scholarly journals The Impact of the Coexistence of Methane Hazard and Rock-Bursts on the Safety of Works in Underground Hard Coal Mines

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 128
Author(s):  
Justyna Swolkień ◽  
Nikodem Szlązak
Keyword(s):  
Rock Burst ◽  
Methane Concentration ◽  
High Energy ◽  
Hard Coal ◽  
Coal Seams ◽  
Safety Level ◽  
Methane Drainage ◽  
Innovative Methods ◽  
Hard Coal Mining ◽  
The Impact

Several natural threats characterize hard coal mining in Poland. The coexistence of methane and rock-burst hazards lowers the safety level during exploration. The most dangerous are high-energy bumps, which might cause rock-burst. Additionally, created during exploitation, safety pillars, which protect openings, might be the reason for the formation of so-called gas traps. In this part, rock mass is usually not disturbed and methane in seams that form the safety pillars is not dangerous as long as they remain intact. Nevertheless, during a rock-burst, a sudden methane outflow can occur. Preventing the existing hazards increases mining costs, and employing inadequate measures threatens the employees’ lives and limbs. Using two longwalls as examples, the authors discuss the consequences of the two natural hazards’ coexistence. In the area of longwall H-4 in seam 409/4, a rock-burst caused a release of approximately 545,000 cubic meters of methane into the excavations, which tripled methane concentration compared to the values from the period preceding the burst. In the second longwall (IV in seam 703/1), a bump was followed by a rock-burst, which reduced the amount of air flowing through the excavation by 30 percent compared to the airflow before, and methane release rose by 60 percent. The analyses presented in this article justify that research is needed to create and implement innovative methods of methane drainage from coal seams to capture methane more effectively at the stage of mining.

scholarly journals Tests to Ensure the Minimum Methane Concentration for Gas Engines to Limit Atmospheric Emissions

2019 ◽  
Author(s):  
Marek Borowski ◽  
Piotr Życzkowski ◽  
Rafał Łuczak ◽  
Michał Karch ◽  
Jianwei Cheng
Keyword(s):  
Carbon Dioxide ◽  
Greenhouse Gas ◽  
Methane Concentration ◽  
Coal Mines ◽  
Drainage System ◽  
Hard Coal ◽  
Atmospheric Emissions ◽  
Coal Seams ◽  
Mining Operations ◽  
Methane Drainage

During the extraction of hard coal in Polish conditions, methane is emitted, which is referred to as mine gas. As a result of the desorption of methane, a greenhouse gas is released from coal seams. In order to reduce atmospheric emissions, methane from coal seams is captured by a methane drainage system. On the other hand, methane, which has been separated into underground mining excavations, is discharged into the atmosphere with a stream of ventilation air. For many years, Polish hard coal mines have been capturing methane to ensure the safety of the crew and the continuity of mining operations. As a greenhouse gas, methane has a significant potential, as it is more effective at absorbing and re-emitting radiation than carbon dioxide. The increase in the amount of methane in the atmosphere is a significant factor influencing global warming, however, it is not as strong as the increase in carbon dioxide. Therefore, in Polish mines, the methane-air mixture captured in the methane drainage system is not emitted to the atmosphere, but burned as fuel in systems, including cogeneration systems, to generate electricity, heat and cold. However, in order for such use to be possible, the methane-air mixture must meet appropriate quality and quantity requirements. The article presents an analysis of changes in selected parameters of the captured methane-air mixture from one of the hard coal mines in the Upper Silesian Coal Basin in Poland. The paper analyses the changes in concentration and size of the captured methane stream through the methane capturing system. The gas captured by the methane drainage system, as an energy source, can be used in cogeneration, when the methane concentration is greater than 40%. Considering the variability of CH4 concentration in the captured mixture, it was also indicated which pure methane stream must be added to the gas mixture in order for this gas to be used as a fuel for gas engines. The balance of power of produced electric energy in gas engines is presented. Possible solutions ensuring constant concentration of the captured methane-air mixture are also presented.

scholarly journals Tests to Ensure the Minimum Methane Concentration for Gas Engines to Limit Atmospheric Emissions

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 44 ◽  
Author(s):  
Marek Borowski ◽  
Piotr Życzkowski ◽  
Rafał Łuczak ◽  
Michał Karch ◽  
Jianwei Cheng
Keyword(s):  
Carbon Dioxide ◽  
Greenhouse Gas ◽  
Methane Concentration ◽  
Coal Mines ◽  
Drainage System ◽  
Hard Coal ◽  
Atmospheric Emissions ◽  
Coal Seams ◽  
Mining Operations ◽  
Methane Drainage

