Extraction of Sm from Sm-Fe-N magnets by the glass slag method

Sm-Fe-N alloys were successfully separated into the metallic component and the slag component by the glass slag method using boron trioxide. X-ray diffraction and magnetic measurements revealed that the metallic component consisted of α-Fe phase and that the slag component consisted of BN and Sm-containing amorphous materials. The chemical analyses confirmed that the Sm content in the metallic component was very limited and the slag component contained a large amount of samarium. The formation of the BN phase was believed to be the reaction between SmN, decomposed from Sm2Fe17N3 phase at high temperatures, and boron trioxide during the glass slag process.