Solvent extraction by dialkyl-substituted diphosphonic acids in a depolymerizing diluent. Part II. Fe(III) and actinide ions.
In this work, the extraction of Am(III), U(VI), Th(IV) and Fe(III) by P,P{prime}-di(2-ethylhexyl) methylene- (H{sub 2}DEH[MDP]), ethylene- (H{sub 2}DEH[EDP]), and butylene- (H{sub 2}DEH[BuDP]) diphosphonic acids dissolved in the monomerizing diluent 1-decanol has been investigated. A comparison of the acid dependencies with those observed in o-xylene has revealed a number of novel features which have been ascribed to extraction of metal nitrates through a solvation mechanism made possible by facile transfer of nitrate ions into the 1-decanol phase. The use of 1-decanol as the diluent gives rise to strong suppression of metal extraction, which increases along the series Fe(III)<U(VI)<Am(III)<Th(IV) and H{sub 2}DEH[MDP]<H{sub 2}DEH[EDP]{<=}H{sub 2}DEH[BuDP]. The extractant dependencies of U(VI) and Th(IV) have slopes equal to 2 with all extractants. Those for Am(III) and Fe(III) exhibit variable slopes with limiting values of 1 at the lowest and 3 at the highest extractant concentrations. From the combined information provided by the acid and extractant dependencies, stoichiometries and probable structures for complexes formed in the organic phase have been proposed. The data obtained in this work suggest a simple route for actinide stripping from diphosphonic acid extractants loaded in nonpolar diluents.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- SC
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 943141
- Report Number(s):
- ANL/CHM/JA-37807
- Journal Information:
- Solvent Extr. Ion Exch., Journal Name: Solvent Extr. Ion Exch. Journal Issue: 3 ; 2001 Vol. 19; ISSN 0736-6299; ISSN SEIEDB
- Country of Publication:
- United States
- Language:
- ENGLISH
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