In this paper, through a combination of experimental research and theoretical analysis, the distribution and change characteristics of oxygen and gas products during coal spontaneous combustion are studied. The Liuhuanggou coal sample, the Mengcun coal sample, and the Cuimu coal sample are selected as the research objects. The oxidation rate during the spontaneous combustion process of three coal samples and the changes of oxygen concentration, oxygen consumption rate and gas products at different locations are studied. The research results provide a certain theoretical basis for the treatment and control of coal spontaneous combustion disasters.

Thermogravimetric experiments were used to study the oxidation process of three coal samples from 30-800℃ under different oxygen concentrations. The kinetic characteristics of the coal oxidation process were analyzed, and 5 characteristic temperatures and 4 characteristic parameters were determined. The oxidation process is divided into 3 stages, and the oxidation reaction rate in the oxygen absorption stage and the high-temperature combustion stage are calculated. The following conclusions are drawn: the initial characteristic temperature of oxygen inhalation and weight gain shows a "W"-shaped fluctuation with the increase of oxygen concentration, and the other characteristic temperatures all decrease with the increase of oxygen concentration. Burnout index and comprehensive combustion Parameters such as characteristic parameters, combustion characteristic parameters, and oxidation reaction rate all increase with the increase of oxygen concentration, and the reaction stability parameters decrease with the increase of oxygen concentration. Under the same oxygen concentration, as the degree of coal sample deterioration increases, the oxidation reaction rate of coal sample gradually decreases.

The self-developed coal fire development and evolution simulation experimental device was used to study the oxygen distribution and migration law in the process of coal spontaneous combustion, and the high temperature area of coal at different depths was determined according to the change law of oxygen concentration. Establish an oxygen consumption rate calculation formula and calculate the oxygen consumption rate of three coal samples. The study shows that the oxygen concentration of the coal samples in Liuhuanggou and Mengcun is similar. The oxygen concentration in the high temperature area decreases rapidly in the initial stage of the experiment, then fluctuates slightly, and finally rises gradually. The oxygen concentration of the Cuimu coal sample decreases rapidly in the initial stage of the experiment, and then fluctuates slightly until the experiment is over. The oxygen consumption rate in the high temperature area is the maximum in each layer, and the maximum oxygen consumption rate of the deep coal is lower than that of the shallow coal.

Finally, the distribution and migration of CO, CO₂, CH₄, C₂H₄ and other major gas products during the spontaneous combustion of coal are studied. The analysis found that the gas concentration in the high-temperature area reached the peak first, and the coal sample with a higher degree of deterioration would produce multiple gas concentration peaks. During the downward movement of the high-temperature region, the peak gas concentration generated during the pyrolysis stage is not necessarily located in the high-temperature region. In the later stage of the experiment, under the influence of thermal buoyancy and chimney effect, the gas concentration changes in the middle and deep coals will affect the shallow part. The gas concentration of coal.