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Colloidal Model for the Prediction of the Extraction of Rare Earths Assisted by the Acidic Extractant
- Source :
- Langmuir, Langmuir, American Chemical Society, 2019, 35 (8), pp.3215-3230. ⟨10.1021/acs.langmuir.8b03846⟩, Langmuir, 2019, 35 (8), pp.3215-3230. ⟨10.1021/acs.langmuir.8b03846⟩
- Publication Year :
- 2019
- Publisher :
- HAL CCSD, 2019.
-
Abstract
- International audience; We propose the statistical thermodynamic model for the prediction of the liquid–liquid extraction efficiency in the case of rare-earth metal cations using the common bis(2-ethyl-hexyl)phosphoric acid (HDEHP) extractant. In this soft matter-based approach, the solutes are modeled as colloids. The leading terms in free-energy representation account for: the complexation, the formation of a highly curved extractant film, lateral interactions between the different extractant head groups in the film, configurational entropy of ions and water molecules, the dimerization, and the acidity of the HDEHP extractant. We provided a full framework for the multicomponent study of extraction systems. By taking into account these different contributions, we are able to establish the relation between the extraction and general complexation at any pH in the system. This further allowed us to rationalize the well-defined optimum in the extraction engineering design. Calculations show that there are multiple extraction regimes even in the case of lanthanide/acid system only. Each of these regimes is controlled by the formation of different species in the solvent phase, ranging from multiple metal cation-filled aggregates (at the low acid concentrations in the aqueous phase), to the pure acid-filled aggregates (at the high acid concentrations in the aqueous phase). These results are contrary to a long-standing opinion that liquid–liquid extraction can be modeled with only a few species. Therefore, a traditional multiple equilibria approach is abandoned in favor of polydisperse spherical aggregate formations, which are in dynamic equilibrium.
- Subjects :
- Colloidal model
solvent extraction
acidic extractants
self-assembly
Chemistry
Inorganic chemistry
Extraction (chemistry)
02 engineering and technology
Surfaces and Interfaces
010402 general chemistry
021001 nanoscience & nanotechnology
Condensed Matter Physics
01 natural sciences
0104 chemical sciences
Condensed Matter::Soft Condensed Matter
Thermodynamic model
Metal
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Colloid
visual_art
Electrochemistry
visual_art.visual_art_medium
General Materials Science
Physics::Chemical Physics
0210 nano-technology
Spectroscopy
Subjects
Details
- Language :
- English
- ISSN :
- 07437463 and 15205827
- Database :
- OpenAIRE
- Journal :
- Langmuir, Langmuir, American Chemical Society, 2019, 35 (8), pp.3215-3230. ⟨10.1021/acs.langmuir.8b03846⟩, Langmuir, 2019, 35 (8), pp.3215-3230. ⟨10.1021/acs.langmuir.8b03846⟩
- Accession number :
- edsair.doi.dedup.....57e3fd6055e51211c789304545bc163c
- Full Text :
- https://doi.org/10.1021/acs.langmuir.8b03846⟩