In the Clinkerisation process in cement kiln, the clinker liquid formation temperature and liquid characteristics have strong influence on the phase formation reactions of cement clinker. In coal fired kilns the ash characteristics (especially the ash fusion temperature) of coal ash thus could have a strong influence on the cement clinker phase formations. Compatibility of the ash fusion temperature and ash composition thus could influence the cement clinker phase morphology of the clinker minerals and their extent of formations , The quantity and quality of coal and its ash constitutes an essential part of raw meal-clinker-ash system.
There is very little information on the chemical characteristics of coal ash and its relation to fusibility and clinker formation, particularly for coals available in India of very high ash content. The clinker liquid formation temperature and its melt characteristics is thus an important aspect of the clinker mineral formation in the cement kilns. Ash content of the coal used, ash characteristics and its compatibility to the Clinkerisation process governs the quality of the clinker produced. The nature of ash distribution in the clinker leads to Micro structural heterogeneity / homogeneity of the clinker mineralogy which relates to the Grindability of the clinker as also to its hydraulic potential. The compatibility of the ash characteristics to the clinker liquid formation has also been observed to influence kiln productivity and quality of clinker.
The paper discusses the chemical composition and fusion characteristics of various coal ashes of different sources before and after beneficiation and application of heating microscope as a tool for the characterization of ash characteristics.
The paper further illustrates through a Case study that optimization of the ash characteristics could help to achieve improved productivity of the kilns, thus exemplifying the pronounced effect of the coal ash characteristics and its influence on kiln productivity and the clinker quality The Paper was presented and published at 10th NCB Int Seminar