During the extraction of hard coal in Polish conditions, methane is emitted, which is referred to as ‘mine gas’. As a result of the desorption of methane, a greenhouse gas is released from coal seams. In order to reduce atmospheric emissions, methane from coal seams is captured by a methane drainage system. On the other hand, methane, which has been separated into underground mining excavations, is discharged into the atmosphere with a stream of ventilation air. For many years, Polish hard coal mines have been capturing methane to ensure the safety of the crew and the continuity of mining operations. As a greenhouse gas, methane has a significant potential, as it is more effective at absorbing and re-emitting radiation than carbon dioxide. The increase in the amount of methane in the atmosphere is a significant factor influencing global warming, however, it is not as strong as the increase in carbon dioxide. Therefore, in Polish mines, the methane–air mixture captured in the methane drainage system is not emitted to the atmosphere, but burned as fuel in systems, including cogeneration systems, to generate electricity, heat and cold. However, in order for such use to be possible, the methane–air mixture must meet appropriate quality and quantity requirements. The article presents an analysis of changes in selected parameters of the captured methane–air mixture from one of the hard coal mines in the Upper Silesian Coal Basin in Poland. The paper analyses the changes in concentration and size of the captured methane stream through the methane capturing system. The gas captured by the methane drainage system, as an energy source, can be used in cogeneration, when the methane concentration is greater than 40%. Considering the variability of CH4 concentration in the captured mixture, it was also indicated which pure methane stream must be added to the gas mixture in order for this gas to be used as a fuel for gas engines. The balance of power of produced electric energy in gas engines is presented. Possible solutions ensuring constant concentration of the captured methane–air mixture are also presented.

scholarly journals Analysis of methane hazard in longwall working equipped with a powered longwall complex

2020 ◽  
Vol 174 ◽  
pp. 01011
Author(s):  
Leszek Sobik ◽  
Jarosław Brodny ◽  
Gennady Buyаlich ◽  
Pavel Strelnikov
Keyword(s):  
High Performance ◽  
Underground Mining ◽  
Practical Knowledge ◽  
Mining Operation ◽  
Mining Area ◽  
Hard Coal ◽  
Coal Seams ◽  
Methane Drainage ◽  
High Degree ◽  
Advanced Model

Most of currently exploited hard coal seams has a very high degree of methane saturation. Consequently, the mining process of such deposits generates substantial amounts of methane. This in turn increases the risk of fire and/or explosion of this gas. Methane hazard is currently one of the most dangerous threats occurring in the process of underground mining exploitation. In particular, this applies to longwall excavations where the rock mass mining process generates the highest level of this gas. Commonly used high-performance longwall complexes cause an increase in the amount of coal output, which also causes an increase in the amount of methane released. In order to prevent hazardous concentrations, appropriate ventilation systems and atmosphere monitoring in mining excavations are used. The paper discusses currently used methods designed to limit risks caused by methane such as methane drainage. The paper presents an example of the use of an innovative method of analysing methane risk status and measures aimed at minimizing it. The developed method is based on air parameters in the actual mining area which were then used to create a method of ventilation for such excavations. The method combines advanced model analysis and experience of mine employees and integrates academic and practical knowledge. The main objective of the activities presented in the article was to improve the safety of mining operation

scholarly journals Testing of Confining Pressure Impacton Explosion Energy of Explosive Materials

2017 ◽  
Vol 62 (2) ◽  
pp. 385-396 ◽  
Author(s):  
Jan Drzewiecki ◽  
Jacek Myszkowski ◽  
Andrzej Pytlik ◽  
Mateusz Pytlik
Keyword(s):  
Occupational Safety ◽  
Initial Pressure ◽  
Confining Pressure ◽  
Hard Coal ◽  
Test Results ◽  
Explosive Materials ◽  
Hard Coal Mining ◽  
Explosive Charges ◽  
Pressure Changes ◽  
The Impact

