Decomposition behaviour of PbSO4 during lead acid battery paste recycling process

This work summarizes shortly the current lead-acid battery (LAB) recycling technologies, and proposes a cleaner and environmentally friendly LABs recycling process: a reductive sulphur-fixing recycling method. The dissociation behaviour of PbSO4, the main component in lead paste, during this new recycling process was investigated in detail. The phase transformation mechanisms during PbSO4 dissociation at Ar and air atmosphere were detected, respectively, with the help of thermogravimetric analysis (TG-DTA) and X-ray diffraction analysis techniques. Moreover, the gaseous dissociation products were separated, collected and analyzed. The investigation revealed that PbSO4 decomposition degree and partial pressures of gaseous products (SO3and SO2) in Ar were higher than in air atmosphere. Furthermore, partial pressure of SO2, (Pso2) was, generally, higher than (Pso3). In other words, increase of temperature promoted the dissociation of PbSO4.