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METHODS FOR SAMPLING OF COAL AND CO@3 PART I SAMPLING OF COAL Section 1 Manual Sampling ( Revised) Ei&th Reprint MAR'bH 1991 ( Incorporating Amendment No. 1 ) UDC 662'66:620'1-13 BUREAU OF IND1A.N STANDARDS MA&K BHAVAN, 9 RAHADUR SHAH ZAFAR MARC3 NEW DELHI lMJO2 Gr 6 February 1965 -
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The coal beneficiation or coal preparation process separates inorganic impurities from raw mined coal, reducing the concentration of unwanted material or gangue and thereby providing improved combustion characteristics to the fuel produced. The commonly used beneficiation methods for coal sorting and processing include jig separation, heavy …
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Many different completion techniques, such as vertical-well multiseam completions and multiple lateral wellbores drilled into a single coal seam, have been used to develop coalbed methane (CBM) …
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This is an expensive method to use and provides only a low level of lateral resolution. Seismic methods are gradually replacing boreholes and becoming more common place in coal industry as an accurate and cost effective alternative method for imaging the seam structure. Burton Downs colliery in central Queensland, was one such …
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speeds while using smaller grinding media. Samples collected from an industrial vertical mill were used to validate the model proposed in this study. Lastly, a numerical model was developed using Discrete Element Method (DEM) and calibrated in terms of power with the results obtained from
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Xie et al., 2014). The first method is based on the traditional descending mining of the single coal seam. After the mining of the UCS, gateways of the LCS will be arranged …
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Although a coal block in the Qinshui Basin is a key location for coalbed methane (CBM) explor-ation and development, the productivity of various vertical wells varies significantly. The product-ivity characteristics of 636 vertical wells were analyzed better to understand the effects of different variables on CBM productivity.
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Published: 11 January 2022. Analysis of coal face stability of lower coal seam under repeated mining in close coal seams group. Yu Xiong, Dezhong Kong, Zhijie Wen, Guiyi …
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the railways, and the waters) coal reserves have been reached13.79billiontonsinChina,andthecoalresources underthebuildingsareover8.76billiontons.ecoal ...
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This study aimed to investigate the internal dislocation law of coal seam working face under coal pillars with different widths and evaluate the safety of using the …
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Downloadable! During the mining process of the near-vertical seam, there will be movement and collapse of the "roof side" rock layer and the "overlying coal seam," as well as the emergence of the "floor side" rock layer roof which is more complicated than the inclined and gently inclined coal seams, which causes problems with slippage or …
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effective imaging of coal seams, and is now of significant importance to the economics and safety of coal mining in Australia. This paper provides an essential, up-to-date overview of the advantages and potential pitfalls of using the seismic method in the coal environment based on the experiences of a number of Australian coal mines.
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The large-scale and high-intensity mining of shallow coal seams in northern Shaanxi has induced serious ground collapse, resulting in land damage in large area, water and soil loss, and vegetation death, and thus leading to the epigenetic environment degradation. In order to understand the development law of ground collapse and fracture in shallow coal seam …
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For each coal particle broken, a size-specific breakage function is used. • The limit to coal strength decreasing with size is 500 mm (i.e. particles over 500 mm were assumed to break according to the 500 mm size-specific breakage function). This is consistent with the Hoek and Brown relation [16].
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In the vertical section of coal seams, the coal body structure may vary significantly. The undeformed coal is more likely to form large vertical stimulated fractures, and the fracture surfaces are flat. ... North China: investigation by a multiple geophysical logging method. Int J Coal Geol 140:9–22. Article Google Scholar Wang T, Zhou WB ...
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A number of empirical grain-size methods are available for the determination of the hydraulic conductivities of porous media. These methods have been summarized by Vukovic and Soro, 1992, Kasenow, 2002.A general formula for calculating K g is written such that (2) K g = g υ · C · φ (n) · d w 2 where K g is the hydraulic …
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Surface mining techniques can be broadly cl assified into the following types: (1) contour strip mining, (2) area strip mining, (3) open-pit mining, and. (4) auger mining. 6.1 Contour strip mining ...
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To show the relation among different variables, the dynamic response of the important coal mill variables for a vertical roller medium speed mill during start-up, shutdown, steady state, and load change condition, is provided in Fig. 3.The real time per minute data is collected from Vadinar Power Corporation Limited (VPCL), a captive …
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Synopsis. Vertical Crater Retreat is compared to other open stoping methods. Various geotechnical factors have been considered including the effects of stress concentration, jointing, dynamic stresses superimposed by blasting vibrations, amount of development required and shrinkage draw. All these factors favour a VCR method in a …
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Yang et al. [38] researched the axial velocity of coal particles for vertical screw conveyor via DEM method. The research outcome provided the axial velocity model of the coal particle via DEM ...
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This work demonstrates that the D-Y model for multi-seam caved zone has a promising potential for obtaining the stress evolution of multiple coal seams mining, …
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1. Introduction. Thickness of a coal seam is an important geological parameter during selection of a suitable underground mining method for its efficient …
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The Measurement Inversion Vertical Electrical Logging (IVEL) in the Regency of Muara Enim Indonesia aims at measuring and mapping the resistivity associated with the spread of lithologi coal seam as Coal Bed Methane reservoirs (CBM). Resistivity measurements of new method performed with the sounding system as much as 5 …
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This study aims to improve the output and production efficiency of a large vertical mill by optimizing its operational parameters. This paper takes a large vertical mill in LGM as the object, a numerical calculation method of particle–fluid coupling system in large vertical mill based on CFD-DPM theory, and a multi-objective optimization method …
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Citation: Zhang, G.; Li, Q.; Xu, Z.; Zhang, Y. Roof Fractures of Near-Vertical and Extremely Thick Coal Seams in Horizontally Grouped Top-Coal Drawing Method Based on the Theory of a Thin Plate.
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There are 636 vertical wells in the coal block, comprising 309 wells in the X1 well block, 146 wells in the X2 well block, and 181 wells in the X3 well block. ... The grey correlation analysis method is utilized to quantitatively evaluate the influence degree of the main controlling factors of CBM productivity, from high to low: cover depth ...
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Abstract. Coal bed methane (CBM) is an unconventional form of hydrocarbon trapped inside the coal seams. It mainly consists of methane gas and is considered to be a clean energy source. The coal seams have natural fractures and a dual porosity nature. The most dominant fractures are the face cleat and butt cleat.
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open access. Abstract. Mining of close coal seams envisages reservation of a large number of section coal pillars of a total width ranging from 30 to 40 m. This results …
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Keywords: CBM, Reservoir, Coal. Resistivity. 1. Introduction. In South Sumatra Basin tectonics lies in active tectonic areas, where its coal layers have experienced at least one period of folds, fault and final experience of extrusion and intrusion of magma activity. This magma activity led to local progress, demonstrated by an increase in rank ...
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This work concentrates on the energy consumption and grinding energy efficiency of a laboratory vertical roller mill (VRM) under various operating parameters. For design of experiments (DOE), the response surface method (RSM) was employed with the VRM experiments to systematically investigate the influence of operating parameters on …
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