<<User's reference>>
In
a Blast Furnace, Hearth life is
a major aspect of economic hot
metal production. In spite of
the achievement of Hearth life
of 10 to 15 years, and upto 21
years in Japan, further investigation
of measures to increase life and
to improve it in practice is need
of the hour. The increase in use
of high capacity Blast Furnaces
has increased the plant productivity;
nevertheless, it has impaired
plant flexibility.
The
development of appropriate repair
techniques means the area above
the tuyeres no longer determines
the length of a furnace campaign.
Hearth life now becomes the decisive
factor. For this reason, extending
the service life of this area
and reducing maintenance times
by improved relining methods,
is imperative.
Apart
from the Thermal solution, Ceramic
solution has been gaining importance
in the Hearth lining. Wear, as
result of the dissolution of Carbon
by unsaturated hot metal, can
be prevented by using Carbon qualities
with good thermal conductivity,
coupled with intensified Hearth
cooling. To displace the dissolution
isotherm of Carbon from 11500C as far as possible to the hot
side, an attempt was made to build
up a solidified protective layer
in front of the Carbon and thus
control heat flow.
Since
a high level of heat flow is an
undesirable outcome form the energy
viewpoint, the installation of
a ceramic bottom layer on the
upper carbon stratum is a measure
being taken. This terminates the
premature wear in the bottom and
reduces heat loss as a result
f bottom cooling. This type of
relining, using the Ceramic Solution
emerged partly as a result of
good experiences in Hearth life
with these ceramic bottom layers.
Ceramic bottom supplemented with
ceramic material sidewall lining
is the origin of CERAMIC CUP.
Ceramic bricks used to protect
the bottom coupled with their
use to clad sidewalls, make the
CERAMIC CUP.
A
study made by Thyssen Krupp Stahl
AG Germany, suggested that use
of Ceramic Cup of "corundum
with Sialon bonding" completely
eliminated the Heart breakouts
being experienced by them. Sialon
bonding is a solid solution combination
of silicon nitride and aluminium
oxide.
