Determining technique of spontaneous combustion hazard zone in the gob of fully mechanized longwall top-coal caving face

The spontaneous combustion characteristic parameters are evaluated using the self ignition experiment oven. Based on the actual survey in the workface, the distributions of the remain coal, the intensity of air leakage and the oxygen concentration in the gob are obtained. And then the three zones are determined according to the actual values of the limit parameters. Finally, on the basis of the shortest self ignition term of coal and the speed of the workface advancing, the spontaneous combustion hazard zone in the gob are determined and the minimum safe speed of face advancing is evaluated.