In this research, the recycling of industrially collected and crushed nickel metal hydride battery waste, rich in valuable metals such as Ni and rare earth elements (REE), was investigated. The crushed waste was characterized based on elemental distribution per particle size class and density. Although issues with sieving, such as agglomeration of shredded separator fibers, were observed, a good separation of Fe and plastics could be achieved by using a 1-mm sieve size. It was observed that, as the waste battery particles were washed with water, some organic compounds were dissolved. Acid consumption of 14 mol H⁺ ions per 1 kg of battery sample (sieve fraction—1 mm) was determined to be sufficient to achieve the desired final pH of < 1. Selectivity of the leaching at higher equilibrium pH was also investigated by using dilute H₂SO₄. Pregnant leach solution rich in Ni (46 g/L) and REEs (La: 9 g/L, Ce: 7.5 g/L, Pr: 1.4 g/L, Sm: 0.29 g/L, Y: 0.17 g/L) was obtained and REE precipitation was investigated as a function of dilute Na₂SO₄ solution concentration (0.01–0.5 M) at a temperature of 50 °C. The best precipitation efficiency was achieved with a Na:REE ratio of 9.1, which resulted in a > 99% precipitation efficiency for the REEs.

中文翻译：

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镍氢电池废料：机械-湿法冶金回收方面的实验研究

在这项研究中，对富含镍和稀土元素（REE）等贵重金属的工业收集和粉碎的镍氢电池废料的回收利用进行了研究。压碎的废物基于每个粒度等级和密度的元素分布进行表征。尽管观察到了筛分问题，例如切碎的分离纤维的团聚，但通过使用1毫米的筛孔尺寸，可以很好地分离铁和塑料。观察到，当废电池颗粒用水洗涤时，一些有机化合物溶解。酸消耗量为14 mol H ⁺确定每1 kg电池样品中的离子（筛分-1 mm）足以达到所需的最终pH值<1。还通过使用稀H ₂ SO ₄研究了在较高平衡pH下的浸出选择性。富含Ni（46 g / L）和REE（La：9 g / L，Ce：7.5 g / L，Pr：1.​​4 g / L，Sm：0.29 g / L，Y：0.17 g / L）的孕妇浸出液在50°C的温度下，获得了REE沉淀，并研究了其与Na ₂ SO ₄稀溶液浓度（0.01–0.5 M）的关系。Na：REE比为9.1时可获得最佳的沉淀效率，这导致REE的沉淀效率> 99％。