In response to the specific underground conditions to coal mines in China, a portable small borehole hydraulic fracturing test rig was developed for in-situ stress measurements in underground roadways. A data quality assurance system was also developed to ensure the quality and reliability of test data.
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Coal mine underground reservoir water storage technology is an effective technical way to achieve high efficiency of coal mining and protection of water resources. The stability of coal pillar dam plays a decisive role in the safe and stable operation of underground reservoirs. Mining of adjacent working faces and long-term water erosion …
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The underground coal mine production of the fully mechanized mining face exists many problems, such as poor operating environment, high accident rate and …
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In the context of underground coal mines, the drawbacks of IEO and EO include potential inefficiencies in quickly adapting to dynamic load variations and the intricate network of tunnels and shafts. Their performance may be hindered by the unique challenges of underground mining, such as the need for rapid response to changing …
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The platform can monitor and record working conditions data of the coal mine production systems as well as location information of underground equipment and miners. Based on cloud computing techniques, big data related to underground coal mining can be analyzed quickly, and critical data associated with user requirements can …
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Methane emitted from underground, surface, and abandoned coal mines is often released. from both the coal seams and surrounding strata. In longwall mines the zone of disturbance can. be large, depending on a variety of factors including size of the long wall, depth of mining, and. thickness of coal extracted.
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However, conditions in underground coal mines change rapidly—a roof that appears adequately supported can quickly deteriorate and fall; stoppings can crush out and short-circuit air currents; conveyor belts can become misaligned or belt roller bearings can fail, resulting in an ignition source; and methane can accumulate in areas where it …
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UNDERGROUND COAL MINING FACT SHEET Ohio Department of Natural Resources Division of Mineral Resources Management (DMRM) minerals.ohiodnr.gov Columbus 614.265.6633 Barnesville 740.425.3973 Cadiz 740.942.9150 New Philadelphia 330.339.2207 Salem 234.206.4240 Zaleski 740.274.4943 Coal is produced from …
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Outburst of coal and gas represents a significant risk to the health and safety of mine personnel working. in development and longwall production face areas. There have been over 878 outburst ...
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Outburst of coal and gas represents a significant risk to the health and safety of mine personnel working in development and longwall production face areas. There have been over 878 outburst events recorded in twenty-two Australian underground coal mines. Most outburst incidents have been associated with abnormal geological …
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The underground coal mine production of the fully mechanized mining face exists many problems, such as poor operating environment, high accident rate and so on. Recently, the intelligent ...
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The decision on whether to operate an above- or underground mine is heavily influenced by a couple of important factors. The major factor in deciding on whether to go underground or open cut …
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Abstract. Mine workers in heavy and dangerous work are under several physical risk factors, for example temperature, humidity, noise, vibration, lighting and air …
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Owing to the continuously increasing the depth and intensity of coal mining, coal bursts have become a major dynamic disaster in global underground coal mining (Jang et al. 2014; Yuan et al. 2018; Mark and Gauna 2020).There are numerous causes of coal burst accidents, with complex geological structures (primarily faults, folds, and …
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Underground coal mining under Modi. In a nutshell, coal (and the entire energy vertical) was in a precarious condition when Modi came to power. Over the last decade, the government steadied the ship and gave it a new direction (by ending the nationalization). ... Lower stress on underground, local geological conditions (like …
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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 6.6 ppm 1, 2, 3. Such concentrations ...
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This paper analyses the effect of pretension on the performance of cable bolts in underground coal mines via field scale numerical models, with considering different geological conditions (in-situ stress, bedding plane stiffness and rock mass properties). Numerical models were developed based on a case study mine in Australia with …
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This paper analyses the effect of pretension on the performance of cable bolts in underground coal mines via field scale numerical models, with considering different geological conditions (in-situ ...
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Abstract. In underground coal mining, the working environment is completely enclosed by the geologic medium, which consists of the coal seam and …
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The study aims to simulate the stage-wise, year-wise mine seepage predictions and the corresponding impact on the groundwater regime (drawdown and heads) in accordance with the approved mine plan for certain coal mines in Central India. To that end, the optimized and efficient watershed area of 997.61 km2 has been …
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The basic objectives of mine roadways are to provide sufficient cross sections to accommodate equipment, transport, personnel travel and ventilation. However, many roadways become damaged to the extent of needing maintenance, generally dinting, and in some cases requiring re-ripping. Strata conditions play important effects on …
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When the 1969 Coal Mine Health and Safety Act was enacted, U.S. coal production was about 600 million tons with about 60 percent underground mining and 40 percent surface mining. Longwall mining accounted for less than 1 percent of the underground production; room-and-pillar continuous mining accounted for about 50 percent of the …
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Transporting materials and mine staff is a vital link necessary to the production process in underground mines. Deteriorating climatic conditions, mainly due to the increasingly deep mining and the usage of machines, force us to look for solutions to improve the underground mine environmental situation. Another essential factor …
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Heat stress is a major concern for the health, safety and productivity of miners working in hot and humid underground mines. At greater depth, heat inside underground mines increases due to geothermal gradient, heat released from high-capacity machinery, exposed rock surface, auto-compression of air, human metabolism, …
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The underground coal gasification (UCG) process represents a modern and effective coal mining technology that enables coal energy extraction through thermic decomposition. The coal is transformed into syngas by oxidizers (e.g., air, technical oxygen, or water steam) and is injected into a georeactor. The produced syngas is exhausted on …
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The conditions that would eventually create coal began to develop about 300 million years ago, during the Carboniferous period. During this time, ... Economically, surface mining is a cheaper option for extracting coal than underground mining. About two and a half times as much coal can be extracted per worker, per hour, ...
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Number of Surface versus Underground Coal Mines 1978 Total 1,412 1,105 Mine Type No. of Mines % of Total Production (millions tons) % of Total Surface 3,176 54% 398 63% ... • current market conditions - demand • national and international economic conditions • logistics - getting from the manufacturer to the buyer
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Risk identification for coal and gas outburst in underground coal mines: A critical review and future directions - ScienceDirect. Gas Science and Engineering. …
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Abstract: Underground coal gasification (UCG) technique provides facilities. for converting underground coal into synthetic gas by remote ignition and. injecting steam as well as air into the coal ...
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Mine water inrush is a phenomenon in which a large volume of water unexpectedly gushes into underground workings or open pit mines when tunneling or …
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Subpart FF-Underground Coal Mines. §98.320 Definition of the source category. (a) This source category consists of active underground coal mines, and any underground mines under development that have operational pre-mining degasification systems. An underground coal mine is a mine at which coal is produced by tunneling into the earth …
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