THE RADIOCHEMISTRY OF PLUTONIUM - Sciencemadness.org

95% of Pu(IV) was removed from a 0.5 ~ Na2C03 solution by passage of 2000-bed
volumes at a flow rate of 1 ml/ cm2/min of the solution through an HTO column. The
absorption of Pu(IV) was not affected by tb.e pre aence of 5 mg/ 1 of U (VI). The absorp-
tion of Pu(VI) was only 20~0 in 1000-bed volumes under the same conditions. A possible
application of this system to recover Pu and other ions from carbonate wastes in
processing plants is discussed.
Paper Chromatography
Clanet 90 determined paper chromatographic Rf values for Pu(III), Pu(IV)
and Pu(VI), U(IV)J and U(VI), and Am(lII) in HC1-butanol mixtures (1:1) ranging from
1 to 10 M HC1. The Rf values “reached a matium around 6 M HC1 and ranged from
— —
0.27 for U(m) to 0.50 for U(VI), the other ions falling in between. The ions of lower
valency tended to have lower Rf values.
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Bildestein et al. separated U and Pu by several paper cbromatographic
methods, using different combinations of solvent and acid. The use of ion-exchange
paper to separate U and Pu was also reported by these w“orkers. For example, with
Whatman ET-20 using 6 M HC1 as a developer, the Rf values are 0.56 and 0.98 for U
—
and Pu, respectively. The oxidation states of the U and Pu were not specified.
Fink and Fink ’31 mve stigated many combinations of solvent and acid to
develop paper chromatograms of both Pu(IV) and Pu(VI). In most systems PuOV)
failed to move or streaked, but in a few cases moved quantitatively. The results
indicated Pu(VI) and U(VI) might be separated in a methyl ethyl ketone - dilute nitric
acid system.
Anion Exchange
The behavior of the actinide elements in various oxidation states on a
strong base anion exchange resin (typically Dowex 1 or 2) in HC1. is shown in Table IV-
29. Strong adsorption of the actinides in the higher ondation states (IV-VI) occurs at
HC1 concentrations above 6 ~ while resorption occurs below 2 M HC1.
—
TABLE IV- 29. Absorption and Resorption of Actinides on Strong Base Anion
Exchangers in HC1 Solutions
Oxidation State of
HC1 Concentration(~) for
Actinide Absorption(a) Resorption@)
m Not absorbed
IV 6-8 2-4
v 6-8 2-4
VI 2-3 0.1-1
(a)Kd . lo-10o for absorption.
(b) Kd = 0.1-1.0 for resorption.
A convenient way of separating Pu from other actinides and most other
elements is to adsorb Pu(IV) or Pu(VI) onto such a resin from > 6 M HC1 solution,
—
wash with HC1, and desorb by reducing the Pu to the trivalent with a suitable reducing
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