Xiao Jiefeng, Gao Ruitong, Niu Bo, Xu Zhenming
School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, People's Republic of China.
J Hazard Mater. 2021 Apr 5;407:124704. doi: 10.1016/j.jhazmat.2020.124704. Epub 2020 Dec 2.
Spent lithium-ion batteries (LIBs) recycling has attracted much attention because it is highly favorable to environment protection and sustainable development. Developing a cleaner method for metals extraction can greatly reduce risk of secondary pollution. Chlorinating technology has been proved as an efficient method for metals extraction instead of traditional hydrometallurgy. In this paper, cathode materials from spent LIBs could be rapidly converted into metal chlorides by NHCl roasting at 623 K for 20 min. The results indicated nearly 100% metal leaching rates were achieved. Further, in-depth study is performed to obtain the mechanism function of chlorinating conversion based on roasting and TGA experiments. The apparent activation energy as 73.40 kJ/mol was firstly obtained, and then the reaction model of chlorination reaction was determined by model fitting and verifying. Herein, sub-reactions of chlorination reaction were figured out and their contributions were used to determinate reaction controlling mechanisms of chlorination reaction. The results indicated that nucleation reaction played a leading role in the initial stage (0.05 <α < 0.43) while phase boundary reaction took the control in next stage (0.43 <α < 0.95), which gave a good explanation to activation energy change. Finally, our findings provided inspirations for studying the controlling mechanism of gas-solid reaction.
废旧锂离子电池（LIBs）回收利用备受关注，因为它对环境保护和可持续发展极为有利。开发一种更清洁的金属提取方法可大大降低二次污染风险。氯化技术已被证明是一种替代传统湿法冶金的高效金属提取方法。本文中，废旧LIBs的正极材料在623K下通过NHCl焙烧20分钟可快速转化为金属氯化物。结果表明金属浸出率接近100%。此外，基于焙烧和热重分析（TGA）实验进行了深入研究以获得氯化转化的机理函数。首先获得了73.40kJ/mol的表观活化能，然后通过模型拟合和验证确定了氯化反应的反应模型。在此，明确了氯化反应的子反应，并利用它们的贡献来确定氯化反应的反应控制机制。结果表明，成核反应在初始阶段（0.05＜α＜0.43）起主导作用，而相界反应在接下来的阶段（0.43＜α＜0.95）起控制作用，这很好地解释了活化能的变化。最后，我们的研究结果为研究气固反应的控制机制提供了启示。
