The No. 25050 working face in Xuehu Coal Mine in Henan Province, China*** was selected to test field EP signals and further analyze the response characteristics of EP signals to the mining process of coal seam. The roadway distribution in the working face is displayed in Fig. 1, with the mining depth of the coal seam reaching 700 m. In this ...
1 Introduction. Recovery of coalbed methane (CBM) from coal seams can not only benefit mining safety, reduce greenhouse gas emissions, and also increase clean energy supply (Karacan et al., 2011; Moore, 2012).In the Junggar Basin, the CBM resources have been estimated at trillion cubic meters, which is the third largest CBM basin in China after the Qinshui Basin and Ordos Basin (Fu et al ...
A Wyoming coal mine that supplies fuel to a power plant that will be converted to burn gas instead of coal will lay off 19 workers ... West ia added 1,500 coal mining jobs in 2022 and ...
As the coal mining depth increases, the coal seam gas pressure and gas content increase, mining conditions become more complicated, and the coal seam permeability decreases. Therefore, only relying on the primary pore and fissure structure of coal reservoirs for free extraction is not conducive to the sustainable development of the energy ...
The borehole, especially that in the soft coal seam with high gas content and low permeability, is often abandoned due to the collapse and blockage of a certain borehole, which makes the coal seam have a blank zone of gas extraction, resulting in potential coal and gas outburst [24, 25]. The mining depth of coal mines in China is extending at ...
In drift mines, a tunnel is dug horizontally into the side of a mountain. In slope mines, this tunnel is diagonal. In shaft mines, elevators are used to move coal through vertical tunnels. Figure c : Subsurface mining involves digging tunnels to access coal deposits that are deep underground.
The occurrence and mining conditions of underground coal seams become more complex with increasing mining depth, making mining gas extraction more and more problematic (Chen et al. 2020; Wang et al. 2021a, b).Gas extraction efficiency directly depends on the coal seam permeability, which, in turn, is controlled by several internal factors (such as coal strength, stress loadingunloading ...
Determining a method whereby the safety level of the coalmining process can be improved while ensuring acceptable levels of coal production is a problem to which we must attach great importance. ... Wang, B. Experimental Study on Rapid Determination Method of Coal Seam Gas Content by Indirect Method. Processes 2023, 11, 925. [Google Scholar ...
That process involved passing an audit to ensure we complied with over 150 international standards. ... In recent years our livelihood has been challenged with the legal requirement for us to coexist with a coal seam gas mining company. In 2018, after a lengthy negotiation process that involved experts, research and considerable time, an ...
At present, the first coal seam in the western mining area has been exhausted, and the mine is gradually mining the lower coal seam 9. During the mining process of shallowburied and close ...
COAL MINING METHODS Surface Mining In surface mining, the ground covering the coal seam (the overburden) is first removed to expose the coal seam for extraction.
It transforms underground coal into synthetic gas (commonly known as syngas). Syngas consists of carbon monoxide, hydrogen and methane. Schematic of the CSG extraction process Hydraulic fracturing in coal seams. Hydraulic fracturing is a method used by the oil and gas industry since the late 1940s to increase the rate and total amount of oil ...
Coal seam groups are widely distributed in mining areas of different regions in China, especially closely spaced coal seam groups (Wang et al. 2013).Selecting a coal seam with the optimal reliability factor as the first mining seam is necessary to achieve safe and highefficiency mining due to the diversified conditions of coal seams during mining (Wang et al. 2017; Li et al. 2021; Wu et al ...
, Kexiang Li, Hongyu Ma, Jianzhong Guo, Hongming Yan, Zibing Liu, and Zhuwen Sheng Cite this: ACS Omega 2023, XXXX, XXX, XXXXXX Publication Date: September 18, 2023 https://// Copyright © 2022 The Authors. Published by American Chemical Society. This publication is licensed under CCBYNCND . Article Views
Coal seam gas (CSG) is a natural gas, consisting primarily of methane, which collects in underground coal seams by bonding to the surface of coal particles.
The stress evolution, deformation characteristics, and threedimensional fracture field characteristics of the strata during coal seam mining were monitored in realtime. In addition, FLAC3D numerical simulation was performed on the coal seam mining process, and the results were compared with those of physical similarity model tests. These ...
Coalbed methane (CBM), is also known as coalbed gas and coal seam gas/methane (CSG/CSM), which are terms referring to the unconventional natural gas resource stored in coal beds and are expected to be an important energy resource of global significance in the future (Rightmire 1984; Rice 1993; Flores 1998, 2013; Palmer 2010; Yang and Liu 2021). ...
The coal seam tested is the No. 7 coal seam that is mainly mined at this particular location. The No. 7 seam has a maximum gas pressure of MPa, an average gas pressure of MPa, and a maximum initial speed of gas release ΔP of mmHg. In addition, its highest gas content is m 3 /tr, and the minimum solidity coefficient is
The Chinese "Coal Mine Safety Regulations" states that the H 2 S concentration of coal mine gas is considered abnormal if it concentration is greater than ppm 1, 2, 3. Such concentrations ...
Gas extraction is the main method to reduce gas content and eliminate gas accidents, and due to the influence of mining stress in the coal seam mining process, there are elastic damage zones and plastic damage zones of coal seams [3, 7]. Therefore, in order to improve the efficiency of gas extraction, it is necessary to study the elastic ...
Methane gas in coal formations was generated at the same time the coal was formed, when plant debris (such as that found in swamps) slowly changed into coal after being buried and covered for a long time through a process known as coalification. Online Training
Coal and gas outbursts are a potentially fatal hazard that must be managed when mining gassy coal seams. Mininginduced stress plays an important role in outbursts, while elastic potential is accumulated to provide energy for an outburst. In this study, a largescale true triaxial (LSTT) apparatus was developed to conduct experiments and to understand the outburst mechanism and mininginduced ...
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