1156 posts
Burning Question 13
Do you have an idea of each point decreased in the standard deviation of the kiln feed and how it affects to the specific heat consumption? (for example: 40kJ/kg of clinker for every additional 0.1 by which the standard deviation is raised in the usual range).
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1156 posts
Re: Burning
The effect of kin feed standard deviation on unit energy consumption is complex and is likely to vary from kiln to kiln. For a precalciner kiln each one per cent increase in the standard deviation of the kiln feed lime saturation factor you might expect an increase in the energy consumption by 150kJ/kg clinker. However, this relationship is unlikely to be linear and will vary around that figure from kiln to kiln.
1156 posts
Burning Question 14
We are manufacturing white cement. Previously we used oil fuel, now gradually we have switch over to petcoke and now a days we are using almost 85 per cent of petcoke and 15 per cent of LSHS oil as a fuel. After this we are facing a problem that clinker is not coming out in a nodular form and it is almost in dusty condition. Kindly suggest that what corrective or preventative measure should be taken for getting the clinker in the nodular form from the kiln.
1156 posts
Re: Burning
This problem of the clinker dusting with the conversion to petcoke firing has been reported from a number of Indian cement factories. I think you will find that your Grasim South factory at Reddipalayam is suffering similar problems. This has prompted me to research the problem and the Tech Forum article in the April issue of ICR will be based on this topic. From my research it seems that the excess sulphate in the clinker flux reduces the viscosity and surface tension of the liquid phases in the kiln. The sulphur content in the petcoke is causing the breakdown of the clinker nodules. With grey cement I would suggest increasing the melt content of the clinker, however with white clinker this is not possible. My only suggestion is to increase the alkali content of the clinker by addition of feldspar to the mix. This should combine the sulphur as alkali sulphate and solve the problem. Unfortunately nodulising the clinker before the cement mill will not solve your problem and will only increase your manufacturing costs.