Department of Mining and Minerals Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Department of Mining and Minerals Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Waste Manag. 2024 Dec 1;189:23-33. doi: 10.1016/j.wasman.2024.08.004. Epub 2024 Aug 14.
The management and sustainable recycling of spent lithium-ion batteries (LIBs) holds critical importance from both economic and environmental standpoints. HO and ascorbic acid are widely used inorganic and organic reductants in the hydrometallurgical process for battery recycling. In this study, citric acid, as a reductant, was found to have superior metal leaching efficiencies under microwave-assisted leaching than HO and ascorbic acid. The enhanced performance was attributed not only to the inherent reducing property of citric acid but also to the chelation of citric acid with Cu and Fe, resulting in the formation of reductive radicals under microwave. The effect of acid type, HSO concentration, citric acid concentration, solid-liquid (S/L) ratio, reaction time, and temperature were investigated. 99.5 % of Li, 99.7 % of Mn, 99.5 % of Co, and 99.3 % of Ni were leached from spent lithium nickel manganese cobalt oxides (NCM) battery black mass using 0.2 mol/L HSO and 0.05 mol/L citric acid at 120 °C for 20 min with a fixed S/L ratio of 10 g/L in the microwave-assisted leaching process. Leaching kinetic results were best fitted with the Avrami model, suggesting that the microwave-assisted leaching process was controlled by diffusion. The leaching activation energies of Li, Mn, Co, and Ni were 30.11 kJ/mol, 27.48 kJ/mol, 21.32 kJ/mol, and 33.29 kJ/mol, respectively, providing additional evidence that supports the proposed diffusion-controlled microwave-assisted leaching mechanism. This method provided a green and efficient solution for spent LIBs recycling.
从经济和环境的角度来看，管理和可持续回收废旧锂离子电池（LIB）至关重要。HO 和抗坏血酸是电池回收水冶金工艺中广泛使用的无机和有机还原剂。在这项研究中，柠檬酸作为还原剂，在微波辅助浸出下，其金属浸出效率优于 HO 和抗坏血酸。这种增强的性能不仅归因于柠檬酸固有的还原性质，还归因于柠檬酸与 Cu 和 Fe 的螯合作用，在微波下形成还原自由基。考察了酸类型、HSO 浓度、柠檬酸浓度、固液比（S/L）、反应时间和温度的影响。使用 0.2 mol/L HSO 和 0.05 mol/L 柠檬酸，在 120°C 下反应 20 分钟，微波辅助浸出过程中 S/L 比固定在 10 g/L，从废旧锂镍锰钴氧化物（NCM）电池黑粉中浸出 99.5%的 Li、99.7%的 Mn、99.5%的 Co 和 99.3%的 Ni。浸出动力学结果与 Avrami 模型拟合最佳，表明微波辅助浸出过程受扩散控制。Li、Mn、Co 和 Ni 的浸出活化能分别为 30.11 kJ/mol、27.48 kJ/mol、21.32 kJ/mol 和 33.29 kJ/mol，这为所提出的扩散控制微波辅助浸出机制提供了额外的证据。该方法为废旧 LIB 回收提供了一种绿色高效的解决方案。
