Study on Recovery of Rare Earth Elements from NdFeB Magnet Scrap by Using Selective Leaching

Abstract:

High power neodymium magnets have been used extensively, such as components of hard disk drives, electric vehicles, and maglev trains. This type of magnet contains of high concentration of rare earth elements. After the device is out of service, the magnet will be removed and the rare earth element contained in the magnet will be extracted in order to reuse for any purposes. Recently, the study on extraction of rare earth elements (REE) from neodymium magnets is increased. However, there was only few research regarding to the extraction of rare earth metals by using a water leaching method. In this study, rare-earth elements were extracted from neodymium magnet scrap by using selective leaching technique. Initially, magnets were leached with 2 M of sulfuric acid for 24 hrs. Then, the leached solution was heated at 110°C in order to remove water and the green powder was remained. The green powder was further roasted in a muffle furnace at various temperatures from 750°C to 900°C for 2 hrs. and subsequently leached by water. Finally, the iron oxide residue was separated from rare earth element solution by filtration. Based on this experiment, it was found that the purity of the rare earth metals can be achieved up to 99.4%.

• Periodical: Materials Science Forum (Volume 1009)
• Pages: 149-154
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.1009.149
• Online since: August 2020
• Authors: Tanongsak Yingnakorn*, Piamsak Laokhen, Loeslakkhana Sriklang, Tapany Patcharawit, Sakhob Khumkoa
• Keywords: Neodymium Magnet, Rare Earth Element, Recycling, Selective Leaching

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