Clean Recycling Process for Lead Oxide Preparation from Spent Lead–Acid Battery Pastes Using Tartaric Acid–Sodium Tartrate AS A Transforming Agent

A clean recycling process for waste lead–acid battery paste was proposed, where tartaric acid-sodium tartrate mixed solution was used as the transforming agent. First, lead tartrate [Pb(C4H4O6)] was prepared by the reaction of paste and the transforming agent, and then it was calcined to obtain lead oxide powder. The lead recovery rate and desulfurization rate were 97.55% and 99.02%, respectively. In addition, pure lead tartrate was obtained with a narrow particle size distribution. Next, the thermal behavior of lead tartrate was investigated, and the results show that it rapidly decomposed into PbO in air and remained stable until 800°C. However, in an argon atmosphere, the weight loss rate approached that of metallic lead generation. The study of the calcination of lead tartrate in air and argon atmospheres showed that the main product was a PbO and Pb mixture; however, the product morphologies were different. Ultra-fine lead oxide particles with a particle size < 100 nm were obtained by calcining in an argon atmosphere. With increasing calcination temperature, more metallic lead was formed. The main advantages of this process are the use of a clean and non-toxic transforming agent and the direct production of ultra-fine lead oxide through calcination.