Effect of Structural Nonuniformity on Spontaneous Combustion Liability of Coal

Abstract—The tests of fossil coal sampled in the Pechora Basin determine the chemical oxygen absorption activity U(25), thermal stability of molecular structure (by the TGA method) and microstructural nonuniformity of coal using the complex–entropy analysis. It is found that distinguishing between coals liable and unliable to spontaneous combustion by the criterion U(25) may be wrong. The thermographic analysis and studies of thermograms in the temperature range of 130–250 °С ensures more reliable identification of coal liable to spontaneous combustion The scanning electron microscopy images (1000-fold magnification) show that the propensity to spontaneous combustion of coal depends on the orderliness of the coal microstructure, which is assumed as the key governing factor in this case.