School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Laboratory of Metallurgical Separation Science and Engineering, Central South University, Changsha, 410083, China.
School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Laboratory of Metallurgical Separation Science and Engineering, Central South University, Changsha, 410083, China; CSIRO Minerals Resources National Research Flagship, Australia.
J Environ Manage. 2024 Apr;356:120729. doi: 10.1016/j.jenvman.2024.120729. Epub 2024 Mar 26.
The recovery of valuable metals from spent lithium-ion batteries (LIBs) is crucial for environmental protection and resource optimization. In the traditional recovery process of spent LIBs, the leaching of high-valence metals has the problems of high cost and limited reagent utilization, and some valuable metals are lost in the subsequent purification process of the leaching solution. To reduce the cost of reagents, this study proposes the use of low-cost SO as a reagent combined with pressure leaching to efficiently recover high-valence metals from delithiated materials of spent LIBs, while selective solvent extraction is used to remove trace impurities in the leaching solution to avoid the loss of valuable metals. Experimental results demonstrated that by optimizing the conditions to 0.25 MPa SO partial pressure and 60 min reaction time at 70 °C, the leaching efficiencies for Ni, Co, and Mn reached 99.6%, 99.3%, and 99.6%, respectively. The kinetic study indicated that the leaching process was diffusion-controlled. Furthermore, the delithiated materials were used to completely utilize the residual SO in the solution to obtain a high concentration Ni-Co-Mn rich solution. Subsequently, Fe and Al impurities were deeply removed through a synergistic extraction of Di-2-ethylhexyl phosphoric acid (D2EHPA) and tributyl phosphate (TBP) without loss of valuable metals, achieving a high-purity Ni-Co-Mn solution. The process developed based on this work has the characteristics of environmental friendliness, high valuable metal recovery, and high product purity, providing a reference technical method for the synergistic treatment of waste SO flue gas with spent LIBs and the deep purification of impurities in spent LIBs.
从废旧锂离子电池（LIB）中回收有价金属对于环境保护和资源优化至关重要。在废旧 LIB 传统的回收过程中，高价金属的浸出存在成本高、试剂利用率有限的问题，而且一些有价金属在浸出液的后续净化过程中损失。为降低试剂成本，本研究提出采用廉价的 SO2 作为试剂，并结合加压浸出，从废旧 LIB 的脱锂材料中高效回收高价金属，同时采用选择性溶剂萃取去除浸出液中的痕量杂质，避免有价金属的损失。实验结果表明，在优化条件为 0.25 MPa SO2 分压和 70℃下反应 60 min 时，Ni、Co 和 Mn 的浸出率分别达到 99.6%、99.3%和 99.6%。动力学研究表明，浸出过程受扩散控制。此外，利用溶液中剩余的 SO2 对脱锂材料进行完全利用，获得高浓度的 Ni-Co-Mn 富液。随后，通过 D2EHPA 和 TBP 的协同萃取，深度去除 Fe 和 Al 杂质，而不损失有价金属，得到高纯度的 Ni-Co-Mn 溶液。基于这项工作开发的工艺具有环保、有价金属回收率高和产品纯度高的特点，为协同处理废 SO2 烟道气和废旧 LIB 中杂质的深度净化提供了参考技术方法。
