COAL FIRE DETECTION AND PREVENTION - MINING ENGINEERING ASPECTS

Coal fires are significant hazard to the environment, to people living in the vicinity and to mining operations. Most coal fires occur in seams close to surface. Often they are caused by spontaneous combustion. The exact location of a coal fire is important information for fire fighting and extinguishing. So far coal fires have been detected by spotting its exhaust gases, heat and subsidence. But these effects only become visible when the coal fire has already been burning for some time and has developed to a significant size. An important factor influencing natural and anthropogenic coal fires are mining activities. In order to narrow down such effects detailed analyses of different coal fire types have been executed. The results are used – among other information – to set up computer aided coal fire simulation models. Such simulation models are similar to 3-D simulation models used in the oil and gas industry. They can help history matching and predicting a coal fire, its direction, size and intensity. Currently the modeling focus is posed on stresses induced by volume deficits caused by coal fires. The models offer an opportunity to locate a coal fire more exactly by creating a link between the fire location and the stress induced cracks, fissures and subsidence on surface. The direction of a coal fire and its speed can also be forecasted, as there is a link to their development over time. Such models have been set up for coal fires in China. Further work will focus on incorporating additional coal fire settings, geometries and locations. Target is to develop or optimize currently applied mining methods to minimize coal fire hazards and impacts.