Spontaneous Combustion Characteristics of Coal by Using the Simultaneous Thermal analysis–Fourier Transform Infrared Spectroscopy Technique

Abstract

ABSTRACT Understanding the development process of coal oxidation reactions can aid in preventing coal spontaneous combustion. Oxidation heating experiments on anthracite, bituminous coal, and lignite at different heating rates were carried out using simultaneous thermal analysis–Fourier transform infrared spectroscopy (STA–FTIR). The experimental results show that combining TG, DSC, CO, CO2 and H2O curves in the spontaneous combustion process of coal, the maximum acceleration point Ta and maximum mass loss rate T4 are important for judging the severity of the coal spontaneous combustion hazard. Meanwhile, Ta is more accurate as the ignition temperature point than the ignition temperature T3. As the coal’s rank and heating rate increases, the characteristic temperatures moved to higher temperature. The higher degree of metamorphism has a higher ignition activation energy. Additionally, the reaction models for ignition activation energy between anthracite and bituminous coal changed from three-way transport to random nucleation and nuclei growth with the increase of metamorphic rank, but were not affected by the heating rate.