Research on prediction and forecast indicators system of easy spontaneous combustion coal seam

This paper is devoted to improve the prediction accuracy and fire prevention effectiveness of spontaneous combustion in western coal mines.Applying the natural combustion method on coal samples of Jurassic and Carboniferous Permian coal-bearing strata, this paper studies the characteristics and laws of coal spontaneous combustion. An early warning and prevention system was established based on grading of spontaneous combustion propensity using five gas indicators, CO, O2, Δφ(CO)/Δφ(O2), C2H6 and C2H4.The applications of the system show that the combined carbon monoxide and oxygen fire coefficient (100×(Δφ(CO)/Δφ(O2))) can accurately measure the oxidation of coal and can also inverse the oxidizing temperature of coal with ethane and ethylene. The system realizes dynamic identification of hidden dangers of coal spontaneous combustion using multiple indexes. At the same time, the active grading prevention and control method, synergistic with technical means of dynamic propulsion, end plugging, nitrogen injection and oxygen reduction, grouting and temperature suppression, and segmentation isolation, has achieved effective control of spontaneous combustion hazards in filed applications.