Micro-structure of crushed coal with different
After the coal body is crushed to a smaller particle size, the effects of oxidation and crushing on the coal free radical concentration are continuously strengthened. The oxidation and crushing effects are both strongest …Web
اقرأ أكثرWashing of Low Volatile Coking (LVC) Coal: Is That Difficult?
The fact that about 83 % of the crushed coal was contributed by +3 mm size fractions (Table 3) showing little liberation, is important. On crushing subsequently by the same DRC to nominal top size of −10 mm, as high as 74 % of the crushed coal reported to +3 mm size fractions.Web
اقرأ أكثرStudy on the evolution of pore structure and desorption …
With the decrease of the particle size of the crushed tectonic coal under the unloading confining pressure, the volume of gas desorption and the desorption speed increase gradually. Combined with the analysis of PSD, it is found that the tectonic coal crushed at a faster unloading speed of confining pressure has a higher gas desorption …Web
اقرأ أكثرExperimental Study on the Determinant Factors and Energy …
Some researchers also used crushed coal powder particles to compress and form coal briquettes for laboratory outburst experiments. 40. ... The size of the coal briquette samples prepared for the outburst experiment was Ø 200 × h 110 mm, the pressure of each pressed sample was uniformly set to 900 kN, and the pressure holding …Web
اقرأ أكثرSpatial Structure Characteristics of Underground Reservoir …
The crushed rocks used in this study were taken from Haragou Coal Mine, Daliuta Town, Shenmu County, Shaanxi Province, with a size range of 5–45 mm and a solid density of 2300 kg/m3 (Figure1a). The crushed rocks were divided into 8 groups based on particle size sieving, with each group having a particle size interval of 5 mm. From eachWeb
اقرأ أكثرISO 23499:2013 (en), Coal ? Determination of bulk density for the …
1 Scope. This International Standard provides description of a cone procedure for determining an uncompacted bulk density of crushed coal less than 37 mm in size, such as is charged into coke ovens. It focuses on the uncompacted bulk density of coal resulting from flowing the material into a measuring container (box) in the absence of ...Web
اقرأ أكثرStandard method of sieve analysis of coal
A sieve method of analysis for determining the particle size of crushed bituminous coal is described. The method is applicable to coal less than 1/sup 1///sub 2/ in. (38.1 mm) in size. Square-hole sieves of the following sizes are used: 3.35 mm, 4.75 mm, 6.7 mm, 9.5 mm, 13.2 mm. 19.0 mm, and 26.5 mm. Detailed instructions are given for the ...Web
اقرأ أكثرDrop-weight impact fragmentation of gas-containing coal particles
For tectonic coal particles from two coal mines with a size range of 2–3 mm, a total of 67 sets of crushing experiments were performed under various gas adsorption pressure (0.5–4.0 MPa) and desorption duration (1–240 min) conditions. The fractal theory was used to analyze the particle size distributions of the fragments.Web
اقرأ أكثرSpatial Structure Characteristics of Underground Reservoir Water …
The crushed rocks used in this study were taken from Haragou Coal Mine, Daliuta Town, Shenmu County, Shaanxi Province, with a size range of 5–45 mm and a solid density of 2300 kg/m 3 (Figure 1a). The crushed rocks were divided into 8 groups based on particle size sieving, with each group having a particle size interval of 5 mm.Web
اقرأ أكثرExperimental study on the secondary breakup properties of …
The inner diameter and the height of the coal sample chamber are 100 mm and 200 mm respectively. According to the ratio standard (1:5 or 1:6) in rock mechanics, …Web
اقرأ أكثرExperimental study on the mechanical characteristics of grouted coal
The crushed coal was divided into three types through screening, with particle sizes of 5–10 mm, 10–15 mm and 15–20 mm, to represent different crushing degrees, as shown in Fig. 4.The grouting device was assembled, and an oily cement release agent was daubed on the inner wall of the grouting chamber and the plates.Web
اقرأ أكثرExperimental study on the secondary breakup properties of crushed coal
The compaction and breakup characteristics of crushed coal rock masses during stress recovery in the strata and its series of influencing factors (e.g., particle size, strength, temperature, and moisture) have been investigated in detail (see Table 1, Table 2). ... Results demonstrated that with the increasing temperature, the size of cracks on ...Web
اقرأ أكثرCompressive deformation and energy dissipation of crushed coal …
Solid backfill coal mining is a new method of green mining in which backfill material is transported by a special handling system and processed through a tamping device behind a hydraulic support at the mining face. ... The particle size distribution of the crushed waste rock specimens after compressive loading has superior fractal ...Web
اقرأ أكثرEffect of particle size on re-crushing characteristics of crushed …
Four types of crushed anthracite with single particle sizes of 2.5–5, 5–10, 10–15, and 15–20 mm were used to investigate the effect of particle size on the internal re-crushing characteristics. 3. Experimental results and discussion. 3.1.Web
اقرأ أكثرCoal comminution and sizing
Depending on the nature of the coal and of the planned processing, during mining the largest lumps may be broken to a topsize as large as 200 mm, or as small as …Web
