Development of correlation between GCV and proximate analysis of indigenous coals

Higher heating value (HHV) is very important for quality of coal when used as a fuel. It is often used for estimating the efficiency of treatment and other beneficiation methods and for research purpose. Although it is a costly process and requires special equipment and experts to operate. Whereas proximate analysis data can be obtained easily using an ordinary muffle furnace Therefore, to simplify the task and to reduce the cost of analysis many correlations were developed for determining HHV from proximate analysis of coal. In the present work, an effort has been made to develop a correlation based on proximate analyses data for calculating HHV of coal (air-dried basis). The models presented here is established using analyses of 50 samples of indigenous coal and its importance lies in role of all the major variables affecting the HHV. The developed models appear to be better than the existing models and have the following: Model 1: HHV (Mj/kg) = 15.788– 0.215M% – 0.148A% + 0.036V.m% + 6.680 F.c% Model 2: HHV (Mj/kg) = 8.804 – 0.061M% + 0.187V.m% + 0.231F.c% Heating values of basic types of indigenous coal samples were measured and calculated using empirical formulae and results were compared. Remarkable differences were observed in heating value of fifty samples of indigenous coal analyzed. It is determined that further study of these other types is merited for better and more economical utilization of the coal. A significant correlation was also observed between the Heating values proximate contents of the coal.