1. Introduction The coal content in gangue is used to determine the performance of the equipment and the level of operators, which is an important technical assessment index in coal preparation plants. However, online detection of the coal content in gangue is currently unfeasible.
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The rebound height was H i (i = 1,2,3.), and the restitution coefficient can be obtained by H x / H i. To measure the rebound height accurately, the first rebound height is generally adopted for calculation, namely H x /H 1. In the calibration of the RC, H x equals 350 mm, and the rebound height with different RCs is shown in Figure 4.
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The optics' depth of field was ±2 cm and since the coal height varied beyond this, an ultrasonic sensor was used that enabled moving the optics to maintain a fixed focal distance to the coal sample. ... Coal measurements were performed at a coalfired power plant using the setup described in Sect. ... H. Modiano, U. Schone, Laser ...
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Therefore, the first 6 influence factors are selected as the combination of input influence factors for the prediction model, which is advancing speed X 11, extraction rate X 12, mining height X 6, original gas content of mining seam X 4, coal seam thickness X 2, and coal seam depth X 1. The sum of the cumulative factor importance of the 6 ...
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Besides analyzing the coal, a coal quality manager system should automatically calculate: Heating Value (kcal/kg, kJ/kg or BTU/lb) Lbs SO2 per million BTU. Volatile Matter. Fixed Carbon. Ash Fusion Temperature (based on customer specific empirical relations) Knowing these measurements in realtime enables coal producers to control sorting and ...
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After coal seam mining, there is inevitable rock movement and changes in the internal stress and fracture fields of the strata [], and the overlying rock layer breaks to form a waterconducting fracture key to the safe mining of coal seams under bodies of water is to accurately measure the height of the waterconducting fracture zone after coal seam mining.
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The ratio of the thickness of the bedrock layer to that of the unconsolidated stratum is about, which differs from that of shallow depth coal seams in western China. Because the −2 coal seam is thick, hard, and shallow depth, it is suitable for applying longwall mining technology with large mining height. The maximum mining height ...
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Pool depth (radial height of liquid) can be changed in most centrifuges. Solid concentration range in the cake is between 46% in thickening operations, and 10 35% in dewatering operations. The length to diameter ratio is between the range of :1 to 4:1 .
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The average thickness of coal seams was m, and the average inclination angle of coal seams was 11°, and the buried depth was about 600 m. The main roof was gray fine sandstone with a thickness of m; The immediate roof was grey strip medium and fine sandstone, with a thickness of m.
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The depth of the coal wall sloughing of the large mining height working surface increases with the mining height rather than linearly, as can be seen from the relationship curve between the mining height of the coal seam and the coal wall sloughing; the fitting curve is " y = x 2 − x + ", which indicates that the ...
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sloughing. The coal wall is most likely to sustain damage at the point where it contacts the roof when the frictional resistance between the coal seam and the roof and floor is less than the uniform load, and at times the mining height when the frictional resistance between the coal seam and the roof and floor is greater than the uniform ...
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Limitations in the installed power, machine height, and automation technology make it difficult to mine hard and thin coal seams. The installed power of existing thin seam shearers is less than 730 kW, the supporting machine face height is greater than 845 mm, and the mining height is greater than m.
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Sun et al. [] used numerical simulation to study the influence of wind flow turbulence on dust pollution and, at the same time, proposed a partial spray closed dust control technology, which improved the dust removal rate (Figure 4).Tan et al. [] compared the measured dust mass concentration distribution onsite with the simulated coal cutting dust movement law on fully mechanized mining face ...
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Logging while drilling. Logging while drilling (LWD or Measurement while drilling (MWD), the terms are used interchangeably) is a general term to describe systems and techniques for gathering downhole data while drilling without the requirement to remove drill pipe from the well. LWD offers similar functionality as wireline logging with ...
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The overburden depth at the test site is about 600 ft. Fig. shows the detailed overburden geology at the test site, which has been interpreted by correlating a test site gamma log and a nearby core hole. Clearly, the overburden geology is a typical Pittsburgh seam geology and is highlighted by many strong and weak rock interfaces, which have been demonstrated to have major influences on ...
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This paper establishes the mechanical model of the coal wall and uses the deflection theory for the mechanics of materials to find the maximum point of the deflection of the coal wall, which is...
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Highwall mining of thick (up to m) steeply dipping (20° or more) coal seams provides many challenges, both geotechnically and operationally, as seam dips near or in excess of highwall mining machine capabilities are encountered.
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The average depth of the ocean is 3,700 meters (12,100 feet). But the deepest part ever recorded is located in the western part of the Pacific Ocean, in the Mariana Trench, at a depth of around 11,000 meters (36,200 feet). Bathymetry is the scientific term for measuring the depth of water in oceans, lakes and rivers. Bathymetric maps are ...
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Every set had different coal height as shown in Figure 1: group "A"—coal height ratio 20%, group "B"—coal height ratio 30%, group "C"—coal height ratio 30%, and group "D"—coal height ratio 50%. The height of floor siltstone samples was always 25 mm, while the height of roof siltstone samples changed with the coal height.
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1. Introduction. China's current coalbased energy consumption structure is determined by the resource endowment characteristics of 'rich in coal, poor in oil, and little in gas' (Li et al., 2020).As the coal resources in the mining areas of eastern China have been exploited for a long time, the mining depth has become deeper and the mining difficulty has increased, the huge cost input ...
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In one case [16] the system has been installed in a coal mine (in South Africa) and, since the instrument working distance was limited to ± 2 cm, an ultrasonic sensor was used to enable a moving optics to maintain a fixed distance from the sample with changes in coal height of the order of ± cm.
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A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
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