Reaction Mechanism On A Novel Enhanced Smelting Technique For Lead-Acid Battery Paste Recycling

Lead-acid batteries contain a lot of valuable metals, such as lead, tin, copper, antimony, as well as waste plastic shells, and other harmful substances. Cleaner and efficient recycling of waste lead-acid batteries is of significance in environmental protection and comprehensive recycling of resources. In this study, oxygen-enriched side-blow pool smelting technique was developed and innovatively employed to recycle lead battery paste. This study investigated the reaction mechanism of lead recycling in lead paste-CaO-FeO-SiO2-C reaction system. Therefore, the phase transformation and evolution of lead paste in oxidizing atmosphere were described in detail. XRD and SEM-EDS analysis results indicated that the whole reaction evolution can be summarized as follows: PbO and PbS were formed from PbSO4 in a weak oxidizing atmosphere through the thermal decomposition and reduction reactions. Then, the lead oxide formed was combined with slag-forming components (CaO, SiO2, and FeC2O4 center dot 2H(2)O) to generate new oxides phase. As the temperature increases, metallic lead was extracted and recycled through the reactions between lead sulfide and the new-formed oxide phase.