Study on solvent extraction of REEs from a NdFeB permanent magnet scrap

In this study recovery of rare earth elements from a NdFeB magnet was investigated. The magnet was firstly demagnetized at 450°C followed by grinding and leaching in 2 M sulfuric acid, wherein the rare earth elements were precipitated as their sodium double sulfate. However, iron and boron as the main impurities remained in the solution. The REEs double sulfate was subsequently treated with oxalic acid to obtain REEs oxalate followed by calcination of the rare-earth oxalates at 950°C for 2 hours to produce rare-earth oxides. After leaching the REEs oxide in 0.5 M hydrochloric acid, solvent extraction was carried out using D2EHPA as the extractant. Results showed that selective extraction of Dy is possible at pH