M. Lamb, S.J. Popova
Oak Ridge National Laboratory,
United States
Keywords: REE separation
Summary:
Rare earth elements (REEs) are critical materials used in advanced technologies, making them vital for economic growth. It is estimated that the demand for magnetic REEs will triple by 2025. With about 90% of the worlds refined rare earth materials being processed in China, it’s critical to develop more efficient separation and purification processes for individual REEs. REEs have similar chemical properties and occur together in natural ores, making the separation process difficult. Solvent extraction is one of the most effective methods for REE separation but can take upwards of 100 processing steps to separate one REE. With the harsh conditions and negative environmental impact, there is plenty of room for improvement. Our present work is looking at replacing the conventional REE separation process using mono-2-ethylhexyl (2-ethylhexyl)phosphonate (PC88A) with an improved two ligand approach process. By using lipophilic N,N,N′,N′-tetraalkyldiglycolamide (DGA-6) with a hydrophilic, lighter REE-selective agent N,N,N',N'-tetraalkyl-3,6-dioxaoctanediamide (DOODA) we create a “Tug of War” concept to improve the separation of the middle and heavy REEs. With this approach we can achieve higher selectivity and significantly reduce the number of processing steps, while maintaining the same throughput. This presentation will highlight our recent results and demonstrate how we can achieve efficient separation of REEs with fewer processing steps using neutral ligands.