ABSTRAKT

The thermochemical processes of spontaneous combustion of coal in an inclined outcrop seam were investigated in order to understand the underground mineral self-ignition, fire propagation, and the loss of reserves. A heat and mass transfer model of porous coal-bearing stratum was employed, combining convection and radiation with a transient exothermic source which is coupled with coal oxidation, oxygen supply, and fuel consumption. It is found that spontaneous combustion firstly occurs under lean oxygen condition. Fire development controlled by the reaction heat release in the early oxidation process shifts to oxygen restriction after coal self-ignition. The stratum porosity significantly affects the fire propagation. The fire propagation rate slightly increases as the inclined angle decreases. Compared with indirect surface survey, the predicted loss of reverses is more reasonable; thus, the present model could provide a useful reference to loss estimation in coal fire hazards.