STUDY OF THE MATERIAL PROPERTIES OF MICACEOUS
VERMICULITE MINERALS OF THE TEBINBULAK DEPOSIT
V. I. Andronova
and P. A. Arifov
Translated from Novye Ogneupory, No. 10, pp. 57 – 62, October 2007.
Original article submitted July 16, 2007.
Studies are performed on the material composition of micaceous minerals of the vermiculite series in the
Tebinbulak deposit. It is established that the micaceous materials studied consist of Mg-biotite, Mg-, Na- and
Ca-hydrobiotite, and the chemical formula for the minerals is worked out. Results of the studies are of consi
derable practical value for developing the technology for preparing expanded vermiculite and preparing vari
ous materials based upon it.
Vermiculite, formed from magnesium-iron micas, i.e. bi-
otite and phlogopite, has practical applications. Under natu-
ral conditions vermiculitization of these micas occurs very
slowly and therefore in minerals not only the final products
of the process, i.e. vermiculite, are encountered, but also
hydrated mica to a different degree of hydration .
There are many deposits of vermiculite. The composition
of micaceous minerals of any deposit has marked differ-
ences. Known deposits of vermiculite ore in the USA (Libby,
Montana and Epury, South Carolina) whose overall reserve
is estimated as 250 – 500 thousand tons and the content of
vermiculite in the rocks is on average 50%, for example rep
resented mainly by weathered vermiculite and hydrophlo
gopite with a different degree of hydration [2, 3].
One of the largest deposits of vermiculite rock, located in
the Republic of South Africa (Lulekon deposit), is repre
sented by micaceous minerals of vermiculite in the form of
two varieties: vermiculite of high quality of golden-brown
color, and hydrobiotite a little worse in quality. A feature of
this deposit is the fact that the natural value of the pH of the
water suspension of micaceous minerals of vermiculite is
6.5, which provides the possibility of using them in hydro
ponics. Vermiculite of the deposit is exported i large amounts
to Japan .
In South West Africa in the territory of Rhodesia there is
a deposit of copper-containing vermiculite. In Uganda and
Sudan deposits of vermiculite in an ore-bearing zone have
been discovered laid down with alkali and carbonate rocks.
The ore consists of phlogopite and vermiculite, within whose
crystal composition there are Ca
ions, so-called calcium
hydrophlogopite. In Sierra Leone in Hangha chromite de-
posit vermiculite is mined containing cations of chromium of
different valency .
A large deposit of vermiculite in Russia is the Kordovsk
deposit in the Murmansk region represented by micaceous
minerals Mg-hydrophlogopite, Mg-vermiculite, weathered
vermiculite and sungulite. The Barchinsk deposit consists of
Ca-hydrophlogopite and Ca- and Na-vermiculite.
The technological properties of micaceous minerals of
vermiculite depend on raw material chemical composition;
the degree of mica hydration, i.e. the amount of water mole
cules within the crystal structure of the original material; the
form of interlayer cations; grain a size and firing regime
(maximum temperature, rate and duration of heating) .
The aim of this work is to study the material composition
of micaceous minerals of vermiculite of the Tebinbulak de
posit that until recently have not been studied in detail.
The Tebinbulak vermiculite deposit is located in the north
ern part of the Sultanuizdag range, 70 km to the south-west
of Nukus of the Uzbekistan Republic. The overall amount of
reserves of vermiculite rock, according to geological calcula
tion, consists of 1,332,520 tons containing 10 – 30% of ver
miculite in ore.
In order to study the material composition of micaceous
minerals of vermiculite the vermiculite ore was taken from
different areas, averaged, and concentrated by elutriation and
screening on a concentration table. Under laboratory condi
tions vermiculite concentrate was obtained is three forms of
micaceous minerals, i.e. dark, dark gray with dark shades,
and dark brown colors. Electron microscope and petro
graphic analysis showed that single crystals of dark color are
Refractories and Industrial Ceramics Vol. 48, No. 5, 2007
1083-4877/07/4805-0373 © 2007 Springer Science+Business Media, Inc.
Institute of General and Inorganic Chemistry, Academy of Sci
ences of the Republic of Uzbekistan.