Experimental study on the influence of associated pyrite content on coal spontaneous combustion

In order to study the influence of associated pyrite interlayer content in coal seam on coal spontaneous combustion, the infrared spectrum of anthracite in Shanxi Yangquan mining area with different content of pyrite was tested by Fourier infrared spectrometer, and the variation law of the influence of the content of associated pyrite on coal surface functional groups was studied. In this paper, the TG, DTG, DSC curves and heat release curves of associated pyrite coal samples during programmed temperature rise were studied by synchronous thermal analyzer experiment. The results show that such features can be found in the spectrum of six coal samples that the aliphatic hydrocarbon content is always higher than that of the AP-0 coal sample. When associated pyrite content is 60%, the content of aromatic hydrocarbons in the AP-0 coal sample is the smallest, and the change of hydroxyl content is the largest. The more vigorous the coal surface functional groups are, the slower the oxidation reaction with oxygen occurs. The higher the content of pyrite associated with the formation of this coal sample, the smaller the relevant weight change during the oxidation reaction. The lower the ignition temperature of coal sample is, the more hematite (Fe2O3) is left in the coal residue, and the lower the maximum heat flow rate, the lower the heat release.