Separation of Rare Earths by Solvent Extraction with an Undiluted Nitrate Ionic Liquid
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- 作者：Kristian Larsson ; Koen Binnemans
- 关键词：Ionic liquids ; Hydrometallurgy ; Lanthanides ; Rare earths ; Solvent extraction
- 刊名：Journal of Sustainable Metallurgy
- 出版年：2017
- 出版时间：March 2017
- 年：2017
- 卷：3
- 期：1
- 页码：73-78
- 全文大小：481KB
- 刊物类别：Metallic Materials; Sustainable Development; Industrial Chemistry/Chemical Engineering;
- 刊物主题：Sustainable Development; Metallic Materials;
- 出版者：Springer International Publishing
- ISSN：2199-3831
- 卷排序：3
文摘
A solvent extraction system based on the ionic liquid tricaprylmethylammonium nitrate, [A336][NO3], has been investigated for separation of mixtures of rare earth elements (REE) at high total REE concentrations (up to 2 M). The chelating agent EDTA was added to the aqueous nitrate feed solution to increase the separation factors (SFs). This improvement of the SFs is based on the fact that [A336][NO3] extracts the light REE (LREE) stronger than the heavy REE (HREE), whereas a chelating agent forms more stable complexes with the HREE than with the LREE. The combination of these two effects makes that the LREE are even more efficiently extracted than in the absence of a chelating agent. The most efficient separation of the LREE La–Nd from the other REE was obtained using a total initial REE concentration of 1 M, an EDTA concentration of 0.2 M, and a total nitrate concentration of 11 M. Stripping of the extracted REE from the ionic liquid phase could be done using water.