1070-4272/05/7811-1801+2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 11, 2005, pp. 1801!1805. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 11,
2005, pp. 1833!1837.
Original Russian Text Copyright + 2005 by Anpilogova, Murinov.
AND ION-EXCHANGE PROCESSES
Selective Sorption of Pd(II) from Nitric!Nitrous Acid Solutions
Simulating PUREX Raffinates with Polymethylene Monosulfide
G. R. Anpilogova and Yu. I. Murinov
Institute of Organic Chemistry, Ufa Scientific Center, Russian Academy of Sciences, Ufa,
Received June 8, 2005
Abstract-Static sorption of Pd(II) from nitric and nitric!nitrous acid solutions, simulating PUREX raffinates,
with laboratory and semicommercial samples of polymethylene monosulfide is studied. The selectivity
of Pd(II) recovery from the simulated solutions is determined.
Currently there is a need in developing hydrometal-
lurgical methods for selective recovery of fission pal-
ladium from high-level raffinates, generated in the
course of reprocessing of spent nuclear fuel using
PUREX process [1, 2]. These aqueous solutions con-
tain 233.5 M HNO
, up to 5 mM Pd(II), and also
up to 10 mM radiolytic HNO
. Tatarchuk et al.
 have demonstrated that, because of strong effect
of nitrous acid in the raffinates, nitric acid solutions
cannot be considered as an adequate model in study-
ing sorption recovery of Pd(II). In simulated nitric3
nitrous acid solutions containing 5 mM Pd(II), 233M
, and up to 10 mM HNO
, the dominating
Pd(II) species are Pd
aqua cation, [PdNO
(<20%), and [Pd(NO
]. The rate of Pd(II) extraction
from such solutions with organic sulfides is consider-
ably higher than that from nitrate and chloride solu-
Since polymethylene monosulfide (PMS), complex-
ing heterochain sorbent, demonstrates high efficiency
and selectivity in recovering Pd(II) from highly saline
nitric acid solutions at room temperature over a wide
range of HNO
concentrations (035 M) , it was
advisable to examine the applicability of this sorbent
for selective recovery of Pd(II) from acidic nitrate3
nitrite solutions simulating PUREX raffinates.
Therefore, in this study we examined the efficiency
and selectivity of the sorption of Pd(II) from such
simulated solutions with laboratory and semicommer-
cial samples of PMS.
In this study we used two different PMS samples:
PMS1 synthesized under laboratory conditions and
PMS2, semicommercial sample partially oxidized as a
result of long-term storage (for several years), as
an aqueous paste (22% H
O). PMS1 was used as
prepared. PMS2 was conditioned as described in .
The samples were screened to obtain the 0.0103
0.020-cm fraction. The composition of the samples,
bulk density d, and the terminal acidic group concen-
tration are given in Table 1. The static exchange ca-
0.1 N NaOH
) was determined by the proce-
dure described in .
The sorption characteristics of the samples with
respect to Pd(II), Fe(III), and Pr(III) were determined
in the static mode at s : l = 1 : 200 at room tempera-
ture (19+ 1oC) or in temperature-controlled cells at
20+ 0.5oC (UH-4 thermostat). The contacting time
was 4 h, and the stirring rate, 800 rpm (magnetic
stirrer). Sorption of the metals from nitrate3nitrite
solutions was studied in the dark.
To prepare the working solutions, we used com-
mercial aqueous palladium(II) nitrate (5 M, pure
(analytically pure grade),
O (chemically pure grade),
O (pure grade), and also 25% aqueous
ammonia (ultrapure grade) and NH
for preparation of the eluents. The Pd(II) solution was
activated prior to use according to the procedure
described in . In the experiments we used nitrate
and nitrate3nitrite solutions containing 5.1+0.1 mM
Pd(II) and 234 M HNO
, simulating PUREX raffi-
nates in the concentrations of a series of components:
Pr(III) 0.0177, Fe(III) 0.0210, and NaNO
in mixed nitrate solutions and 0.010 M NaNO
nitrate3nitrite solutions. Also we used individual
Pr(III) nitric and nitric3nitrous acid solutions.