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GHG
dry anti-penetration mix |
Photos
of application results for GHG dry anti-penetration
mix |
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Residual
lining of cathode , GHG anti-penetration
layer shown up |
Residual
lining of cathode after cleaning , the
GHG anti-penetration layer keeping integrated |
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| Anti-penetration
layer opening up, under which the insulation
brick keeping no damage |
Complementing
some new material, GHG mix can be used
again. |
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Technical
advantages of GHG anti-penetration mix |
The
anti-penetration mix is a new material for
electro-bath which came out in the early
1990¡¯s last century. It is a kind of unshaped
refractory composed of different raw materials
of different grain size. A chemical anti-penetration
mechanism has been used to restrain and
reduce the penetration of electrolyte and
vapors corrosion on the insulation layer
in the lower part of the bath during electrolyzing
process of aluminum. The advantages of the
mix are as below:
1.
Simplifying construction, saving man power
and time.
During
construction, the dry anti-penetration mix
is paved and pressed directly instead of
traditional pavement of refractory brick.
It saves 70% manpower and time, and possesses
favorable lining integrity.
2.
It guarantees the electrobath good heat
insulation and rational heat balance.
As the electrolyte
penetration can be prevented and the heat
insulation layer will not be damaged, the
heat insulation property of the electrobath
doesn¡¯t change during its operation (especially
during later period). This ensures stable
voltage of the bath, rational heat distribution
and high efficiency. It is proved by practice
that using dry anti-penetration mix in building
furnaces to replace traditional way, the
service life of the bath will be prolonged
for more than one year, and current efficiency
of the bath during the late period of the
operation will be increased by over 0.5%.
3. In the second
repairing of the bath, the bottom insulation
lining can be used again.
Once
the bath is damaged, it can be repaired
by removing the damaged carbon blocks and
reacted lining layer before supplementing
some new anti-penetration mix, and directly
laying new carbon blocks. It is unnecessary
to replace heat insulation lining of the
lower part.
4.
Keeping the surface temperature of the insulation
lining under 800¡æ in bath designing
One difficult problem
in electrobath insulation designing is how
to guarantee the surface temperature of
the insulation lining under 800¡æ. The lining
of three-layered fireclay bricks does not
meet this requirement. The alumina lining
could satisfy it, but its electrolyte penetration
resistance is poor. And furthermore, it
reacts with electrolyte, leading to higher
heat conductivity and going up of the surface
temperature, as a result, the insulation
lining would be damaged by further penetration
of the electrolyte and temperature rising.
Whereas GHG dry anti-penetration mix possesses
lower heat conductivity which is only one
third of the refractory brick. On reacting
with electrolyte GHG transforms into nepheline
layer with high viscosity, which effectively
restricts and slows down further penetration
of the electrolyte
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