铜冶炼酸性废水浸出废旧三元锂离子电池正极材料中Co的动力学研究

Kinetic Study of Leaching Co from Cathode Material of Waste Ternary Lithium-Ion Batteries with Copper Smelting Acidic Wastewater

采用铜冶炼酸性废水浸出废旧三元锂离子电池正极材料,考察了浸出温度、酸性废水中初始H_(2)SO_(4)浓度、搅拌速度对Co浸出率的影响。结果表明,当浸出时间150 min、浸出温度363 K、液固比12.5、还原剂淀粉用量10 g L、酸性废水中初始H_(2)SO_(4)浓度1.5 mol L时,正极材料中Co的浸出率可达99.12%。利用未反应收缩核模型分析了还原浸出过程中Co的动力学。结果表明,Co的浸出过程受内扩散和界面化学反应混合控制,表观活化能为23.657 kJ mol,动力学方程为:1-(1-x)^(1/3)+β[1-2/3x-(1-x)^(2/3)]=4.5243C^(1.29211)V^(1.60337)[exp(RT/23657)]t。

Copper smelting acidic wastewater was used to leach cathode material of waste ternary lithium-ion batteries.The influences of leaching temperature,initial concentration of H_(2)SO_(4) in acidic wastewater and the mixing speed on leaching rate of Co were investigated.The results indicate that the leaching rate of Co in cathode material is 99.12% under the conditions including leaching time of 150 min,leaching temperature of 363 K,ratio of liquid to solid of 12.5,dosage of reductant starch of 10 g L,and initial concentration of H_(2)SO_(4) in acidic wastewater of 1.5 mol L.The unreacted shrinking core model was used to analyze the kinetics of Co in the process of reduction leaching.The results show that the leaching process of Co is controlled by the mixture of internal diffusion and interfacial chemical reaction with the apparent activation energy of 23.657 kJ mol,and the kinetic equation is as follows:1-(1-x)3/1+β[1-3/2x-(1-x)3/2]=4.5243C^(1.29211)V^(1.60337)[exp(RT/23657)]t.