Safe strategy for coal and gas outburst prevention in deep-and-thick
In this paper, a stereoscopic gas extraction system for coal and gas co-mining of deep-and-thick coal seams is proposed. As described above, the suitable soft rock was selected as a protective layer for mining. The mining of the protective layer provides "pressure relief and permeability enhancement" and "spatial-temporal guarantee ...
اقرأ أكثر
Energies | Free Full-Text | Study on the Slurry …
To further explore the remaining space distribution law of the collapsed goaf in thick seam fully mechanized top coal caving mining and the effect of coal gangue fluidization filling, the caving goaf of the 3307 …
اقرأ أكثر
Cutouts and rolls, Coal Mining Geology, Kentucky …
A cutout is where roof rock truncates the entire coal bed and a roof roll is where the roof rock cuts down to the top of the coal without loss of seam height. Both examples are from the Pond Creek (Lower Elkhorn) coal bed in eastern Kentucky. Roof rolls can become cutouts, and cutouts can become roof rolls, essentially rising or falling …
اقرأ أكثر
IRJET- A Critical Review of Indian Underground …
The Indian thick seam coal mining by time is allowed for the strata to settle down. Independent underground methods evolved with tremendous growth in development roadways are then driven for the next slice terms of …
اقرأ أكثر
Characteristics Analysis of Roof Overburden Fracture in Thick Coal Seam …
With the increase of the depth of coal seam mining, the height of roof failure increases continuously, and the number of cracks in the roof rock also increases greatly (Jiang et al. 2016; He et al. 2016; Zhu et al. 2016).In the process of deep mining thick coal seam, the roof is often severely damaged, the cracks are developed and enlarged, and …
اقرأ أكثر
Underground mining of thick coal seams
This paper reviews underground mining methods for total thickness of a thick coal seam in single lift (TTTCSSL). Review shows the required engineering for extraction of thick seams needs to be fitted with thickness of the seam, behavior of rock-mass and surrounding stress conditions for efficient mining. Variants of TTTCSSL are …
اقرأ أكثر
A Critical Review of Indian Underground Thick Coal …
NASINA BALASUBRAHMANYAM1, DR G.BUDI2. Abstract - Thick seams are nearly 40% of proven Indian coal reserves and their extraction by underground mining methods are …
اقرأ أكثر
Systematic principles of surrounding rock control in longwall mining …
technique of large mining height coal wall in thick coal seam with dirt band. during topple mining. J Min Saf Eng 2014;31(6):831–7. [7] Wang JC, Yang SL, Kong DZ. Failure mechanism and control ...
اقرأ أكثر
Coal seam
A coal seam is a dark brown or black banded deposit of coal that is visible within layers of rock. These seams are located underground and can be mined using either deep mining or strip mining techniques depending on their proximity to the surface. These seams undergo normal coal formation and serve as a conventional coal resource.The reserves of coal …
اقرأ أكثر
IRJET- A Critical Review of Indian Underground Thick Coal Seam Mining
The Indian thick seam coal mining by time is allowed for the strata to settle down. Independent underground methods evolved with tremendous growth in development roadways are then driven for the next slice terms of production and technology and the 21st century except level entries. ... R VI,4.8m 4 SHANXI TIANDI SCCL , ug Project, EM …
اقرأ أكثر
Energies | Free Full-Text | Development Patterns of Fractured …
The key to the safe mining of thick coal seams under rivers is understanding the development patterns of fractured water-conducting zones (FWCZ) when various mining methods are used. To solve this problem, we employed numerical simulation to investigate FWCZ when slice mining and longwall caving mining are performed. …
اقرأ أكثر
Modelling of strata movement with a special reference to …
During the high-intensity mining of super-thick coal seam, the coal seam and roof strata are gradually fractured in front of the mining face due to the large impaction of the breaking and movement ...
اقرأ أكثر
Ultra-thick Seam Longwall Mining in China
In the three mines where the ultra-thick whole seam 7-m single-slice longwall mining is employed, there are 5-10 minable coal seams ranging from less than 1-m to 9.4-m (<3.3-31 ft) thick with seam …
اقرأ أكثر
Floor Failure Characteristics of Thick Coal Seam Mining …
The mining-induced failure of the coal seam floor is essential for water inrush. The mining disturbance to the floor, especially in the thick coal seam, is severe, and the water inrush risk is also higher than that in regular thick coal seam excavation. The superposition of many stresses, including in situ stress, mining-induced stress, and …
اقرأ أكثر
Underground mining of thick coal seams | Semantic Scholar
1 Excerpt. A Study of Stability Investigation of Immediate Roof for Extraction of Thick Coal Seam in India. A. Mangal. Engineering, Geology. 2021. This study …
اقرأ أكثر
Thick seam coal mining and its ground control
The Carboniferous Taiyuan Formation coal seam 3~5 # is the main coal seam in the Tashan coal mine. The seam depth is 300~500 m. The coal seam varies considerably in thickness, but averages 19.4 m, and the average dip angle is 0~4 degrees. Its UCS is 10~25 MPa. The immediate roof is carbonaceous mudstone 8 m thick.
