Eco-friendly and efficient strategy for lead recovery from spent lead paste by bagged cathode solid-phase electroreduction

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 473; p. 145208
• Main Authors: Wang, Lei, Xie, Feng, Wang, Wei, Wu, Zhongyun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2023
• Subjects: Bagged electrode; Eco-friendly recycling; Lead recovery; Solid-phase electroreduction; Spent lead paste; Lead recovery; Spent lead paste; Bagged electrode; Eco-friendly recycling; Solid-phase electroreduction
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.145208

[Display omitted] •Specific energy consumption is 587.2 kWh with a high current efficiency of 98.5%.•Lead recovery ratio reached 97.3% with a desulfurization rate of 99.6%.•The mechanism of the solid-phase electroreduction of spent lead paste is discussed.•The electrolyte can be facilely regenerated and recycled using lime.•A green and efficient process for producing lead from spent lead paste is proposed. Spent lead paste is a registered hazardous solid waste containing high-grade lead. Disposal of spent lead paste with high efficiency and the low energy consumption is of great importance in the view of environment and resource recycling. Herein, a novel, eco-friendly and cost-effective process for direct electroreduction of spent lead paste with bagged cathode to produce metallic lead in Na2SO4 electrolyte is proposed. Thermodynamic analysis proves that direct solid-phase electroreduction of spent lead paste in Na2SO4 electrolyte is feasible. The bagged cathode improves the lead recovery ratio and current efficiency. The mechanism of the solid-phase electroreduction is discussed, and the optimum electroreduction conditions are established, under which a cathode current efficiency of 98.5%, desulfurization rate of 99.6%, lead recovery ratio of 97.3%, and energy consumption of 587.2 kWh per ton paste are achieved. The electrolyte can be facilely regenerated and recycled by neutralization with lime. A closed-loop, economical and high-efficiency process for manufacturing metallic lead from spent lead paste has thus been proposed, which can be potentially used for practice.