Combustion Kinetics of No. A3 Coal in the Paner Coal Mine of the Huainan Coalfield, Anhui, China

Due to the huge reserves and great commercial potential of No. A group coal seam, the study on its thermal properties and combustion kinetics have attracted much attention. Via thermogravimetric (TG) analysis, the combustion characteristics and kinetics of No. A3 coal were studied with three types of coal samples, with the grain diameter less than 200 meshes, 200~100 meshes, 100~60meshes, seperately. Under three characteristic temperatures such as Tt, Tp and Tb, the whole combustion process could be roughly divided into 4 stages. Combined with the Tmax and Ti, these five characteristic temperatures increase with elevating heating rates. The Kissinger-Akahira-Sunose (KAS) method and Flynn-Wall-Ozawa (FWO) method as reliable methods were used to verify the results of activation energy (Ea) determined by of model-fitting methods. As complementary, the Coats-Redfern method was used to calculate the pre-exponential factor (A) and the correlation coefficient (R2). According to the evaluation criteria of Ea and R2, D1 mechanism was the most probable model to depict the combustion kinetics.