skip to main content

SciTech ConnectSciTech Connect

Title: Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction

In this paper, the rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets and industrial scrap magnets via membrane assisted solvent extraction (MSX). A hollow fiber membrane system was evaluated to extract REEs in a single step with the feed and strip solutions circulating continuously through the MSX system. The effects of several experimental variables on REE extraction such as flow rate, concentration of REEs in the feed solution, membrane configuration, and composition of acids were investigated with the MSX system. A multimembrane module configuration with REEs dissolved in aqueous nitric acid solutions showed high selectivity for REE extraction with no coextraction of non-REEs, whereas the use of aqueous hydrochloric acid solution resulted in coextraction of non-REEs due to the formation of chloroanions of non-REEs. The REE oxides were recovered from the strip solution through precipitation, drying, and annealing steps. Finally, the resulting REE oxides were characterized with XRD, SEM-EDX, and ICP-OES, demonstrating that the membrane assisted solvent extraction is capable of selectively recovering pure REEs from the industrial scrap magnets.
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Nuclear Materials Processing Group
  3. Idaho National Lab. (INL), Idaho Falls, ID (United States). Center for Advanced Energy Studies
  4. Molycorp Magnequench, Greenwood Village, CO (United States)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Environmental Science and Technology
Additional Journal Information:
Journal Volume: 49; Journal Issue: 16; Journal ID: ISSN 0013-936X
American Chemical Society (ACS)
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Critical Materials Institute (CMI)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Advanced Manufacturing Office (EE-5A)
Contributing Orgs:
Idaho National Lab. (INL), Idaho Falls, ID (United States)
Country of Publication:
United States
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY membrane solvent extraction; rare earth elements; hollow fiber membrane; extractant