The effect of temperature on the synergistic extraction of thorium(IV) and uranium(VI) by 2-ethylhexyl phenylphosphonic acid and micelles of dinonyl naphthalene sulphonic acid

Journal Article · Sat Aug 01 04:00:00 EDT 1998 · Solvent Extraction and Ion Exchange

DOI:https://doi.org/10.1080/07360299808934574· OSTI ID:346976

Otu, E O ^[1]

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1. Indiana Univ., New Albany, IN (United States). Dept. of Chemistry

The influence of temperature in the range 15 to 75 C on the extraction of thorium(IV) and uranium(VI) from nitric acid solutions into ligroine solutions of 2-ethylhexyl phenylphosphonic acid (HEH{Phi}P), micellar dinonyl naphthalene sulfonic acid (HDNNS) extractants and mixture of the two extractants is reported. From the variation of the distribution ratio with temperature, the enthalpy changes associated with the extraction were determined, and an attempt was made to estimate the free energy and entropy changes associated with the extraction process. The results indicate that the extraction of thorium is favored by both entropy change and enthalpy change when the solvent is HEH{Phi}P and the mixture of HEH{Phi}P and HDNNS, but entropy controlled when HDNNS is the extractant. On the other hand, the extraction of uranium by HEH{Phi}P is enthalpy controlled by favored by entropy change when the solvent is HDNNS or a mixture of the two ligands. Temperature did not affect the extraction stoichiometry.

• Sponsoring Organization: USDOE
• OSTI ID: 346976
• Journal Information: Solvent Extraction and Ion Exchange, Journal Name: Solvent Extraction and Ion Exchange Journal Issue: 5 Vol. 16; ISSN 0736-6299; ISSN SEIEDB
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
40 CHEMISTRY
PHOSPHONIC ACIDS
SOLVENT EXTRACTION
SULFONIC ACIDS
TEMPERATURE DEPENDENCE
THERMODYNAMICS
THORIUM
URANIUM