Dust generation and its dispersion in a longwall mine pose significant health and safety issues. The concern is prominent at both the working face, where coal excavation exposes workers to high dust concentrations, and also in the return, where float dust accumulates. To address this issue, researchers at the University of Kentucky designed and fabricated a floodedbed dust scrubber integrated ...
The general process of surface subsidence caused by longwall mining is as follows. The longwall face is mined to form a hollow area, ... Palchik, V. Analysis of main factors influencing the apertures of mininginduced horizontal fractures at longwall coal mining. Géoméch. Geophys. GeoEnergy GeoResour. 2020, 6, 37.
ChengZhuang Coal Mine is located in Qin Shui Mining Area, Jin Cheng City, Shanxi Province, China. Its longitude is 112° 43ʹ 49ʺ E, and its latitude is 35° 34ʹ 11ʺ N. Figure 2 and show the location of this coal mine in elevation of No. 4308 longwall panel is m, and its designed advance and net faces are 2431 m and 196 m, respectively.
The transition of mining from surface mining to underground mining is being considered to extend/enhance coal production. Longwall mining is a typical underground coal mining method with a high production rate. However, the guidelines for a longwall mining operation in other countries with major coal mining operations are not applicable to ...
Large scale mechanised mining methods we use include: longwall mining, where a long wall of coal is mined in a single slice, usually by a large machine. sublevelcaving, where levels of the ore are blasted by explosives; and ; block caving, where large areas of the ore body are blasted and then extracted with the assistance of gravity.
As is known, the movement of rock strata and ground caused by longwall coal mining is a complicated spatialtemporal process. There are many factors controlling the evolution of movement of caved and fractured zones, such as mining height, mining and roof control methods, rock property and stratigraphic sequence, dip angle, mining sufficiency ...
In the longwall mining method, mine development is carried out in such a manner that large blocks of coal, usually 100 to 300 metres wide and 1,000 to 3,000 metres long, are available for complete extraction (see photograph).A block of coal is extracted in slices, the dimensions of which are fixed by the height of coal extracted, the width of the longwall face, and the thickness of the slice ...
When the longwall (LW) face is approaching its finishoff line, the coal mining process generally slows down and then stops to allow the LW equipment to be relocated to a newly prepared installation face following standard procedures, which usually takes approximately 1 ~ 2 months (Kang et al. 2016).During this period, the air is highly likely to penetrate into the active goaf via various ...
Wang et al. (2022) proposed a Gompertz time function model suitable for the longwall coal mining process based on the "three original consistency" modeling idea. Through comparison with the ...
Context 1 ... mining has become a standard technology for excavating coal from underground mines [4]. This technology, summarized in Figure 1, employs a longwall shearer which is a machine...
Dowty Mining Equipment manufactured and supplied thousands of power roof supports and other mining equipment to the Longwall Mining process worldwide. Longwall mining is a form of underground coal mining where a long wall of coal is mined in a single slice. The longwall panel is typically 3 4 km long and 250 400 m wide.
Principle of advancing longwall. Advancing longwalls were once common in Europe in relatively thin seams where packs were constructed using stone, which had to be cut in order to produce sufficient height for the gate roads, and sometimes using coal fines which were not very marketable at one time. Usually a pillar of coal referred to as a ...
Longwall mining technology . Longwall coal mining is an extraction process in which large panels of a coal seam up to 7 m thick are completely mined in a series of slices. Fundamental equipment in modern longwall mining are the armoured face conveyor (AFC), powered supports and the shearer (coal cutting machine) (Figure 1).
Hence this method is termed the longwall method. In simple words, longwall mining is a method of underground mining, in which coal is extracted from 60m to 200m long faces, moving continuously in one direction over large distances, leaving behind the goaf. The goaf is packed or allowed to cave. Longwall Mining is currently the main method of ...
AFC: improvement of manufacturing process and wear resistance, increasing chain strength and haulage capacity, longer life and reliability. ... The role of ground control in US longwall mining. Since US coal industry was a newcomer in longwall mining in the 1970s and early 1980s, there had been quite a few failures in the startup of longwall ...
The interruption of a coal extraction process in the longwall results in the relative stabilization of pressure redistribution. ... Zhingel, A method to forecast coal of the stopefissure network contact while longwall mining of coal seams. Coal 1970, 1, 5859. [Google Scholar]
Many features in longwall mining, including the caving and compaction of gob strata and the associated stress evolution, are reproduced in the model. ... Coal (mining) ...
Abstract. Since the early 1980s, the longwall method has developed into the safest, highest producing and most productive form of underground coal mining, rivalling the performance of many surface ...
Therefore, for longwall coal mining in similar areas like this, an appropriate advancing speed of coalface is necessary so that the watertable drawdown of shallow aquifer can be controlled within an allowable scope. ... Although coal mining process continues after that, aquifer watertable gradually recovers on account of recharge from surface ...
The DsLMF+ dataset of the coal mine image in the fully mechanized longwall mining face has been publicly available at the figshare data repository annotations include YOLO format and COCO ...
Longwall mining is a highly productive underground coal mining technique. Longwall mining machines consist of multiple coal shearers mounted on a series of selfadvancing hydraulic ceiling supports. The entire process is mechanized. Longwall mining machines are about 800 feet (240 meters) in width and 5 to 10 feet ( to 3 meters) tall.
Conventional longwall layout (CLL) for mining coal, trona, etc. is still fraught with problems including low resource recovery, wavy ground surface subsidence, bumps or rockbursts, gateroad ...
The fully mechanized mining with large mining height is the main method for high yield and efficient coal mining in China. The key stratum structure (KSS) is the basis of revealing the mechanism of roof weighting and determination of support working resistance of the longwall face with large mining height (LFLMH) in the shallow coal seam. The height of the caving zone at LFLMH is large, the ...
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