Phase equilibria of the system Fe-Mg-Nd at 1076Â K

Phase equilibria of the system Fe-Mg-Nd have been investigated in order to develop a new recycling process for Nd-Fe-B magnet scraps using molten Mg as the extraction medium. The phase relations between Fe-Nd alloy and Mg-Nd alloy were studied at 1076 K by isothermal equilibration experiments and composition analysis of the quenched samples. Liquid Mg-Nd alloy containing about 24 mol% Nd (65 mass% Nd) was found to be in equilibrium with both Nd2Fe17 compound and iron solid solution. The results indicate that the Mg-Nd alloy with less than 24 mol% Nd is capable of extracting Nd from the Nd2Fe17 compound, and iron solid solution is formed after extraction. The results show the usefulness of directly extracting neodymium metal as a pure metal out of magnet scraps.