EFFECT OF FINE ANDALUSITE ON THE PROPERTIES
AND MICROSTRUCTURE OF LOW-CEMENT
M. Nouri Khezrabadi,
and S. Kh. Mirhosseini
Translated from Novye Ogneupory, No. 7, pp. 33 – 38, July, 2012.
Original article submitted November 6, 2011.
Results are presented from the development and study of cordierite-mullite panels which are based on low-ce
ment refractory castables (LCC) and can be used as kiln furniture. Cordierite powder was synthesized from
talc, kaolin, and alumina. Synthetic cordierite aggregate was used as the main component in addition to anda
lusite, Kerphalite, cement Secar 71, calcined alumina, and microsilica. It was established that samples of the
cordierite-based material with a mullite binder had a satisfactorily low CLTE (3.72 ´ 10
1/K), which is in
dicative of their excellent thermal shock resistance.
Keywords: cordierite, andalusite, low-cement cordierite-mullite castables, kiln furniture, SEM-micrography,
·2MgO) is a technically impor-
tant ceramic material. Cordierite ceramics exhibit excep-
tional high-temperature properties, including excellent ther-
mal shock resistance and chemical stability at elevated tem-
peratures [1, 2]. While the superior thermal shock resistance
of these ceramics make it possible to use them as kiln furni
ture , their relatively poor structural durability makes
them unsuited for long-term use [4 – 6]. Since mullite ceram
) have a high melting point, good creep resis
tance, and a moderate coefficient of linear thermal expansion
(CLTE), cordierite and mullite can be used in combination
with one another to obtain advanced ceramics with high ther
mal shock resistance [7, 8].
Although kiln furniture is traditionally made by pressing,
other ceramic-forming methods such as vibrocasting are also
now being used. The production of kiln furniture by refrac
tory-castables technology has certain advantages over con
ventional pressing. Refractory castables generally undergo
little shrinkage during manufacture of the product, and this is
especially true of large products. Since refractory castables
are easily cast in complex molds, the restrictions on the
shape of the finished product are negligible [9, 10]. Several
studies have been made of the production and properties of
cordierite-mullite refractory castables. Hipedinger, et al.
[11, 12] developed cold-setting cordierite-mullite refractory
castables with the use of magnesium phosphates as the
binder. Chen, et al. [13 – 15] made several studies of the
physical properties of cordierite castables — properties such
as thermal shock resistance and hot modulus of rupture
(HMOR). However, there have not been any comprehensive
studies of the phase evolution and microstructural develop
ment of cordierite-mullite refractory castables with a hydrau
The results obtained in previous studies of the micro
structure and properties of conventionally made cordierite
ceramics with a mullite binder were included in our investi
gation . The goal of the study being discussed in this arti
cle was to examine the physical and mechanical properties
and microstructural changes of andalusite-based low-cement
cordierite-mullite castables and the phase changes they un
dergo after sintering at different temperatures.
First we synthesized cordierite powder by mixing talc,
kaolin, and alumina. The mixture was then subjected to hy
draulic pressing at a pressure of 40 MPa in a cylindrical die.
Refractories and Industrial Ceramics Vol. 53, No. 4, November, 2012
1083-4877/12/05304-0220 © 2012 Springer Science+Business Media New York
Academic Center for Education, Culture, and Research (ACECR),
Yazd Branch, Iran.
School of Materials Engineering and Metallurgy, Iran University
of Science and Technology (IUST), Tehran, Iran.