RESEARCH IN THE FIELD OF PREPARING MOLDED
AND UNMOLDED REFRACTORIES BASED ON HIGH-ALUMINA HCBS.
PART 8. EFFECT OF FIRING TEMPERATURE ON PROPERTIES
OF MATERIALS BASED ON MIXED HCBS COMPOSITION:
BAUXITE, QUARTZ GLASS, AND REACTIVE ALUMINA
Yu. E. Pivinskii,
P. V. Dyakin,
and A. Yu. Kolobov
Translated from Novye Ogneupory, No. 12, pp. 26 – 35, December 2016.
Original article submitted April 5, 2016.
The effect of firing temperature on shrinkage or growth indices, porosity, and ultimate strength in bending is
studied in specimens prepared from bauxite HCBS, and also additionally containing reactive alumina
CTC-30. For all material compositions there are typical preferred sintering temperature ranges
(900 – 1200°C) with prevalent mullitization accompanied by an increase (1200 – 1400°C) in sintering or
shrinkage of mullitized material (1400 – 1600°C).
Keywords: HCBS, bauxite, reactive alumina, quartz glass, sintering, mullitization, non0isothermal heating,
shrinkage, growth, ultimate strength in bending.
As applied to technology of high-alumina or corundum
ceramic concretes for different purposes the material of their
matrix system may be specified by different Al
Therefore it may be promising not only to study bauxite
HCBS with addition of very fine quartz glass (VFQG)
[1 – 4], but also HCBS prepared on the basis of high purity
forms of reactive alumina , and also binary systems pre
pared on the basis of these HCBS [5 – 7]. It should be noted
that one of the possible reserves for development of
high-alumina HCBS technology and ceramic concretes con
sists of the following. Until recently in ceramic concrete
technology there has primarily been use of standard raw ma
terials, having a significant impurity content. This leads to
unavoidable deterioration of a number of their properties (for
example a reduction in high-temperature strength). Therefore
use in ceramic concretes of high-purity and synthetic raw
materials, which are normal for producing refractory con-
crete, will make it possible to increase the level of ceramic
concrete property indices to values exceeding those for the
best contemporary low-cement concretes [1, p. 650].
In particular, results of our previous studies performed
using quite pure mullite that in a test order was synthesized
by the Pervoural Dinas Plant, point to the promising nature
of creating mullite-corundum concretes. On the basis of pure
mullite HCBS was prepared with a volume concentration
= 0.75. The process of vibration compaction and vibra
tion casting of ceramic concretes with a corundum filler was
accomplished with a moisture content of 3.2 and 4.5% .
In the present work the effect of heating temperature and
isothermal firing on the properties of specimens was studied,
prepared both on the basis of fired Chinese bauxite contain
ing 11% VFQG, and also containing addition of 10 – 30
highly pure (99.9%) reactive alumina grade CTC-30 (pro
duced by Almatis).
AND SPECIMEN PROPERTIES
In contrast to preceding work of this series of publica
tions [9 – 16], where the starting material was Chinese baux
Refractories and Industrial Ceramics Vol. 57, No. 6, March, 2017
1083-4877/17/05706-0637 © 2017 Springer Science+Business Media New York
Parts 1 – 3 of the article were published in Novye Ogneupory
Nos. 8, 10, and 12 (2015), and parts 4 – 7 in Nos. 2, 4, 6, and 10
OOO NVF Kerambet-Ogneupor, St. Petersburg, Russia.
FGBOU VPO St. Petersburg State Technological University
(Technical University), St. Petersburg, Russia.
OAO Dinur, Pervoural’sk, Russia.