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There are two principal phases of underground mining: development mining and production mining. Development mining is composed of excavation almost entirely in (non-valuable) waste rock in order to gain access to the orebody. There are six steps in development mining: remove previously blasted material (muck out round), scaling (removing any unstable slabs of rock hanging from the roof and ...
Longwall mining is a form of underground coal mining where a long wall of coal is mined in a single slice (typically 0.6–6.0 m (2 ft 0 in – 19 ft 8 in) thick). The section of rock that is being mined, known as the longwall panel, is typically 3–4 km (1.9–2.5 mi) long, but can be up to 7.5 km (4.7 mi) long and 250–400 m (820–1,310 ft) wide.
Underground mining (hard rock) Underground mining (soft rock) There are three directions by which an underground mine may be conducted: Drift mining, mining horizontally; Shaft mining, mining vertically; Slope mining, mining at an inclined angle Stoping is the process of extracting out the ore from underground, leaving a hole called a stope ...
Drift mining is either the mining of an ore deposit by underground methods, or the working of coal seams accessed by adits driven into the surface outcrop of the coal bed. [1] A drift mine is an underground mine in which the entry or access is above water level and generally on the slope of a hill, driven horizontally into the ore seam. [2]
Diagram of a coal tipple with screens for up to 4 grades of coal Diagram of a rotary dump. A tipple is a structure used at a mine to load the extracted product (e.g., coal, ores) for transport, typically into railroad hopper cars.
Although most strongly associated with mining, the term adit is sometimes also used in the context of underground excavation for non-mining purposes; for example, to refer to smaller underground passageways excavated for underground metro systems, to provide pedestrian access to stations (pedestrian adits), and for access required during ...
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Room and pillar mining can be advantageous because it reduces the risk of surface subsidence compared to other underground mining techniques. [2] It is also advantageous because it can be mechanized, and is relatively simple. However, because significant portions of ore may have to be left behind, recovery and profits can be low. [1]