A new pre-desulphurization process of damped lead battery paste with sodium carbonate based on a “surface update” concept

•A desulfurization process of lead paste based on surface update was developed.•The optimum reaction conditions were investigated and the process worked well.•The effect of the new process is better than the traditional process.•It may boost the development of lead recycling industry in developing countries.

Recycling of lead-acid batteries is an important sector of the lead-acid battery industry, and green technologies with low energy consumption and pollutant emission are in urgent demand. A new pre-desulfurization process of damped lead battery paste sodium carbonate based on “surface update” was developed, and the optimum reaction conditions were investigated. According to the experimental results, the process can maintain the sulfur content of lead paste under 0.5% at the optimum reaction conditions: pH = 8–10 and a molar ratio of Na2CO3 to PbSO4 of 1.00–1.10:1. The desulfurization efficiency increases with the reaction temperature and can be qualified within 40 min in each experiment. The effect of “surface update” contributes to the enhancing effect in the desulfurization process. The new process has a great advantage in desulfurization efficiency compared with the traditional processes.