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

The peculiarities of changes in the composition of SS grade coal prone to spontaneous combustion after its treatment in gas environments of various chemical activities (nitrogen, air, and carbon dioxide) were 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 was established. The EPR-spectroscopic data indicated the recombination of free radicals at the initial stages of coal oxidation followed by an intensification of their formation when coal samples were exposed to air. An analysis of changes in the rate of oxygen absorption and the composition of the gas phase indicated the highest sorption activity to oxygen of a coal sample treated in an inert nitrogen environment. The crushing of coal in an atmosphere of air led 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 was accompanied by a transformation of its functional composition and, thereby, a slowdown at the initial stages of oxidation.