PARAMETERS OF OXYGEN ADSORPTION ON COAL SURFACE
Purpose. To investigate the process of the oxygen adsorption on the coal surface with the help of a gas chromatographic method.Methods. Experimental study of the oxygen adsorption isotherms using the “ХРОМОС ГХ-1000” chromatographic complex with the automatic peaks marking that allows improving the precision of the parameters calculation for confinement of an analyzed substance.Results. The Henry and Langmuir principle of plotting the isotherms has been studied on the example of the oxygen adsorption by the T-rank coal from the “Kommunarskaya” coal mine using thechromatographic parameters of confinement. It has been determined that the dependence of the adsorbed oxygen concentration decreases with the temperature increase. It is connected with the influence oftemperature conditions on the progress of the physical adsorption process. The values of the adsorbed oxygen maximum concentration have been calculated within the temperature range from 303 up to 403 K. It is shown that the minimum concentration corresponding with the critical temperature of the coal spontaneouscombustion determined as a result of the investigation of its chemical activity within this temperature range is characteristic for the values of the ultimate concentration of the adsorbed oxygen. The adsorption heat fortwo temperature ranges has been calculated using the plotted Langmuir isotherm by the similar degree of filling the monolayer. The obtained data permit to state that the mechanism of oxygen interaction with the coal surface changes when coal reaches the critical temperature of the spontaneous combustion.Scientific novelty. The chromatographic method allows observing the coal oxidation process which is responsible for the development of its self-heating using the adsorption parameters.Practical value. The obtained results permit to estimate the contribution of the physical and chemical adsorption to the coal oxidation process using the data of the chromatographic investigation of its chemical activity.