1. Introduction. As the companion of coal seam, coal mine gas (CMG) is a major hazard source to coal mining practice. During the mining process, gas disasters such as gas explosion, gas combustion, and coal and gas outburst may occur, resulting in serious casualties and property losses. 1, 2 Especially when it enters deep mining, stress and gas pressure rise markedly, while permeability of the ...
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 ...
Reservoir properties governing the emission of methane from coal seams can be divided into two groups: (1) properties that determine the capacity of the seam for total gas production,, adsorbed gas and porosity, and (2) properties that determine the rate of gas flow,, permeability, reservoir pressure, and diffusivity of coal.
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
Each link of the coal mining process will produce corresponding carbon emissions, so the carbon emissions of each link should be measured comprehensively. ... Xiaocun C, Hui T (2018) Technical scheme and application of pressurerelief gas extraction in multicoal seam mining region. Int J Min Sci Technol 28(3):483489. Article Google Scholar
% methane, whereas gas drained from the seam before mining can contain 60% to more than 95% methane depending on the presence of other gasses in the coal seam. Gas drained from fractured formations above mined seams (gobs), on the other hand, may contain 3095% methane depending on the locations of the boreholes and other
From this, the primary equipment and key production technologies were determined for the proposed softrock protective seam mining. Finally, in combination with the optimal arrangement of the working face, the pressurerelief gas extraction technology accomplished the pressurerelief mining of the protected coal seam. 2.
Hilt's Law states that the deeper the coal seam, the higher its rank. At deeper depths, the material encounters greater temperatures and pressure, and more plant debris is transformed into carbon. ... the Surface Mining Control and Reclamation Act of 1977 regulates the process of coal mining, and is an effort to limit the harmful effects on the ...
In addition, mining disturbance and gas drainage will break the gasair balance in the coal seam, resulting in gasair migration driven by the pressure difference (Liu et al., 2020a, Liu et al., 2020b). Gasair migration in coal seams is shown in Fig. 1(a) and (c).
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 ...
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 ...
Based on the miningenhanced permeability model, the effect of damage on the permeability is considered and the 3D finite element program is established, which can be used to calculate the damage and permeability characteristics of coal seam during the mining process. 2. The gas permeability test of coal samples was conducted.
This gas is also called coal bed methane (CBM) if extracted from a coal deposit as unconventional natural gas for economic purposes. Coal mine methane (CMM) must be captured for safety reasons and should be utilized. However, not all seam gas can be captured in the mining process. Some of the gas naturally flows to mine workings and is emitted ...
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 ...
Coal seam predrainage technology is widely used to prevent and control gas in China's highgas coal seams, and upward drilling is a safe and reliable technology. Using the Luling Coal Mine as the study location, according to the actual situation of the site, a layerthrough drilling process was proposed. Relying on a crosslayer extraction borehole, coal seam water injection efficiency ...
Hilt's Law states that the deeper the coal seam, the higher its rank. At deeper depths, the material encounters greater temperatures and pressure, and more plant debris is transformed into carbon. ... the Surface Mining Control and Reclamation Act of 1977 regulates the process of coal mining, and is an effort to limit the harmful effects on the ...
Coal seam gas is a form of natural gas typically extracted from coal seams at depths of 3001,000 metres. Coal seam gas (CSG), also known as coal bed methane, is a mixture of a number of gases but is mostly made up of methane (generally 9597 per cent pure methane). It is typically attached by adsorption to the coal matrix, and is held in the ...
Australia is "coal seam gas" and in the United Kingdom is "firedamp". In the, CBM production is defined as methane extraction from coal seams that have not been disturbed ... and surrounding rock strata during the mining process. This total is determined by summing the volume of methane emitted from the ventilation system and the volume of ...
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 ...
History Coalbed methane grew out of venting methane from coal seams. Some coal beds have long been known to be "gassy," and as a safety measure, boreholes were drilled into the seams from the surface, and the methane allowed to vent before mining.
prospecting for coal seam gas, (b) development for the purposes of petroleum production, but only in relation to the recovery, obtaining or removal of coal seam gas, but does not include the following— (c) the recovery, obtaining or removal of coal seam gas in the course of mining, (d) development to which section or applies.
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 ...
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.
In fact, 20 times the amount of energy you would do from a similar coal seam gas extraction process. ... What are some of the environmental problems with traditional coal mining? 2.
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.
The comining of coal and gas is the inevitable future direction of the mining of coal resources. Taking coal mining and gas extraction as the two subsystems of the coal and gas comining system, to reveal the mechanism of action between coal mining and gas extraction is the premise of orderly comining.
1. Introduction. Coal mine gas disaster is always the most dangerous in the process of coal mining [1].The determination of coal seam gas content is one of the fundamental key works involving the regional prediction of coal and gas outburst, validity check of outburst prevention, prediction of coal mine gas emission and designing gas drainage systems [2], [3].
However, in the current process of coal mining, coal mine disasters occur frequently, and the level of coal mine safety control and management is still very insufficient. ... high cost and low efficiency in the process of indirect determination of coal seam gas content, the basic gas parameters and coal quality indexes of 24 coal samples from 5 ...
What is CSG. Coal seam gas is a nonrenewable energy resource that is a byproduct of coal. It is a 'pure' and 'nontoxic' gas and for this reason has attracted a lot of commercial interest. During the process of coal formation, biogenic and thermogenic methane gas forms. Much of this methane remains trapped in the microspores of the ...
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 ...
Moreby, R. Management of seam gas emission and spontaneous combustion in a highly gassy, thick and multi seam coal mine a learning experience (2005). Itay, M., Hill, C. R. Glasser, D. A study of ...
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). ...
Integrated coal production and gas extraction must be considered as a system which involves the exploration and measurement of stress field redistribution, deformation and failure of coal and rock, gas pressure and permeability, and gas desorption and migration during the process of coal mining. Fundamental theory
The nation's coal mines are major emitters of methane, and that is complicating global talks on reducing this potent greenhouse gas. By Christian Shepherd. December 1, 2023 at 5:00 EST ...
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