Abstract This paper presents the results of testing the explosion effects of two explosive charges placed in an environment with specified values of confining pressure. The aim of this study is to determine the impact of variable environmental conditions on the suitability of particular explosives for their use in the prevention of natural hazards in hard coal mining. The research results will contribute to improving the efficiency of currently adopted technologies of natural hazard prevention and aid in raising the level of occupational safety. To carry out the subject matter measurements, a special test stand was constructed which allows the value of the initial pressure inside the chamber, which constitutes its integral part, to be altered before the detonation of the charge being tested. The obtained characteristics of the pressure changes during the explosion of the analysed charge helped to identify the work (energy) which was produced during the process. The test results are a valuable source of information, opening up new possibilities for the use of explosives, the development of innovative solutions for the construction of explosive charges and their initiation.

scholarly journals The Impact of the Management System on Developing Occupational Safety Awareness Among Employees

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Marta SUKIENNIK ◽  
Patrycja BĄK ◽  
Mariusz KAPUSTA
Keyword(s):  
Occupational Safety ◽  
Safety Management ◽  
Management Systems ◽  
Hard Coal ◽  
Mining Company ◽  
Safety Awareness ◽  
Hard Coal Mining ◽  
The Subject ◽  
The Impact

This paper discusses the subject of occupational safety using the example of a leading hard coal mining company in Poland. It presentssome examples of occupational safety management systems implemented and functioning in enterprises. It also characterisesthe role of awareness in developing the appropriate attitudes and conduct among employees in the workplace. The paper presentsthe selected results of surveys conducted among the executive employees of JSW S.A. The obtained results served as the basis forpreparing preliminary conclusions and identifying potential areas for further studies in this field.

scholarly journals Seismicity induced by hard coal mining in the vicinity of faults

2018 ◽  
Vol 66 ◽  
pp. 01008 ◽  
Author(s):  
Zbigniew Burtan ◽  
Jerzy Cieślik ◽  
Dariusz Chlebowski
Keyword(s):  
Seismic Activity ◽  
High Energy ◽  
Hard Coal ◽  
Seismic Events ◽  
Mining Operations ◽  
Rockburst Hazard ◽  
Inherent Feature ◽  
Hard Coal Mining ◽  
High Level ◽  
Time And Energy

An inherent feature of Polish collieries within the Upper Silesia Coal Basin is the high level of mining induced seismicity, resulting in elevated rockburst hazard levels. One of the major causes of high-energy seismic events is that mining operations are continued in the vicinity of major faulting zones. The study summarises the results of geo-mechanical and statistical analysis of mining-induced seismic activity in the region of major faults, in a selected section within a colliery. Seismic activity assessment involves the categorisation of seismic events due to tectonic movements in the context of various face development systems with respect to the faulting zone: perpendicular (advancing towards the faulting zone or retreating) or parallel (along the faulting zone). Registered seismic activity was analysed in the context of epicenter locations and variations of seismic activity in relation to the developing face operations in the function of time and energy ratings (Gutenberg-Richter formulas). Results have demonstrated that increased levels of seismic activity in the strata can be attributable to mining operations in the vicinity of major faulting zones.

scholarly journals The influence of the fault zone width on land surface vibrations after the high-energy tremor in the “Rydułtowy-Anna” hard coal mine

2018 ◽  
Vol 36 ◽  
pp. 02007 ◽  
Author(s):  
Elżbieta Pilecka ◽  
Dariusz Szwarkowski
Keyword(s):  
Rock Mass ◽  
Fault Zone ◽  
Seismic Wave ◽  
Coal Mine ◽  
Land Surface ◽  
High Energy ◽  
Hard Coal ◽  
Surface Vibrations ◽  
The Impact ◽  
Damage Risk

In the article, a numerical analysis of the impact of the width of the fault zone on land surface tremors on the area of the “Rydułtowy – Anna” hard coal mine was performed. The analysis covered the dynamic impact of the actual seismic wave after the high-energy tremor of 7 June 2013. Vibrations on the land surface are a measure of the mining damage risk. It is particularly the horizontal components of land vibrations that are dangerous to buildings which is reflected in the Mining Scales of Intensity (GSI) of vibrations. The run of a seismic wave in the rock mass from the hypocenter to the area’s surface depends on the lithology of the area and the presence of fault zones. The rock mass network cut by faults of various widths influences the amplitude of tremor reaching the area’s surface. The analysis of the impact of the width of the fault zone was done for three alternatives.

scholarly journals Application of Remote Sensing, GIS and Machine Learning with Geographically Weighted Regression in Assessing the Impact of Hard Coal Mining on the Natural Environment

