Magnetic Field Directed Rare‐Earth Separations. (12th December 2019)

• Record Type: Journal Article
• Authors: Higgins, Robert F.; Cheisson, Thibault; Cole, Bren E.; Manor, Brian C.; Carroll, Patrick J.; Schelter, Eric J.
• Is Part Of: Angewandte Chemie. Volume 132:Number 5(2020)
• Page Start: 1867
• Page End: 1872
• Publication Date: 2019-12-12
• Subjects: Koordinationschemie -- Kristallographie -- Magnetismus -- Seltene Erden -- Stofftrennung; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201911606
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The separation of rare‐earth ions from one another is challenging due to their chemical and physical similarities. Nearly all rare‐earth separations rely upon small changes in ionic radii to direct speciation or reactivity. Herein, we show that the intrinsic magnetic properties of the rare‐earth ions impact the separations of light/heavy and selected heavy/heavy binary mixtures. Using TriNOx 3− ([{(2‐ t BuNO)C6 H4 CH2 }3 N] 3− ) rare‐earth complexes, we efficiently and selectively crystallized heavy rare earths (Tb–Yb) from a mixture with light rare earths (La and Nd) in the presence of an external Fe14 Nd2 B magnet, concomitant with the introduction of a concentration gradient (decrease in temperature). The optimal separation was observed for an equimolar mixture of La:Dy, which gave an enrichment factor of EF La:Dy =297±31 for the solid fraction, compared to EF La:Dy =159±22 in the absence of the field, and achieving a 99.7 % pure Dy sample in one step. These results indicate that the application of a magnetic field can improve performance in a molecular separation system for paramagnetic rare‐earth cations. Abstract : Feine Unterschiede : Die Stofftrennung von Seltenerdelementen beruht normalerweise auf kleinen Differenzen in den Ionenradien der dreiwertigen Oxidationsstufe. Ein Trennverfahren für Seltenerdelemente wurde entwickelt, das durch das Vorhandensein eines externen Magnetfeldes verstärkt wird.