The Method of Combating Coal Spontaneous Combustion Hazard in Goafs—A Case Study

Dawid Szurgacz,Jarosław Brodny,Magdalena Tutak,Leszek Sobik,Olga Zhironkina

doi:10.3390/en13174538

Abstract

One of the major natural hazards occurring during the process of mining exploitation are endogenous fires. They cause very large material losses and constitute a threat to the health and life of the workers. Such fires usually start and develop in the goafs. The remaining coal and the oxygen-containing air flowing at a certain rate may lead to endogenous fires. The basic element of the assessment of the occurrence of an endogenous fire and the degree of its development is the chemical composition of the air flowing out of the longwall and the goafs. The monitoring of this composition also makes it possible to assess the severity of such a fire. The damage that can be caused by the endogenous fire requires scientific and experimental research being carried out on a wide scale in order to limit its occurrence and development. All papers and research mentioned in the paper aim to find a tool that will help to control the fires. The paper discusses the development of a new and original method of combating the threat of endogenous fires. It is based on the installation designed to feed an ash and water mixture or an ash and water mixture with carbon dioxide to goafs. The foundation of the paper is a method based on a vast depth of expertise and knowledge gained by the authors in the field of combating endogenous fires. The developed installation prepares and transports ash and water mixtures together with carbon dioxide to the zones with high probability of endogenous fires. The mixture is a preparation of the surface of a mine, and later, it is transported underground by pipelines to the goafs where a high level of the fire hazard was identified. The construction of the system and the composition of the mixture used are both original solutions; their practical application limited the process of spontaneous heating of coal. Monitoring the chemical composition of gases in the air of the goafs made it possible to control the effects of applied measures; it proved that carbon dioxide used as an inert gas disturbs the process of carbon oxidation, and the water and ash mixture limits the inflow of the air with oxygen. The advantage of the method is particularly evident in the case of the exploitation of deposits where coal has a short incubation time. This original approach allows for a better and more effective response to endogenous fires.

Highlights

Coal is mainly used to generate electricity: As commercial heat in households and different branches of the industry [1,2,3,4]
The method presented in the paper designed to combat the endogenous fire hazard in the goafs was implemented in KWK ROW Ruch Chwałowice in Rybnik, Poland (Figure 2)
Caused by presented the injectionmethod of carbon dioxide together with the ash water mixture the goafs.Several measurements of the concentration of the gases that are the by-products of the process prove that

Summary

Introduction

Coal is mainly used to generate electricity: As commercial heat in households and different branches of the industry [1,2,3,4]. The global forecast of coal resources estimates that the coal resources will last for another 130 years [5]. Coal is the third-largest source of primary energy. Its position will continue to be high in the world in terms of energy consumption. The mining industry is linked to a high-risk factor in terms of work safety, difficulty in mining, and geological conditions [6,7,8,9]. One of the most dangerous natural hazards are endogenous fires, commonly referred to in the literature as spontaneous combustion of coal [10]

Methods

Results

Conclusion