Applying European approach to predict coal self-heating in Ukrainian mines

Abstract

Purpose is the prediction of coal self-heating and determination of the factors effecting the dynamics of emission of tracer gases (TG) used for routine control of coal self-heating within the production unit involving European approach. Methods. To determine the composition of mine ventilation flows, mine air was sampled into a rubber chambers with the volume of 1 liter; after that, gas content (%) was determined in State Militarized Mine-Rescue Service (SMMRS) gas analytical laboratory with the help of "SIGMA-SO-V" and "Kristall" gas analyzers. Arrangement of sampling points is specified according to the normative document. Sampling periodicity while identifying a threat of coal self-heating within the worked-out area was three hours; in terms of standard conditions, the periodicity was not less than once a day. Period of monitoring within the mine working areas is not less than 9 -10 days. Experimental observations were performed in terms of the production unit of "Pioner" mine and "Pokrovske" mine office.Findings. Innovative approach to routine control of coal self-heating taking into consideration TG dynamics has been tested in terms of the pillar system with return-flow ventilation of a mine section. It has been defined that within the area of expected place of coal self-heating, carbon oxide (CO) consumption within the mine workings was up to 20.59 l/min, and the worked-out area was the source of TG emission; if there were no signs of self-heating, selfheating was not more than 4 -6 l/min. It has been determined that the TG emission nature is effected by geological (coal grade, seam occurrence, and seam disturbance) and technological (development system, ventilation scheme, rate of stoping advance, downtime periods etc.) factors.Originality. It is for the first time when, in terms of mining-geological and mining-technical conditions of Donbas, the factors, determining dynamics of tracer gases within the production unit in terms of pillar system of seam development, have been defined.Practical implications. Possibility to use European methodology of routine control of coal self-heating in Ukrainian mines has been substantiated and validated.

The deformation dynamics of the experimental adit's material during a coal dust explosion

“…To devise more effective technologies to combat such emergencies, it is necessary to elucidate in detail the mechanism that forms the conditions for the occurrence of a dangerous environment. The most efficient tool to address this issue is to conduct experimental explosions at the experimental facilities such as adits [2][3][4]. As evidenced by the results of investigating the circumstances and causes of accidents related to the explosions of coal dust, the conditions that preceded the emergence of an emergency were mostly normal.…”

“…The base of the workings, walls, and ceilings contained the accumulation of dust but they did not have oxygen in their composition that would be sufficient for the deflagration or detonation combustion. The sources of ignition of the combustible environment are most often the drilling blasting, malfunction of electrical equipment, heating of metallic parts or rocks [4,5].…”

Dynamics of Motion of Gases From a Source of Spontaneous Combustion of Coal in Mine Workings

“…The European method of current control of endogenous processes makes it possible to detect the fact of the appearance of a source of self-heating or spontaneous combustion of coal in the mining area. This requires the availability of information about the relative (%) and absolute (l/min) content in the air flow of the so-called indicator gases, carbon monoxide (CO) or hydrogen (H 2 ) (Gamiy et al, 2020, Gamiy et al, 2019. Thus, the issue is to consider a purely ventilation task to determine the nature of the release of fire gases from the hearth and their motion along the working.…”

Review of up-to-date approaches for extinguishing oil and petroleum products

“…An additional polluting component is auxiliary reagents that can be used in the extraction of these minerals [4]. Emergencies at the facilities also have a negative impact [5]. At the same time, the fires of oil product are one of the most common types of emergency situations that have both a direct negative impact on humans and the environment, and an indirect impact by using the various extinguishing methods, technical elements and types of extinguishing compounds.…”