PERICLASE-CARBON COMPONENTS FOR USE IN THE REFRACTORY
LINING OF THE STEEL-TAPPING CHANNEL OF A 370-TON CONVERTER
V. G. Ovsyannikov,
O. B. Voronina,
V. F. D’yachenko,
B. A. Sarychev,
T. K. Prishchepova,
and L. T. Loginova
Translated from Ogneupory i Tekhnicheskaya Keramika, No. 1, pp.7–9,January, 2002.
Tests of periclase-carbon blocks for the converter’s steel-tapping channel available from the Kombinat
Magnezit JSC were carried out in an oxygen-converter shop at the Magnitogorskii Metal-and-Steel Works
JSC. The new refractory materials are shown to have a higher endurance as compared to the conventional
periclase blocks, which made it possible to increase the operational efficiency of converters.
Experience gained from the operation of the oxygen-
blowing converters at the Magnitogorskii Metal-and-Steel
Works Joint-Stock Co. (MMSW JSC) shows that the taphole
unit is the area of the lining that is most subjected to wear.
Thus, according to records as of 1999, the endurance of the
taphole unit made of conventional PLK-grade periclase re-
fractory was 65 heats as compared to the average endurance
of 2003 heats of the periclase-carbon lining of the entire
Replacement of the used taphole lining requires a shut-
down time of 60 – 70 min, which results in a substantial
cooling of the converter’s lining and a loss of productive
ness. For this reason, the increase in endurance of the taphole
unit is an issue of important technological concern.
Over a period of May – September 2000, PUPL-2-180-
grade periclase-carbon taphole blocks with an increased re
sistance to thermal corrosion were tested at an oxygen-con
verter shop (OCS) in the MMSW JSC. The blocks, based on
fused periclase, are available as a commercial product from
the Kombinat Magnezit JSC.
For testing, sets of serial PUPL-2-180-grade products
were used, along with four experimental sets with an antioxi
dant added to the refractory material of the channel lining
and four sets of taphole blocks made of high-purity periclase
with various antioxidants added to the mixture. Of this lot,
specimens were selected for measuring the physicochemical
properties of the refractories before and after service. Rele
vant results and properties of the antioxidant-coated compo
nents (reported from the Kombinat Magnezit JSC) are pre
sented in Tables 1 and 2.
The components to be tested were mounted in a con-
verter using a technique conventionally adopted in the OCS.
The blocks were “dry-mounted” on a tube, secured with ar-
resters, and placed in the taphole box. The gap between the
brickwork of the taphole box and the blocks was filled with a
refractory mixture based on fused periclase. During testing,
operating parameters of the taphole blocks and heat-technol-
ogy parameters, essential for the endurance of taphole unit,
were monitored. As was established, the endurance of exper-
imental periclase-carbon taphole blocks was adversely af-
fected by disturbances of the converter’s working cycle (such
as prolonged shutdowns resulting in the oxidation of car
bon); another adverse effect came from overoxidized heats.
Thus, the average endurance of a steel-teeming channel lined
with PUPL-2-180 blocks was 103 heats in a converter with a
productivity of 30.5 heats/day; by contrast, in a converter
with a productivity of less than 18 heats/day, the endurance
was 45 – 50 heats.
A total of 52 sets of experimental taphole blocks were
tested; of these, 13 sets were composed of 11 blocks, 8 sets
— of 10 blocks, 22 sets — of 9 blocks, and 9 sets — of
8 blocks. Relevant results are given in Tables 3 and 4.
The average endurance of serial blocks was 84 heats (the
maximum was 128 heats, and the minimum was 38 heats).
This endurance was rather low, which is explained by the
fact that in this particular campaign, the overoxidized heats
accounted for 32%.
The average endurance of components with an antioxi
dant-coated channel (mixtures 1 – 4 ) was 102 heats. The
maximum endurance was 122 heats (11 blocks, mixture 1 ),
with an average tapping time of 6.9 min; the minimum en
Refractories and Industrial Ceramics Vol. 43, Nos.1–2, 2002
1083-4877/02/0102-0006$27.00 © 2002 Plenum Publishing Corporation
Magnitogorskii Metal-and-Steel Works Joint-Stock Co., Magnito