Rock burst occurs frequently as coal mining depth goes deeper, which seriously impacts the safety production of underground coal mines. Coal seam water injection is a technique commonly used to prevent and control such accidents. Moisture content is a critical factor tightly related to rock burst; however, an in-depth insight is …
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Water injection in coal seams will lead to the increase of moisture content in coal, which plays an essential role in the physical and mechanical properties of coal. In order to study the influence of moisture content on the mechanical properties of soft media, the forming pressure (20 MPa) and particle size ratio (0-1 mm (50%), 1 …
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The intrinsic factors concerning coal particles are universally considered to be coal category [30], coal particle diameter [13], specific surface area [31], moisture percentage [32], and coal ...
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Due to the high moisture in the mine, the moisture content of the fresh coal sample (Marked as Coal C: M = 9.4%) is close to the critical moisture value. The fresh coal sample was dried at 105 °C under nitrogen to obtain coal samples A and B, with a moisture content of 2.8 % and 6.6% (Marked as Coal A: M = 2.8%, Coal B: M = …
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the coal's porous structure with moisture, removal of the surface moisture, and the establishment of equilib-rium of the coal's sorbed moisture with the atmo-sphere in a thermostat at 30.0 ± 0.1°C, with subse-quent drying of the conditioned sample at 105–110 °C. In Fig. 1, we show a system for measuring the moisture-holding capacity of ...
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The moisture content adsorbed on the coal matrix influences the gas storage and gas flow characteristics in wet coal reservoirs. This study shows that the …
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The calorific value mainly comes from the volatile matter (excluding moisture) and the fixed carbon content. The ultimate analysis is used to determine …
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In part 2 the influence of coal particle size and ambient conditions on the rate and depth of moisture evaporation within the stockpile is investigated. ... low-moisture-content coal is needed for ...
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Both of the curves indicated that the moisture content significantly influences the CH 4-induced deformation capacity of the coal. The volumetric strain of coal with a high moisture content was less than that of coal with a low moisture content at a constant equilibrium pressure, which indicated that the moisture content would …
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In this paper, coal fly ash-based tubular ceramic membrane for flue gas moisture is prepared using coal fly ash (> 80 wt.%) as raw material, adding dextrin and other additives by extrusion. The effects of dextrin content and sintering temperature on the properties of coal fly ash-based tubular ceramic membrane are studied.
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To recover CBM from coal seams on the east coast of Australia, Levy et al. [6] studied the influence of static factors such as different coal ranks, moisture contents, temperatures, and specific surface areas on methane adsorption based on coal samples from the Bowen Basin. Levy et al. reported that when the carbon content of coal is in …
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Moisture content has a negative influence on coal sorption capacity [41, 42]. The coal seams in the Cracow Sandstone Series have the highest moisture contents (4-8 wt.% on average; Figures 5 and 6
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Excessive coal moisture leads to a lower heating value and power plant efficiency, and increased transportation costs. Therefore, coal stockpile management …
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Increasing moisture content reduces coal gas adsorption capacity upto critical moisture content, and after that increment in moisture content generally will not reduce its adsorption capacity as ...
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Apart from the process water carried over into the mine and mineral processing final product, extra water after rainfall can increase the total moisture in a coal stockpile. The coal moisture content can be adjusted by way of the natural drainage and evaporation. When the rain falls on the stockpile, it either runs off the surface or infiltrates.
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Wang et al. [24] probed into the relationship among moisture content, porosity, and permeability of fractured coal. Yin et al. [25], Liu et al. [26], Wei et al. [27], and Yuan and Jiang [28 ...
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Received 08 Apr 2021. Revised 05 Jul 2021. Accepted 20 Jul 2021. Published 02 Aug 2021. Abstract. Water injection in coal seams will lead to the increase of moisture content in coal, which plays an essential role in …
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The AE activity decreases with increasing moisture content as the water reduces the internal connections between the coal particles and increases the possibility of sliding failure. Studying the RA (rise time divided by peak amplitude) and AF values (counts divided by duration) demonstrated that the cracks generated in the coal samples consist ...
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The moisture content at maximum RH of 96% was defined as moisture holding capacity of lignite at 30°C. 29 From Figure 5, the moisture holding capacity fell dramatically from 0.225 g/g dry coal in ...
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The moisture content in coal reservoirs is one of the main factors affecting gas content and gas production (Wang et al., 2016; Yao et al., 2014). Under the effect of groundwater, the water in coal is basically in the state of equilibrium, in competitive adsorption with methane molecules, which in turn affects the gas content of coal …
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Coal rank influences the chemical and physical properties of macerals. Whilst coal rank can be inferred from chemical analyses (fixed carbon, volatile matter, and moisture content), vitrinite reflectance analysis, using a petrographic microscope and its accessories, is the most accurate method to report rank. Following calibration with ...
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moisture content of coal will repress the occurrence of AE events [30–32], and meanwhile, the load-carrying induced failure of moisture-containing coal-rock mass is
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Anthracite: The highest rank of coal. It is a hard, brittle, and black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter. Bituminous: Bituminous coal is a middle rank coal between subbituminous and anthracite. Bituminous coal usually has a high heating (Btu) value ...
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Moisture can also cause coal to freeze in rail cars in the winter, which can be a major issue in power plants in colder climates. Moisture is used to define low-rank coals in some rank classification systems, and is an important criteria for determining coal …
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The effect of dynamic loss of moisture content, both on moisture and gas sorption-induced coal swelling/shrinkage strains, during the coalbed methane (CBM) production, is crucial.
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Through the analysis of measurements of bituminous coal moisture content, the maximum moisture content investigated in this paper was about 2.4%. Taking sample HB6, we studied the influence of the moisture content on gas adsorption characteristics at six values of the content: 0.0, 0.5, 1.0, 1.5, 2.0, and 2.4%.
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Moisture content in coal is an important factor affecting the coal seam gas extraction. It directly affects the storage and flow of gas in bituminous coal.
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The fitted first-order adsorption rate constant k 1, the improved formula adsorption rate constant k 2, and the second-order adsorption rate constant k 3 all decreased with an increase of moisture content in the …
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Fig. 6 shows the percentage of the two types of water in coals. The percentage of bound water content, ranging from 68.39% to 92.11%, with an average …
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DOI: 10.1016/J.COAL.2008.04.004 Corpus ID: 94700637; Influence of moisture content and temperature on methane adsorption isotherm analysis for coals from a low-rank, biogenically-sourced gas reservoir
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