废旧锂离子电池正极材料有价金属湿法浸出

Leaching valuable metals from waste lithium-ion battery cathode materials

本研究采用高效、环保的“还原焙烧-H_(2)SO_(4)浸出”工艺从废旧三元锂电池正极材料中回收Li、Ni、Co和Mn等金属。考察了碳用量(质量分数)、焙烧温度、焙烧时间、H_(2)SO_(4)浓度、浸出温度、浸出时间、液固比等对金属浸出率的影响。采用未反应收缩核模型和Arrhenius公式对酸浸过程进行了动力学分析,并根据对数定律方程拟合了浸出动力学参数。结果表明:在碳用量10%、焙烧温度600℃、焙烧时间120 min、H_(2)SO_(4)浓度2 mol/L、浸出温度85℃、液固比10∶1和浸出时间60 min的优化条件下,Li、Ni、Co和Mn的浸出率分别可达98.87%、97.03%、98.89%和96.47%。Li、Ni、Co和Mn的浸出活化能分别为21.160 kJ/mol、26.538 kJ/mol、19.553 kJ/mol和28.981 kJ/mol,表明酸浸为内扩散控制过程。

In this study,Li,Ni,CO and Mn were recovered from the cathode material of waste ternary lithium battery by reduction roasting sulfuric acid leaching.The effects of carbon dosage,roasting temperature,roasting time,sulfuric acid concentration,leaching temperature,leaching time and liquid-solid ratio on the leaching rates of these four metals were investigated.The unreacted shrinking core model and Arrhenius formula were used in the kinetic analysis of acid leaching process.The leaching kinetic parameters were fitted based on the logarithmic law equation.The results show that under the optimum conditions as follows:carbon dosage of 10%,roasting temperature of 600 ℃,roasting time of 120 min,H_(2)SO_(4) concentration of 2 mol/L,leaching temperature of 85 ℃,liquid-solid ratio of 10∶1 and leaching time of 60 min,the leaching rates of lithium,nickel,cobalt and manganese are 98.87%,97.03%,98.89% and 96.47%,respectively.The leaching activation energies of lithium,nickel,cobalt and manganese are 21.160 kJ/mol,26.538 kJ/mol,19.553 kJ/mol and 28.981 kJ/mol,respectively,indicating that acid leaching is an internal diffusion control process.