1156 posts
Burning Question 69
We are having to stop our kiln at frequent intervals because of ring build-ups. When we raise the alumina modulus to 1.7 we have better results.
Secondly, what's the difference between a snowman and a ring formation.
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1156 posts
Re: Burning
Ring formation is caused by the formation of liquids in the kiln at a particular position. These penetrate the refractory lining and cause a localised thickening of the coating. Fe2O3 can be a cause of these problems and I am not surprised that raising the alumina modulus has solved the problem. Many cement factories operate with higher alumina modulus than1.7 and I would recommend keeping the kiln feed mix design with the higher alumina modulus. A snowman is the formation of a large build-up on the first grate of the cooler where the clinker falls from the kiln rather than a build-up in the kiln.
1156 posts
Burning Question 70
We are manufacturing white cement. Previously we used oil fuel, now gradually we have switch over to petcoke and nowadays 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 preventive 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 TechForum 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. his 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.