The concentration of different maceral groups and minerals in coal influence the quality as each of them behaves differently during heat treatment. The purpose of this study is to know how the maceral groups and minerals are behaving at different temperature conditions. Therefore, various maceral groups and minerals were concentrated by using heavy liquids of different specific gravities (1.3, 1.7 and 1.9). The generated density fractions were treated with heat at 400, 600, 800 and 1000°C. All the density fractions at various temperature conditions along with feed sample were investigated by Optical Microscopy, X-ray Diffractometry (XRD), Electron-probe Micro Analysis (EPMA) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The results from these analyses suggest that fusinite and sclerotinite are the most stable macerals, whereas quartz is the most stable mineral during pyrolysis. Telocollinite found to be oxidized very prominently at 400 °C . Siderite and pyrite thermally altered to form hematite above 400°C and 800 °C respectively. Kaolinite converted to metakaolin followed by mullite with increasing temperature.