ABSTRACT

Li-ion batteries (LIBs) should be recycled because of the environmental reasons and this type of waste represents an important secondary source of metals. This work aimed to evaluate the recovery of Co and Li from LIBs by hydrometallurgy. The efficiency of different leachants was tested: H₂SO₄ (2 M), fermentation effluent with supplementation of organic acids (lactic, acetic, butyric and propionic acids) (3.4 M) and a combination of fermentation effluent (0.75 M) and H₂SO₄ (1.25 M). In addition, the effect of H₂O₂, glucose P.A., lactose P.A. and from milk whey permeate (MWP) as reducing agent was tested. The leaching solution composed of H₂SO₄ and fermentation effluent showed high potential of metals recovery in addition to being an alternative of reducing the volume of inorganic acid and the cost by using a fermentation effluent since its use may be integrated with a waste treatment process. Based on Central Composite Designs, optimum conditions of leaching were established, as temperature of 86°C, solid–liquid ratio of 18.5 g/L, leaching time 2.5 h, agitation of 300 rpm and concentration of 0.09 M of lactose from MWP and recovery level achieved was 93.35% of Co and 90.50% of Li. In order to evaluate the influence of each organic acid present on the fermentation effluent, testes were carried out using pure organic acid with H₂SO₄ (0.75 M:1.25 M) or isolated (3.4 M) and inferior recoveries were detected proving that mixture of organic acids and further compounds as phenolic groups characteristic of fermentation effluent improves the leaching process.

摘要

由于环境原因，锂离子电池 (LIB) 应回收利用，此类废物是重要的二次金属来源。这项工作旨在评估湿法冶金从 LIB 中回收 Co 和 Li。测试了不同浸出剂的效率：H ₂ SO ₄ (2 M)、添加有机酸（乳酸、乙酸、丁酸和丙酸）的发酵流出物（3.4 M）以及发酵流出物（0.75 M）和 H 的组合₂ SO ₄ (1.25M)。此外，还测试了 H ₂ O ₂、葡萄糖 PA、乳糖 PA 和乳清渗透物 (MWP) 作为还原剂的效果。H ₂ SO ₄组成的浸出液和发酵流出物显示出金属回收的巨大潜力，除了通过使用发酵流出物减少无机酸的体积和成本之外，因为它的使用可以与废物处理过程相结合。基于Central Composite Designs，确定了最佳浸出条件为：温度86°C，固液比18.5 g/L，浸出时间2.5 h，搅拌300 rpm，MWP乳糖浓度0.09 M，回收率达到的水平是 93.35% 的 Co 和 90.50% 的 Li。为了评估存在的每种有机酸对发酵流出物的影响，使用纯有机酸和 H ₂ SO ₄进行睾丸试验。 (0.75 M:1.25 M) 或分离 (3.4 M) 和较差的回收率被检测到，证明有机酸和其他化合物的混合物作为发酵流出物的酚类特征改善了浸出过程。