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Planning for the development of room and pillar mines operates in much the same way as other mining methods, [10] and begins with establishing ownership of the mine. . Following this, the geology of the mine must be analysed, as this will determine factors like the lifespan of the mine, the production requirements, and the cost to develop and
Once room and pillar mines have been developed to a stopping point limited by geology, ventilation, or economics, a supplementary version of room and pillar mining, termed second mining or retreat mining, is commonly started. Miners remove the coal in the pillars, thereby recovering as much coal from the coal seam as possible.
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.
The configuration of a car body is typically determined by the layout of the engine, passenger and luggage compartments, which can be shared or separately articulated. A key design feature is the car's roof-supporting pillars, designated from front to rear of the car as A-pillar, B-pillar, C-pillar and D-pillar.
The A-pillar is the forward-most pillar on a vehicle, supporting its roof at each corner of the windshield. [3] The B-pillar is located between a vehicle's front and rear side glass, where it serves as a structural support of its roof. [4] The C-pillar is the rearmost on two- and four-door sedans and hatchbacks. [5]
The following other wikis use this file: Usage on ar.wikipedia.org ستيشن واغن; Usage on bg.wikipedia.org Комби; Usage on ca.wikipedia.org
The U.S. Consumer Financial Protection Bureau fired some probationary staff on Tuesday, according to a recipient of a termination letter and people familiar with the matter, the latest move in an ...
The BMW i3 electric car is one of the rare modern passenger cars with a separate body and frame design (2013). Body-on-frame is a traditional motor vehicle construction method whereby a separate body or coach is mounted on a strong and relatively rigid vehicle frame or chassis that carries the powertrain (the engine and drivetrain ) and to ...