extraction pillar

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• Room and pillar — (also called bord and pillar) is a mining system in which the mined material is extracted across a horizontal plane while leaving pillars of untouched material to support the roof overburden leaving open areas or rooms underground. It is usually… …   Wikipedia

• coal mining — Coal was very important in the economic development of Britain. It was used as fuel in the factories built during the Industrial Revolution and continued to be important until the 1980s. The main coalfields are in north east England, the north… …   Universalium

• Coal mining — Men leaving a UK colliery at the close of a shift Surface coal mining in Wyo …   Wikipedia

• mining — /muy ning/, n. 1. the act, process, or industry of extracting ores, coal, etc., from mines. 2. the laying of explosive mines. [1250 1300; ME: undermining (walls in an attack); see MINE2, ING1] * * * I Excavation of materials from the Earth s… …   Universalium

• Mining — This article is about the extraction of geological materials from the Earth. For the municipality in Austria, see Mining, Austria. For the siege tactic, see Mining (military). For name of the Chinese emperor, see Daoguang Emperor. Simplified… …   Wikipedia

• History of coal mining — Due to its abundance, coal has been mined in various parts of the world throughout history and continues to be an important economic activity today. Compared to wood fuels, coal yields a higher amount of energy per mass and could be obtained in… …   Wikipedia

• Reach (Planet) — Infobox Planet name = Reach caption = The Covenant armade turn Reach to glass with Plasma. apsis = astron discovery ref = discoverer = discovery site = discovered = discovery method = alt names = periastron = apoastron = semimajor = avg speed =… …   Wikipedia

• History of ferrous metallurgy — Iron (material) redirects here. For the chemical element Fe, see Iron. Bloomery smelting during the Middle Ages. The history of ferrous metallurgy began far back in prehistory. The earliest surviving iron artifacts, from the 5th millennium BC in… …   Wikipedia

• India — /in dee euh/, n. 1. Hindi, Bharat. a republic in S Asia: a union comprising 25 states and 7 union territories; formerly a British colony; gained independence Aug. 15, 1947; became a republic within the Commonwealth of Nations Jan. 26, 1950.… …   Universalium

• Économie du Tibet — Marché de produits agricoles à Lhassa. L’économie de l’ancien Tibet était dominée par une agriculture de subsistance[citation nécessaire]. Selon la Mission permanente de la République popula …   Wikipédia en Français

• Underground mining (hard rock) — A three dimensional model of an underground mine with shaft access Underground hard rock mining refers to various underground mining techniques used to excavate hard minerals, mainly those containing metals[1] such as ore containing gold …   Wikipedia