Optimization of Resource Recovery Technologies in the Disassembly of Waste Lithium Batteries: A Study on Selective Lithium Extraction

This study focuses on optimizing resource recovery technology in the dismantling process of retired lithium batteries to mitigate environmental pollution. Addressing the challenge of significant precious metal losses in traditional hydrometallurgical recycling methods, this study employs a reductive roasting-carbonation leaching process to selectively extract lithium from cathode materials using a reducing agent. The study examines the effects of parameters such as roasting temperature, time, and reducing agent dosage on lithium leaching efficiency, and explores additional factors including carbonation leaching time, carbon dioxide flow rate, liquid-to-solid ratio, and leaching temperature in conjunction with multi-stage countercurrent leaching technology. Characterization of the roasting products and leaching process is performed using X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The results demonstrate that, under conditions of a 700 °C roasting temperature, a 3-h roasting time, and a 15 % reducing agent dosage, the lithium leaching rate can achieve approximately 90 %. Following multi-stage countercurrent leaching, the lithium leaching rate exceeds 97 %, satisfying the purity requirements for battery-grade lithium carbonate. The innovation of this study is evident in its optimization of the recycling process, effectively separating and recovering cathode materials while reducing environmental pollution. This approach supports environmentally friendly waste treatment and contributes to the sustainable development of the battery industry.