基于规则破碎的废旧锂离子动力电池分选回收工艺研究

Separation and Recovery of Spent Lithium Ion Power Batteries Based on Regular Crushing

据预测,到2020年,我国锂离子动力电池的累计报废量将达到32.2万吨,废旧锂离子动力电池中含有高价值金属和有毒有害物质,对其进行回收再利用,不仅能够实现资源循环利用,还能减轻其对环境的污染,目前的处理方法以物理分选和冶金处理联合回收工艺为主。本文以市场应用前景广的废旧三元材料锂离子动力电池为研究对象,针对目前物理分选工艺中存在的破碎方式简单、物理分选方式单一、回收产品纯度和回收率低的问题,提出了以规则破碎为基础,筛分、重力分选、涡电流分选与热处理法相结合的分选工艺,实现了极芯中负极材料、隔膜、铜箔、铝箔和正极材料的有效回收。经浸泡、搅拌和筛分回收负极材料,重力分选回收隔膜,负极材料和隔膜的回收率分别为99.43%和99.84%;经涡电流分选后,正极片的回收率达到88.19%;正极片经热处理后正极材料的脱落率达到96.60%。感应耦合等离子体发射光谱仪(ICP)和X射线衍射(XRD)分析结果表明,规则破碎条件下,回收正极材料中只含有镍、钴、锰、锂,杂质元素,铜、铝的含量几乎为0,为下一步正极材料的冶金处理提供了良好的基础。

It was predicted that the cumulative amount of discard lithium ion power batteries in China would reach 322000 tons by 2020. Recycling of the spent lithium ion power batteries could not only prevent environmental pollution, but also relieve the shortage of metal resources. At present, the recovery process mainly includes physical separation and metallurgical processing. Due to the simple crushing way and single physical separation, physical separation method leads to the result of low purity and recovery rate in the recycling process. Focusing on the used ternary lithium ion power batteries which was applied widely to electric car, this study improved the separation process which was based on regular crushing, with the combination of screening, gravity separation, eddy current separation and heat treatment. Through the separation process, the anode materials, membrane, copper foil, aluminum foil, and the cathode materials were recycled. The anode materials were recycled by soaking, stirring and screening, the recovery rate of anode materials was 99.43%. The membrane was separated by gravity separation that the recovery rate of membrane was 99.84%. After the eddy current separation, the recovery rate of cathode was 88.19%. The separation efficiency of cathode materials after heat treatment was 96.60%. In the condition of regular crush, the inductively coupled plasma(ICP) and X-ray diffraction(XRD) analysis results showed that the metal elements only contained nickel, cobalt, manganese and lithium and the content of copper and aluminum was almost 0, which could provide favorable conditions for the next step of the metallurgical treatment.