Integrated Method of Reducing the Threat of Endogenous Fires in Hard Coal Mines

Abstract

Underground exploitation of hard coal based on a longwall system is increasingly exposed to various types of threats. In particular, this applies to endogenous fire threat. It results from coal left in the goaf, which due to favourable climatic conditions may lead to self-heating and self-ignition. In practice, due to the maintenance of the roof or the passage through the fault zones, coal is often left in the caving zone, which significantly increases the possibility of endogenous fires in this zone. Therefore, it is necessary to develop an effective prevention solution. The method presented in this paper combines all previously used methods aimed at reducing fire hazard. The levels of fire hazard indicators significantly dropped in the areas where the method had been applied. This, in turn, enabled safe mining operation in the tested longwalls, their decommission and the isolation of longwall workings. The results confirm the validity of the adopted assumptions. The method is based on practical and effective use of preventative measures designed to reduce endogenous fire threat. It can be successfully applied not only in mines without extensive fire prevention system but also in mines where other prevention methods are successfully used. It may support and supplement them. The article discusses basic assumptions of the method and presents a model of application.