Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 7, pp. 1029−1033.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © E.E. Mal’tseva, A.A. Blokhin, Yu.V. Murashkin, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 7, pp. 1061−1065.
AND INDUSTRIAL INORGANIC CHEMISTRY
Kinetics of Rhenium Sorption from Weakly Basic
Macroporous and Gel Anion Exchangers Purolite A170
and Purolite A172 from Sulfuric Acid Solutions
E. E. Mal’tseva, A. A. Blokhin, and Yu. V. Murashkin
St. Petersburg State Technological Institute, St. Petersburg, Russia
Received March 14, 2012
Abstract—Effect of the grain size of anion exchangers, agitation intensity, and temperature on the kinetics of
rhenium sorption on weakly basic macroporous and gel anion exchangers Purolite A170 and Purolite A172 from
a 1 M H
solution was studied.
One of the most effective ways to recover rhenium
from acid solutions of various compositions is by the
ion-exchange method, which consists in selective
sorption of rhenium on a specially selected weakly
basic anion exchanger, desorption of rhenium with an
ammonia solution, and its recovery from the desorbate
in the form of ammonium perrhenate [1–3]. Among the
presently manufactured weakly basic anion exchangers,
a pronounced selectivity toward rhenium is exhibited
by anion exchangers Purolite A170 and Purolite A172,
which have the same functional groups and differ in the
matrix morphology [4, 5]. However, the choice of an ion
exchanger in development of an ion-exchange technique
for recovery of particular components from solutions is
determined not only by its selectivity and capacity for
the ion being recovered, but also by the rate of the ion-
exchange sorption process.
The goal of our study was to examine the kinetics
of rhenium sorption from a sulfuric acid solution on
weakly basic macroporous and gel anion exchangers
Purolite A170 and Purolite A172.
Anion exchangers Purolite A170 and Purolite A172
(in what follows, A170 and A172, respectively) were
preliminarily converted to the sulfate form and sieved
into 0.25–0.5- and 0.5–0.63-mm (A172) and 0.63–0.8-
and 1.0–1.5-mm (A170) fractions in the air-dry state.
The kinetics of rhenium sorption was analyzed by the
limited-volume method . The sorption was performed
from a 1 M H
solution with an initial rhenium
concentration of 1 g L
. In our experiments, we varied
the grain size of the anion exchangers, stirrer rotation
speed (200 and 400 rpm), and temperature (20, 30,
40, and 50°C). When studying the kinetics of rhenium
sorption, we charged a vessel with a 100-mL portion of
a starting solution, placed the vessel in a thermostat, and
kept it there until a prescribed temperature was reached.
Then, a weighed portion of an anion exchanger (1 g in
terms of dry mass) with certain grain size was placed
in a cell with apertures, whose design was described in
. The cell was attached to the axis of a mechanical
stirrer and brought in contact with the solution,
immediately after which agitation was switched on.
Under the action of the centrifugal force, the solution
was sucked into the cell through its bottom and then
was discharged into the vessel through side apertures,
passing in the process through the anion exchanger bed.
After certain intervals of time, the solution was sampled
for analysis for rhenium. The total volume of samples
did not exceed 1% of the total volume of the solution.
The equilibrium capacities of the anion exchangers were