SCIENTIFIC RESEARCH AND DEVELOPMENT
EFFICIENCY OF ADDING VERY FINE SILICA IN HIGH-ALUMINA
AND CORUNDUM CERAMIC CONCRETE TECHNOLOGY. PART 1
Yu. E. Pivinskii
and P. V. Dyakin
Translated from Novye Ogneupory, No. 1, pp. 32 – 38, January 2009.
Original article submitted November 14, 2008.
Experimental data are provided and summarized for the efficiency of adding very fine quartz glass (VFQG) in
high-alumina and corundum ceramic concrete technology. Similar suspensions are prepared for very fine
quartz sand (VFQS) and a mixed suspension in the bauxite – VFQS system. The properties of both mixed sus
pensions and some materials based on them are studied.
Keywords: ceramic concretes, highly concentrated binding suspension (HCBS), low-cement refractory con
crete (LCRC), microsilica, micro-silicon dioxide, very fine quartz glass (VFQG), very fine quartz sand
(VFQS), mixed suspensions, mullite, integral and differential curves.
A basic tendency in development of the refractory indus-
try is expansion of production and application of
multifunctional molded and unmolded refractory objects
with improved operating characteristics . In this respect a
significant role may be played by improved (with respect to
technology and properties) high-alumina and corundum
There is a common tendency of increasing the proportion
of out put and use of unmolded refractories whose produc
tion in Japan reached 67% . Here refractory concretes,
torcrete mixes within the balance of unmolded refractories is
about 70%. It is supposed that 60 – 70% of the latter relate in
composition to high-alumina or corundum refractories
whose production is spread universally. Taking this factor
into account and the known volume of production in Japan of
molded objects of this chemical and mineral composition, it
may be assumed that in the overall balance of refractories
they are in first place. According to data , production of
high-alumina and corundum objects in Russia is insignificant
(116 thousand tons/year) and is less by about a factor of
seven than chamotte refractories, i.e. within the country as
before chamotte molded refractories predominate. In addi
tion the development of the production noted in recent years
in the field of unmolded refractories in Russia mainly con-
cerns high-alumina and corundum materials.
In order to improve the quality of low-cement refractory
concretes (LCRC) of high-alumina and corundum composi-
tions there is extensive use of addition of very fine amor-
phous silica, given the name micro-silica or micro-silicon
oxide (MS) [3, 4]. The main form of high-alumina
refractories may be considered as ceramic concrete, i.e.
molded or unmolded refractories (vibration poured and
rammed concretes, torcrete mixes), prepared on the basis of
HCBS and refractory fillers [5, 6].
EFFECT OF VERY FINE QUARTZ GLASS (VFQG)
ON CERAMIC CONCRETE PROPERTIES
Applied to LCRC technology addition micro-silica has a
polyfunctional effect consisting of improving both the
rheotechnological properties of the original molding systems
and also the properties of refractory concretes prepared with
this addition. It is well known that the size of the finest parti
cles in LCRC matrix systems (reactive alumina, high-alu
mina cement (HAC)) is 0.5 – 0.1 mm. In this case the MS
particles introduced are a unique microfiller. On mixing (sus
pension) they are packed within the gaps between relatively
coarse matrix system particles, that is accompanied by dis
placement of dispersed medium particles. Thus, as a result of
introducing microfiller in the form of MS it is possible to re
duce either the viscosity of the molding system with different
Refractories and Industrial Ceramics Vol. 50, No. 1, 2009
1083-4877/09/5001-0043 © 2009 Springer Science+Business Media, Inc.
OOO NVF Kerambet-Ogneupor, Saint Petersburg, Russia.
Saint Petersburg State Institute of Technology (Technical Univer
sity), Saint Petersburg, Russia.