SCIENTIFIC RESEARCH AND DEVELOPMENT
PLANNING OF SKULL FORMATION AT AN OXYGEN CONVERTER
LINING SURFACE AND OPTIMIZATION OF MODIFIER CONSUMPTION
S. A. Suvorov
and V. V. Kozlov
Translated from Novye Ogneupory, No. 1, pp. 35 – 37, January 2011.
Original article submitted November 9, 2010.
A software package has been developed for planning skull formation dynamics on an oxygen converter lining
surface in the faculty of high-temperature materials chemical technology (HMCT) of SPbGTI (TU). An infor-
mation base is provided making it possible making it possible to use to the software package developed under
converter production conditions.
Keywords: skull, lining, converter, modifier, slag wear.
Application a previously modified final converter slag
skull to the working layer of a lining by blowing through a
lance with a jet of nitrogen is an effective way of increasing
the life of an oxygen converter. Formation of a skull at a con-
verter lining surface occurs due to hardening of a slag sus-
pension, prepared by modifying the final converter slag with
magnesia materials and with emergence of heat through the
converter lining, i.e. from an inner layer in contact with a
slag suspension to the outer layer. Hardening (loss of mobil-
ity) of slag and skull formation is observed when the volume
fraction of solid phases crystallizing within it crosses a
boundary, required for their percolation, forming a solid car-
case within the volume of slag. The dynamics of skull forma-
tion at the surface of a converter lining determines its
thermophysical properties, primarily heat resistance, depend-
ing on the residual thickness, and also the temperature field;
the temperature of the final slag, prepared for application to
converter walls; the thermal effect of slag hardening; the vol-
ume fraction of solid phases, contained in a slag suspension.
In the HMCT faculty of SPbGTI (TU) on the basis of
thermophysical presentations about skull formation using an
experimental information base and thermodynamic model-
ling of the effect of heat of crystallization for a modified slag
suspension, a software package has been developed intended
for planning the dynamics of skull formation at the surface of
an oxygen converter lining and optimizing the consumption
of the final converter slag and modifier  (Fig. 1). In order
to use the software package developed under conditions of
specific converter production it is necessary to create a pro-
duction statistical information base, including the following
– chemical composition of the final converter slag, re-
maining for skull application operation;
– the amount and temperature of remaining slag;
– the temperature of the converter working lining sur-
face after discharging the melt;
– the residual thickness of the converter lining layer;
– the thermophysical properties of refractory materials
of the converter lining.
This information is required for modification of the
chemical and phase composition of the final converter slag,
providing an increase in its hardening temperature to the
temperature level of the lining surface, and prediction of
skull formation dynamics in order to optimize the time re-
gime for the process. Modelling of the process showed that
the dynamics of skull formation at an oxygen converter lin-
ing surface does not depend linearly on the duration of the
process (skull formation slows down with an increase in its
thickness and inherent heat resistance), and also on the resid-
ual thickness of the lining working layer (Fig. 2). The rate of
skull formation is slow in the initial stages of the lining cam-
paign and increases sharply during lining operation with a re-
duction in working layer thickness.
The practical data provided in scientific and technical
publications [3, 4] confirms that the life of a lining is not dis
tributed uniformly over a whole converter campaign. The
different dynamics of skull formation with a change in resid
Refractories and Industrial Ceramics Vol. 52, No. 1, May, 2011
1083-4877/11/05201-0029 © 2011 Springer Science+Business Media, Inc.
GOUVPO St Petersburg State Technological University (Techni
cal University) (SPbGTI (TU)), St Petersburg, Russia.