| 1. |
- Ekberg, Christian, 1967, et al.
(författare)
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The structures of CyMe4-BTBP complexes of americium(III) and europium(III) in solvents used in solvent extraction, explaining their separation properties
- 2015
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 44:42, s. 18395-18402
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Tidskriftsartikel (refereegranskat)abstract
- Separation of trivalent actinoid (An(III)) and lanthanoid (Ln(III)) ions is extremely challenging due to their similar ionic radii and chemical properties. Poly-aromatic nitrogen compounds acting as tetradentate chelating ligands to the metal ions in the extraction, have the ability to sufficiently separate An(III) from Ln(III). One of these compounds, 6,6'-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzol[1,2,4]triazin-3-y l)-[2,2]bipyridine, CyMe4-BTBP, has proven to be resistant towards acidic environments and strong radiation from radioactive decomposition. EXAFS studies of the dicomplexes of CyMe4-BTBP with americium(III) and europium(III) in nitrobenzene, cyclohexanone, 1-hexanol, 1-octanol and malonamide (DMDOHEMA) in 1-octanol have been carried out to get a deeper understanding of the parameters responsible for the separation. The predominating complexes independent of solvent used are [Am(CyMe4-BTBP)(2)(NO3)](2+) and [Eu(CyMe4-BTBP)(2)](3+), respectively, which are present as outer-sphere ion-pairs with nitrate ions in the studied solvents with low relative permittivity. The presence of a nitrate ion in the first coordination sphere of the americium(III) complex compensates the charge density of the complex considerably in comparison when only outer-sphere ion-pairs are formed as for the [Eu(CyMe4-BTBP)(2)](3+) complex. The stability and solubility of a complex in a solvent with low relative permittivity increase with decreasing charge density. The [Am(CyMe4-BTBP)(2)(NO3)](2+) complex will therefore be increasingly soluble and stabilized over the [Eu(CyMe4-BTBP)(2)](3+) complex in solvents with decreasing relative permittivity of the solvent. The separation of americium(III) from europium(III) with CyMe4-BTBP as extraction agent will increase with decreasing relative permittivity of the solvent, and thereby also with decreasing solubility of CyMe4-BTBP. The choice of solvent is therefore a balance of a high separation factor and sufficient solubility of the CyMe4-BTBP ligand.
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| 2. |
- Halleröd, Jenny, 1987, et al.
(författare)
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Development of the Chalmers grouped actinide extraction process
- 2015
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Ingår i: Nukleonika. - : Walter de Gruyter GmbH. - 1508-5791 .- 0029-5922. ; 60:4, s. 829-835
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Tidskriftsartikel (refereegranskat)abstract
- Several solvents for Grouped ActiNide EXtraction (GANEX) processes have been investigated at Chalmers University of Technology in recent years. Four different GANEX solvents; cyclo-GANEX (CyMe4--BTBP, 30 vol.% tri-butyl phosphate (TBP) and cyclohexanone), DEHBA-GANEX (CyMe4-BTBP, 20 vol.% N,N-di-2(ethylhexyl) butyramide (DEHBA) and cyclohexanone), hexanol-GANEX (CyMe4-BTBP, 30 vol.% TBP and hexanol) and FS-13-GANEX (CyMe4-BTBP, 30 vol.% TBP and phenyl trifluoromethyl sulfone (FS-13)) have been studied and the results are discussed and compared in this work. The cyclohexanone based solvents show fast and high extraction of the actinides but a somewhat poor diluent stability in contact with the acidic aqueous phase. FS-13-GANEX display high separation factors between the actinides and lanthanides and a good radiolytic and hydrolytic stability. However, the distribution ratios of the actinides are lower, compared to the cyclohexanone based solvents. The hexanol-GANEX is a cheap solvent system using a rather stable diluent but the actinide extraction is, however, comparatively low.
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| 3. |
- Halleröd, Jenny, 1987, et al.
(författare)
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Stability of phenyl trifluoromethyl sulfone as diluent in a grouped actinide extraction process
- 2015
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 304:1, s. 287-291
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Tidskriftsartikel (refereegranskat)abstract
- In this work, stability experiments have been performed on a phenyl trifluoromethyl sulfone based solvent containing 6,6'-bis(5,6-dialkyl-[1,2,4-]triazin-3-yl)-2,2'-bipyridine and tri-butyl phosphate. This solvent is intended to be used in a grouped actinide extraction process for partitioning and transmutation purposes. The distribution ratio for americium was determined to approximately 20 and for europium approximately 0.26 giving a separation factor of 77. The solvent maintain good distribution ratios and separation factors during both gamma irradiation of 6.6 kGy h(-1) for up to 24 h and acid contact for up to 6 weeks at room temperature.
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