Thermal kinetics analysis of coal-gangue selected from Inner Mongolia in China

Thermal behavior and kinetics analysis of coal-gangue sample selected from Inner Mongolia Autonomous Region in China were investigated by using thermogravimetry-derivative thermogravimetry, X-ray diffraction (XRD) analysis, and Fourier transform infrared (FT-IR) spectroscopy. The mineralogy of coal-gangue was mainly determined as kaolinite, quartz, and boehmite. The XRD and FT-IR results showed that the structure change in coal-gangue with the temperature increased. The structure parameters of the microcrystal carbon in coal-gangue sample, including interlayer spacing (d (002)), average lateral sizes (L (a)), stacking heights (L (c)), and aromaticity (f (a)), were calculated based on XRD data. With the increase in temperature, the values of d(002) and L (a) decreased from 3.982 and 0.223 to 3.373 and 0.198 nm, respectively; however, the values of L (c) and f (a) increased from 0.111 and 0.633 to 0.156 and 0.852 nm, respectively. The average activation energy of coal-gangue was 102.66 and 103.73 kJ mol(-1), respectively, based on the Coats-Redfern and Flynn-Wall-Ozawa method.