废旧锂离子电池正极活性材料的焙烧及其浸出

采用湿式破碎分选、钴酸锂与碳粉混合物预焙烧、钴酸锂预焙烧产物与硫酸钠和浓硫酸混合体系焙烧、热水浸出焙烧产物中的钴,研究了钴酸锂的焙烧及浸出过程。实验结果显示:锂离子电池经湿式破碎分选后铜箔的回收率大于97%,钴酸锂粉末回收率大于98%;钴酸锂与碳粉混合物经700℃预焙烧2 h后再与硫酸钠和浓硫酸在200℃下焙烧4 h,焙烧产物用70℃热水浸出30 min,钴的浸出率可达97%;XRD分析焙烧产物发现生成了Na2Co(SO4)2和Na6Co(SO4)4。

Roasting and Leaching of the Positive Electrode Active Materials from Spent Lithium-ion Batteries

Roasting process and leaching behavior of lithium cobalt oxide was studied via several steps, including wet crushing and separation, pre - roasting the mixture of lithium cobalt oxide and carbon powder, followed by further roasting in the presence of sodium sulfate and concentrated sulfuric acid. The results showed that more than 97wt% copper and 98wt% lithium cobalt oxide powders can be recovered after wet crushing and separation process. Moreover, 97wt% of the cobalt can be recovered by pre - roasting at 700 ℃ for 2 h, then further roasting in the presence of sodium sulfate and concentrated sulfuric acid at 200 ℃ for 4 h, and final leaching of the roasted mixture at 70 ℃ for 30 min with hot water. Also, the result of X- ray Diffraction （XRD） test indicated that Na2Co（ SO4 ）2 and Na6Co（ SO4 ）4 were produced during roasting process.