COMPOSITION AND FABRICATION OF MAGNESIA BRIQUETTES
FROM REFRACTORY SCRAP FOR REPAIRING THE LINING
OF OXYGEN CONVERTERS
V. A. Osipov,
V. N. Kungurtsev,
É. V. Stepanova,
Z. G. Timofeeva,
and N. A. Bosyakova
Translated from Novye Ogneupory, No. 1, pp. 17 – 19, January, 2005.
Original article submitted December 7, 2004.
A technology for fabrication of refractory briquettes from spent periclase and periclase-carbon materials sal
vaged from decommissioned steel ladles has been developed. The briquettes can be used as a patching mate
rial to repair the worn refractory lining in oxygen converters. Tests of the patching briquettes were conducted
at the MISW JSC with satisfactory results.
Thermal power units in service in metallurgy and other
sectors of industry require continuous control over the ope-
rating and maintenance conditions of the refractory lining.
For the oxygen converter, the most effective methods for re-
covery of the lining are patching and protecting slag coating
(scull) applied by means of a slag splashing technique. For
preparation of the refractory material for patching and repair,
production wastes — broken ceramics, rejected products,
and spent refractory bricks — are typically used.
At the MISW JSC, the waste lining materials, in particu
lar periclase and periclase-carbon refractories, dismantled
from decommissioned steel ladles and other heat engineering
units have been directed in large quantities to a dump site for
outdoor storage. It was deemed expedient to use these wastes
as the precursor material for fabricating refractory briquettes
for patching the converter lining. Initially, laboratory tests
were carried out. Therefore the precursor materials tested
were periclase and periclase-carbon powders prepared from
spent refractory components. The physicochemical proper-
ties of the powders are given in Table 1. The bonds tested
were powdered commercial lignosulfonates (CLS) and a
powdered phenol-based binder (PB). Water was added to the
mix components to a moisture content of 2.0 – 2.5%.
The test specimens were molded using a PG-100 hydrau-
lic laboratory press under a pressure of 60 MPa; the green
preforms were dried in a laboratory drying cabinet at 150°C
for 8 h and then at 160°C for 17 h in the drying tunnel oven
No. 1 installed in a chamotte work shop (CWS). Relevant
data are given in Table 2.
Table 2 shows that the initial compressive strength of
raw materials is mainly determined by properties of the pow
der and the binder; in specimens based on periclase powder
(PP) with binders CLS, or PB (compositions Nos.1–3,12,
and 13), the compressive strength is lower than in specimens
based on periclase-carbon powder (PCB) (compositions
Nos.4–6,10,and11).Thestrength of the dried specimens
is likewise controlled by the powder properties and
heat-treatment regime. In periclase-based specimens, the
Refractories and Industrial Ceramics Vol. 46, No. 2, 2005
1083-4877/05/4602-0087 © 2005 Springer Science+Business Media, Inc.
Magnitogorsk Iron and Steel Works (MISW) Joint-Stock Co.,
TABLE 1. Physicochemical Properties of Powders
Fraction percentage, %, particle size, mm Chemical composition, %
> 3 3 – 2 2 – 1 1 – 0.5 < 0.5 MgO CaO Fe
Periclase, PP-grade 1.2 2.5 22.9 20.0 53.4 82.5 2.4 1.06 0.67 0.90
Periclase-carbon, PPU-grade 0.5 3.3 30.7 20.2 45.3 83.9 1.9 1.04 8.71 8.66