热解预处理条件下废旧锂电极材料高效解离与浮选强化行为

High-efficiency liberation and flotation enhancement of electrode materials derived from spent lithium-ion during pyrolysis pretreatment

为提高废旧锂离子电池电极材料的解离与浮选行为,采用热解手段脱除废旧锂电极材料中的有机质并同步实现电极材料的高效解离以及正、负极电极材料的浮选分离,采用扫描电镜、X射线光电子能谱对热解前后电极材料表面形貌及化学元素赋存形态进行分析,结合破碎及浮选试验探究热解对电极材料解离及可浮性的影响。研究结果表明:在500℃热解处理15 min即可有效脱除电极材料中的有机黏结剂,正、负极电极材料解离效率分别达到98.13%和98.71%;550℃为最佳热解强化浮选温度,在此温度下热解处理后,电极材料表面的有机官能团、热解有机残留物减少,并且颗粒表面变得更加光滑,经一段浮选正极材料纯度高达到94.72%,回收率可达到83.75%;经550℃热解处理可实现废旧锂离子电池电极材料解离与浮选的“双强化”。

In order to improve the liberation and flotation efficiency of electrode materials derived from spent lithium-ion batteries(LIBs),pyrolysis technology was used to remove organics in spent electrode materials of LIBs for improving liberation and flotation efficiency of electrode materials.The surface morphology of the electrode material before and after pyrolysis was analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy.The effects of pyrolysis on the liberation and floatability of electrode materials were investigated by means of crushing and flotation tests.The results show that organics can be removed at pyrolysis temperature of 500℃with 15 min.The liberation efficiency of cathode and anode material is up to 98.13%and 98.71%respectively.However,the optimum pyrolysis temperature for flotation is 550℃because of the removal of organic groups and pyrolysis residues.The grade of cathode material is up to 94.72%with a recovery rate of 83.75%by one-step flotation.Pyrolysis treatment at temperature of 550℃can synchronously realize the liberation and flotation enhancement of electrode materials derived from spent LIBs.