Possibilities of Effective Inertisation of Self-Heating Places in Goaf of Longwall in Hard Coal Mines

Abstract

Underground fires in coal mines belong to the most common hazards, the exposure to which frequently requires long term and costly rescue operations. It is mainly connected with the specific character of underground excavations which have limited volume. This makes the maximum permissible concentration of harmful gases rapidly exceeded and may also cause changes in air flow direction. The most certain way of improving a safety situation in Polish coal mining industry is taking early prevention steps. One of the prevention methods is inertisation of the atmosphere in longwall goaf. These activities rely on partial or total replacement of air or combustible atmosphere by inert gas. Thanks to them the risk of spontaneous fires hazard and gas explosion decreases. The main reason for the use of inert gases is to reduce the oxygen content to a limit which prevents further development of fire. This article presents methods for assessing inert gas to replace oxygen in the atmosphere in goaf.

Study on Nitrogen Injection Fire Prevention and Extinguishing Technology in Spontaneous Combustion Gob Based on Gob-Side Entry Retaining

“…Wang 31 implemented an engineering project on fire prevention by nitrogen injection and concluded that the diffusion radius of nitrogen gas decreases and fluctuates with increasing nitrogen injection intensity. Nikodem 32 replaced the O 2 in the gob of a coal mine with inert gas and demonstrated that inertization effectively mitigates the danger of spontaneous combustion. Tao et al 33 developed a closed mining face to improve the purity of extracted gas and studied the effect of micropores in coal on residual coal spontaneous combustion using low-temperature nitrogen adsorption.…”