The Impact of the Ventilation System on the Methane Release Hazard and Spontaneous Combustion of Coal in the Area of Exploitation—A Case Study

Abstract

Various types of natural hazards are inextricably linked to the process of underground hard coal mining. Ventilation hazards—methane and spontaneous combustion of coal—are the most dangerous; they pose a major threat to the safety of the workers and decrease the effectiveness of the whole coal production process. One of the methods designed to limit the consequences of such hazards is based on the selection of a ventilation system that will be suitable for the given mining area. The article presents a case study of an active longwall area, where—due to increasing ventilation hazard (methane and spontaneous combusting of coal)—the whole system was rebuilt. The U-type ventilation system was used in the initial stage of the extraction process, however, it often generated methane in amounts that exceeded the allowable values. Consequently, such conditions forced the change of the ventilation system from a U–type to Y–type system. The new system was installed during the ongoing mining process, unlike the usual practice. The article presents the results of tests on mine gas concentrations and descriptive statistics for both types of ventilation system. The results clearly demonstrate that the U-type longwall ventilation system, in the case of high methane release hazard, prevents safe and effective operation. At the same time, the use of this system limits the carbon oxidation reactions in the goaf, leading to spontaneous heating and combustion, which is confirmed by the low concentrations of gases—by-products of these reactions. In turn, the use of the Y-type longwall ventilation system ensures safe and effective operation in areas with high methane release hazard, but at the same time deteriorates the safety associated with the spontaneous combusting of coal. The presented case—both from a scientific and practical perspective—is quite interesting and greatly broadens the knowledge in the scope of an efficient ventilation system for underground workings.

Digital Modernization of the Russian Mining Sector in Accordance with the National Technology Initiative and Mining 4.0

“…In a Smart Mining system, it is also possible to provide real-time monitoring of equipment performance and safety of personnel. Through the use of the Internet of Things (IoT) [11], Big Data, machine-to-machine communication (M2M), artificial intelligence for data analytics, Smart Censors [12] on excavators, drilling rigs, dump trucks, observation drones, intelligent mining, also called Mining 4.0, based on digital and robotic technologies of Industry 4.0, will completely exclude a human from drilling and blasting, excavation and loading, transport processes, geodetic surveying, planning and operational management [13][14][15]. At the same time, the highest degree of coordination and flexibility in managing the processes of mining operations will ensure profitable mining at any level of prices and demand for raw materials in the global and domestic markets.…”

Ecological Convergence in the System of Sustainable Development of the Russian Economy

“…Criteria of the economy's perceptibility to environmental innovations (intensity of commercialization of inventions, transfer of innovations). Special role here is played by innovations in new sources of energy [5] and industrial safety [6] -key stones of extracting industries sustainable development. It is possible to assess the ecological identity of an economy using these criteria.…”

Distribution and Prevention of CO in a Goaf of a Working Face with Y-Type Ventilation

“…The concentration of gas at the same time will increase the risk of spontaneous combustion of coal. 40 Li et al used the numerical simulation software Comsol Multiphysics to numerically simulate the goaf and revealed the law of air leakage and gas distribution in the goaf of a fully mechanized mining face under the condition of ″Y″ ventilation, compared with the “U”-type ventilation, the “Y”-type ventilation can reduce the gas concentration in the upper corner and the working face. The three-dimensional space distribution law of the gas in the goaf is similar to the “O” circle theory of mining cracks.…”