Simultaneous recovery of rare earth elements from waste permanent magnet (WPMs) leach liquor by solvent extraction and hollow fiber supported liquid membrane

Abstract Recovery of rare earth elements (REEs) i.e. neodymium (Nd), dysprosium (Dy), and praseodymium (Pr) from waste permanent magnet (WPMs) leach liquor has been investigated using solvent extraction followed by hollow fiber supported liquid membrane (HFSLM). In the solvent extraction studies, optimum parameters have been obtained for 1 mol/L D2EHPA at pH 2 and 2 mol/L nitric acid for stripping agent. In the HFSLM system, the best percentage achieved at 90 minutes for neodymium, dysprosium, and praseodymium was 58.62%, 98.46, and 85.59%, as well as for the recovery 63.13%, 15.21%, and 56.29%, respectively. In this study, the optimum transport rate was achieved at 90 minutes, the transport of rare earth’s ion follows the order was Nd > Pr > Dy. The highest transport and permeability coefficient of rare earths ion was achieved by neodymium with values of 0.0083 min-1 (R2>0.94) and 9.34 × 10-8cm s-1, respectively. According to the results, HFSLM system is a promising and feasible technique for the recovery of REEs and separation REEs from iron in WPMs leach liquor. HFSLM system was successfully applied in the lab-scale for the recycling of REEs from industrial waste materials.