DEVELOPMENT OF NEW CERAMIC MATERIALS
FOR HIGH-TEMPERATURE FILTERS
A. V. Aksenov,
O. A. Nekrashevich,
and A. V. Bugaev
Translated from Ogneupory i Tekhnicheskaya Keramika, No. 9, pp. 26 – 28, September, 2001.
The technology for fabrication of ceramic cells of high-temperature filters, designed for simultaneous treat
ment of industrial flue gases for dust and nitrogen oxides, was studied. Two types of ceramic cells for use in
industrial plants with a two-stepped scheme of gas treatment are proposed. Parameters characterizing the effi
ciency of gas treatment for dust and nitrogen oxides at the 1st and 2nd steps and the corresponding overall pa
rameters are determined.
Currently, dust-collection techniques are gaining ever-in-
creasing acceptance in the electric steelmelting technology.
One reason for this is the high dust level (up to 20 g/m
the waste gases from melting furnaces [1, 2]. Effective tech-
niques for handling the dust emission are Venturi scrubbers
or bag filters . However, the wet treatment of waste gases
from electric furnaces requires high energy expenditure, and
the service life of bag filters is limited by the durability of the
Experience in the use of ceramic filters for gas cleaning
is rather modest, which is explained, on the one hand, by the
low throughput of filtering units and, on the other hand, by
the high cost of filter cells. For one thing, a condition that
does not promote the large-scale use of ceramic filters in do
mestic electric steelmaking technologies is that the filter
cells are mainly supplied by foreign manufacturers. Still, ce
ramic filters exhibit a range of advantages such as high ther
mal stability, no need to use units for pre-cooling of the
waste gases or to pre-heat these gases for dispersal units and,
the most important, the feasibility of simultaneous treatment
of waste gases for dust and nitrogen oxides . The latter cir
cumstance is of special importance under conditions where
the flue gases from electric melting furnaces contain nitrogen
oxides — notorious toxic agents — at concentrations of up to
. It was shown in [3, 5] that the high-tempera
ture catalytic oxidation of nitrogen oxides in the combustion
products of natural gases can proceed with an efficiency as
high as 80%, which is much higher than the degree of neu
tralization of wet-treated nitrogen oxides (h = 30 – 40%). Of
the utmost importance in these processes are the concentra
tion of catalyst in the filter cloth through which the flue gases
pass and the flow rate of these gases in pores and channels.
In view of the aforementioned, development of catalysts for
semi-commercial and production units is an issue of major
concern considering that its successful solution will mini-
mize the negative environmental impact from the entire elec-
tric steelmaking industry.
In Russia, studies on catalyst materials for the operating
cells of ceramic filters were conducted in two directions:
(i) development of catalysts for coating the filter cells and
(ii) development of ceramic materials for filter cells on
which catalytic components are supported.
Concerning the former task, catalyst coatings such as
IVAKS-2, IVAKS-1, AVAKS-1 were developed  which,
supported on refractory or ceramic materials, showed supe
rior performance characteristics and gave satisfactory results
on the conversion of nitrogen oxides (Fig. 1). It was estab
lished that the high-temperature reduction of nitrogen oxides
Refractories and Industrial Ceramics Vol. 42, Nos. 9 – 10, 2001
Moscow State Evening Machine-Building Institute, Moscow,
Russia; Alfa State Unitary Venture, Moscow, Russia.
Fig. 1. Graphical illustration of the efficiency of catalyst coatings
used for conversion of nitrogen oxides: open bars) calculated data;
hatched bars) experimental data.
1083-4877/01/0910-0310$25.00 © 2001 Plenum Publishing Corporation