废弃锂离子电池回收处理的污染物分析

本研究针对废锂钴电池及锂铁电池于不同热处理条件下的污染特性作实验分析,实验条件包括不同温度、时间、气体及投料量;实验流程包含样品收集、放电处理、拆解并通过原子光谱仪分析组成成分,直至热处理与采样分析。实验结果表明,废锂电池热处理的最佳温度为600℃,此时金属回收率最高且污染排放最低,锂钴电池的金属回收率分别为锂95.38%、钴93.99%、铜96.24%、铝85.28%,锂铁电池的金属回收率分别为锂90.01%、铁85.49%、铜83.72%、铝73.75%;不同进气组成会影响其热处理效果与金属回收率,但差距不大,若考虑操作成本与金属回收率,3种不同热处理操作气以空气最佳。废气中HCl和HF浓度在2~16μL/L,需要特别注意处理过程中酸性气体的控制去除。金属气固相分布结果表明,99.9%以上的金属成分仍存在于燃烧后残留物中,虽气相金属含量随着操作温度提高而有增加趋势,但比例极低。

Analysis of pollutants in the recycling of waste lithium batteries

The experimental analysis of polluting emission characteristics of waste lithium-cobalt and lithium iron battery under different heat treatment conditions, which including the different temperature, time, gas, and inputs, was conducted in this paper. The experiment process contains from samples collection, discharge processing, dismantling and composition analysis, until heat treatment and sampling analysis. The experimental results showed that the optimum temperature for heat treatment of waste lithium iron battery is 600℃, at which the metal recycling rate is the highest. The recycling rate of lithium, cobalt, copper, aluminum in lithium-cobalt battery is 95.38%, 93.99%, 96.24%, and 85.28%, respectively. The recycling rate of lithium, iron, copper, aluminum in lithium iron battery is 90.01%, 85.49%, 83.72%, 73.75%, respectively. Different composition of gas-intake will affect the heat treatment and metal recycling rate, but the gap is small. Taking the operating costs and metal recycling rate into consideration, air is the best among the three different heat treatment gases. In waste gas, the concentration of HCl and HF is about two to sixteen per million, so a special attention is needed to pay to get rid of acidic gas in the recycling process. Metal gas-solid phase distribution although the content of gas phase metal has a rising trend with the operation temperature increase, but the proportion is extremely low.