What is lime used for in cement ? Many people tell me different answers. What is the ratio of lime to cement and when to use in a particular job ?

What will be the effect of clinker on cement grinding which is produced from 100 per cent petcoke. The chemistry of clinker is as equivalent as when produced with other fuels. Also nodulisation of petcoke clinker is good. Kindly advice how to improve cement grinding performance with petcoke clinker.

It is not clear what problem you are suffering from. With petcoke clinker I expect there is a higher sulphate content in the clinker. Therefore you have to reduce the amount of gypsum addition and that will adversely affect the performance of the cement mill. I'm afrain there is no ready solution to that problem. The clinker might also be denser resulting in loss of milling efficiency. In that case addition of calcium fluoride to the kiln feed will probably help.

We are having Polysius design ILC six-stage kiln have dimension of 3.8m ID and 64m length. We are firing 100 petcoke in both main firing and calciner firing. We are facing problem of reduction in output and percentage of fines generation in clinker increased.The kiln feed and petcoke chemical analysis are as under: SiO₂ 13.80 - 14.10 Al2O₃ 3.6 - 3.75 Fe₂O₃ 3.4 -3.6 CaO 42.7 - 42.9 MgO 0.7 - 0.9 SO₃ 0.1 -0.16 K₂0 0.28 - 0.35 Na₂O 0.10 - 0.12 Cl 0.06- 0.09 Petcoke Analysis C 88.5 - 89.5 H₂ 3.8 - 4.2 S 6.0 - 6.5 Violatile Content 9.8 -10.4 Calorific Value 7960 - 8020 Kcal/Kg Coal Ash Content 0.30 - 0.70 Please suggest suitable counter measures to increase throughput rate and stable running of kiln.