Hello to all:
Our kiln is 82m long, we stopped kiln for changing refractory just like annual shutdown,
we removed all bricks, but we observed from I/L at 15m, around 3m of kiln shell is wet, some kind of black liquid is falling down from the kiln shell,
What are the possible reasons for this kind of wetness on Kiln Shell ?
The black liquid is the reaction of these deposits (in the form of iron oxides) from water in the air.
These black depsoits are signs of high temperature corrosion and possibly chemical attack. Have it analyzed at you X-ray lab.
What I recommend is the use of more denser bricks preferably basic bricks with Zirconia. Expensive but suits your case.
Denis
Sir thanku for your answer ,
But our kiln Feed is rich in alkalis i.e Chloride 0.22 %
and fuel is HFO and Sulphur content : 3.28 %
Hi Shafi,
With such a high chloride level in the kiln feed, the liquid is likely to be a concentrated solution of ferric chloride. (FeCl3) You could test a sample of the liquid to confirm this.
Ferric chloride can be produced by the reaction of gaseous chloride salts attacking the kiln shell. This ferric chloride is anhydrous under normal kiln operation, but is extremely deliquescent and will very rapidly absorb atmospheric moisture and form a dark red liquid, which looks almost black if concentrated enough.
Because of your very high chloride levels, it may not be possible to prevent this attack from happening. However if you consult a bricking supplier/expert there are certain techniques or products available to minimise such chloride attack of the kiln shell, as Denis (DPM) has suggested above.
Regards,
Ted.