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Stoping
Stoping is the process of extracting the desired ore or other mineral from an underground mine, leaving behind an open space known as a stope. Stoping is used when the country rock is sufficiently strong not to collapse into the stope, although in most cases artificial support is also provided. The earliest forms of stoping were conducted with hand tools or by fire-setting; later gunpowder was introduced. From the 19th century onward, various other explosives, power-tools, and machines came into use. As mining progresses the stope is often backfilled with tailings, or when needed for strength, a mixture of tailings and cement. In old mines, stopes frequently collapse at a later time, leaving craters at the surface. They are an unexpected danger when records of underground mining have been lost with the passage of time. Stoping is considered "productive work", and is contrasted with "deadwork", the work required merely to access the mineral deposit, such as sinking shafts and win ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underground Mining (hard Rock)
Underground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals, usually those containing metals, such as ore containing gold, silver, iron, copper, zinc, nickel, tin, and lead. It also involves the same techniques used to excavate ores of gems, such as diamonds and rubies. Soft-rock mining refers to the excavation of softer minerals, such as salt, coal, and oil sands. Mine access Underground access Accessing underground ore can be achieved via a decline (ramp), inclined vertical shaft or adit. *Declines can be a spiral tunnel which circles either the flank of the deposit or circles around the deposit. The decline begins with a box cut, which is the portal to the surface. Depending on the amount of overburden and quality of bedrock, a galvanized steel culvert may be required for safety purposes. They may also be started into the wall of an open cut mine. *Shafts are vertical excavations sunk adjacent to an ore body. Shafts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gunnis
A gunnies, gunnis, or gunniss is the space left in a mine after the extraction by stoping of a vertical or near vertical ore-bearing lode. The term is also used when this space breaks the surface of the ground, but it can then be known as a coffin or goffen. It can also be used to describe the deep trenches that were dug by early miners in following the ore-bearing lode downwards from the surface – in this case they are often called open-works; their existence can provide the earliest evidence of mining in an area. William Pryce, writing in 1778, also used the term as a measure of width, a single gunnies being equal to three feet. History That the gunnis was an element of mining in ancient times has been shown by archaeological investigation, such as that performed in the 1990s at Bir Umm Fawakhir, an ancient gold mine in Egypt. The exploration revealed that some 20th-century drives had broken into ancient gunnises which were filled in by rocks that had fractured off the hangi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Room And Pillar
Room and pillar or pillar and stall is a variant of breast stoping. It is a mining system in which the mined material is extracted across a horizontal plane, creating horizontal arrays of rooms and pillars. To do this, "rooms" of ore are dug out while "pillars" of untouched material are left to support the roof overburden. Calculating the size, shape, and position of pillars is a complicated procedure, and is an area of active research. The technique is usually used for relatively flat-lying deposits, such as those that follow a particular stratum. Room and pillar mining can be advantageous because it reduces the risk of surface subsidence compared to other underground mining techniques. 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. Room and pillar mining was one of the earliest methods used, although with significantly more man-power. The roo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stope In Treadwell Gold Mine
Stope may refer to: * Stope, Velike Lašče, a settlement in central Slovenia * Stope, an underground space produced by stoping (mining) Stoping is the process of extracting the desired ore or other mineral from an underground mine, leaving behind an open space known as a stope. Stoping is used when the country rock is sufficiently strong not to collapse into the stope, although ... Stopes may also refer to: * Marie Stopes (1880-1958), Scottish palaeobotanist and pioneer in the field of family planning See also * Stoping (geology) {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Room And Pillar
Room and pillar or pillar and stall is a variant of breast stoping. It is a mining system in which the mined material is extracted across a horizontal plane, creating horizontal arrays of rooms and pillars. To do this, "rooms" of ore are dug out while "pillars" of untouched material are left to support the roof overburden. Calculating the size, shape, and position of pillars is a complicated procedure, and is an area of active research. The technique is usually used for relatively flat-lying deposits, such as those that follow a particular stratum. Room and pillar mining can be advantageous because it reduces the risk of surface subsidence compared to other underground mining techniques. 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. Room and pillar mining was one of the earliest methods used, although with significantly more man-power. The roo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolcoath Mine
