Separation of Neodymium (III) and Lanthanum (III) via a Flat Sheet-Supported Liquid Membrane with Different Extractant-Acid Systems

Lin Li; Ben Yu; Krystal Davis; Aaron King; Mauro Dal-Cin; Andrzej Nicalek; Naiying Du

doi:10.3390/membranes12121197

Separation of Neodymium (III) and Lanthanum (III) via a Flat Sheet-Supported Liquid Membrane with Different Extractant-Acid Systems

Membranes (Basel). 2022 Nov 28;12(12):1197. doi: 10.3390/membranes12121197.

Authors

Lin Li¹, Ben Yu¹, Krystal Davis¹, Aaron King¹, Mauro Dal-Cin¹, Andrzej Nicalek¹, Naiying Du¹

Affiliation

¹ National Research Council of Canada, Ottawa, ON K1A 0R6, Canada.

Abstract

The increasing demand for neodymium (Nd) permanent magnets in electric motors has revived research interest of Nd recovery and separation from other rare earth elements (REEs). Typically, Nd/La separation is necessary for Nd recovery from primary ores and secondary resource recycling. This research used a flat sheet-supported liquid membrane (FSSLM) with different extractant-acid systems to extract Nd from a Nd/La mixture. The recovery and separation of Nd/La with 204P-H₂SO₄, 507P-HCl, and TBP-HNO₃ were discussed. The results showed effective Nd recovery and promising Nd/La selectivity could be achieved in the 507P-HCl system, compared to 204P-H₂SO₄ and TBP-HNO₃. The addition of citric acid to the feed solution was effective for pH buffering but did not improve the Nd transport or Nd/La selectivity. Long-term stability of the 507P-HCl extractant system was demonstrated by extending the processing time from 6 h to 6 days.

Keywords: Lanthanum(III); Neodymium(III); extractant; solvent extraction; supported liquid membrane.

Grants and funding

This research was funded by the Office of Energy Research and Development (OERD) of Natural Resources Canada (NRC-20-07).