292 / 2022-03-01 04:51:19

Electrochemical Leaching of NdFeB Magnets

NdFeB magnets, recycling, leaching, methanesulfonic acid, electrochemistry

（9）能源资源清洁加工与转化 > 1. 矿物分选过程强化

Methanesulfonic acid (MSA) is a green acid with a remarkably high solubility for metals, making it an interesting leaching agent. Nowadays efficient technology for recovery of critical rare-earth elements (REEs) from permanent magnets scrap is one of the important technological challenges. In this study, chemical and electrochemical leaching of NdFeB magnets was investigated in 0.1−1 mol/L MSA and identified using inductively coupled plasma mass spectroscopy (ICP-MS). NdFeB magnet was extensively characterized before and after leaching using electron (scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX)) as well as chemical analyses. The influence of MSA concentration on leaching efficiency and morphological properties of the NdFeB magnets surface was discussed. Some incorporation of rare-earth element in the cathodic sediment was also observed. Efficient green hydrometallurgical route of separation of NdFeB magnet including electrochemical leaching with MSA, precipitation of REEs with oxalic acid and recovery of iron as a cathode deposit was proposed. This study provides a new insight on recycling of electronic waste by implementing principles of electrochemical leaching.