Dolcoath mine ( kw, Bal Dorkoth) was a copper and tin mine in Camborne, Cornwall, England, United Kingdom. Its name derives from the Cornish for 'Old Ground', and it was also affectionately known as ''The Queen of Cornish Mines''. The site is north-west of Carn Brea. Dolcoath Road runs between the A3047 road and Chapel Hill. The site is south of this road. History The mineral rights were owned by the Basset family of Tehidy who are recorded on a deed in 1588 as leasing the ground to a family called Crane. By 1720 the mine was being worked for copper, and it was almost deep in 1746, when William Borlase called it a "very considerable mine". In 1778 it was nearly deep, according to William Price. The mine closed in 1787 because the large amount of copper ore that was being cheaply mined from Parys Mountain on Anglesey had depressed the price. However the price of copper slowly recovered and the mine reopened in 1799. Of around 470 copper-producing mines in Cornwall and Devo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic viability of investing in the equipment, labor, and energy required to extract, refine and transport the materials found at the mine to manufacturers who can use the material. Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backfill (mining)
This page is a glossary of archaeology, the study of the human past from material remains. A B C D E F G H I K L M N O P Q R S T U V W X Y Z See also * Outline of archaeology * Table of years in archaeology * Glossary of history References Bibliography * * * * * * * External links About.com Archaeology Glossary {{Glossaries of science and engineering Archaeology Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swell Factor
Swell may refer to: In nature *Swell, another name for a geographic hillock *Swell (ocean), a formation of long wavelength ocean surface waves * Swell (geology), a large domed area Places * Swell, Somerset, a hamlet in the Somerset parish of Fivehead * Swell, Gloucestershire, England Music *Expression pedal, a control found on many organs and synthesizers, also called a swell box or swell pedal * Swell (band), an indie rock band from San Francisco *''Swell'', album by Psyched Up Janis *''Swell'', album by Tiny Moving Parts *Swell Maps, an experimental English rock group of the 1970s People * George Gilbert Swell (1923–1999), Indian academic and politician *Steve Swell (born 1954), American musician, composer and educator *Steven Wells (1960–2009), punk poet and journalist known as Swells Other uses * Swell (bookbinding), a term in bookbinding *Swell (gum), a brand of chewing gum produced by Philadelphia Gum * Swell (exhibit), an art exhibition *Swell, another word for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Situ
''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in many different contexts. For example, in fields such as physics, geology, chemistry, or biology, ''in situ'' may describe the way a measurement is taken, that is, in the same place the phenomenon is occurring without isolating it from other systems or altering the original conditions of the test. The opposite of ''in situ'' is ''ex situ''. Aerospace In the aerospace industry, equipment on-board aircraft must be tested ''in situ'', or in place, to confirm everything functions properly as a system. Individually, each piece may work but interference from nearby equipment may create unanticipated problems. Special test equipment is available for this ''in situ'' testing. It can also refer to repairs made to the aircraft structure or flight con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strike And Dip
Strike and dip is a measurement convention used to describe the orientation, or attitude, of a planar geologic feature. A feature's strike is the azimuth of an imagined horizontal line across the plane, and its dip is the angle of inclination measured downward from horizontal. They are used together to measure and document a structure's characteristics for study or for use on a geologic map. A feature's orientation can also be represented by dip and dip direction, using the azimuth of the dip rather than the strike value. Linear features are similarly measured with trend and plunge, where "trend" is analogous to dip direction and "plunge" is the dip angle. Strike and dip are measured using a compass and a clinometer. A compass is used to measure the feature's strike by holding the compass horizontally against the feature. A clinometer measures the features dip by recording the inclination perpendicular to the strike. These can be done separately, or together using a tool such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philip Deidesheimer
Philip Deidesheimer was a mining engineer in the Western United States. Deidesheimer was born in 1832, in Darmstadt, Hesse before German unification. He attended the prestigious Freiberg University of Mining (''Technische Universität Bergakademie Freiberg'') and emigrated to California in 1852. He died on 21 July 1916 in San Francisco, California. Career In 1852, at nineteen, the young mining engineer traveled to the California gold fields to work for several years, including in Georgetown. In April 1860 he was hired by W. F. Babcock, a trustee of the Ophir Mine, part of the Comstock Lode silver mining boom in Nevada, and solved one of the Comstock mines' most critical engineering needs. Comstock Lode Square set timbering Deidesheimer invented a system, now known as square set timbering, using heavy timber "cubes" as supports for underground mining tunnels and shafts, that enabled skilled miners to open three-dimensional cavities of any size. In large openings, the cubes cou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
