Quality of clinker related to preheater performance

Comparable indicators for clinker quality are its chemical composition, the calculated Bogue chemical compounds and observed clinker mineralogy by microscopy. Very often we find that there is a difference between the theoretical Bogue chemistry and the practical results in microscopy, especially where alternative fuels are used. Also the size and shape of crystals have an influence in clinker reactivity. The final formation and shape of the cementious mineralogical crystals produced in the kiln is dependent on the reaction zones in the kiln, and also can be affected by preparing of the raw mix in the preheater tower. Normally, a better calcined hot meal will be easier to control and thus a more reactive clinker will come out of the kiln. This paper starts with an overview and a comparison of preheater kilns and the factors that influence clinker reactivity. An analysis of the operating factors is made and finally, a relation to the preheater performance and opportunities for optimization is made.