اقرأ أكثر
THICK SEAM MINING METHODS | Mine Portal
2453. 1. Thick seam mining: Bord and pillar and longwall methods in multi-section; multi-slice methods; inclined slicing; horizontal slicing and cross slicing in ascending and descending orders; under winning methods; sublevel caving; integral caving; blasting gallery. CLICK HERE TO DOWNLOAD NOTES FOR THICK SEAM MINING.
اقرأ أكثر
Numerical Study on Stress Relief and Fracture Distribution
Approximately 92% of coal production in China is from underground mining, with an average mining depth of more than 600 m, and the mining depth is still extending downward at a rate of 30–50 m per year (Li et al. 2014; Kong et al. 2019).The underground coal seam occurrence and mining conditions are complicated, and the gas content is …
اقرأ أكثر
Evaluating the Safety of Using the Combined Mining …
This study aimed to investigate the internal dislocation law of coal seam working face under coal pillars with different widths and evaluate the safety of using the combined mining of close-distance coal seams under different layer spacing. Based on elastic–plastic mechanics and mine pressure theory, theoretical calculation and numerical …
اقرأ أكثر
Coal Seams: Things You've Always Wanted to Know
National Park Service. A coal seam is a black banded or dark brown coal deposit evident in rock layers. These deposits are below the ground level and, based on their distance from the surface, can be extracted using techniques of either deep or strip mining. Such seams undergo natural formation of coal and function as a typical supply …
اقرأ أكثر
An innovative approach to thin coal seam mining of …
1. Introduction. Thin coal seams are fairly pervasive in coal measures. For example, in China, the coal reserve of thin coal seams accounts for approximately 20% of total coal resource and its distribution covers over 85% of mining areas of China [1], [2].In order to maximise the recovery rate, the extraction of thin coal seams, especially for …
اقرأ أكثر
Thick seam coal mining and its ground control
Abstract. Thick coal seam is the main coal seam to achieve high efficiency coal mining. In this chapter, the common mining methods for thick coal seams are introduced. There is a large-cutting-height mining method and a top-coal caving mining method. Also, the ground control for the thick coal seam mining is described in this …
اقرأ أكثر
Thick Coal Seam Mining Challenges and Prospect
A coal seam is considered thick, if the entire seam thickness cannot be extracted in a single lift with available equipment and technology. In India, seams more than 4.8m are …
اقرأ أكثر
Study on overburden failure characteristics in deep thick loose seam …
characteristics in deep thick loose seam and thick coal seam mining, Geomatics, Natural Hazards and Risk, 11:1, 632-653, DOI: 10.1080/19475705.2020.1737584 To link to this article: https://doi.or ...
اقرأ أكثر
Strata Control in Mining: A Study of Strata Control in an …
To achieve the set objectives, an underground coal mine located at Nagpur region is chosen. The following details are collected from the mine: i. Name of Seam: Seam V ii. Thickness of the Seam: 3.0 to 4.6m iii. Roof rock Shale & Sand Stone iv. Floor rock Sand Stone v. RMR 31.5 vi. Pillar Size 25m X 25m vii. Gallery Size 3.6m X 2.5 m viii.
اقرأ أكثر
Coordinated Top Coal Caving Mining Technology of Thick Seam …
2017. 2. In order to liberate coal under reservoir dam and to improve the mining rate of the coal resources,with the theoretical analysis,simulated calculation,site observation and other method,a top coal caving coordinated mining technology of the thick seam under the reservoir dam was provided.Five factors of the coal mining face forward ...
اقرأ أكثر
Mass Production Technologies for Underground Coal Mining …
The concept of a thick seam varies from country to country, the basis for the lower limit of a thick seam being the thickness up to which a seam could be extracted in one lift (pass) with the available equipment and technology . In India, over 60% of coal reserves are thick seams, and a considerable % of coking coal belongs to thick seams.
اقرأ أكثر
EXTRACTION OF THICK COAL SEAM
2.1 Problems associated with mining of thick coal seams 16 2.2 Methods of mining thick coal seams 16 2.2.1 Slice mining 17 2.2.2 Sublevel caving method 18 2.2.3 Integral caving method 19 2.2.4 Blasting Gallery method 21 2.2.5 Thick seam mining with cable bolting 22 2.3 Numerical Modelling 23 2.3.1 Comparison with other methods 24
اقرأ أكثر
Mass Production Technologies for Underground Coal Mining …
Thick seams in India range from flat to steeply inclined, vary in thickness and rate of a dip in the same area, and are, in some places, contiguous and interlaced …
اقرأ أكثر
Strata Stability Investigation and Convergence Monitoring
Depillaring with caving in the thick seam is a big challenge for the coal mine operators especially in Raniganj coalfields [].Some of the immediate roofs of the deep-seated seam at Raniganj coalfields contain massive hard sandstone having a thickness of 66 m, density of 2201 kg/m 3, compressive strength 26.2 MPa, tensile strength 3.4 MPa, …
اقرأ أكثر