USE OF WOLLASTONITE FROM THE KOITASHSKOE DEPOSIT
IN THE PRODUCTION OF CERAMICS AND REFRACTORY MATERIALS
G. T. Adylov,
G. V. Voronov,
S. A. Gornostaeva,
N. A. Kulagina,
É. P. Mansurova,
and M. Kh. Rumi
Translated from Ogneupory i Tekhnicheskaya Keramika, No. 11, pp. 41 – 43, November, 2002.
Results for wollastonite from the Koitashskoe deposit used as a component for manufacturing faience and por
celain products, glazes, and refractory materials are presented. The use of wollastonite gives a positive eco
nomic effect, which is seen in the reduction of energy costs and rejection rate, and in the replacement of ex
pensive or not readily available materials without impairment of product quality.
Wollastonite is a nonmetallic mineral that has many uses
in numerous branches of national economies over the world.
Viewed chemically, wollastonite is calcium silicate (CaSiO
Wollastonite-based ceramic materials are well known to
technologists and have always been an issue of never-abating
interest for them. The reason behind this is that wollastonite
has important technological implications . As is known,
the addition of wollastonite to ceramic mixtures makes it
possible to shorten the firing time, to decrease the firing tem-
perature, to reduce shrinkage, to impart strength to the mate-
rial, etc. [2 – 3]. The wollastonite-containing material is used
for production of special radioceramics, porcelain and fai
ence, low-loss insulators, sanitary engineering components,
lining brick, glaze, flux, etc. Wollastonite added to glazes
renders them more resistant to cracking, spalling, and other
types of damage, and improves luster.
Wollastonite-based ceramics occupy a firm place among
refractory and lining materials for the aluminum industry.
They are used for fabricating filter containers, crystallizer in
serts, adapter plates, refractory lining components for molten
aluminum runners, etc. .
With regard for the vast reserves of wollastonite minerals
in the Republic of Uzbekistan and for improving the quality
of ceramic products, we have focused our research on
wollastonite rocks from the Koitashskoe deposit for their po
tential use in the manufacture of ceramic components, glaze,
and refractory materials.
The Koitashskoe deposit is located in the Galla-Aral’skii
district, Dzhizak Region. The raw materials were characte
rized using chemical analysis, x-ray diffraction, thermal and
microstructure methods. Wollastonite in the ore occurs in the
form of acicular, flabellate, or radial-axial aggregates. The
ore wollastonite concentration is normally 20 – 50% (here
and henceforth in mass fractions), rarely — 8 – 87%; on
average, it is 38%.
Typically, the chemical composition of wollastonite ores
is (%): SiO
, 31.99; Al
, 2.27; Fe
+ FeO, 1.32; TiO
0.09; CaO, 43.12; MgO, 1.47; MnO, 0.1; K
calcination loss, 17.34.
To prepare ceramic mixtures, we used VK-2-grade en
riched wollastonite concentrate whose major components
were wollastonite (70%), calcite (10%), quartz (10%), pyro
xene (5%), and granate (5%).
Wollastonite concentrate was added at a concentration of
5 – 15% to the ceramic mixtures for preparing electric insu
The plastic component of the mixture was enriched se
condary kaolin from the Angrenskoe deposit and bentonite
from the Navoiiskoe deposit. The flux and the nonplastics
were quartz-sericite and quartz-kaolinite-pyrophyllite rocks
from the Boinaksaiskoe deposit and alumina from the
The chemical composition of main mixture components
is given in Table 1, and the compositions of mixtures are
given in Table 2.
In the x-ray diffraction patterns of sintered specimens,
lines characteristic of mullite, quartz, cristobalite, and anor
thite appear with an increase in the concentration of
wollastonite in the mixture; also, the glassy phase tends to in
Characteristics of the ceramic prepared are given in Table 3.
Refractories and Industrial Ceramics Vol. 43, Nos. 11 – 12, 2002
1083-4877/02/1112-0359$27.00 © 2002 Plenum Publishing Corporation
Institute for Materials Science, Physics – Sun Research and Pro
duction Association, Academy of Sciences of the Republic of
Uzbekistan, Tashkent, Uzbekistan.