Cement Energy and Environment

• c3s in the given clinkers is found to be varying in the range of 47-64% • C 2 S in examined clinkers is found to be in the range of 15-34% • Crystal sizes of Alite grains are found to be in the range of 16.5-28 .81Jm • Belite crystal sizes in given clinkers are observed to be in the range of 13.2-17 j.Jm. • Pore size of clinker nodules, as determined using OM, is observed to be varying from 57- 98.51Jm However, due to interaction of numerous attributes of the given clinkers and their cumulative roles in clinker grinding, Bond indices could not be predicted only based on mineralogical and microscopically compositions in isolation. But, factors like clinker granulometry and crystal morphology are observed to be having more decisive role in determining energy consumption. For illustrating these effects, the examined clinker samples are classified in four categories depending upon their work indices viz. < than 11 kWh/t, between 11-13 kWh/t, between 13-15 kWh/t & between 15-17 kWh/t. Based on this classification 5 samples from different categories are considered showing the effect of clinker granulometry on increasing Bond index. The samples used for illustrations are S-19: Bond work index = 16.99, S-16: Bond work index= 14.64, S-7: Bond work index= 12.30, S-3: Bond work index = 11 .02 Particle size distributions of Bond test feed for these samples (i.e. jaw crushed samples passing through 3.35mm) are shown in figure 1. From figure 1 it can be seen that there is a considerable influence of clinker feed particle size distributions for the Bond test on the corresponding work index. This is expected due to the fact that energy requirements during size reduction are inversely proportional to particle size. Thus, sample S -19, having finest size distribution amongst the samples compared is observed to be having highest grinding energy requirement for producing product of predefined fineness. Further, for more or less similar mineralogy, an increase in fineness is seen to be causing increased work index (see for example comparison between (S-3 & S-19) and (S-7 & S-16)). Table 1: Samples examined for grindability characterization and their mineralogical constituents 4