Method for recovering rare earth elements from NdFeB waste materials Selective leaching method

High-power neodymium magnets have been widely used, such as components of hard disk drives, electric cars and maglev trains. This type of magnet contains a high concentration of rare earth elements. After the equipment is stopped, the magnet will be removed and the rare earth elements contained in the magnet will be extracted for any purpose. Recently, research on the extraction of rare earth elements (REE) from neodymium magnets has increased. However, there are few studies on the extraction of rare earth metals by water leaching. In this study, selective leaching technology was used to extract rare earth elements from neodymium magnet waste. Initially, the magnet was leached with 2 M sulfuric acid for 24 hours. Then, the leached solution was heated at 110°C to remove water and leave a green powder. The corn flour was further calcined in a muffle furnace at various temperatures from 750°C to 900°C for 2 hours. Then it was leached out by water. Finally, the iron oxide residue is separated from the rare earth element solution by filtration. According to this experiment, it was found that the purity of rare earth metals can reach 99.4%.