The present study aims to evaluate the chemical and mineralogical compositions of coal samples collected from three different seams of a particular borehole of Samaleswari Block, Ib river coalfield, Odisha, India. Different experimental and theoretical studies were conducted to predict and correlate the chemical and mineral composition of coal ash to ash fusion temperatures. The experimental techniques used include proximate analysis, ultimate analysis, gross calorific value determination and chemical analysis of coal ash for quantification of major oxides such as SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, SO3 and TiO2. In addition, X-ray diffraction (XRD) and electron probe micro analysis (EPMA) techniques were used to identify the mineral phases present in coal and ash samples. Finally, FactSage Thermodynamics Model (FactSage 6.3) was used to understand the ash fusion behavior and to predict the phase transformations that occur during the process of coal combustion. (C) 2015 Elsevier Ltd. All rights reserved.