A novel process combined with flue-gas desulfurization technology to reduce lead dioxide from spent lead-acid batteries

The study presents a novel lead dioxide reduction process which combined with flue-gas desulfurization technology to recover lead from lead-paste in the spent lead-acid batteries. With three different reducing agents, i.e. hydrogen peroxide(H2O2), sodium sulfite(Na2SO3) and sodium bisulfite(NaHSO3), reduction of lead dioxide(PbO2) under the same condition were studied comparatively. Synthesizing each kind of factors, NaHSO3 was selected as the optimum lead dioxide reducing agent, and sodium sulfate(Na2SO4) was generated as by-product in the process. A regeneration process of NaHSO3 combined with flue-gas desulfurization technology was studied by mechanism analysis and simulation study, Na2SO4 reacted with calcium oxide(CaO) and sulfur dioxide(SO2) from the exhausted gas to recycle NaHSO3. The new process presented in this study provides a practicable and clean method to recycle the lead from the used batteries.