2020 ◽  
Vol 12 (22) ◽  
pp. 9338
Author(s):  
Anna Kopeć ◽  
Paweł Trybała ◽  
Dariusz Głąbicki ◽  
Anna Buczyńska ◽  
Karolina Owczarz ◽  
...  
Keyword(s):  
Machine Learning ◽  
Remote Sensing ◽  
Coal Mining ◽  
Geographically Weighted Regression ◽  
Machine Learning Algorithms ◽  
Weighted Regression ◽  
Hard Coal ◽  
Mining Operations ◽  
Hard Coal Mining ◽  
The Impact

Mining operations cause negative changes in the environment. Therefore, such areas require constant monitoring, which can benefit from remote sensing data. In this article, research was carried out on the environmental impact of underground hard coal mining in the Bogdanka mine, located in the southeastern Poland. For this purpose, spectral indexes, satellite radar interferometry, Geographic Information System (GIS) tools and machine learning algorithms were utilized. Based on optical, radar, geological, hydrological and meteorological data, a spatial model was developed to determine the statistical significance of the selected factors’ individual impact on the occurrence of wetlands. Obtained results show that Normalized Difference Vegetation Index (NDVI) change, terrain height, groundwater level and terrain displacement had a considerable influence on the occurrence of wetlands in the research area. Moreover, the machine learning model developed using the Random Forest algorithm allowed for an efficient determination of potential flooding zones based on a set of spatial variables, correctly detecting 76% area of wetlands. Finally, the GWR (Geographically Weighted Regression (GWR) modelling enabled identification of local anomalies of selected factors’ influence on the occurrence of wetlands, which in turn helped to understand the causes of wetland formation.

Analysis of Inducing Factor of Thin Seam Rock Burst in Xinxing Mine

2014 ◽  
Vol 522-524 ◽  
pp. 1371-1376
Author(s):  
Zhu Peng Jin ◽  
Tao Qin ◽  
Zhen Wen Liu
Keyword(s):  
Rock Burst ◽  
Pressure Control ◽  
Hard Coal ◽  
Prevention Focus ◽  
Deep Mining ◽  
Mining Conditions ◽  
Pressure Control System ◽  
Inducing Factors ◽  
Thin Seam ◽  
The Impact

For occurring frequent thin seam rock burst disasters in deep mining stage in Xinxing Mine, through summarizing the mineral basic geological and mining conditions, on this basis, analysing the occurrence characteristics of rock burst with statistical method in Xinxing Mine, analyzing the inducing factors of thin seam rock burst, and through FLAC3D roadways along on 41,051 workface exploitation right beside left stacks of rock burst was simulated, and made a rock burst prevention focus for the impact of land pressure control system provides an effective basis. On thin hard coal burst prevention of important guiding significance.

scholarly journals Possibilities of Capturing Methane from Hard Coal Deposits Lying at Great Depths

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3542
Author(s):  
Nikodem Szlązak ◽  
Justyna Swolkień
Keyword(s):  
Underground Mining ◽  
Drainage System ◽  
Hard Coal ◽  
Coal Seams ◽  
Second Stage ◽  
Methane Drainage ◽  
Coal Deposits ◽  
Significant Difference ◽  
Flammable Gas ◽  
Deposition Depth

Methane present in coal seams is a natural hazard present during the exploitation of underground mining plants. It is an explosive and flammable gas that is released into mining excavations, and it is necessary to reduce its concentration. Capturing methane while preparing extraction is virtually impossible due to the low permeability of coal resulting from its deposition depth. After the beginning of exploitation and disrupting the seam’s structure, methane is released into mine air. The most common method of minimizing gas released into ventilation air is draining the rock mass. This method allows achieving the desired ventilation parameters but requires appropriate mining techniques in hazardous areas. The article presents the example of methane capture during the operation in the longwall B-15 with an overlying drainage gallery. The authors have highlighted an example of the longwall B-15 that when using this particular drainage method, allowed capturing twice the amount of methane forecasted, thus increasing the efficiency of methane drainage. At the preliminary stage of longwall development, the amount of methane charged by the drainage system had relatively low values, reaching 15 m3/min. In the next few months, these parameters increased and varied between 35 to 55 m3/min. A significant difference in methane capture appeared in the second stage of exploitation, where the highest value of captured methane reached 82 m3/min. This particular longwall example shows that it is crucial to properly design the drainage system for seams with high forecasted methane release. It is worth remembering that using a drainage gallery provides an increase in the methane capture from the desorption zone areas, thus increasing total methane capture in comparison to forecasts.

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