Extraction of rare earth elements from NdFeB scrap by AlF 3 –NaF melts

Abstract

To conserve both energy and rare earths, a new technology for recycling of NdFeB magnet scrap was proposed in this paper based on the selective fluorination with AlF₃–NaF melts. After fluorination, the reaction products were examined by scanning electron microscopy equipped with energy dispersive X-ray spectrometry, X-ray diffraction and inductively coupled plasma. Rare earth elements in the scrap were selectively converted to rare earth fluorides in the yield of ca. 94·2%, leaving Fe, B and impurities in the solid residue. The differences in chemical activity between Fe, impurities and rare earth should be mainly responsible for the selective fluorination process. The obtained fluorides can be subsequently processed with molten salt electrolysis for the direct production of Al–Nd based alloy.