Alteration behavior of mineral structure and hazardous elements during combustion of coal from a power plant at Huainan, Anhui, China

摘要

The alteration behavior of minerals and hazardous elements during simulated combustion (100 -1200 degrees C) of a raw coal collected from a power plant were studied. Thermogravimetric analysis indicated that there were mainly four alteration stages during coal combustion. The transformation behavior of mineral phases of raw coal, which were detected by X-ray polycrystalline diffraction (XRD) technique, mainly relied on the combustion temperature. A series of changes were derived from the intensities of mineral (e.g. clays) diffraction peaks when temperature surpassed 600 degrees C. Mineral phases tended to be simple and collapsed to amorphous glass when temperature reached up to 1200 degrees C. The characteristics of functional groups for raw coal and high-temperature (1200 degrees C) ash studied by Fourier transform infrared spectroscopy (FIR) were in accordance with the result obtained from XRD analysis. The volatilization ratios of Co, Cr, Ni and V increased consistently with the increase of combustion temperature, suggesting these elements were gradually released from the organic matter and inorganic minerals of coal. (C) 2018 Elsevier Ltd. All rights reserved.