1070-4272/04/7711-1754C2004 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 77, No. 11, 2004, pp. 1754 !1756. Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 11,
2004, pp. 1772!1774.
Original Russian Text Copyright + 2004 by Akimbaeva, Ergozhin.
AND ION-EXCHANGE PROCESSES
Sorption of Gold(III) Ions from Hydrochloric Acid Solutions
by Aminated Shungite
A. M. Akimbaeva and E. E. Ergozhin
Bekturov Institute of Chemical Sciences, Ministry of Education and Science of Kazakhstan Republic,
Received August 4, 2004
Abstract-Sorption of gold ions by aminated shungite from chloride solutions was studied. The effects of
the solution pH and process duration on the degree of recovery were considered.
Sorption methods of concentrating precious metals
(PM) using various materials occupy a prominent
place in their analytical chemistry [1!3]. The use of
known organopolymer sorbents with good sorption
characteristics for PM recovery involves certain prob-
lems associated with their swelling, low rate of the
process, and insufficient desorption of metal ions .
Widely used activated carbons are able to sorb quanti-
tatively microamounts of platinum metal and gold
ions from solutions; however, the equilibrium is at-
tained within a rather long time, and the carbon re-
generation involves problems .
Recently we initiated studies of the sorption of PM
ions by modified shungites, which appeared to be
effective sorbents [4!6].
The sorption technology involving expensive
AM-2B anion exchanger is in wide use at enterprises
of gold mining industry of the Kazakhstan Republic
and CIS countries. Therefore, along with the problem
of increasing gold mining, the search for new avail-
able and cheap sorbents is necessary. We developed
anion exchangers based on modified epoxy and amino
derivatives of shungites abundant in our region [4! 6].
The results of recovering silver and platinum ions by
aminated natural sorbents showed that surface-modi-
fied shungite rocks quantitatively recover precious
metal ions within a short time [5, 6].
The study of sorption parameters of the new sor-
bent based on aminated shungite containing poly-
vinylpyridine in granules showed that functional
groups with nitrogen donor atoms determine its
chemical and analytical properties and its ability to
extract precious metal ions.
The aim of this work was a study of the properties
of aminated shungite as a sorbent for gold(III) ions
from standard solutions and the subsequent analytical
determination of these ions.
A shungite concentrate containing 80% carbon was
prepared by demineralizing natural shungite (20%
carbon) with subsequent granulation . Aminated
shungite was obtained by the polymerization of
2-methyl-5-vinylpyridine in shungite granules. Ac-
cording to the elemental analysis, the content of ni-
trogen in the aminated product was 27.16%; the
weight gain of the sorbent after polymerization was
We prepared the starting solution of gold(III) by
dissolving gold metal in a mixture of hydrochloric and
nitric acids (3 : 1) with subsequent boiling down with
concentrated HCl. Working solutions of gold(III) were
prepared by dilution of the starting H[AuCl
The required acidity was created by adding HCl and
NaOH and was monitored by an EV-74 pH-meter
with an ESL-43-07 glass electrode. The sorption of
gold(III) ions was studied under static conditions.
To study the process kinetics, we brought 0.5 g of the
sorbent into contact with 50 ml of Au(III) solution
). The mixture was stirred with a
magnetic stirrer at a rate of 400!500 min
temperature. At certain time intervals, we took sam-
ples and determined the metal ion concentration by
the atomic adsorption method on an AAS-3 spectrom-
eter in a propane!butane!air flame. The analytical
signal of gold was measured by the resonance line at
242.8 nm at the spectral aperture width of 0.25 nm
and the current of a lamp with a hollow cathode of
5 mA. The degree of gold(III) recovery was deter-
mined from the difference between the starting metal
ion concentration and its residual concentration in
the solution after sorption.