Coal Fly Ash (CFA)

Free-swelling index (FSI) and dilation are useful indicators to predict the strength of coke that may be derived from a particular coal. FSI is a measure of a coal ability to swell and cake during heating. Both coal from Ovbiowun and Oloku are considered to have poor coking and swelling tendencies as inferred from the derived FSI values (2.04 and 1.48 respectively) as well as > 36% in volatiles. GCV/HHV is determined from both proximate and ultimate analyses values as input parameters using a generally proven formula. GCV of Ovbiowun coal is 28.7MJ/Kg which is within range of 26.7 – 30.2 MJ/Kg for " high volatile C bituminous ". Oloku coal has GCV of 25.3 MJ/Kg which is within the range of 24.4 – 26.7 MJ/Kg for " Sub bituminous A grade ". For Ovbiowun coals, the Ibs of CO2/ MMBtu (gross) = 167.44 Ibs/Btu, 4596 Ib/tonne and for Oloku coals, Ibs of CO2/ MMBtu (gross) = 164.21 Ibs/Btu, 4376 Ib/tonne. This strongly agrees with Oloku coals as sub-bituminous and Ovbiowun coals as bituminous, having higher carbon content and thus more CO2 production. The fuel ratio for both Ovbiowun and Oloku is 0.98 and 0.91 respectively which is a referral to bituminous grade. The vitrinite reflectance as determined for the studied samples was 0.48 for Ovbiowun coals and 0.43 for Oloku coals implying bituminous and sub-bituminous coals respectively. No coal bedded methane is produced from both coals. The Roga index as well as their dilation is inferred to be around 0-20. Ovbiowun coals have 65 HGI and Oloku coal is 87 HGI due to higher moisture content. The moisture content of Oloku coal (15.0) is higher than Ovbiowun (10.8) while the volatile matter (as received) for Oloku (40.7) is lower than Ovbiowun (41.7). From the > 10% moisture and ash content, coal in both study area is unsuitable for coke production. Also the derived Hydrogen % for Ovbiowun (63.3%) is greater than Oloku (57.43) implying more maturity in Ovbiowun coals.