电解浸出废旧锂电池中钴的热力学和动力学

发布时间：2019-02-18 20:42

【摘要】：以废旧锂电池正极条为阴极,以铅板作阳极,在稀硫酸溶液中,电解浸出正极材料中的钴,从热力学和动力学两方面对钴的电解浸出过程进行研究。实验及热力学数据分析表明:LiCoO2主要通过Co(OH)3还原浸出得到Co2+,考查浸出温度和时间表明在电解前期5~30 min电解浸出由缩核模型的化学反应过程控制,浸出率α与时间t满足未反应核收缩模型1-(1-α)1/3=Kt,其表观活化能为7.32 kJ/mol;中期是混合控制;后期75~180 min符合内扩散控制模型1-2α/3-(1-α)2/3=Kt,表观活化能17.05 kJ/mol。浸出液中的铝主要是铝箔表面氧化铝层不受阴极保护而溶于硫酸溶液,正极材料从铝箔上剥离与氧化铝层的溶解有关,剥离时间影响钴的浸出率。
[Abstract]:Cobalt from cathode material of waste lithium battery was electrolytically leached in dilute sulfuric acid solution with lead plate as anode and cathode strip of waste lithium battery as cathode. The electrolysis leaching process of cobalt was studied from two aspects of thermodynamics and kinetics. The experimental and thermodynamic data analysis showed that LiCoO2 was mainly leached by Co (OH) _ 3 reduction to obtain Co2. The examination of leaching temperature and time showed that the electrolysis leaching was controlled by the chemical reaction process of the model of shrinking nucleus at the early stage of electrolysis at 5 ~ 30 min. The leaching rate 伪 and time t satisfy the unreacted nuclear contraction model 1- (1- 伪) 1 / 3 Kt.The apparent activation energy is 7.32 kJ/mol;. In the middle stage, mixing control is used, and in the late stage, 75g 180 min accords with the internal diffusion control model 1-2 伪 / 3- (1- 伪) 2 / 3 Kt, and the apparent activation energy is 17.05 kJ/mol.. Aluminum in leaching solution is mainly dissolved in sulfuric acid solution without cathodic protection. The stripping of positive material from aluminum foil is related to the dissolution of aluminum oxide layer, and the stripping time affects the leaching rate of cobalt.
【作者单位】：中南大学化学化工学院;中南大学有色金属资源化学教育部重点实验室;
【基金】：国家自然科学基金资助项目(21046007)
【分类号】：TM912.9

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