废旧三元锂电池回收中间产物铝渣的资源化研究

采用氢氧化钠碱浸-碳分工艺处理废旧电池回收中间产物——铝渣, 实现了废渣中的镍钴锰与铝分离并分步回收。结果表明, 在反应温度200 ℃、氢氧化钠浓度6 mol/L、苛性比为5、碱浸5 h条件下, 碱浸液中铝浸出率可达97.70%, 镍钴锰浸出率小于0.23%; 碱浸渣经浸出-除杂-萃取后, 得到Ni、Co、Mn含量均大于100 g/L, Fe、Al含量均小于0.001 g/L的纯净硫酸镍、硫酸钴、硫酸锰溶液, 从而实现废旧三元锂电池中铝与镍钴锰的资源化高效回收利用。

Resource Utilization of Aluminum Slag in Recycling of Spent Ternary Li-ion Batteries

Aluminum slag, as the intermediate in recycling spent batteries, was treated with a technical process of alkaline leaching with sodium hydroxide followed by carbon separation to achieve the separation and respective recycling of nickel, cobalt, manganese from aluminum. It is found that after a 5-h alkali leaching at 200 ℃, with sodium hydroxide concentration of 6 mol/L, molar ratio of Na₂O to Al₂O₃ at 5, the leaching rate of aluminum from the alkali leaching solution can reach 97.70%, and the Ni-Co-Mn leaching rate is less than 0.23%. Then, the obtained alkali residue is subjected to a combined process of leaching, impurity removal and extraction, resulting in pure nickel sulfate, cobalt sulfate and manganese sulfate solution, with the concentration of Ni, Co and Mn all more than 100 g/L, and the concentration of Fe and Al less than 0.001 g/L. With this technique, high-efficient utilization of Ni, Co and Mn resources from spent ternary Li-ion batteries can be actualized.