1070-4272/05/7811-1806C2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 11, 2005, pp. 1806!1812. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 11,
2005, pp. 1838!1844.
Original Russian Text Copyright + 2005 by Ovchinnikova, Glazunov, Starkov, Chernyak.
AND ION-EXCHANGE PROCESSES
Sorption of Silver and Chemiluminescent
Activity of Clinoptilolite
O. V. Ovchinnikova, O. O. Glazunov, E. N. Starkov, and A. S. Chernyak
Vinogradov Institute of Geochemistry, Siberian Division, Russian Academy of Sciences, Irkutsk, Russia
Irkutsk State University, Irkutsk, Russia
Received March 16, 2005
Abstract-Sorption conditions of ions and colloidal particles of silver by a zeolite (clinoptilolite) and clays,
and specific features of distribution of absorbed silver in clinoptilolite grains were studied. Temperature
dependences of the intensity of heterogeneous chemiluminescence from samples of natural clinoptilolite and
its modified forms were obtained. The activation energies of the luminescence-active chemisorption of oxygen
on electron-donor centers of the zeolite surface and relative amount of centers were determined.
Active search for effective means for concentrating
noble metals and ways to diminish their loss in their
secondary absorption by minerals in the slurry during
leaching, and also the need to elucidate the mechan-
ism of sorption processes that occur in nature make
urgent a study of sorption of ions and colloidal par-
ticles of gold and silver on inorganic ion exchangers
and minerals [1, 2]. A known mineral sorbent is a
natural zeolite, clinoptilolite, whose deposits widely
occur in Russia and other countries . The consider-
able resources of the zeolite, simplicity of its mining,
and its unique properties (acid resistance, selectivity,
thermal stability, etc.) promote studies of its structure
 and properties, aimed to reveal the possibility of
modifying this zeolite and extending its application
areas [3, 5, 6].
Previously we studied the absorption of complex
cations of gold and silver from acid thiourea solutions
by clinoptilolite from the Dzegvi deposit (Georgia)
. Later, data on the mechanism and kinetics of gold
sorption in the form of complex anions from hydro-
chloric acid solutions were reported . Further,
studies of the physicochemical parameters of zeolite
samples from deposits of Eastern Siberia and Far East
and the concentration of noble metals by these zeolites
were continued .
The aim of this study was to examine sorption of
ions and colloidal particles of silver by a natural zeo-
lite (clinoptilolite) and clays and to reveal possibilities
of using heterogeneous chemiluminescence for analy-
sis of the chemiluminescent activity of the surface
of clinoptilolite, its modified forms, and products
of silver sorption.
The clinoptilolite from the Shivyrtuiskoe deposit
(Transbaikalia) with grain size from 0.4 to 2.8 mm
The chemical composition of the clinoptilolite (%)
is presented below: SiO
2.20, FeO 0.10, CaO 4.20, CaCO
MgO 1.50, K 2.68, Na 0.76, Mn 0.12, calcination loss
In addition to clinoptilolite, the zeolite tuff contains
an admixture (up to 20%) of clayey minerals (mont-
morillonite, kaolinite, etc.), micas, quartz, and iron
oxides. In the composition of the crystalline phase,
the sample is close to clinoptilolite from the Tedzami
deposit (Georgia) .
As a major part of impurity minerals in clinoptilo-
lite tuffs is, as a rule, constituted by clays, which also
exhibit sorption properties, we studied also the sorp-
tion of silver by the most typical samples of clays
from deposits of Irkutsk oblast and by palygorskite
(Cherkassy deposit, Ukraine). Data on the chemical
composition of the clays are listed in Table 1.
The Bulusinsk clay is a mixture of kaolinite and
montmorillonite, and the Novorazvodninsk clay, a
mixture of silicon oxide with montmorillonite, albite,
Silver(I) solutions were obtained by dissolving
a precisely weighed portion of silver nitrate of chemi-
cally pure grade in double-distilled water (pH 6.9).
The zeolite and data on its chemical composition were placed
at authors’ disposal by Priargunskii Mining and Chemical
Combine, Joint-Stock Company.