废旧磷酸铁锂电池正极材料回收方法

Recovery Method of Cathode Material of Waste Lithium Iron Phosphate Battery

探讨废旧磷酸铁锂电池正极材料的回收方法。先对废旧磷酸铁锂电池进行放电,接着去除电池中的黏结剂,使用氢氧化钠和pH为2.5的硫酸进行碱浸除铝,净化后的含锂滤液加入标准用量1.01~1.10倍的碳酸钠,然后碳化精制即可得到电池级碳酸锂产品。经酸浸条件优化后,在液固比为4的条件下水洗2~3次、烘干即为纯度98%以上的高纯石墨碳产品。完成湿法浸出后,分别采用(NH_(4))_(2)S_(2)O_(8)、DMG和H_(2)C_(2)O_(4)对有价金属进行回收。实验组中镍、钴、锰、锂的回收率分别为94.1%,94.7%,90.9%和91.1%,其他对照组的各金属回收率最高不超过90%。研究废旧磷酸铁锂电池正极材料的回收方法,基于湿法回收的回收方法具有最大的金属回收率,且能够做到工业化推广。

The recovery method of cathode material of waste lithium iron phosphate battery is discussed.Firstly,the waste lithium iron phosphate battery is discharged,then the binder in the battery is removed,and the aluminum is leached by alkali with sodium hydroxide and sulfuric acid with pH of 2.5.The purified lithium-containing filtrate is added with 1.01 to 1.10 times of the standard dosage of sodium carbonate,and then carbonized and refined to obtain the battery-grade lithium carbonate product.After optimization of acid leaching conditions,high purity graphite carbon products with purity over 98%can be obtained by washing with water for 2 to 3 times and drying at liquid-solid ratio of 4.After wet leaching,(NH_(4))_(2)S_(2)O_(8),DMG and H_(2)C_(2)O_(4) were used to recover valuable metals respectively.The recovery rates of nickel,cobalt,manganese and lithium in the experimental group were 94.1%,94.7%,90.9%and 91.1%respectively,and the highest recovery rates of metals in other control groups were less than 90%.The recovery method of cathode materials for waste lithium iron phosphate batteries is studied.The recovery method based on wet recovery has the highest metal recovery rate and can be industrialized.