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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 ... [...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. Shaft ... [...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 han ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire-setting
Fire-setting is a method of traditional mining used most commonly from prehistoric times up to the Middle Ages. Fires were set against a rock face to heat the stone, which was then doused with liquid, causing the stone to fracture by thermal shock. Some experiments have suggested that the water (or any other liquid) did not have a noticeable effect on the rock, but rather helped the miners' progress by quickly cooling down the area after the fire. This technique was best performed in opencast mines where the smoke and fumes could dissipate safely. The technique was very dangerous in underground workings without adequate ventilation. The method became largely redundant with the growth in use of explosives. Although fire-setting was frequently used before modern times, it has been used sporadically since then. In some regions of the world, notably Africa and Eurasia, fire-setting continued to be in use until the 19th and 20th centuries. It was used where rock was too ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tailings
In mining, tailings are the materials left over after the process of separating the valuable fraction from the uneconomic fraction ( gangue) of an ore. Tailings are different to overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed. The extraction of minerals from ore can be done two ways: placer mining, which uses water and gravity to concentrate the valuable minerals, or hard rock mining, which pulverizes the rock containing the ore and then relies on chemical reactions to concentrate the sought-after material. In the latter, the extraction of minerals from ore requires comminution, i.e., grinding the ore into fine particles to facilitate extraction of the target element(s). Because of this comminution, tailings consist of a slurry of fine particles, ranging from the size of a grain of sand to a few micrometres. Mine tailings are usually produced from the mill in slurry form, whic ... [...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) Stopes may also refer to: * Marie Stopes Marie Charlotte Carmichael Stopes (15 October 1880 – 2 October 1958) was a British author, palaeobotanist and campaigner for eugenics and women's rights. She made significant contributions to plant palaeontology and coal classification ... (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] |
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 Artifact (archaeology), art ... [...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 a dandy ... [...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 ... [...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 a ... [...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 co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virginia City, Nevada
Virginia City is a census-designated place (CDP) that is the county seat of Storey County, Nevada, and the largest community in the county. The city is a part of the Reno–Sparks Metropolitan Statistical Area. Virginia City developed as a boomtown with the 1859 discovery of the Comstock Lode, the first major silver deposit discovery in the United States, with numerous mines opening. The population peaked in the mid-1870s, with an estimated 25,000 residents. The mines' output declined after 1878, and the population declined as a result. As of the 2020 Census, the population of Virginia City was 787. History Peter O'Riley and Patrick McLaughlin are credited with the discovery of the Comstock Lode. Henry T. P. Comstock's name was associated with the discovery through his own machinations. According to folklore, James Fennimore, nicknamed Old Virginny Finney, christened the town when he tripped and broke a bottle of whiskey at a saloon entrance in the northern section of Gold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
