Abstract:

Under the condition of spontaneous combustion of residual coal in goaf causing huge economic loss and heavy environmental pollution every year, limitation of application of carbon dioxide in preventing spontaneous combustion of residual coal greatly restrict the full exertion of its fire preventing effect. Against these problems, field experiment of leaving dry ice in goaf to prevent spontaneous combustion of coal seam was carried out in two mining faces of SHIGANG coal mine, and the mechanism of leaving dry ice in goaf to prevent spontaneous combustion of residual coal was verified, and then transferring and spreading situation of carbon dioxide in goaf and changing law of temperature field under different conditions of leaving dry ice were analyzed, and finally the effect of leaving dry ice in goaf to prevent spontaneous combustion of residual coal was studied. Concentration of carbon monoxide of 15108 mining face sharply decreased from over 50ppm to about 20ppm and kept stable, and temperature in its goaf basically sustained at about 19℃, in addition, concentration of carbon monoxide of 15202 mining face also decreased to about 20ppm and kept stable, and temperature in its goaf basically sustained at about 21℃, which all show that the effect of leaving dry ice in goaf to prevent spontaneous combustion of residual coal was evident. The research results can further expand range of preventing technologies against spontaneous combustion of coal and supply larger assurance for safe production of coal mines.

Key words: goaf, spontaneous combustion of residual coal, dry ice, safe production