STUDY OF THE EFFECT OF Al
AND THERMAL SHOCK RESISTANCE OF ACID-RESISTANT
REFRACTORIES USING A REGRESSION ANALYSIS METHOD
A. K. Kairakbaev,
V. Z. Abdrakhimov,
E. S. Abdrakhimova,
and A. V. Kolpakov
Translated from Novye Ogneupory, No. 5, pp. 58 – 62, May 2015.
Original article submitted November 27, 2014.
The dependence of the effect of Al
on acid-resistant refractory acid and thermal shock resistance is studied.
Regression analysis is used in this work, which is a basic method of contemporary mathematical statistics for
revealing concealed and implicit connections between observed data. A model dependence is plotted on the
basis of actual experimental results, and the dependence of test results is described analytically. Regression
analysis makes it possible to obtain mathematical models making it possible to predict ceramic properties at
points not within a series of experiments.
Keywords: acid-resistant refractories, kaolin clay, exhausted catalyst, regression analysis, acid resistance,
thermal shock resistance.
Acid-resistant refractory materials have a dense struc-
ture. They exhibit high strength, abrasion resistance, and re-
sistance to action of acids and gases . The demand for var-
ious branches of industry for acid-resistant materials com-
pels aiming at the most accessible raw material during their
output . Currently some experience of using technogenic
raw materials is applied to building material technology,
however usage volumes for these purposes is small.
In spite of the fact that in studying acid-resistant ceramic
objects there has been a considerable amount of work, the
mechanism of their acid resistance has not been studied ade
quately. An important index of acid-resistant materials is
thermal shock resistance, which mainly ensures their endur
ance in service. Thermal shock resistance governs the capac
ity of material to withstand sharp temperature variations
without breaking or loss of strength. However, there is no
single index qualitatively specifying thermal shock resis
tance for al ceramic materials.
The clay component used for producing acid-resistant
materials is Chapaevsk deposit kaolin clay of the following
mineral composition, wt.%: 45 – 50 kaolinite, 20 – 30 feld-
spar, 10 – 20 quartz, 3 – 4 calcite, 1 – 3 iron oxide, 1.8 – 2.0
organic impurities (humous substances). The average chemi-
cal composition of kaolin without enrichment is given in Ta-
ble 1. With respect to overall content (Al
is classified as a semi-acid clay with a high content of col
ored oxides (Fe
> 3%), with respect to particle size con
tent less than 0.005 mm (35 – 38%) it is coarsely dispersed,
with respect to plasticity it is medium-plastic plasticity num
ber 10 – 15), for drying sensitivity it is weakly sensitive, for
refractoriness it is refractory (refractoriness 1520 – 1550°C),
and with respect to sintering capacity it is medium-sintering
with a sintering range 100 – 120°C.
The shortening material used for acid-resistant material
production is exhausted catalyst IM-220 (see Table 1), repre
senting a high-alumina petrochemical slurry waste of the
Novokuibyshev Petrochenical Combine [2, 3]. This waste is
ditinguished from very fine powder-like materials of natural
and technogenic origin by a nanosize (from 80 to 3000 nm),
which depends on formation conditions. In order to prepare
refractory porous filler of exhausted catalyst IM-2201 with a
size from 100 – 200 nm is used. The effect of introducing
nanoparticles is expressed in the fact that within the system
not only do additional interfaces develop, but also they are a
carrier for quantum-mechanical phenomena. Presence within
the system of nanoparticles facilitates an increase in the vol
Refractories and Industrial Ceramics Vol. 56, No. 3, September, 2015
1083-4877/15/05603-0276 © 2015 Springer Science+Business Media New York
Kazakh-Russian International University, Aktobe, Kazakhstan.
FGBOU VPO Samara State Economic University, Samara, Rus
FGBOU VPO S. P. Korolev Samara State National Aerospace
University, Samara, Russia.