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University of Wollongong Research Online

2011 Underground Coal Operators' Conference The AusIMM Illawarra Branch 12 10 – 11 February 2011. Table 1 - Duncan method remnant coal pillar dimensions, factor of safety, length of lift, theoretical extraction percentage, and extraction tonnes per development metre at Tasman mine . Fassifern Seam Height 2.4 m. 45 m x 45 m Development . Remnant

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coal - Deutsch-Übersetzung – Linguee Wörterbuch

coal extraction n — Kohlegewinnung f ... stresses that it cannot accept such a passive role, which is contradictory to present-day requirements of transparency and accountability; considers that the legislative acts laying down the annual financial and technical guidelines of the Coal and Steel Research Fund should be brought under ...] the co-decision procedure, [...] whereby the ...

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Characteristic of stress evolution on fault surface .

01.07.2020 · Liu et al. (2011) simulated the double coal seam extraction process by constructing a physical model and studied the movement and stress relief effect in overlying strata. The physical model employed in the investigation should satisfy the similarity principles in which the relationship between field prototype (p) and laboratory model (m) should be determined. This is to say that the physical ...

Author: Hongwei Wang, Ruiming Shi, Daixin Deng, Yaodong Jiang, Gang Wang, Weili GongGet Price
Stress-state monitoring of coal pillars during room and ...

Stress-state monitoring of coal pillars during room and pillar extraction . Abstract . Current mining activities of the OKD mines are primarily focused on coal seams within the Karvina Formation in the Karvina sub-basin. A considerable amount of coal reserves are situated in protection pillars that lie under built-up areas. The longwall mining method is not applicable in these areas because ...

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In‐site investigation of regional outburst .

In this study, based on zonal disintegration characteristics of deep surrounding rock, a regional strip outburst prevention method, called strip stress relief combined with gas extraction through stress‐relief floor roadway, was proposed, and relevant in‐site investigations were carried out in the Qujiang coal mine in China. Our results show that the zonal disintegration phenomenon occurs ...

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Risk management of underground coal pillar .

Pillar extraction practices in South Africa have consumed a significant proportion of safety and fatality statistics in relation to its relative output (less than 5% of total South African coal ...

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Coal Extraction Revenue and Spending: A Comparison Among ...

generated from coal extraction and how the revenues are spent by state and local governments, and how much each state sets aside in permanent savings. Summary Findings • How states collect and spend coal revenue varies widely. We identify 15 sources of coal production revenue in the six states, including value-based and volume-based taxes and royalties paid to by federal, state, and local ...

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Depillaring: Arrangement, Precautions and Pillar ...

During extraction of coal a rib about 1 metre thick is left against the goaf. When all the slices are removed, and the area is to be abandoned, the rib coal is "robbed" to the maximum extent possible. When no more coal is extractable from the stooks, without endangering safety, props and roof supports are withdrawn and the area is then abandoned. Chocks are erected at goaf edges and the ...

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Hydraulic flushing in soft coal sublayer: Gas .

After hydraulic flushing in the soft sublayer, stress‐unloading and plastic failure could be achieved in the overlying and underlying hard coal masses, which significantly improves their gas extraction condition. Moreover, stress concentration occurs in the soft sublayer; thus, its permeability decreases notably. Under this special gas extraction condition, interlayer gas flow is the main ...

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Fracking can cause social stress in nearby areas: .

Coal seam gas extraction has increased social stress in Darling Downs. University of Queensland, Author provided. Fracking can cause social stress in nearby areas: new research April 23, 2018 4 ...

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MISG 2011, Problem 1: Coal Mine pillar extraction

stress Group 1 Coal Mine pillar extraction January 14, 2011 15 / 30. Buckling of a Strut Buckling of a Strut v p p x y • Two equations for the bending moment at point x along the strut EI d2v dx2 = M(x), M(x) = −pv(x). (18) • These equations gives d2v dx2 + p EI v(x) = 0. (19) • Solving (19) with the corresponding boundary conditions v(0) = 0, v(L) = 0, gives v(x) = Asin(nπ L x), n ...

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Coal Mining Pillar Extraction - kwaliteitsvoeger

Provision of a single working place 2. Extraction of coal in stress relieved areas 3. Utilisation of the coal in stress as a support. Coal pillar design procedures - Mine Health and Safety . 2 Executive Summary Examination of collapsed pillar cases outside of the empirical limits of Salamon and Munro's in situ database has highlighted the need for additional parameters to be considered in the ...

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Subsidence from Underground Mining: Environmental Analysis ...

The void created by the underground extraction of coal or other resources causes significant changes in the magnitude and orientation of the in situ stress field and results in deformations both in the remaining coal and in the surrounding rocks. In general, the sides of the excavated area move inward, the floor upward, and the roof downward. The initial deformations may be elas­ tic, that is ...

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EXTRACTION OF THICK COAL SEAM - National Institute of ...

23 Stresses on ribs after extraction of two and half pillars in 9m thick seams 43 . 10 24 Stresses on ribs after extraction of two and half pillars in 11m thick seams 43 25 Stress result plot for developed pillar at 150m depth for 7m thick seam (shallow depth) 44 26 Stress results plot for stook and rib after extraction of two and half pillar at150m depth (shallow depth) 44 27 Stress result ...

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Mechanical Behavior and Permeability Evolution of Coal ...

showed that the slice extraction of coal would introduce large amounts of caving in the mine roof. Zhang et al. [29] built a three-dimensional numerical extraction model based on the geologic and mining conditions of a specific coal mine and explored the mining-induced localized stress concentration and interlayer rock failure behavior using field investigations and numerical calculation ...

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Coal mining in Brazil - Wikipedia

Coal mining in Brazil is the country's largest source of non-renewable energy, and is an important part of Brazil's energy economy.Brazil is the tenth largest energy consumer and the third largest in the Western Hemisphere, Coal accounts for approximately 5.8 percent of the country's total primary energy supply.

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An explanation of large-scale coal and gas outbursts in ...

relief gas extraction, and strengthening gas extraction in ad-vance, are the main technical approaches in China (Cheng and Yu, 2007). Protecting seam exploitation is the preferred approach for coal seam group. For efficient resource utiliza-tion and atmospheric environment protection, co-extraction of coal and methane has become a widely accepted idea in recent years (Guo et al., 2012 ...

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Stress-state monitoring of coal pillars during room and ...

Stress-state monitoring of coal pillars during room and pillar extraction . Abstract . Current mining activities of the OKD mines are primarily focused on coal seams within the Karvina Formation in the Karvina sub-basin. A considerable amount of coal reserves are situated in protection pillars that lie under built-up areas. The longwall mining method is not applicable in these areas because ...

Get Price
ACARP Reports for Category

Coal Extraction Drilling & Blasting Environment General Geology Highwall Mining ... Self Heating of Spoil Piles from Open Cut Coal Mines. 1301-C1301 Stress Control Methods for Optimised Development... Stress Control Methods for Optimised Development and Extraction Operations . 0033-C1356 Commissioned Report: Australian Thermal Coals... Commissioned Report: Australian Thermal Coals .

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EVALUATION OF UNDERGROUND COAL PILLAR DESIGN

Mining is the extraction of valuable minerals or other geological materials from the earth, usually from an ore body, vein or (coal) seam. Mining involves different processes like prospecting for ore bodies, analysing the feasibility of extraction, profitability of the operation, extraction of the desired materials. One of such methods is the Bord and Pillar method of mining which is one of ...

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