(PDF) Crushing properties of coal
Crushing properties of coal December 2014 Coke and Chemistry 56 (12):449-455 DOI: 10.3103/S1068364X13120090 Authors: Denis Miroshnichenko National Technical University "Kharkiv Polytechnic...Web
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Crushing properties of coal December 2014 Coke and Chemistry 56 (12):449-455 DOI: 10.3103/S1068364X13120090 Authors: Denis Miroshnichenko National Technical University "Kharkiv Polytechnic...Web
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For example, the compressive strength of the coal sample can be obtained by calculation, and the elastic modulus and Poisson's ratio can be further converted to determine the relevant parameters of the coal sample. The crushing pressure, tensile strength, shear modulus, crushing volume strain, and damage parameters can be …Web
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This demonstrates that the submerged condition will weaken the jet impact strength, thus affecting the coal crushing effect and the flushing efficiency. Therefore, in underground coal mines, HPWJ flushing operations should be carried out under the nonsubmerged condition. To achieve this goal, it is necessary to keep the drainage …Web
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The main objective of this research is to investigate the possibility of estimating the crushability of rocks from the impact strength test. For this purpose, the results of the crushing test on twenty-four different rock types were compared with the corresponding results from the impact strength test. 2.Web
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The coal under the action of stress wave had experienced the process from no damage, fracture, crushing and severe crushing. The dynamic strength of the coal sample increased gradually, and the energy of failure process increased gradually. Mechanical Constitutive Model of Coal Sample and its Verification.Web
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Coal strength will also increase with increased confining pressure (Hobbs, 1964), as shown in Figure 3.2.At atmospheric pressure or unconfined conditions, dull coals can be two to three times stronger than brighter-banded lithotypes from the same seam with the same rank (Medhurst and Brown, 1998, and Lawrence, 1978), and low rank coals can be up to …Web
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Compared with intact coal, tectonic coal shows low strength properties and a crushing work ratio of 22.11 J/m 2. The specific surface area and total pore volume of the minipores, mesopores, and macropores of the coal strongly increase under conditions of intense tectonism, which indicates that tectonic coal has a very high capacity for rapid ...Web
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The results show that one of the traditional statistical models that receives little attention is more suitable than the others to describe the size effect on particle crushing strength. The intact coal strength, i.e., the strength when particle size d → 0, is in the range 10–88.79 MPa, and the coal mass strength, i.e., the strength when d ...Web
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The change in coal strength directly affects the degree of coal crushing. The number of elements deleted due to coal failure in the first 0.01 s in each experiment is counted. Figure 15a shows that based on statistical analysis, the number of failure elements after coal impacts the tail beam decreases with the increasing failure standard. The ...Web
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coal body was under pressure, the degree of crushing intensified. e fractal dimension of the particle sizes of broken coal particles followed a logarithmic relationship with the increase in the ...Web
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An analysis reveals that the absorbed energy—synonymous with crushing work—escalates as the impact strength augments, instigating a nearly linear rise in the …Web
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Section snippets Coal samples preparation and basic parameter determination. To systematically study the impact crushing of coal with the different hardness under different gas pressure, coal samples from Xiaoqing Coal Mine 7# coal seam in Liaoning (XQ) and Zouzhuang Coal Mine 3 2 # coal seam in Anhui (ZZ) were …Web
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The crushability of twenty-four different rock types were determined and correlated with the corresponding results from the impact strength test. It was found that there is a strong inverse linear relation between the crushability index and the impact strength index. It was shown that there is a strong influence of porosity and density on …Web
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The maximum strain rate of the tested coal specimens ranged from 67.465 to 99.879 s −1, while the compressive strength ranged from 25.999 to 43.743 MPa. The impact compression test results of hard coal …Web
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The results show that one of the traditional statistical models that receives little attention is more suitable than the others to describe the size effect on particle crushing strength. The intact coal strength, i.e., the strength when particle size d → 0, is in the range 10–88.79 MPa, and the coal mass strength, i.e., the strength when d ...Web
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Coal and gas outburst is a kind of complex dynamic disaster with short duration and strong explosiveness, and the modes and strength of the outburst are determined by the in situ stress, gas pressure, and physical and mechanical properties of the coal mass. In this paper, the status quo of research on the mechanism of coal and …Web
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tion of coal seams in the UK. The test was then, modified by Paone. et al. ... which allows for obtaining a bigger index of crushing strength than in the case of crushing using the 4–8 mm ...Web
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1 Introduction Coal and gas outbursts are a dynamic phenomenon controlled by the geo-stress, gas pressure, and mechanical properties of the coal itself. They …Web
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Results show that the crushing strength of coke is improved greatly when the hot pressing is conducted at 420 ℃∼440 ℃ for the 1/3 coking coal. Coke's crushing strength is mainly affected by porosity and pores' spatial distribution. For the high porosity, the coke has thin pore walls and the cracks could easily penetrate the entire coke.Web
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The sample was broken gradually and the average particle size decreased gradually, while the large amount of coal crushing required more energy. At the same time, the mechanical strength of coal under (3,2,1) MPa was higher than that under (3,0,0) MPa, and the three-way static load prestress also increased the mechanical strength of coal …Web
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crushing strength of coal agglomerates and agglomerates diameters show that coal diameters have effect on its compressive (crushing) strength. As the coal …Web
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Moreover, the microstructure mechanical properties of anisotropic coal gangue are highly dispersed, so that concentrated stress is easily generated in the use process, which leads to poor strength of coal gangue. The solmdness and crushing value of gravel were 52 times and 1.46 times that of coal gangue. Therefore, the strength of …Web
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The coal crushing ability (the ease with which it may be ground. to a size enough for use as pulverized fuel) is a physical property affected by parameters of ... Shear strength of fine coal in a ...Web
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Ring granulators are used for crushing coal to a size acceptable to the mills for conversion to powdered coal. A ring granulator prevents both the oversizing and undersizing of coal, helping the quality of the finished product and improving the workability. ... At this tensile strength, austenitic manganese steel displays elongation in the 35% ...Web
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The crushing strength index of ferro-coke can be expressed by the following formula, Equation (1): Crushing strength Index = m30 m0 × . (1) where m0 is the initial mass of the ferro-coke before crushing, and m30 is the mass of the ferro-coke whose diameter is greater than 10 mm after crushing 30 min. 2.2.3.Web
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The crushing of raw coal consumes a huge amount of energy, and generally, the coal strength must be overcome. When the load is large and the coal is fully compacted, it will enter a compaction crushing state [13–16]. The crushing of coal is affected by its strength, local particle size, and impact energy [17–21]. The coal loading …Web
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According to the new surface theory [43, 44], the coal crushing energy was all used to create new surfaces, ... the coal fails, the strength of the system decreases sharply, and the rock is ...Web
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The strength stress and peak strain of the CRCB specimens have obvious strain-rate effects. Besides, with increased impact velocity, the incident energy increases …Web
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It is thus fully demonstrated that hydraulic fracturing technology bears a positive effect on weakening the strength and integrity of high-level thick and hard gangue, thus promoting the crushing and …Web
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Coal and gas outburst is a dynamic phenomenon in underground mining engineering that is often accompanied by the throwing and breakage of large amounts of coal. To study the crushing effect and its evolution during outbursts, coal samples with different initial particle sizes were evaluated using a coal and gas outburst testing device. …Web
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It was observed that increase in crushing fineness resulted in improved coal cake shear strength because of stronger particle-particle binding in case of higher crushing fineness. Also, as blend moisture increases from 7 to 11%, the cake shear strength increases and reaches its maximum value at 11% blend moisture but later on it shows a ...Web
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