اقرأ أكثرDrop-weight impact fragmentation of gas-containing coal particles
The particle size distributions of crushed coal at room temperature and ∼100 kPa are shown in Fig. 4. Although the particle sizes of the original screened coal particles were between 5 mm and 10 mm, the initial particle size for statistical analysis is 7 mm.Web
اقرأ أكثرStudy on the distribution pattern of particle re-crushing in the …
where d is the particle size of the broken coal gangue, mm; D is the largest particle size of the broken gangue, mm; M d is the mass of broken gangue in the rock sample with a particle size smaller than or equal to d, g; M t is the total mass of broken gangue in the sample, g; and n is the Talbol power exponent. 2.2 Test procedure The above crushed rock mass …Web
اقرأ أكثرFractal Fract | Free Full-Text | Experimental Investigation of the
In the process of screening crushed coal gangue in the different particle size ranges, to avoid errors caused by manual screening, a crushed coal rock body automatic screening device was used for screening. ... 4.3. Particle Size Distribution Characteristics of Crushed Coal Gangue 4.3.1. Particle Size Interval Distribution.Web
اقرأ أكثرSize analysis of coal crushed to 75 mm (all five benches)
A run-of-mine coal (58.5% ash) was crushed to -75 mm and screened into six size fractions. The individual size fractions and the composite coal -75 +0.5 mm were …Web
اقرأ أكثرStudy on mechanical properties of coal gangue and fly ash
The permeability of crushed coal gangue follows a hierarchical distribution law and the permeability changes in the magnitude range of 10–11 ~ 10–9 m2. The fractal dimension is inversely related to the permeability of crushed coal gangue. ... Among them, the particle size ranges of coal gangue are 2.5–5 mm, 5–8 mm, 8–12 mm, and 12 ...Web
اقرأ أكثرDeformation Behaviour of Crushed Waste Rock Under Lateral …
The crushed gangue specimens used in this study are collected from the gangue hill at Huayuan Coal Mine, Jining City, China. The gangue must be crushed before backfilling the underground space as a backfilling material. The crushed gangue with the particle size smaller than 50 mm is normally used for backfilling the mining goaf.Web
اقرأ أكثرSeepage properties of crushed coal particles
The gas seepage properties of crushed coal specimens with five particle sizes of a (2.5–5 mm), b (5–10 mm), c (10–15 mm), d (15–20 mm) and e (mixed sizes) under the variable axial displacement of 10, 15, 20, 25, 30, 35, and 40 mm, respectively are measured by the revised MTS815.02 system. The results of test show that: The porosity ...Web
اقرأ أكثرStudy on the distribution pattern of particle re-crushing in the coal
The test results show that: the crushing of coal rock particles exists in almost the whole compaction process of the crushed coal rock body, and the crushing of coal rock particles has a non-negligible influence on the deformation of the whole crushed rock body; the structural stability of large-size coal rock particles is not as good as that ...Web
اقرأ أكثرExperimental study on particle size distribution of impact crushed …
Five standard screens with apertures of 3 mm, 1 mm, 0.25 mm, 0.2 mm, and 0.074 mm were used to screen the crushed coal samples. The coal samples with the …Web
اقرأ أكثرMicro-structure of crushed coal with different
Taking the low-rank lignite as an example, which is the most prone to spontaneous combustion, an analysis was conducted on the oxidation reactivity after the coal was crushed to five different particle size ranges: 0.224−0.280 mm, 0.180−0.224 mm, 0.125−0.180 mm, ConclusionsWeb
اقرأ أكثرFractal Fract | Free Full-Text | Experimental Investigation of the …
A lateral limit compression test with the crushed coal bodies was carried out to illustrate the effect of the porosity on the permeability, In addition, a compressive …Web
اقرأ أكثرanthracite
Anthracite is the form of coal containing the highest percentage of carbon. Three classes are distinguished: Name Fixed Carbon (percent) Volatile Matter (percent) meta-anthracite >98% <2%: anthracite: ... Size Screen sizes, inches (through and over) egg: 2.5 to 1.75: stove: 1.75 to 1.25: chestnut: 1.25 to 0.75: peas: 0.75 to 0.50: …Web
اقرأ أكثرInvestigating the effects of effective stress on pore-dependent
The accurate determination of permeability is one of the parameters essential for the study of fluid flow and transport state. However, a large number of fractured coal bodies are faced during the production of coal mines. The study of permeability of these special media composed of grains of a certain size, whose structure is different from that …Web
اقرأ أكثرExperimental study on the permeability of crushed coal medium …
To investigate the permeability characteristics of this special porous medium composed of crushed coal particles, the permeability parameters of crushed coal …Web
اقرأ أكثرEffect of Coal Size on Coking Pressure and Coke Strength
size and gas pressure in the plastic coal layer. The mean particle size (horizontal axis) in tests 1 to 4 is that of only finely crushed high-coking pressure coals B and C. The mean particle size in tests 5 and 6 is that of the entire blended coal. Figure 2 shows that under all the conditions, as the mean coal particle size is smaller, the gas ...Web
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