In this research, thermogravimetry (TG/DTG) was used to determine the combustion characteristics of two different rank coals (Tunçbilek and Afşin Elbistan) before and after cleaning process. Applying sink−float process cleaned raw coal samples, and optimum-separating densities for each sample was determined using the criteria of "degree of washability". The results indicated that coal cleaning was very effective on Tunçbilek sample due to its high rank. TG/Dtg analysis of raw and cleaned samples indicated different reaction regions occurring at different temperature intervals. Easy combustibility and long-lasting combustion were the distinctive effects of coal cleaning on raw coals. Kinetic analysis of the samples showed that clean coals require lower activation energies to initiate the combustion process than raw coals.