Turkish Journal of Chemistry
Abstract
Rare earth elements (REEs) are increasingly being used in advanced materials, but their extraction remains a major challenge. This is primarily due to their nearly identical ionic radii and similarity in chemical and physical properties. Therefore, this study aims to explore the use of a hydrophobic protic ionic liquid (PIL) composed of decanoic acid and trioctylamine (TOA) to selectively extract scandium (Sc) from other REEs using acid or salt as the extraction medium. In the acidic medium, the extraction efficiency of all tested REEs was inversely proportional to the acid concentration. Meanwhile, the extraction percentage of Sc was significantly higher than that of other REEs in the HCl medium, showing that the condition could be used to selectively extract Sc. The results showed that HNO3 medium led to a higher overall extraction percentage but lower selectivity among REEs. The extraction efficiency of REEs in salt media was directly proportional to salt concentration. At higher salt concentrations, the extraction efficiencies became similar, suggesting that the condition could be used for collective extraction. At an organic-to-aqueous phase volume ratio of 0.7, Sc was fully extracted, and dysprosium extraction remained below 17%, offering a promising approach for the selective extraction of Sc from advanced materials and addressing a key challenge in REE separation.
Author ORCID Identifier
PIUS OLA: 0000-0003-4462-5750
REO NISHIOKA: 0009-0006-4908-469X
YOSHIRO TAHARA: 0000-0002-6818-3005
MICHIAKI MATSUMOTO: 0000-0001-6879-1150
DOI
10.55730/1300-0527.3745
Keywords
Selective extraction, scandium, rare earth elements, protic ionic liquid
First Page
470
Last Page
478
Publisher
The Scientific and Technological Research Council of Türkiye (TÜBİTAK)
Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
OLA, P. D, NISHIOKA, R, TAHARA, Y, & MATSUMOTO, M (2025). Selective extraction of scandium from other rare earth elements using a hydrophobic protic ionic liquid composed of decanoic acid and TOA. Turkish Journal of Chemistry 49 (4): 470-478. https://doi.org/10.55730/1300-0527.3745