Influence of the nature of the components of extraction systems used for the extraction of radionuclides on the interfacial tension. VIII. compounds of thorium(IV) nitrate with di-2-ethylhexylphosphoric acid
The influence of the type of metal compounds formed in the organic phase under various conditions of extraction on the interfacial tension at the interface with aqueous nitric acid solutions was studied on the example of systems including the extraction of Th(IV) by di-2-ethylhexylphosphoric acid (D2EHPA). It was established that a solvate of the Th(NO/sub 3/)/sub 4/ . (HA)/sub 2/ type (where A/sup -/ is the D2EHPA anion), extracted from a 6 M HNO/sub 3/ solution, does not differ in interfacial activity from free D2EHPA. This can be explained by the fact that the D2EHPA molecules contained in the solvate are bonded to the neutral metal atom only through the P=O groups, while the hydrophilic -OH groups of the indicated molecules remain free and preserve the interfacial activity of the solvate. The same pattern was found for compounds with the composition Th(NO/sub 3/) . (HA/sub 2/)/sub 3/, which also contain free -OH groups of D2EHPA, extracted from a solution of 1 N HNO/sub 3/. The addition of tributyl phosphate (TBP) to the latter system in an amount sufficient to replace the D2EHPA molecules not bound in a chelate and to form a chelatosolvate, for example, Th(NO/sub 3/)A/sub 3/ . Th(NO/sub 3/)/sub 4/ . 3TBP, in which all the D2EHPA molecules are bonded to thorium by chelate bonds, while the remaining coordination places are occupied by tributyl phosphate, leads to a substantial increase in the interfacial tension in the system. The results obtained indicate the following general principle: the formation of extractable compounds of metals, in which all the hydrophilic groups of the extraction reagent molecules prove to be bound, leads to a substantial decrease in the interfacial activity of these compounds in comparison with the corresponding extraction reagents.
- OSTI ID:
- 5973242
- Journal Information:
- Sov. Radiochem. (Engl. Transl.); (United States), Vol. 27:2; Other Information: Translated from Radiokhimiya, Vol. 27, No. 2, pp. 179-183, March-April, 1985
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NITRIC ACID
SURFACE TENSION
PHOSPHORIC ACID
THORIUM ISOTOPES
SOLVENT EXTRACTION
THORIUM NITRATES
ACTIVATION ENERGY
AQUEOUS SOLUTIONS
ISOTOPE SEPARATION
RADIOCHEMISTRY
REAGENTS
ACTINIDE COMPOUNDS
ACTINIDE ISOTOPES
CHEMISTRY
DISPERSIONS
ENERGY
EXTRACTION
HYDROGEN COMPOUNDS
INORGANIC ACIDS
ISOTOPES
MIXTURES
NITRATES
NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
SEPARATION PROCESSES
SOLUTIONS
SURFACE PROPERTIES
THORIUM COMPOUNDS
400700* - Radiochemistry & Nuclear Chemistry