The Effect of Treatment of Fusenized Coal with Gaseous Media on the Initial Stages of Oxidation in an Air Environment

The peculiarities of the change in the composition of SS grade coal prone to spontaneous combustion after its treatment in an environment of gases of various chemical activity (nitrogen, air, carbon dioxide) are investigated. The effect of gases on changes in the chemical composition of the coal surface and the adsorption capacity to oxygen during low-temperature oxidation of coal in the air has been established. EPR spectroscopy data indicate a recombination of free radicals at the initial stages of coal oxidation, followed by an intensification of their formation when coal samples are exposed to air. Analysis of changes in the rate of oxygen absorption and the composition of the gas phase indicates the highest sorption activity to oxygen of a coal sample treated in an inert nitrogen environment. The crushing of coal in the air atmosphere leads to the primary oxidation of the native outer surface and a decrease in the sorption capacity to oxygen at the initial stage of its determination. The adsorption of carbon dioxide on an accessible coal surface is accompanied by a transformation of its functional composition and, thereby, a slowdown in the initial stages of oxidation.