Processing of spent Ni-MH batteries for the recovery of cobalt, nickel and rare earth elements bearing materials by means of a chemical and electrochemical sequential process

3rd International Meeting for Researchers in Materials and Plasma Technology; 1st Symposium on Nanoscience and Nanotechnology

物理学;材料科学

Delvasto, P.^1 ; Rodríguez, R. Orta^2 ; Blanco, S.^3

Universidad Industrial de Santander, Bucaramanga, Colombia^1

Universidad Simón Bolívar, Caracas, Venezuela^2

Fundación Instituto de Ingeniería Para la Investigatión y Desarrollo (FIIID), Caracas, Venezuela^3

关键词: Bearing materials;    Electrode material;    Free solutions;    Metal content;    Sequential process;    Spent batteries;    Strategic metals;    X ray fluorescence techniques;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/687/1/012107/pdf
DOI  :  10.1088/1742-6596/687/1/012107

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Rechargeable Ni-MH batteries contain strategic metal values which are worth to be recovered. In the present work, a preliminary sequential chemical and electrochemical procedure is proposed, in order to reclaim materials bearing Ni, Co and rare earth elements (REE) from Ni-MH spent batteries. Initially, spent batteries are disassembled to separate the electrode materials (anode and cathode), which are then leached with an aqueous solution of 5w% sulphuric acid. The metal content of this solution is checked by atomic absorption spectrometry techniques. The obtained solution is pH-adjusted (with NaOH), until pH is between 4.0 and 4.3; then, it is heated up to 70°C to precipitate a rare earth elements sulphate (Nd, La, Pr, Ce), as determined by means of x-ray fluorescence techniques. The solids-free solution is then electrolyzed, in order to recover a Ni-Co alloy. The electrolysis conditions were established through a cyclic voltammetry technique.