sands, the particle crushing strength of granulated coal ash did not depend on the particle size. Moreover, the crushing strength affected the shear characteristics, i.e., as the crushing strength increased, the shear stiffness became higher and the shrinkage of the volumetric strain became smaller.Therefore, crushing strength can be a
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Understanding the mechanical properties of coal is crucial for efficient mining and disaster prevention in coal mines. Coal contains numerous cracks and fissures, resulting in low strength and challenges in preparing standard samples for testing coal fracture toughness. In engineering, indicators such as the hardness coefficient (f value) …
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The parameter of coal rock crushing degree is a power function that is influenced by the impact velocity; the greater the impact velocity, the higher the coal rock crushing degree, but the characteristic index of coal rock crushing fluctuates with the increase in impact velocity. ... According to Table 1, the strength of six of the nine hard ...
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Methods of assessing coal strength are compared on the basis of a literature review. The Hardgrove grindability index (HGI) is the most expedient.There is a close relation between HGI and the coal quality, as well as the power consumed in grinding. Accordingly, the HGI values of coal samples may be used to optimize the crushing of …
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6. coal of adequate crushing strength. 2.3 Describe depillaring method with stowing and caving. DEPILLARING WITH STOWING : Depillaring with stowing is a method of pillar extraction in which the goaf is completely packed with incombustible material and in generally practiced where it is
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By combining these results with the experimental results from the literature, the suitability of the Weibull model to describe the size effects on the breakage strength of rock grains is discussed. To understand why larger grains possess lower strength, a bonded particle model (BPM) is established in YADE to simulate the particle crushing …
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Coal agglomerates of 0.015-0.0277m were produced and the weight and crushing strength of the agglomerates were determined. Kerosene (paraffin oil) was …
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The main business includes: coal crushing technology and equipment, non-coal crushing technology and equipment, dry environmental protection technology and equipment, intelligent control technology and equipment, etc. ... ESTABLISHED IN 2001 58078 M². OVERALL FLOORAGE 58078.68 square meters 1000 + Project Site 1000 The strength …
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Comparing the mean crushing strengths of granulated coal ash, it was found that G.C.A. B with the highest cement content had higher strengths than G.C.A. A. Looking at the results for G.C.A. C and D, which had the same cement content as G.C.A. A but were manufactured in a different way, it appeared that G.C.A. C had the same …
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Outburst coal is the low strength coal formed after the raw coal is crushed and bonded under the ground stress because it is difficult to core on-site; therefore, imitating the …
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The densification parameters for sub-bituminous coal briquette were optimized in this study to obtain 12 maximum drop to fracture (DF), water resistance index (WRI), and cold crushing strength (CCS).
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strength variations of pre-tensioned rocks, with Zhao33focusing on the fractal traits of coal-bearing seam crack extensions under similar conditions. Li 34 entailed introducing radial …
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However, the mechanical properties of coal are of value as a means of predicting the strength of coal and its behavior in mines when the strength of coal …
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The results show that at the moment of gas release, coal particles and gas are ejected at high speed, crushing coal particles into smaller particles. With the increase in gas pressure and gas adsorption performance, the crushing effect will increase. Also, the coal ejection strength (CES) will increase nonlinearly.
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The factors affecting the mechanical strength of coal and coal charges, deviations of the crushing capacity coefficients' actual values of coal charges from their calculated values, and the ...
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In the case of the 10% coal tar pitch addition, the cold crushing strength of ferro-coke was increased from 18.15% to 76.41%; meanwhile, its hot compression strength during gasification improved ...
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of coking pressure decrease caused by fine crushing of coal is un-clear. Meanwhile regarding the coke strength, it is considered that the size reduction of inertinite texture (hereinafter, inertinite) in coal by fine crushing of the coal contributes to enhancing the coke strength.6) However, a method to measure the size of representative
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Coal and gas outburst is a dynamic disaster that poses a significant threat to coal mines. Energy analysis is an effective tool for understanding the mechanisms behind such outburst. The energy sources and dissipation during outbursts were explored using a multifunctional test system, and the energy transformation relationship was analyzed …
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Abstract Determination of the coal-strength coefficient in accordance with State Standard GOST 21153.1–75 is clear and simple. No complex equipment is required, and capital expenditures and energy costs are relatively low. This method satisfactorily reproduces the crushing conditions of coal in hammer systems, and the granulometric …
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In solid backfill coal mining (SBCM), loose gangue backfill material (LGBM) is used to backfill the goaf after coal resources are exploited from the underground mines. ... In order to study the impact of grain crushing on the strength and the deformation characteristics of LGBM, there is a need to quantitatively reflect the crushing degree of ...
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Based on the new surface theory, the internal of coal smashing is that the coal rock mass obtains power and produces a new surface [9, 11, 12, 37].The physical meaning of crushing work ratio refers to the quantity of crushing work used up by the new surface area per unit area formed by coal in the crushing course [28, 29, 34].The …
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Methods of assessing coal strength are compared on the basis of a literature review. The Hardgrove grindability index (HGI) is the most expedient.There is a close …
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When the amount of iron ore was 30%, the crushing strength of ferro-coke dropped to 18.15%. Among the four binders, coal tar pitch could significantly enhance the cold crushing strength of ferro-coke through decreasing the porosity of ferro-coke and improving the bonding effect between carbon matrix particles.
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Estimating compressive strength. General rock failure criterion can be reduced to a few parameters dependent on lithology (m) and the uniaxial compressive strength (C 0).Lithology is commonly derived during log analysis, so m may be estimated (Table 1).What is needed still is an initial measure of rock strength provided by C 0. C 0 …
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CO 2 fracturing enhances gas permeability by creating a complex network of fractures in coal seams. Crushing serves as the foundation of fracture development, and studying the coal crushing behavior under supercritical CO 2 transient high-pressure fracturing is of great significance to understand fracture evolution and guide precise …
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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 …
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Energy Evolution and Coal Crushing Mechanisms Involved in Coal and Gas Outburst Chaolin Zhang,1,2 Peizhong Wang,1 Xianfeng Liu,3,4 Enyuan Wang,1,2 Qiaozhen Jiang,1 and Mingliang Liu1 Received 5 July 2023; accepted 14 November 2023 Published online: 16 December 2023 Coal and gas outburst is a dynamic disaster that poses a …
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Cold crushing strength of the briquettes. Figure 4 shows the cold crushing strength (CCS) for the briquettes. The CCS depicts the ease of breakage or wear during transportation, handling and ...
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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.
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The changing rules of dynamic strength, crushing, fractal dimension and damage modes of coal under different stress conditions were analyzed. A total of nine …
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