REFRACTORIES IN HEATING UNITS
EXPERIENCE OF USING DIFFERENT GRADES OF TROUGH MIXES
IN BLAST FURNACE PRODUCTION AT OAO NMLK
G. I. Shulyakov,
É. M. Shcheglov,
S. S. Lyapin,
and D. N. Vorogushin
Translated from Novye Ogneupory, No. 9, pp. 8 – 13, September 2008.
Original article submitted March 10, 2008.
In 2005 – 2007 a change-over was accomplished OAO NMLK blast furnaces to the use of contemporary
poured and rammed trough mixes. Results are provided for manufacturing technology, operation and repair of
rammed and poured trough linings made from low and ultralow mixes of corundum-silicon carbide composi
tion. The existing structure of troughs and casting yards for BF-2, BF-3, BF-4, and BF-6 do not permit use of
refractory concrete linings, and therefore in order to line the main troughs of these furnaces ramming mixes
produced by OAO Dinur and the firm Calderys are used.
Within OAO NLMK there are five blast furnaces (BF)
with a usable total volume of 11,400 m
BF-2 (1000 m
), and BF-3 (2000 m
) each having one
casting yard and two tap-holes, BF-4 (2000 m
) has two cast-
ing yards with one iron tap-hole for each yard, BF-5 and
BF-6 (each 3200 m
) have four circular casting yards and
four tap-holes each.
In 2005 OAO NLMK used trough mixes of in-house pro-
duction that were manufactured as individually prepared re
fractory mixes (IPRM), introduced in the 1960s. From the
time of introduction of IPRM the mix composition and pro
duction technology remained almost unchanged:
– trough mixes had a traditional composition based on
clay and broken coke, and the binder used was coal-tar me
dium-temperature pitch or lignosulfonate;
– IPRM were not disposed to modern technical means
for maintaining a high level of production technology.
Manufacture of troughs from IPRM materials was ac
complished by ramming using electric
vibratory ramming units, whose shape corresponded to
that of the rammed trough. Use of in-house mixes with tradi
tional ramming technology provided low quality trough lin
ing, i.e. the life was 7 – 14 days (19 – 27 thousand tons of
iron), and the specific consumption of mix varied within the
limits of 1.5 – 3 kg/ton of iron. An increase in production in
tensity, a requirement for the continuous reduction in the cots
of iron, more stringent requirements for ecological safety, led
to a decision to cease producing trough mixes and an end to
In the course of a second category major overhaul of
BF-5 (April – August 2005) the casting yard was recon-
structed according to a plan developed by OAO Gipromez in
accordance with recent achievements in this field and the
specification of safety rules in blast furnace production. New
metal structures were installed for the main a transport
troughs, and the trough system was covered, lined from be
low with refractory concrete, a modern aspiration system
was introduced for the casting yard with cleaning of captured
gases on electric filters dug into the floor of the casting yard.
The main troughs were manufactured from four sections
with natural cooling.
The following equipment was acquired for lining manu
facture and repair: an induced action cement mixer Strojstav
PX-800 for preparing the concrete mix, a Wacker submers
ible electric vibrator for concrete compaction, a Velko
torcrete machine for lining repair, and a Bobcat mini-excava
tor for breaking worn lining.
Vibration pouring low and ultra-low cement refractory
mixes of corundum-silicon carbide composition produced by
Plibrico (two troughs), Lafarge Refractories and Vesuvius
(one trough each) were used for lining the troughs. In
2006 the firms Plibrico and Lafarge Refractories combined
and created the firm Calderys, and here there was unification
of the materials and schemes used in repair work. The
Refractories and Industrial Ceramics Vol. 49, No. 5, 2008
1083-4877/08/4905-0330 © 2008 Springer Science+Business Media, Inc.
OAO Novoliptesk Metallurgical Combine (NMLK), Cherepovets
Vologod Region, Russia.