Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 10, pp. 1767−1773.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
O.N. Kononova, A.S. Glebova, A.M. Mel’nikov, D.M. Kashirin, S.G. Konontsev, 2010, published in Zhurnal Prikladnoi Khimii,
2010, Vol. 83, No. 10, pp. 1628−1634.
OF SYSTEMS AND PROCESSES
Sorption Recovery of Rhodium(III) from Chloride
and Chloride-Sulﬁ de Solutions
O. N. Kononova, A. S. Glebova, A. M. Mel’nikov, D. M. Kashirin, and S. G. Konontsev
Siberian Federal University, Krasnoyarsk, Russia
Received December 17, 2009
Abstract—Sorption of rhodium(III) from chloride and chloride-sulfate solutions on anion exchangers of varied
physical and chemical structure was studied.
Platinum metals with unique properties are widely
used in various industries, with the demand for these
metals steadily increasing . However, the exhaustion
of natural resources of noble metals makes necessary
their recovery from secondary sources and, in particular,
from spent catalysts [1, 2]. Platinum metals and, in
particular, rhodium are recovered from secondary raw
materials by precipitation, extraction, and sorption on
activated carbons and other sorbents [1–8]. Of particular
importance in this case is the sorption concentration
on ion exchangers, which is characterized by high
efﬁ ciency, selectivity, and ecological safety, and can
be conveniently combined with methods employed in
subsequent determination of noble metals [1, 3–5, 9–12].
Materials containing noble metals are commonly
decomposed and the metals are transferred to solution
by using aqua regia, as well as by fusion, chlorination,
assay analysis, and other methods [1, 8–10, 13, 14]. As
a result, solutions of complex noble metal compounds
differing in stability and chemical inertness are obtained.
In addition, platinum metal complexes are subjected to
hydrolysis and activation [1, 15–17]. Because of the
complexity of systems of this kind, the sorption recovery
of noble metals may be hindered and associated with
loss of valuable components, and, therefore, improving
the sorption selectivity is a topical task. In this context,
it is necessary to study the sorption concentration of
platinum metals from model solutions, which could
make it possible to choose conditions for raising the
degree of sorption, possibly dependent on the solution
acidity, nature and concentration of components, and
composition of complexes [1, 15–18].
At present, the best studied solutions are hydrochloric
and chloride solutions of noble metals [1, 3–5, 15–17,
19, 20]. Researchers’ attention has also been attracted by
sulfate solutions, especially those of rhodium, iridium,
and ruthenium, because, in sulfuric acid media, these
metals can exist in uncommon and uncharacteristic
oxidation states and can be easily converted from one
oxidation state to another [1, 15–17, 21–24]. However,
chloride-sulfate solutions of rhodium(III) have hardly
been studied at all, although in the opinion of the
authors of , they must be more effective in recovery
of rhodium from secondary sources.
The present study is concerned with the sorption
concentration of rhodium(III) from chloride-sulfate
solutions, with these systems compared with chloride
The starting solution of rhodium(III) was prepared
by sintering a weighed portion of metallic rhodium
(0.5 g) with barium peroxide (2.5 g) in a mufﬂ e
furnace at a temperature of 800–900°C for 1–2 h .
The resulting solution of H
] was transferred
to a 200-ml volumetric ﬂ ask and brought to the mark
with distilled water. The initial concentration of
hydrochloric acid in this solution was 6 M, and the
rhodium(III) concentration, 9.0 mM. Working solutions