ACIDIC ESTERS OF PHOSPHONIC ACID AS SELECTIVE EXTRACTANTS FOR METALLIC CATIONS SELECTED M(III) TRACER STUDIES

Journal Article · Tue Feb 28 23:00:00 EST 1961 · J. Inorg. & nuclear Chem.

DOI:https://doi.org/10.1016/0022-1902(61)80394-1· OSTI ID:4007099

Peppard, D F; Mason, G W; Hucher, I

English) The extraction of Pm(III), Cm(III), and Cf(III) from aqueous mineral acid phases of constant ionic strength into solutions of (G'O)(G)PO(OH) in toluene as carrier diluent was investigated as a function of hydrogen ion concentration in the aqueous phase, extractant concentration in the organic phase and the nature of G, using the radioactive tracer technique. The distribution ratio, K, defined for a given radioactive nuclide as its concentration in the organic phase divided by its concentration in the aqueous phase, has been found, for each of the M(III) examples studied, to have an inverse third-power dependency upon the hydrogen ion concentration in the aqueous phase and a direct thirdpower dependency upon the extractant concentration in the organic phase. For both Pm and Cm the value of K/sub s/ (an extraction constant empirically defined in the text) increases as G progresses: 2-ethyl hexyl to phenyl to chloro- methyl, the over all range exceeding 10/sup 5/. Selected (G'O)/sub 2/PO(OH) studies were included for comparison. In the one instance in which a direct comparison was made, in which G was 2-ethyl hexyl, the K/sub s/ in the (GO)(G)PO(OH) system was lower than that in the (GO)/sub 2/PO(OH) system by a factor of fifty for Pnn and 100 for Cm. The effect of a varying mu upon K/sub s/ and upon the application of liquid-liquid extraction to the determination of stability constants of metallic complexes in an aqueous phase was investigated briefly. The system, 2-ethyl hexyl hydrogen phenyl phosphonate (in toluene carrier diluent) vs. aqueous HCl + NaCl, mu = 1.0, was demonstrated to differentiate in favor of Cf with respect to Cm by a factor of approximately 105. The same extractant vs. an aqueous HCl phase differentiates between adjacent lantharides(III) by a factor of 2.8, the log K vs. Z plot being a line of constant positive slope throughout tbe range studied. The K/sub s/ for a specific lanthanide(III) in this system exceeds that in a comparable bis(2-ethyl hexyl) phosphoric acid vs. HCl system by a factor of approximately 200. (auth)

• Research Organization: Argonne National Lab., Ill.
• NSA Number: NSA-15-026120
• OSTI ID: 4007099
• Journal Information: J. Inorg. & nuclear Chem., Journal Name: J. Inorg. & nuclear Chem. Vol. Vol: 18
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACIDS
ALKYL RADICALS
CALIFORNIUM
CATIONS
CHEMISTRY
CURIUM
DEHPA
DISTRIBUTION
ESTERS
ETHYL RADICALS
HYDROCHLORIC ACID
HYDROGEN
IONS
MINERAL ACIDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHORIC ACID
PHOSPHORUS COMPOUNDS
PROMETHIUM
RADIOISOTOPES
RARE EARTHS
SOLUTIONS
SOLVENT EXTRACTION
STABILITY
TOLUENE
TRACER TECHNIQUES
WATER