horizontal coal mining

To overcome the above defects, a model for analysing stresses on coal masses in horizontal section of SICSs was established based on the coal burst that occurred in LW5521-20, Yaojie No. 3 Coal ...

Coal mine degasification started in 1970s and it is an established practice by now in all gassy mines. A reduction of 50% in the in situ gas content was achieved in the Pittsburgh coal seam of United States. For highly gassy coal seams, the coal was first degassed by vertical wells and later by in-mine horizontal drillings.

The proposed horizontal well drill-string model is more suitable for rotary drilling in a coal mine, and the nonlinear influencing factors are considered more comprehensive. Discover the world's ...

The entry from the surface to an underground mine may be through a horizontal or vertical tunnel, known as an adit, shaft or decline. Underground mining is practical when: ... We use these three different types of underground mining techniques for coal, diamonds and copper. 3. Underwater mining

For example, for a coal mine at 300 ft (90 m) of cover and a modulus of 3 x 106 psi (4.3 GPa), the total predicted horizontal stress is 1693 psi (11.9 MPa). The excess stress …

PDF | On Apr 1, 2019, Huang Xuchao and others published Study on Gas Emission Prediction of Steeply Inclined Coal Seam Applied Horizontal Slice Mining | Find, read and cite all the research you ...

Top coal caving is the main mining method used at this mine. The coal seam strike was located north by east 30°–45°, and the dip angle of the coal seam was 4°. This was regarded as an approximately horizontal tectonic coal seam. Cover depth was roughly 500 m and the average thickness was 11.17 m. The thickness of the coal cutter mining was ...

Abstract. This study identifies the relative magnitude of horizontal stress change below a series of parallel longwall panels as a consequence of multi-seam mining. The investigation method yields an upper bound to the horizontal stress change by assuming that the fractured and caved overburden above the supercritical longwall …

To ensure safety mining during shallow horizontal coal mining based on the monitoring data of the roof weighting of a typical mining engineering in China, the load distribution characteristics of the roof in the mining field were analysed, and the mechanical model of the pressure-arch in the surrounding rock was established. Then the evolution …

Theoretical Analysis of Mining Induced Overburden Subsidence Boundary with the Horizontal Coal Seam Mining The …

Main factors influencing the wide range of apertures (from 50 to 400 mm) of mining-induced horizontal fractures (Torezko-Snezhnyanskaya coal area, Ukraine) at traditional (without grout injection ...

Main factors influencing the wide range of apertures (from 50 to 400 mm) of mining-induced horizontal fractures (Torezko-Snezhnyanskaya coal area, Ukraine) at …

Keywords Coal mining Horizontal fracture Compressive strength Aperture of fracture 1 Introduction There is no doubt that theoretical, experimental and numerical studies related to energy and resources (Wasanthaetal.2015;Singh2020)areveryimportant to sustain development of societies and to further

auger mining, method for recovering coal by boring into a coal seam at the base of strata exposed by excavation. Normally one of the lowest-cost techniques of mining, it is limited to horizontal or slightly pitched seams that have been exposed by geologic erosion.Augering is usually associated with contour strip-mining, recovering coal for a limited depth …

Field tests were conducted to examine the UIS horizontal gas drainage borehole sealing performance of the new ECS material and the DPG sealing method. The tests are in the Changcun coal mine of Shanxi province, China. The length and width of this coal field are 17 km and 7.4 km, respectively. Gas content in this coalmine is as high as …

Mining - Drifts, Tunnels, Shafts: All horizontal or subhorizontal development openings made in a mine have the generic name of drift. These are simply tunnels made in the rock, with a size and shape depending on their use—for example, haulage, ventilation, or exploration. A drift running parallel to the ore body and lying in the footwall is called a …

Mining Publication: Horizontal Stress and Longwall Headgate Ground Control. Horizontal stresses are caused by global plate-tectonic forces. During 1995 alone they were largely responsible for the closing of two longwall mines in the United States. This paper presents six case histories from Pennsylvania, West ia, Kentucky and …

Rock bursts have recently become a serious problem in the horizontal section mining of steeply inclined extra-thick coal seams (SIETCSs). However, few studies have been carried out to investigate their mechanisms and prevention. In this study, numerical simulation and field measurements were carried out to investigate the …

Formation of a shift trough during underground mining of coal reserves: (a)—graphs of the rock mass vertical deformations; (b)—normal stress curves; (c)—boundary of the rocks mass ...

Understanding the advantages and disadvantages of in-mine horizontal boreholes, and the benefits of degasification years in advance of mining if drilled from the surface, the U.S. Bureau of Mines drilled an experimental CBM horizontal well from the surface in 1978 in southwestern PA to degasify a coal area to be mined in the future …

For the purpose of investigating the effect of the height of the coal seam on the general variation trend of the mining induced horizontal stress in the panel floor, four different heights of the coal seam, which are 3, 4, 5 and 6 m, respectively, are used while the unit weight of the coal seam is kept as a constant of 2400 kg m −3 in the ...

Coal mining - Underground mining: In underground coal mining, the working environment is completely enclosed by the geologic medium, which consists of the coal seam and the overlying and underlying strata. ...

Applications of in-mine horizontal drilling are discussed chronologically for (a) coal mine degasification, (b) gas production from mine shafts, (c) oil production from shallow/depleted oil fields, (d) improved auger mining, and (e) mine water disposal.

It is an important problem for the alternated strong and weak roof weighting to threat the safety of working face during shallow coal mining and the total thickness breaking of the thin bedrock to ...

Drift mining refers to the working of coal seams by driving sub-horizontal or horizontal passageways (adits), through the outcrop. When compared to tunneling, drift mining offers a more economical, less invasive way of extracting precious natural resources like coal, gold, quartz, or zinc.

Underground mining, sometimes called deep mining, is used when the coal is more than 200 feet below the surface. Some underground mines are thousands of feet deep, with tunnels that may extend out from the vertical mine shafts for miles. Miners ride elevators down deep mine shafts and travel on small trains in long tunnels to get to …

The stress field caused by continental-scale tectonic motion of the earth's crust is called the "regional stress field." The regional stress field creates directionally oriented horizontal stresses in the crust, called "in-situ stress." Fractures resulting from horizontal stress commonly form in mines as rib cutters or kink zones oriented in ...

Horizontal sublevel fully mechanized caving mining is a common mining method in steeply inclined thick coal seam ( Jiang et al., 2020 ), which has the …

Butt entry - A coal mining term that varies in meaning depending on location, signifying either a panel entry, ... Universal coal cutter — A type of coal cutting machine designed to make horizontal cuts in a coal face at any point between the bottom and top or to make shearing cuts at any angle to the horizontal or vertical.

With the increase of mining depth, rock burst disasters frequently occur in steeply inclined coal seams. Firstly, this paper analyzes the rock burst of 5521-20 working face in Yaojie No. 3 coal mine and summarizes the characteristics of rock burst in horizontal section mining of steeply inclined extra-thick coal seam (SIETCS). Then, the …