EFFECT OF FIRING TEMPERATURE AND GAS ATMOSPHERE
ON ACID-RESISTANT MATERIAL PORE STRUCTURE FORMATION
E. S. Abdrakhimova
and V. Z. Abdrakhimov
Translated from Novye Ogneupory, No. 1, pp. 56 – 61, January, 2016.
Original article submitted September 2, 2015.
A dependence is established for acid-resistant material pore structure on firing temperature and gas parame
ters. It is expedient to fire acid-resistant materials up to 1100°C in an oxidizing atmosphere, and at
1100 – 1200°C in a reducing atmosphere. With this regime firing provides an improvement for acid-resistant
material pore structure.
Keywords: argillaceous part of zircon-ilmenite ore gravitation tailings (ZIG), feldspar concentrate (FSC),
pyrophyllite, acid-resistant material, pore structure.
An important factor governing the main physicotechnical
properties of ceramic objects is their pore structure. A con-
siderable amount of research in various scientific fields has
been devoted to studying porosity. However, processes of
pore formation and the final structure of ceramic objects
have not been studied adequately.
It has been established [1 – 3] that the most critical pores
have a size of 10
m. Pores with a size of less than
m are not critical since water does not freeze within
them. Researchers Berkman and Mel’nikov consider that
pores with a size of 10
m are redundant . Galperin
considers the most critical pore size of 10
m, and re
dundant pores concern sizes of 10
m . It has been
established [4 – 7] that if the radius of capillary pores is more
m, then they cannot be filled with water due to
moisture absorption from moist air and conversely deliver
moisture to the atmosphere. Thus, macrocapillary pores may
only be filled with water on direct contact with it. Such con
siderable scatter in the sizes of critical and noncritical pores
is are due not only to procedural features of studying a po
rous-capillary structure, but also forms of ceramic materials
studied by the authors. Creation of a single classification for
pores and porous materials and media is connected with sig
nificant difficulties, and therefore there is currently no gener-
ally accepted classification for ceramic materials.
The considerable demand of different branches of the na-
tional economy for acid-resistant materials is aimed at the
ceramic industry for use of accessible and cheap raw mate-
rial [8 – 10].
Results are given in this article for studying the effect of
temperature and gas atmosphere at different firing tempera-
tures on acid-resistant material pore structure formation, pre
pared on the basis of the argillaceous part of zircon-ilmenite
ore gravitation tailings (ZIG), a by-product of rare-earth met
als, and pyrophyllite.
For manufacturing acid-resistant materials the argilla
ceous component used is ZIG, the aluminum-containing
shortening material is pyrophyllite, and the flux used is a
by-product of rare-earth metals (feldspar concentrate, FSC)
[10 – 13]. Research has shown that during production of
acid-resistant materials the optimum composition is as fol
lows, wt.%: ZIG 50, pyrophyllite 40, FSC 10 (Table 1)
[13, 14]. The chemical composition of the starting compo
nents is given in Table 2. ZIG is formed after disintegration
and screening ore in the form of pulp with a moisture content
of 37 – 45% and is a refractory clay [14 – 16]. Qualitative
characteristics are given in Table 3 for five ZIG samples. As
is seen from Table 3, ZIG in contrast to a traditional refrac
tory phase is more uniform and to a considerable extent is
Refractories and Industrial Ceramics Vol. 57, No. 1, May, 2016
1083-4877/16/05701-0059 © 2016 Springer Science+Business Media New York
FGBOU VPO S. P. Korolev Samara State Aerospace University
(S. P. Korolev National Research University), Samara, Russia.
FGBOU VPO Samara State Economic University, Samara, Russia.