Efficient Desulfurizer Recycling during Spent Lead–Acid Batteries Paste Disposal by Zero‐Carbon Precursor Hypothermic Smelting

• Published in: Advanced science Vol. 11; no. 43; pp. e2405168 - n/a
• Main Authors: Li, Fei, Zhu, Neng‐Wu, Xi, Yun‐Hao, Xiong, Wu‐Wan, Ruan, Ju‐Jun, Wei, Xiao‐Rong, Guo, An‐Qi, Chen, Yi‐Jun, Wu, Ping‐Xiao, Dang, Zhi
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01.11.2024; John Wiley and Sons Inc; Wiley
• Subjects: Acids; Carbon; Chemical bonds; desulfurizer recycling; Efficiency; Energy consumption; Handbooks; hypothermic smelting; Metallurgy; Phase transitions; Reagents; Recycling; sodium molybdate; spent lead–acid batteries; Sustainable development; Temperature; zero‐carbon precursor; spent lead–acid batteries; sodium molybdate; hypothermic smelting; desulfurizer recycling; zero‐carbon precursor
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202405168

Recycling of spent lead‐acid batteries (LABs) is extremely urgent in view of environmental protection and resources reuse. The current challenge is to reduce high consumption of chemical reagents. Herein, a closed‐loop spent LABs paste (SLBP) recovery strategy is demonstrated through Na2MoO4 consumption‐regeneration‐reuse. Experimental and DFT calculations verify that MoO42− competes Pb/Ca ions and weakens the metal‐oxygen bond of PbSO4/CaSO4.2H2O in SLBP, facilitating PbMoO4/CaMoO4 formation and 99.13 wt% of SO42− elimination. Pb of 99.97 wt% is obtained as zero‐carbon precursors (PbO2 and PbMoO4) by green leaching coupled with re‐crystallization. The regeneration of Na2MoO4 is realized at 600 ℃ using LABs polypropylene shells and NaOH as reagents. Compared with the traditional smelting technologies, the temperature is reduced from ＞1000 to 600 °C. The extraction of Na2MoO4 require only water, and satisfactory re‐used desulfurization efficiency (98.67 wt%) is achieved. For the residual Na2MoO4 after first SLBP desulfurization, the desulfurization efficiency remains above 97.36 wt% after adding fresh reagents for two running cycles. The new principle enables the reuse of 99.83 wt% of Na2MoO4 and the recycling of 95.27 wt% of Pb without generating wastewater and slags. The techno‐economic analysis indicates this strategy is efficient, economical, and environmentally‐friendly. For lead recovery from spent LABs paste, chemical reagents consumption, lead yield, and environmental risk are crucial factors for the low‐cost sustainable development of recycled lead enterprises. Herein, a closed‐loop lead recovery strategy is demonstrated through Na2MoO4 consumption–regeneration–reuse. Noteworthily, 99.83 wt% of Na2MoO4 is reused and 95.27 wt% of Pb is recycled without generating wastewater and slags.