镉镍废电池湿法回收工艺

Hydrometallurgical recovery process for waste Ni-Cd batteries

研究了镉镍废电池的湿法回收工艺过程。考察了废电池中镍和镉的浸出热力学及其在硫酸溶液中的浸出动力学。结果表明 ,废电池中镍和镉的浸出热力学及动力学规律有较大差异 ,通过控制硫酸溶液的温度和酸度等因素 ,可以使镉和镍分别浸出 ,达到在浸出阶段就实现Cd与Ni分离的目的。对电解法和碳酸盐沉淀法回收浸出液中镉的工艺也进行了研究。由于选择性浸出 ,镉浸出液中的镍钴铁离子浓度很低 ,电解回收镉时可以提高电流密度。而以CdCO3 沉淀的形式回收镉时 ,不必加入大量的 (NH4 ) 2 SO4 就可以取得较高的镉沉淀率及产品纯度。在上述实验研究的基础上 ,提出了镉镍废电池湿法回收的工艺流程。

Hydrometallurgical processes for recovery metal values from waste nickel-cadmium batteries were studied. The leaching thermodynamics and kinetics of cadmium and nickel in the waste batteries were investi-gated. The results show that cadmium and nickel assume different leaching thermodynamics and kinetics in the waste batteries. Cadmium and nickel in the waste batteries can leached selectively at different temperature and H 2SO 4 concentration. This process leads to the nearly complete separation of cadmium from nickel in the leaching stage. Electrolysis and CdCO 3 precipitation technology were investigated to recover cadmium from cadmium-rich leach solution. Because of selective leaching of cadmium, Ni, Co and Fe ion concentrations in cadmium-rich leach solution are so low that the electrolytic current density of cadmium can be raised markedly. A selective leaching process of cadmium and flow of hydrometallurgy technology for recycling of waste nickel-cadmium batteries were developed.