Investigation of metal ion extraction and aggregate formation combining acidic and neutral organophosphorous reagents

Conference · Mon Jul 01 04:00:00 EDT 2013

OSTI ID:22264212

Braatz, A. D.; Nilsson, M. ^[1]; Ellis, R.; Antonio, M. ^[2]

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1. Department of Chemical Engineering and Materials Science, 916 Engineering Tower, University of California-Irvine, Irvine, CA 92697-2575 (United States)
2. Chemical Science and Engineering Division, Argonne National Laboratory, Building 200 9700 South Cass Ave, Argonne, IL 60439-4831 (United States)

In the present study, we investigate how varying mixtures of tri-n-butyl phosphate (TBP) and dibutyl phosphate (HDBP) results in enhanced extraction of lanthanum(III), La{sup 3+}, and dysprosium(III), Dy{sup 3+}. Water and metal ion extraction were carefully monitored as a function of TBP:HDBP mole ratio.In addition to these techniques, EXAFS was used to determine the coordination environment of the metal ion in this system. To produce the necessary signal, a concentration of 1.25*10{sup -3} M La{sup 3+} and Dy{sup 3+} was used. Although previous studies of synergistic extraction of metal cations using combinations of neutral and acidic reagents explain the enhanced extraction by increased dehydration of the metal ion and the formation of mixed extractant complexes, our evidence for the increased water extraction coupled with the aggregate formation suggests a reverse micellar aspect to synergism in the system containing TBP and HDBP. It is quite possible that both of these phenomena contribute to our system behavior. The EXAFS data shows that, based on coordination numbers alone, several possible structures may exist. From this study, we cannot provide a definitive answer as to the nature of extraction in this system or the exact complex formed during extraction.

• Research Organization: American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22264212
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
ABUNDANCE
CONCENTRATION RATIO
DYSPROSIUM IONS
ECOLOGICAL CONCENTRATION
FINE STRUCTURE
LANTHANUM
LANTHANUM IONS
TBP
X-RAY SPECTROSCOPY