Scientific Achievement
A fundamental study demonstrating that tailored deep eutectic solvents selectively strip Nd³⁺ over Yb³⁺ from ion‑adsorption clays, with a choline chloride:lactic acid DES achieving high Nd³⁺ recovery and strong Nd³⁺/Yb³⁺ separation while retaining Yb³⁺ on the solid.
Significance and Impact
Tailored deep eutectic solvents provide a tunable, low‑volatility alternative to conventional lixiviants for rare‑earth recovery from ion‑adsorption clays. They link solvent composition to Nd³⁺/Yb³⁺ selectivity, establishing greener separation design principles that strengthen and diversify REE supply chains for clean energy and advanced technologies.
Research Details
- Deep eutectic solvents selectively strip Nd³⁺ over Yb³⁺ from REE‑loaded clay, rather than indiscriminately dissolving all REEs.
- A choline chloride:lactic acid (1:8) formulation emerges as an optimal DES, delivering high Nd³⁺ recovery and a Nd³⁺/Yb³⁺ separation factor of 8.85.
- DES composition, contact time, and temperature govern ion binding strength and coordination, providing design rules for tuning REE selectivity in greener media.
Shu-An Hsieh, Siyuan Liu, Faiyaz Md. Efaz, Dapeng Jing, Pan Sun, Scott A. Southern, Frederic A. Perras, Tanya Prozorov, Jared L. Anderson. "Adsorption of Rare Earth Elements by Kaolinite and Their Selective Desorption Using Deep Eutectic Solvents." ACS Appl. Nano Mater. 2026, 9, 437. https://doi.org/10.1021/acsanm.5c04729
The work was performed at Ames National Laboratory.