduces power consumption and secondary pollution, and is excellent for commercial applications.