(PDF) Measurement of Crushing Strength of Coal Agglomerates
The aim of this research is to produce coal agglomerates 15-27.51mm and to determine the crushing strength of the agglomerates for good handling of fine …Web
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Mechanical properties and failure modes of CRCB specimen …
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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The fracture characteristics and enhancement mechanism of crushing
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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Energies | Free Full-Text | Technique to Investigate Pulverizing
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 the crushing system. ... (p ¯ = 1.5 MPa) was found to be 20 to 30 times lower than the compressive strength of the coal being pulverized .Web
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Analysis on the Shape and Impact Pressure of the High
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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Study of Coal Cake Bulk Density and Its Shear Strength for …
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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The fracture characteristics and enhancement mechanism of …
The mechanism of enhancing coke's crushing strength by hot pressing was explored. Keywords Hot pressing Crushing strength Fracture characteristics Pore …Web
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Predicting the crushability of rocks from the impact strength index
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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An analysis of impact load and fragmentation dimension to
This research delineates the energy dissipation characteristics in coal crushing under impact loads, leveraging the capabilities of Separated Hopkinson Pressure Bar …Web
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Minerals | Free Full-Text | Mechanism and Application …
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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Crushing force, crushing energy and technical performance
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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Experimental study on evolution law for particle breakage during coal
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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A review of coal pillar strength formulas | Rock Mechanics and …
A Review of Coal Pillar Strength FormulasSince 1900 a number of investigators have studied the problem of predicting the strength of coal mine pillars on the basis of compression tests performed on small samples. From these studies, a number of quite different formulas relating compressive strength and sample size and shape factors …Web
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Role of Tectonic Coal in Coal and Gas Outburst Behavior During Coal
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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Research on Particle Size and Energy Consumption …
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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Experimental Study on Crushing Characteristics of Lignite under
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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Rock mechanical failure characteristics and energy evolution
The deformation and failure of the coal-rock combination after loading have gone through four stages (Qin et al. 2017): the compaction stage, elastic stage, plastic deformation stage, and post-peak failure stage are similar to the failure process of coal and sandstone specimens.For the coal-rock combination with 0° dip angle, its ultimate …Web
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Effect of Binders on the Crushing Strength of Ferro-Coke
In this paper, phenolic resin, silicon metal powder, corn starch, and coal tar pitch were used as binder for the fabrication of ferro-coke. I-type drum machine (I 600), scanning electron microscope (SEM), and X-ray diffraction (XRD) were applied to test the crushing strength, morphology, and microcrystalline structure of the ferro-coke.Web
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Study on Impact Dynamic Behavior and Failure Characteristics of Coal
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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Investigation on tectonically deformed coal particle crushing by …
The crushing characteristics and strength of coal particles have been explored through numerous experiments. In addition to researches on the crushing of single TDC particles, triaxial loading seepage experiments were also conducted on those with different particle size distributions. The study revealed that varying particle size …Web
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Experimental and numerical investigation of the size effect
crushing strength. Theoretical and experimental tests show that the crushing strength of granular materials follows a weibull distribution [2429– ]. Previous studies showed that the Weibull model can also describe the distribution char-acteristics of the crushing strength of rockll particles, and the power function relationship is adopted …Web
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Effect of Binders on the Crushing Strength of Ferro-Coke
In this paper, the addition amount of iron ore powder (10%, 20%, 30%, 40%, 50%) were used to reveal the effect of iron power amount on the crushing strength of ferro-coke. Then four types of binders (phenolic resin, silicon metal powder, corn starch, and coal tar pitch) were added into the coal to test their effect on the cold and hot …Web
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Predicting the crushability of rocks from the impact strength index
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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Experimental study on the mechanical characteristics of grouted coal
As the particle size of the crushed coal increased, the crushing degree of coal decreased, and the area of the coal-grout cemented surfaces increased, resulting in an increase in the bond strength. In general, the internal degree of damage of the specimens under uniaxial compression experiments increased with the crushing degree of coal.Web
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Experimental study on particle size distribution of impact crushed coal
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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Strain Rate Effect and Mechanical Constitutive Model of Coal
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
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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Effect of coal properties on the strength of coke under simulated …
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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Experimental and numerical investigation on the dynamic
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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Predicting the crushability of rocks from the impact strength index
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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