Cement Energy and Environment

Table 4: Clinker parameters and potential phase compositions ' Clinker LSF SM AM C3S C2S C3A C4AF Liquid code [ i content CL-C 0.91 2.42 1.00 57.62 CL-1 0.91 2.40 0.98 57.42 CL-2 0.91 2.38 0.98 57.09 CL-3 0.91 2.39 0.99 57.45 CL-4 0.91 2.38 0.99 57.49 CL-5 0.91 2.37 1.00 57.11 CL-6 0.90 2.27 0.96 54.67 3.3 Burnability studies The burnability of raw mixes RM-1 to RM-6 carried out at the temperatures of 1450°C at the retention time of 20 minutes showed increase in rate of lime assimilation in presence of jarosite as compared to control mix (RM-C) . Free lime contents in clinker samples CL-1 to CL-6 were found be decreased with increasing dosages of ja10site in raw mixes showing its mineralizing effect (Fig. 1). Although, the free lime content in all clinker samples were found to be in considerable amount but lime assimilation was increased with increasing doses of jarosite. Poor lime assimilation in all above samples could be due to coarse calcite and quartz grained limestone used in designing of above raw mixes in spite of maintaining their finer nature. Improvement in reactivity of raw mixes in presence of Fe, S, Na, K and Zn has also been reported by Gies and Knofel , 1986; Vonlampe and seydel, 1989. 3.4 X-ray diffraction studies of clinker samples The X-ray diffraction studies of clinker CL-5, prepared using 1.5 wt.% dose of jarosite in raw mix and fired at the temperature of 1450°C showed appropriate development of OPC '"' - 20.45 4.38 14.07 27.13 20.61 4.25 14.27 27.25 20.67 4.28 14.33 27.37 20.22 4.36 14.19 27.28 20.10 4.36 14.18 27.29 20.39 4.48 14.17 27.41 21.96 4.20 15.06 28.32 3 2.5 c --------- c J!! 2 r:: ~ 0 0 " .s 1.5 ..J " e u. 1 0.5 CL·C (0.0) CL·1 CL·2 CL·3 CL-4 CL·5 CL·6 (0.25) (0.50) (1.00) (1.25) (1.50) (2.00) Clinker Sample (%of jarosite) Fig 1: Free lime assimilation in jarosite doped clinker samples fired at 145fYC clinker CL-5 indicated 52% alite, 25% belite, 4% C3A and 13% C4AF as compared to control clinker CL-C, with 48% alite, 30% belite, 4.5% C3A and 13% C4AF, thus showing improved alite formation in presence of jarosite. Kakali and Parissakis,1995 reported increase in the rate of Portland clinker formation in presence of ZnO. clinker mineral phases as compared to control clinker CL-C, fired at the same temperature (Fig 3). Semi– quantitative estimation of Fig 2: XRD patterns of clinkers CL-C and CL-5 fired at 1450oC 14 ..