Influence of the combined ventilation schemes of extracting area on endogenous fire hazard of high-performance coal mines

The most commonly used practice to assess fire hazard development in underground coal mines is based on the measurement of the concentration of selected gases in the mine’s air. The main goal of this study was present a strategy to monitor the gaseous atmosphere in the mine in order to identify the onset of an endogenous fire in the coal seam. For that purpose, the principal component analysis (PCA) and the hierarchical clustering analysis (HCA) were applied. The monitoring covers the measurements of concentration of CO, CO2, H2, O2, N2, and selected hydrocarbons, respectively throughout the whole of one year. The chemometric methods applied allow for effective exploration of the similarities between the studied samples collected both under fire hazard conditions and under safe conditions. Based on the constructed models, the groups of objects characterized with the highest content of ethylene, acetylene, propylene, and carbon monoxide were identified. These samples indicate the endogenic fire in coal mine.

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The current state of the problem of predicting spontaneous combustion and explosiveness of sulfide ores and host rocks at a depth of more than 1500 m.

Горная промышленность ◽

10.30686/1609-9192-2021-2-77-80 ◽

2021 ◽

pp. 77-80

Author(s):

Z.G. Ufatova

Keyword(s):

Moisture Content ◽

Air Temperature ◽

Initial Phase ◽

Spontaneous Combustion ◽

Fire Hazard ◽

Free Access ◽

Sulfide Ores ◽

Working Face ◽

Time In Treatment ◽

Endogenous Fire

The mining factors of ore fire hazard during mining of the lower horizons of the Oktyabrskiy and Talnakhskiy northern deposits are considered. It is noted that the probability of self-heating of sulfide ores and the sulfide dust’s tendency to spontaneous combustion and explosiveness in certain sections of rich sulfide copper-nickel ores are quite high. The oxidation of sulfide ores occurs continuously due to the absorption of oxygen from the mine atmosphere and is accompanied by the release of heat. The oxidation can be accompanied by intense heating of the ore in mining conditions, with the accumulation of large volumes of broken rock mass for a long time in treatment and preparation workings and with free access of air to the bulk of the ore mass. The processes of ore and rock oxidation are especially intense when their moisture content is 1–4%. When the ore is heated above 35 °C, sulfurous gas (SO2) may be released. The main signs of the above-mentioned oxidative processes’ development and signs of the initial phase of a possible underground endogenous fire are indicated along with a constant increase in the temperature of the air coming from the bottom of the face. It is noted that in case of detecting at least one of the signs of a possible underground endogenous fire’s initial phase, urgent measures are taken to improve the ventilation of this working face, to ensure maximum intensity of shipped ore from the fresh stream and the content of sulfurous gas and hydrogen sulfide and mine air temperature are determined every 4 hours. If after two days on the outgoing stream there is no decrease in the content of sulfur dioxide and air temperature, then it should be considered that an endogenous fire has occurred. Measures for the prevention, localization and elimination of foci of spontaneous combustion are given. As an additional safety measure, it is recommended to moisten the dust, since sulfide dust becomes non-explosive at a moisture content of 9–9,5%, and at a humidity of 10% the dust does not transmit an explosive impulse.

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INVESTIGATION OF RESONANT PHENOMENA IN UNDERGROUND ELECTRICAL NETWORKS OF HIGH-PERFORMANCE COAL MINES

Vesti vysshikh uchebnykh zavedenii Chernozem'ya ◽

10.53015/18159958_2021_17_2_13 ◽

2021 ◽

pp. 13-25

Author(s):

Leonid Aleksandrovich Plaschansky ◽

Sergey Nikolaevich Reshetnyak ◽

Maria Yuryevna Reshetnyak

Keyword(s):

High Performance ◽

Coal Mines ◽

Electrical Networks ◽

Resonant Phenomena

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Current aspects of energy efficiency improving in high performance coal mines

Energy Safety and Energy Economy ◽

10.18635/2071-2219-2017-3-21-24 ◽

2017 ◽

Vol 3 ◽

pp. 21-24

Author(s):

Sergei Reshetnyak ◽

Maria Reshetnyak

Keyword(s):

Energy Efficiency ◽

High Performance ◽

Coal Mines

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Preliminary results of tests on nitrogen cushion for combating fire hazard in longwalls rich in methane

E3S Web of Conferences ◽

10.1051/e3sconf/202017401066 ◽

2020 ◽

Vol 174 ◽

pp. 01066

Author(s):

Dawid Szurgacz ◽

Leszek Sobik ◽

Jarosław Brodny ◽

Maxim Grigashkin

Keyword(s):

Fire Hazard ◽

Main Idea ◽

Extraction Process ◽

Coal Extraction ◽

Hard Coal ◽

High Tendency ◽

Preventive Actions ◽

Wide Range ◽

Endogenous Fire ◽

Roof Support

Ventilation hazard is the most dangerous phenomena occurring in the hard coal extraction process. This particularly applies to endogenous fire hazard. In order to reduce it, it is necessary to improve the effectiveness of preventive measures. Hence this paper presents new solutions that substantially improve fire prevention effectiveness. The main idea is to develop and create an additional nitrogen cushion in the zone behind the powered roof support operating in a longwall face. The solution is based on installations for inerting of goafs and sections of the powered roof support. The nitrogen cushion restricts the access of air and oxygen to the area of goafs and limits the possibility of fire. Practical application of the developed solution allowed for effective reduction of fire hazard in conditions of a very high tendency of coal to self-ignite at short incubation period. This, in turn, enables safe exploitation and decommissioning of the longwall. Undoubtedly, the solution presented and the results obtained constitute a new approach to preventive actions in mines. It is the result of the work of theoretical and practical researchers. The solution is a combination of the potential of these two environments. The developed solution should find wide range of applications in the areas where endogenous fire and methane hazards occur.

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Using pillar-free mining technologies in gently dipping and self-ignitable coal seams

MINING INFORMATIONAL AND ANALYTICAL BULLETIN ◽

10.25018/0236-1493-2020-7-0-64-77 ◽

2020 ◽

pp. 64-77

Author(s):

D. D. Golubev

Keyword(s):

Fire Hazard ◽

Coal Pillar ◽

Kuznetsk Coal ◽

Coal Seams ◽

State Behavior ◽

Mining Depth ◽

Study Results ◽

Endogenous Fire ◽

Determination Of Parameters ◽

Coal Seam Thickness

Gently dipping coal seams of the Kuznetsk Coal Basin are cut exclusively by longwalls with preliminary drivage of twin gate ways. At the same time, the source of self-ignition in mines is pillars of coal left in mined-out areas. Endogenous fire hazard grows with higher losses of loose coal in mined-out areas due to a persistent increase in mining depth and in size of longwalls. This research aims at development of an alternative mining technology for gently dipping coal seams to reduce the risk of initiation of self-ignition sources in mined-out areas and at the determination of parameters of the technology elements as functions of coal seam thickness and mining depth. A new concept of preparatory works and actual mining in selfignitable coal seams is described. The study results obtained with numerical modeling of the stress-state behavior of rock mass and the developed technology elements at different stages of longwalling are presented. The studies show that endogenous fire hazard is reduced by means of extraction of coal pillar on the same line with face and due to elimination of aerological connection between the operating longwall and earlier mined-out area owing to construction of a separation belt made of solidifying materials between them. The cross-effect of the widths of the solidifying material belt and coal pillar as the elements of the developed technology is estimated.

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