REFRACTORY CERAMIC SETS FOR NONFERROUS METALLURGY
AND EXPERIENCE OF THEIR OPERATION
N. N. Savanina,
M. Yu. Rusin,
T. M. Khranovskaya,
L. I. Gorchakova,
L. N. Rusanova,
and G. K. Rogov
Translated from Novye Ogneupory, No. 8, pp. 6 – 10, August 2009.
Original article submitted June 10, 2009.
Refractory ceramic materials have been developed in FGUP ONPP Tekhnologiya, and technology has been
created for preparing ceramic objects for use in nonferrous metallurgy. Crucibles, burner hoods, and other
forms of objects are manufactured from material based on aluminum oxide, required for pouring metals and
alloys. A broad range of objects for aluminum casting installations are manufactured from materials based on
wollastonite. Information is presented about the ceramic objects produced and experience of their operation in
nonferrous metallurgy enterprises.
Keywords: ceramics, mullite-corundum, wollastonite, technology, nonferrous metallurgy, refractory ceramic
A series of refractory ceramic materials has been devel-
oped in ONPP Tekhnologiya, and technology has been cre-
ated for preparing objects based on them, that have found
practical application in nonferrous metallurgy.
Ceramics based on aluminum oxide remain some of the
most requested materials from a broad spectrum of ceramic
materials due to their physicomechanical properties.
Mullite-corundum materials, grade OTM-959, are prepared
by casting from a highly concentrated corundum suspension
with a granular filler. Introduction of coarser mullite grains
and other components into a very fine corundum base makes
it possible to prepare a microcracked material structure that
markedly increases its thermal shock resistance. Shrinkage
during firing of the material does not exceed 1%. The tech
nology developed makes it possible to prepare objects for
metallurgy: crucibles, pouring lips of different configuration,
elements of the slag belt, burner hoods, screens, isolators and
other objects required during pouring of metals and alloys
In a number of Russian metallurgical enterprises for
melting nickel and its alloys crucibles are used made from
corundum-mullite material OTM-959. The crucibles are pre
pared by casting an aqueous concentrated suspension to
which 25 – 30% of granular filler is added before molding.
The main raw material for preparing these suspensions is
white electrocorundum. The specific surface of the fine frac-
tion (50 wt.%) is 2500 – 3000 cm
/g, 25 – 30 wt.% com-
prises particles with a size of 50 – 80 mm, and the rest of the
particles have a size of £3 mm. The special way of suspen-
sion preparation makes it possible to obtain ceramic material
after firing with a high density. i.e. up to 3.1 g/cm
, and open
porosity of not more than 16%. The long life of crucible ma
terial with molten metals is provided by using pure fuzed raw
material. The main properties of the material; obtained are
Apparent density, g/cm
...................3.08 – 3.11
Open porosity, %, not more than ...................16
Ultimate strength, MPa:
in compression .......................100–180
Operating temperature, °C..................Upto1800
Crucibles have been tested successfully in the
Motorostroitel’ (Samara), Aviadvigatel’ (Perm) and Mtsensk
prokat (Mtsenk) Plants. Nickel alloys are prepared in induc
tion vacuum furnaces at a temperature of about 1700°C. The
layout of a crucible unit in an inductor is presented in Fig. 4.
A crucible is molded in the inductor container as follows:
at the bottom of the container there is a granular refractory
filler, the crucible is installed upon it, and the gap between
the container walls and the crucible is packed with refractory
granular filler. The upper part of the crucible, projecting
above the conductor, is cemented with refractory mortar
Refractories and Industrial Ceramics Vol. 50, No. 4, 2009
1083-4877/09/5004-0247 © 2009 Springer Science+Business Media, Inc.
From the proceedings of the International Conference of Refrac
tory Workers and Metallurgists (23 – 24 April, 2009, Moscow).
FGUP ONPP Tekhnologiya, Obninsk, Kaluga Region Russia.