磁场强化废旧锂电池正极粉中钴浸出的研究

以废旧锂电池正极粉为原料，在磁场条件下，采用硫酸-双氧水体系浸出正极粉中的钴，探讨了磁感应强度、磁化浸出时间和浸出温度对钴浸出率的影响。结果表明，在磁感应强度为230 mT磁场、浸出时间为100 min、反应温度为70 ℃、固液比为1:100（其中硫酸浓度为3 mol/L）条件下，加入3 mL/g H₂O₂进行试验，钴的浸出率达到99.61%，相比较未磁化同等条件下，钴的浸出率提高了6.02个百分点。同时在硫酸用量减少20%的情况下，磁场强化浸出可以提高钴的浸出率4.62个百分点。磁场强化浸出的机理是加快了氢离子的扩散速度以及促进双氧水对Co3+的还原，从而提高了该浸出反应中钴的浸出率。 

Study on Magnetic Field Intensification of Cobalt Leaching From Anode Powder of Used Lithium Battery

Using used lithium battery cathode powder as raw material, under the condition of a magnetic field, the cobalt in the cathode powder is leached by sulfuric acid-hydrogen peroxide system. The influence of magnetic induction intensity, magnetization leaching time and leaching temperature on the cobalt leaching rate are discussed. The results show that, in a magnetic field of 230 mT, the leaching time is 100 min, the reaction temperature is 70 ℃, and the solid-to-liquid ratio is 1:100 (the sulfuric acid concentration is 3 mol/L), and 3 mL/g H₂O₂ is added for the test. The leaching rate of cobalt reaches 99.61%. Compared with the same condition without magnetization, the leaching rate of cobalt is increased by 6.02 percentage point. At the same time, when the amount of sulfuric acid is reduced by 20%, magnetic field enhanced leaching can increase the leaching rate of cobalt by 4.62 percentage point. The mechanism of magnetic field-enhanced leaching is to accelerate the diffusion rate of hydrogen ions and promote the reduction of Co3+ by hydrogen peroxide, thereby increasing the leaching rate of cobalt in the leaching reaction.