Dastgir:

Alkali sulphate, perhaps, will not have to do much here, since it should be evaporating back towards inlet.

Hello Gulam, 

No, definitely not. Apart from incorporation of a small amount of Na2O and K2O in the clinker phases, alkali sulphates are the only way for the majority of alkalis (and indeed sulphur) to exit the kiln. This is due to the significantly lower volatility of sulphates compared to other alkali compounds found in the kiln (such as oxides or chlorides).

Alkali sulphates are further stabilised by an adequate excess of oxygen in the burning zone and kiln inlet. This is because an excess of O₂ inhibits the thermal decomposition of sulphates which, occurs according to the following reversible reaction;-

K₂SO₄ <—––> K₂O + SO₂ + ½ O₂

Since the reaction is reversible, its equilibrium is controlled by the amount of oxygen in the kiln inlet and burning zone. An increase in oxygen concentration shifts the reaction equilibrium towards the left, in favour of K₂SO₄ . The excess oxygen effectively increases the temperature at which the sulphates decompose, hugely increasing the chance of them leaving the kiln.

It is fortunate for us that alkali sulphates don't evaporate back towards the kiln inlet very much, otherwise it would be virtually impossible to operate a modern kiln, due to continuous, massive blockages in the preheater and kiln inlet.

 

Regards,

 Ted.

 

Please do not go to much into chemistry of the process and mineralogy of clinker. It is too early. Are you sure your coal mill will be able to provide amount and fineness needed? Start with that one, might be you will not need any other discussion

Hello Gulam,

I posted this paper in another thread, but not sure if you've seen it. It may be relevant to you;-

http://tinyurl.com/245chxd

“PETROLEUM COKE UTILIZATION FOR CEMENT KILN FIRING”, by Efraim Kaplan and Nery Nedder, Nesher Israel Cement Enterprises Ltd.

Regards,

Ted.

Dear Saddam,

 

I am not clear what you wanted to say. 

Regards,

Gulam Dastgir