Dear Expert,
I overhear from technocrats that if we replace coal with pet coke following issues may arise -
1. Clinker will be hard to grind due to increased temp .of burning zone
2. Thermal energy will increase due to increased primary air input for the sake of more oxygen to fully utilise high carbon content of petcoke.
3. Low 28 days strength since, high SO3 content of petcoke may cannibalize on lime content of raw mix.
Expert views invited on the matter
Regards,
Gulam Dastgir
Dastgir,
I guess that you use the word "technocrat" in a pejorative way.
Then I wonder why you could not forget about their ideas and just trust yours!
In this case, you might first start by giving more information.
Is it a precalciner kiln or a long wet kiln?
Are you using alternative fuels or not?
What are the specificities of your raw materials, do they contain SO3?
etc ...
More infor would mean more fun to answer.
Michel
Dear Michael,
I am really sorry if i have unknowingly connote any pejorative remarks through my words.
I have no intention to that effect at all. I simply pick the words during typing my query.
Lets bygone be bygone and come to point.
Yes i am talking about precalciner kiln, there is proposal of use of 5 % of fuel of agro waste and SO3 content in raw mix is about 0.01 %.
Regards,
Gulam Dastgir
Dear Dastgir,
Hard grinding of clinker is possible because of the hard burning condition of petcoke. While using petcoke the flame will be longer than coal willynilly. This will cause a longer time of burning; means overburned clinker. Result is hard grinding.
To burn petcoke; a higher momentum of burner is needed; which will increase the primary air % compared with secondary air (even with the same amount of air) then cold air needs to be heated up. Extra energy!
For the 3rd problem. It is more likely a result of the change in the burning zone. Longer sintering zone, dusty kiln condition, hard burning of petcoke. This comes to my mind. Probably microscopical analyses can tell us the reason.
what about ash content of coal? is it more reactive than the raw meal?? therefore petcoke without ash content has lower burnability properties?
Certainly, I've heard from one of our group plants, after changing 50% of export coal with petcoke 5-6 MPa fall has been observed for the 28th day strength.