OCNITES — A NEW CLASS OF REFRACTORIES
IN THE SYSTEM OXIDE – CARBON – NITROGEN
G. P. Shveikin
and L. B. Khoroshavin
Translated from Novye Ogneupory, No. 6, pp. 25 – 28, October, 2002.
Theoretical principles for the development of ocnites, a new class of oxycarbonitride refractories, are pre
sented, and manufacturing technologies and properties of ocnites are discussed. The potentialities and uses of
ocnites in ferrous and nonferrous metallurgies are emphasized.
Development of high-grade refractory materials can be
successfully accomplished only through the combined efforts
of metallurgists and refractory engineers — this is a motto
consistently professed by S. V. Kolpakov, President of the In-
ternational Union of Metallurgists, [1, 2] and other adherents
[3 – 5].
Improving quality and reducing the structural mass of
material (broadly speaking, the consumption of all materi-
als — mixtures, refractories, electrodes, etc. — per ton of
steel) and production costs depends on closer cooperation
between academic research and industry. Only by combining
efforts can one reach the high product competitiveness of
metallurgical and refractory industries both in domestic and
foreign markets. Strengthening links between industrial and
academic research is a direct route to success. At present,
academic science claims 96.5% of all achievements in metal
lurgy, and only 3.5% — industrial research .
The essential features that metallurgists require of
refractories are increased heat resistance of the lining of ther
mal units and improved quality of the metal . To comply
with these requirements, a new generation of refractories is
In this paper, we are concerned with a new class of
refractories in the system oxide – carbon – nitrogen, which
are oxycarbonitride refractories (for short, ocnite refrac
tories, or simply ocnites); sialon — complex phases SiAlON
of the aluminosilicate type in which oxygen is partially re
placed by nitrogen — is a prototype of this new class.
Ocnites are complex phases in the Me
tem composed of oxides, carbides, nitrides, and oxycarbo
nitrides in which oxygen is partially replaced by both carbon
and nitrogen. Ocnite refractories can be prepared by carbo
thermal nitriding of natural and man-made materials:
natural — quartzites, bauxites, magnesites, dunites, ser-
pentinites, talcomagnesites, barites, leucoxenes, zircon, etc.;
man-made — chamotte, dinas, mullite, alumina, corun-
dum, periclase, forsterite, spinels, aluminates, cements, oxy-
gen-free compounds (borides, carbides, nitrides, silicides), etc.
Typically, the carbon-containing components in ocnites
are graphite, kish (refining foam), graphite waste, crushed
electrodes phenolic powder binder (PPB), ethylene glycol,
etc. For nitrogen-containing components, one can use: gase-
ous nitrogen N
; nitrates — Mg(NO
etc.; nitrites — Mg(NO
, etc.; nitrides — Mg
, VN, ZnN, etc.; nitrile salts R – C º N; nitrogen fertili
zers, for example, carbamide CO(NH
N, 20% C, 26.6% O, and 6.8% H; nitrogen fertilizer wastes,
nitrogen ferrochrome (6 – 10% N), and others.
All nitrates are readily soluble in water and can be used
to advantage as binders. Nitrides are insoluble in water and
are recommended for use as additions to refractory materials.
Also, boron-containing can be used as an additive to ocnites.
It is seen, therefore, that the primary advantage of ocnites is
the vast raw materials base — perhaps unrivalled by other
There are two major reasons for introducing nitrogen
into carbon-containing refractories. The first reason is that
nitrogen is one of the best antioxidants that increases slag re
sistance in these refractories. For example, the service life of
the lining in converters can be extended substantially by us
ing nitrogen for slag blowing and by reducing the MgO slag
concentration to 10 – 14% to suppress slag reactivity .
By way of comparison, the resistance of converter linings in
the U.S. reaches 33 thousand heats, whereas in Russia, it is
merely about 3 thousand heats .
Refractories and Industrial Ceramics Vol. 44, No. 1, 2003
1083-4877/03/4401-0042$25.00 © 2003 Plenum Publishing Corporation
Institute of Solid-State Chemistry, Ural Branch of the Russian
Academy of Sciences, Ekaterinburg, Russia; Eastern Institute of
Refractories, Ekaterinburg, Russia.