Dear Prisoner,

Ted is correctly replied that the formation of C2S begins @ the temperature range of 900-1050 deg C,it will create the blockages of the kiln feed pipe.So,it is advisable to ensure the calcination % not to exceed more than 97%.Thanks Mr.Ted for nice replying to uncalcined material entering inside the hot kiln..

tanx ted and mohan brothers.    sir any thumb rule for finding length of  burning zone?      sir if we have ball mill and which  supported with roller press then what will be the ideal clinker size for grinding.

ted brother plz explain it.  high calcination degree could also mean that the burning zone is probably too long, so clinker formation will occur earlier than intended in the kiln which may adversely affect the clinker mineralisation and ultimately cement performance and possibly even clinker grindability.

Hello Prisoner,

A longer than optimum burning zone will promote the formation of large alite (C3S)crystals due to the longer time spent >1250oC  Large alite crystals are difficult to grind, so the length of time spent at clinkering temperature should be minimized to promote better clinker grindability.

With regarad to the final cement, large alite crystals are less reactive than small alite crystals because the larger crystal fragments have a smaller surface area per unit mass. Often large alites which spend too long at sintering temperatures are also coated with secondary belite (C2S), this further limits their reactivity.

So, if you want to produce clinker that is easier to grind and more reactive, you should ensure a short, sharp flame which will promote a short but efficient burning zone.

Hope this helps,

Ted.