THE RADIOCHEMISTRY OF PLUTONIUM - Sciencemadness.org

affinity of several ions was Th(IV), U{IV) > U(VI), Fe(DI) > La(HI) > H+> CU(II),
Co(II), Ca(Jl) > Na+. Pu was not measured, but Pu(IV) would presumably be with Th
and U.
Inorganic Ion Exchangers
Although inorganic ion exchangers have been long known, they have been
largely superseded by the synthetic resins, principally because of the higher
capacities and more tractable physical characteristics obtainable in the synthetic
exchangers. However, experimentation has continued on natural and synthetic com-
pounds. In the actinide field this work has proceeded primarily toward the finding of
better separations from fission products. The inorganic exchangers are also quite
resistant to radiation damage, which is an advantage in process applications.
A general discussion of the ion exchange properties of hydrous oxides has
been given by Kraus et al. 242
Inorganic phosphates as ion exchange materisls have
been reported.
31,13r
The use of zirconium phosphate to separate Pu, U, and
fission products has been reported by Gal and Ruvarac.
140
Equilibrium distribution
coefficients for a number of ions are shown in Fig. 46, plotted agairmt nitric acid
concentration. The solution containing U, Pu and fission products was loaded onto a
column at O. 5 M HN03 + 0.02 M NaN02. The U, Ce, Sr, and Ru pass through the
— —
colurnm After washing the column, the Pu and Cs are removed with 8 M HN03. The
—
Zr and most. of the Nb stay on the column Of the ions studied, only Cs follows the
Pu and must be separated by an additional step.
Ahrland et al. 21, 22 studied the behavior of several ions on sflica gel
and proposed a separation of Pu, U and fission products similar to the one described
for zti conium phosphate above. The distribution coefficients are plotted as a function
of pH in Fig. 47, revealing an easy separation of ZrJ U, PUJ and other ions by pH
and vale ncy adjustment.
341
Rydberg
separated Zr-Nb from Pu by adsorption of the former on
silica gel from a 6 — M HN03 solution (see Procedure 11 in Sect. VHI).
112
Cvjet canin extracted Pu(VI) and U(VI) with hexone in the presence of
silica gel to effect a Zr-Nb separation
Cvjet canin and Cvjet canin
113 used a column of Mn02 to separate U and
Pu from long-lived fission products. The method is adsorb the fission products from
0.1 N HN03, w~e passing U(VI) and Pu(VI) through the colurmz
— over 99~0 of the Zr,
Ru, and Cs activity was adsorbed on the columm The capacity for zirconium for
Mn02 dried at 11 O“ C was determined to be 1 milliequivalent/ gram.
An exchanger composed of Zr and Si oxyhydrates has been prepared and
applied to Pu separations.
297
Pu has been concentrated from environmental water samples by chemi -
sorption of Pu(IV) on calcium fluoride from a nitric acid solution 352 (see Procedure
13 in Sect. V~).
Ke nmedy et al. 223 describe the absorption of Pu(IV), U(VI), Ru, Zr,
and Nb from aqueous carbonate solutions by hydrated titanium oxide (HTO). About
82