REFRACTORIES IN HEATING UNITS
SHS FERROSILICON NITRIDE NITRO-FESIL
AS A NEW TAP-HOLE CLAY REFRACTORY COMPONENT
FOR BLAST FURNACES
I. M. Shatokhin
, M. Kh. Ziatdinov
, and É. M. Manasheva
Translated from Novye Ogneupory,No.9,pp.3–7,September, 2013.
Original article submitted March 22, 2013.
The scientific and technical manufacturing firm Étalon developed and perfected industrial technology for
manufacturing SHS ferrosilicon nitride NITRO-FESIL
TL, which is a composite consisting of silicon
nitride, iron silicide, and free iron. On an industrial scale together with OAO MMK and ZAO Metallurg
remont test tap-hole clays are provided containing ferrosilicon nitride NITRO-FESIL
TL. Taphole clays with
the new component demonstrate higher corrosion and erosion resistance, and oxidation resistance, and also
better sintering capacity. As a result of this reliable sealing of iron tap-holes, a smooth, more prolonged iron
and slag flow regime with stable discharge parameters is provided. The clay is recommended for introduction.
Keywords: iron tap-hole, tap-hole clay, self-propagating high-temperature synthesis, ferrosilicon nitride,
The taphole is the most vulnerable area of a blast fur-
nace. It is periodically heated to high temperature, and then
cooled rapidly to a tap-hole clay temperature applied to its
channel. During tapping the tap-hole is subject to mechanical
and thermal action of molten products, gases, and is also sub
ject to abrasive wear by incandescent coke. During blast fur
nace taphole operation  the following problems may arise:
arbitrary opening of the tap-hole after removal of the gun; se
vere thermal erosion during tapping of iron and slag, dis
charges during tapping, contraction of the tap-hole length.
These problems are mainly connected with furnace operating
conditions (tapping temperature, iron and slag chemical
composition), and materials within the tap-hole clay compo
Many problems during tap-hole operation may be over
come if constant geometric dimensions of the channel are
provided, (length and diameter) during tapping, which has a
favorable effect on blast furnace operation and work safety
for personnel. In turn, the life of an iron tap-hole channel
mainly depends on the tap-hole clay used. Tap-hole clay
should fulfil three main functions:
– seal the tap-hole reliably in order to create safe work-
– provide a possibility of controlled tapping molten
products after opening (retain the tap-hole channel length
– protect the area of the hearth lining around a tap-hole:
spread during opening in the working layer of the hearth re
fractory lining, which increases lining life of this stressed
section, and consequently facilitates an increase in period be
tween repairs for blast furnace operation.
In developing contemporary tap-hole clays it is neces
sary to satisfy two main criteria. On one hand in order to
achieve constancy of tap-hole length and diameter it is nec
essary to increase its high-temperature strength, crack resis
tance, and also corrosion and erosion resistance. On the other
hand, in order to perform operational opening of a tap-hole
the refractory clay should drill easily using existing equip
ment. In addition, in the original condition tap-hole clay
should have a sufficient level of plasticity and reliably seal a
tap-hole and form a protective layer on the inner surface of a
lining in the form of a so-called tap-hole mushroom.
Refractories and Industrial Ceramics Vol. 54, No. 5, January, 2014
1083-4877/14/05405-0345 © 2014 Springer Science+Business Media New York
From proceedings of International Conference of Refractory
Workers and Metallurgists (14 – 15 March, 2013, Moscow).
OOO NTPF Étalon, Magnitogorsk, Russia
G. I. Nosov FGBOU VPO MGTU, Magnitogorsk, Russia.