55 posts
537 posts
Re: sand stone...
armankhan:
thanks to all my friends for reply..... friends plz tell me in which case we to become compell to increasing SM
Hello Armankhan,
The Silica Modulus (SM), often called Silica Ratio, has two functions;-
1. It inversely controls the quantity of liquid phase in the burning zone of the kiln, and therefore the burnability of the raw mix, as well as the degree of coating formation and clinker nodulisation.
2. It also controls the percentage of total silicate minerals (C2S + C3S) in clinker.
Since both of these functions are important for optimum kiln operation and cement performance, there is usually a narrow optimum range for any particular kiln.
In most literature, it is generally accepted that the SM should lie between 2 and 3.
Very low SM values (<2) would result in excessive liquid phase, possibly causing unstable coating, snowman formation, kiln instability, clinker balling, excessive coating, kiln rings, dense hard to grind clinker, possible attack to the bricks and low cement strengths.
High SM values (>3) would result in hard to burn kiln feed, too little liquid phase, high thermal loads, lack of adequate coating, brick wear, dusty clinker, high clinker free limes, unstable kiln and increased cement set times.
A case where you might wish to increase the SM would be if your liquid phase quantity was already on the high side and you had frequent kiln rings, snowman formation, clinker balling or excessive coating... or, if you wished to marginally increase late strengths.
Any change in SM should be made taking into consideration all of the possible effects described above. Also, sudden large changes in SM (>0.2) should be avoided.
Regards,
Ted.
55 posts