Selective Chlorination of Rare Earth Elements from a Nd-Fe-B Magnet Using Zinc Chloride

To develop an efficient recycling process for the selective recovery of rare earth elements (REEs) from neodymium (Nd)-iron (Fe)-boron (B) magnets, a selective chlorination process using zinc chloride (ZnCl 2 ) was investigated. A mixture of Nd-Fe-B magnet powder and ZnCl 2 was set in a gas-tight quartz tube, and the tube was placed in a vertical furnace preheated to 1000 K. During the experiment, the magnet powder reacted with ZnCl 2 for 1.5 – 5 h to selectively chlorinate the REEs in the magnet. The influence of the particle size of the magnet powder, reaction time, and premelting of ZnCl 2 on the chlorination efficiency of REEs was investigated. Under certain conditions, the chlorination efficiencies of Nd, dysprosium (Dy), and praseodymium (Pr) were 96.5%, 57.2%, and 97.6%, respectively. In addition, Fe and neodymium chloride (NdCl 3 ) were found to have been generated after the selective chlorination reactions. The results of this study demonstrate that the selective recovery of REEs, such as Nd, Dy, and Pr, from Nd-Fe-B magnets is feasible by utilizing the selective chlorination process using ZnCl 2 . Graphical Abstract