Combustion synthesis of PbO from lead carboxylate precursors relevant to developing a new method for recovering components from spent lead-acid batteries

BACKGROUND: In the conventional recycling process, lead battery pastes are recovered as metallic lead by using an energy intensive decomposition and reduction process. Decomposition of PbSO4 requires the use of relatively high temperature and causes environmental pollution, i.e. emission of SO2 and lead particulates. A new process for treating the pastes at low temperature has been developed.

RESULTS: Three major lead compounds are individually reacted with an aqueous solution of citric acid in order to leach and to crystallize lead citrate precursors, which are then subjected to calcination at relatively low temperatures to recover the lead directly as PbO the most common active material for preparing pastes for a new battery. Characterization of the citrate precursors have been carried out using DSC, XRD, and SEM. The combustion products were characterized by XRD and SEM.

CONCLUSION: Lead(II) oxides along with a small amount of lead metal are the combustion products, which can be produced at a relatively low temperature of 350 °C. Resulting morphologies show that combustion products are in the 100–200 nm size range, providing high‐surface‐area PbO for making new battery paste materials. The work is aimed to develop a sustainable process for recovering lead from spent lead battery paste.