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To research the impact of oxygen consistency on the thermal dynamic characteristics and the change of gas products of weakly caking coal oxidation, differential scanning calorimetry and temperature programmed experiments were used to study, and the correlation between the intensity of heat release at distinct consistencies of oxygen and concentration of gas products was computed applying grey correlation method. The outcomes indicated that the coal low-temperature oxidation process can be categorized into three phases: speedy endothermic, slow endothermic, and exothermic. The apparent activation energy in the slow heat absorption phase exceeded the speedy endothermic stage, and the apparent activation energy in the heat release phase increased by 20.83 kJ/mol. The concentration of gas products generated at the spontaneous combustion process of coal growth when temperature went up. However, CH4 concentration increased with the temperature rising after 120 °C. C2H6 gas does not appear until 100 °C. C2H4 gas appeared after 90 °C. At various O2 consistencies, the correlation between exothermic intensity and CO2 remained the largest, the correlation between exothermic intensity and CO and CH4 was larger at lower oxygen consistencies. As concentration of oxygen increased, the correlation between exothermic intensity and C2H4 and C2H6 increased first and then decreased.

Abstract: The float coal in the gob of re-mining face spontaneous combustion mechanisms was studied and the physical model was build. With the boundary condition determined by analyzing the on-the-spot data, the distribution of oxygen concentration and the velocity of air flow in the gob were calculated by numerically simulating the flow field. Basis on the results,a type of composite gel was chosen to used controlling the development of the spontaneous combustion dangerous zone,at the same time,the characteristics and form of the gel was introduced,and showen the equipments and systems of injectting gel.The spontaneous combustion zone was controlled after injecting the composite gel with fly ash,with the temperature and CO gas reducing. [Copyright &y& Elsevier]