RESEARCH AND DEVELOPMENT
USING FERROSILICON NITRIDE OF NITRO-FESIL GRADE
IN GATE AND SPOUT COMPONENTS
M. Kh. Ziatdinov
and I. M. Shatokhin
Translated from Novye Ogneupory, No. 9, pp. 45 – 50, September, 2008.
Original article submitted May 5, 2008.
Development results are presented for the new NITRO-FESIL strengthening additive, which is intended for
gate and spout parts in blast furnace production. Researches on the high-temperature process in the ferrosili
con-nitrogen system have provided a new industrial technology for making materials based on silicon nitride.
The technology is characterized by the absence of energy consumption, complete ecological safety, and a
product distinguished by good working properties.
Silicon nitride is one of the few oxygen-free refractory
compounds; it is widely used in industry on account of its
unique physicochemical characteristics. It is used as a
heat-resistant constructional material in parts of engines and
turbines; silicon nitride is used in the cutting parts of tools
for automatic lathes, corrosion-resistant protective jackets
for thermocouples, high-temperature filters for corrosive liq-
uids, and so on. However, the largest consumption volume
for silicon nitride and materials based on it lies in the
refractories industry. Refractory components for lining blast
furnaces are common, as are those for lining aluminum
electrolyzers, furnace devices, coking batteries, and other
high-temperature plants. These purposes are usually met by
composites, which are based on silicon carbide with a silicon
Another area of large-scale use for silicon nitride materi
als is in the production of unmolded refractories: spout and
gate parts for blast-furnace use. The current production of
cast iron is based on large blast furnaces, which have long
production periods for the cast iron and slag with elevated
temperatures in the metal. Consequently, cyclic operation of
the gates and spouts is very important, since the state of the
gates and the space around them and the spouts governs the
stability of operation for the entire furnace. Although the
gates and spouts are subject to the action of molten cast iron
and slag only during tapping, the action is exceptionally in
tensive, because the usual combination of high temperature
and corrosive media is accompanied by vigorous erosion
caused by the high-speed flow of molten metal and slag.
Also, there are high thermal shocks during the initial period
of liquid movement.
The working state of the gates and adjacent zones is en-
tirely determined by the quality of the gate materials, which
are intended to handle two basic tasks: firstly, during the
flow of the cast iron and slag, the diameter of the gate should
not alter, and secondly, the length of the gate should not be
reduced by damage to the internal layers of the lining. The
gate materials must therefore have high corrosion and ero
sion resistance and must maintain the maximal volume sta
bility. Similar specifications apply for the packing materials
in blast-furnace spouts.
These items contain bonding materials as well as refrac
tory components. While the latter fillers determine the re
fractory and strength properties of the materials, the proper
ties of the bonding agents are dependent on the plastic char
acteristics of them. Development trends for current plastic
refractories involve the transition to water-free and ecologi
cally safe bonding agents, while as the refractory fillers one
uses aluminum and silicon oxides, as well as silicon carbide
and carbon. The initial components for making these are in
troduced in the form of natural minerals (bauxite, shungite,
and so on), or as previously processed materials (corundum,
firebrick, silicon carbide, coke, and so on). Another major
development trend for mortar-type refractories for blast fur
naces has involved the extensive transfer to materials addi
tionally containing silicon nitride.
Refractories and Industrial Ceramics Vol. 49, No. 5, 2008
1083-4877/08/4905-0383 © 2008 Springer Science+Business Media, Inc.
Tomsk State University, Tomsk, Russia
Étalon Scientific Company, Magnitogorsk, Russia.