REFRACTORIES IN HEAT UNITS
OPENING STEEL-POURING LADLE SLIDE GATES
WITHOUT USING OXYGEN
É. A. Visloguzova,
L. V. Serova,
and M. A. Khoroshikh
Translated from Novye Ogneupory, No. 5, pp. 9 – 10, May 2010.
Original article submitted March 19, 2010.
In OAO Nizhnetagil Metallurgical Combine in order to open steel-pouring ladle slide gates without using oxy
gen starting mixes of domestic and imported production were checked instead of a quartzite starting mix. With
their use the number of slide gate openings was 50%. Since this result should not be considered satisfactory,
the search for suitable starting mixes continues.
Keywords: slide gate, steel-pouring ladle, starting mix, quartzite, burn through of nozzle channel with oxygen.
Successful operation of metallurgical units and prepara-
tion within them of high quality metal depends to a consider-
able extent on the quality of refractories that are in contact
with molten metal and its movement through the production
chain, starting from the blast furnace and ending with heat
treatment furnaces of the rolling workshops. The role of re-
fractory materials in the production chain involves provision
not only of protection of a unit from the action of molten
metal, but also its high quality. Starting mixes relate to these
refractory materials, whose use is unavoidable in putting a
steel-pouring ladle into operation.
For quite a long time in the Combine a starting mix has
been used based on quartzite, mainly due to its low cost and
low specifications for poured metal quality. However, poly
morphic transformation of quartzite has a favorable effect on
loosening material in the nozzle channel, and consequently
on its emergence during slide gate opening, and it is not pos
sible to avoid sintering of the mix due to the low quartzite
melting temperature. Sintering of starting mix in the channel
of the steel-pouring nozzle complicates metal pouring, since
it is necessary to burn through the nozzle channel with oxy
gen. This operation leads to deterioration of the refractory
nozzle channel and in some cases the collector and opening
plate of the slide gate. Use of a starting mix based on quartz
ite has not made it possible to carry out pouring of steel from
a ladle with direct connection of a protection pipe to the col
lector, since in 98% of cases of opening the slide gate the
channel is burnt out with oxygen. The duration of burning
was 8 – 10%. Burn-out led to secondary metal oxidation, and
consequently worsening of its quality.
In view of start-up in the converter workshop of four
CBCM the situation with slide gate opening required funda-
mental resolution. First, specifications were laid down for
the starting mix: it should be highly refractory, not enter into
reaction with slag and metal, not sinter, pass through the
steel-pouring nozzle channel without the need to burn out the
channel with oxygen. Satisfactory pouring assumed opening
of the slide gate and appearance at the installed protection
pipe, and unsatisfactory pouring was absence of appearance
of a metal stream on the opening the slide gate, with unlock
ing the protection the protection pipe and burning out the
nozzle channel with oxygen independent of burning dura
A technical prescription was formulated fro supply to the
Combine of starting mixes and testing of them on their ar
rival. Tests were performed on both imported materials and
domestic materials, differing sharply with respect to grain
size and chemical composition from the quartzite mix. With
their use there was an increase in the number of slide gate
openings without burning with oxygen: in 30% of openings
with use of domestic mixes, and in 50% of openings with use
of imported materials. The main difference of imported ma
terials from domestics counterparts is a fixed grain size com
position, within which there is almost no fine (.063 mm)
dusty fraction, so that the mix did not sinter. At the same time,
the fine grain size composition of the material (0.5 – 0.2 mm)
Refractories and Industrial Ceramics Vol. 51, No. 3, 2010
1083-4877/10/5103-0135 © 2010 Springer Science+Business Media, Inc.
From the proceedings of the International Conference of Metal
lurgists and Refractory Workers (April 22 – 23, 2010, Moscow).
OAO Nizhnetagil Metallurgical Combine, Nizhnii Tagil, Russia.