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Shaft Mining
Shaft mining or shaft sinking is the action of excavating a mine shaft from the top down, where there is initially no access to the bottom. Shaft (civil engineering), Shallow shafts, typically sunk for civil engineering projects, differ greatly in execution method from deep shafts, typically sunk for mining projects. Shaft sinking is one of the most difficult of all mining development methods: restricted space, gravity, groundwater and specialized procedures make the task quite formidable. Shafts may be sunk by conventional drill and blast or mechanised means. Historically, mine shaft sinking has been among the most dangerous of all the mining occupations and the preserve of mining contractors called sinker (mining), sinkers. Today shaft sinking contractors are concentrated in Canada, Germany, China and South Africa. The modern shaft sinking industry is gradually shifting further towards greater mechanisation. Recent innovations in the form of full-face shaft boring (akin to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auguste Victoria Mine Shafts, Marl
Auguste may refer to: People Surname * Arsène Auguste (1951–1993), Haitian footballer * Donna Auguste (born 1958), African-American businesswoman * Georges Auguste (born 1933), Haitian painter * Henri Auguste (1759–1816), Parisian gold and silversmith * Joyce Auguste, Saint Lucian musician * Jules Robert Auguste (1789–1850), French painter * Tancrède Auguste (1856–1913), President of Haiti (1912–13) Given name * Auguste, Baron Lambermont (1819–1905), Belgian statesman * Auguste, Duke of Leuchtenberg (1810–1835), prince consort of Maria II of Portugal * Auguste, comte de La Ferronays (1777–1842), French Minister of Foreign Affairs * Auguste Baillayre (1879–1961), French-born Romanian painter * Auguste Capelier (1905–1977), French art director * Auguste Clot (1858–1936), French art printer * Auguste Comte (1798–1857), French philosopher * Auguste de Marmont (1774-1852), Marshal of the Empire * Auguste Dick (1910–1993), Austrian historian of mathemat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tempe, Arizona
Tempe ( ; ''Oidbaḍ'' in O'odham language, O'odham) is a city in Maricopa County, Arizona, United States, with the Census Bureau reporting a 2020 population of 180,587. The city is named after the Vale of Tempe in Greece. Tempe is located in the East Valley (Phoenix metropolitan area), East Valley section of Phoenix metropolitan area, metropolitan Phoenix; it is bordered by Phoenix, Arizona, Phoenix and Guadalupe, Arizona, Guadalupe on the west, Scottsdale, Arizona, Scottsdale and the Salt River Pima–Maricopa Indian Community on the north, Chandler, Arizona, Chandler on the south, and Mesa, Arizona, Mesa on the east. Tempe is the location of the main campus of Arizona State University. History The Hohokam lived in this area and built canals to support their agriculture. They abandoned their settlements during the 15th century, with a few individuals and families remaining nearby. Fort McDowell, Arizona, Fort McDowell was established approximately northeast of present dow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mine Ventilation
Underground mine ventilation provides a flow of air to the underground workers of a mine with sufficient volume to dilute and remove dust and noxious gases (typically NOx, SO2, methane, CO2 and CO) and to regulate temperature. The source of these gases are equipment that runs on diesel engines, blasting with explosives, and the orebody itself. Regulations often require airflow to be distributed within mines to improve air quality. The largest component of the operating cost for mine ventilation is electricity to power the ventilation fans, which may account for one third of a typical underground mine's entire electrical power cost. Types of ventilation Flow-through ventilation is the main ventilation circuit for the mine. Air enters the mine from the surface via a shaft, ventilation raise or adit. The air is distributed through the mine via internal ventilation raises and ramps, and flows are controlled by regulators and permanently mounted ventilation fans. An auxiliar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reinforced Concrete
Reinforced concrete, also called ferroconcrete or ferro-concrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (known as rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials. In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion. Description Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheave
Sheave without a rope A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and a shaft. A pulley may have a groove or grooves between flanges around its circumference to locate the cable or belt. The drive element of a pulley system can be a rope, cable, belt, or chain. History The earliest evidence of pulleys dates back to Ancient Egypt in the Twelfth Dynasty (1991–1802 BC) and Mesopotamia in the early 2nd millennium BC. In Roman Egypt, Hero of Alexandria (c. 10–70 AD) identified the pulley as one of six simple machines used to lift weights. Pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also assembled as part of belt and chain drives in order to transmit power from one rotating shaft to another. Plutarch's ''Parallel Lives'' recounts a scene where Archimedes proved the effectiveness of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoist (mining)
In underground mining a hoist or winder is used to raise and lower conveyances within the mine shaft. Modern hoists are normally powered using electric motors, historically with direct current drives utilizing Ward Leonard control machines and later solid-state converters ( thyristors), although modern large hoists use alternating current drives that are variable frequency controlled. There are three principal types of hoists used in mining applications: Drum hoist Drum hoists are the most common type of hoist used in North America, South Africa and South America. When using a drum hoist the hoisting cable is wound around the drum when the conveyance is lifted. Single-drum hoists can be used in smaller applications, however double-drum hoists easily allow the hoisting of two conveyances in balance (i.e. one skip being lifted while a second skip is being lowered). Drum hoists are mounted on concrete slabs within a hoistroom, the hoisting ropes run from the drum, up to the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Headframe
A headframe (gallows frame, winding tower, hoist frame,Ernst, Dr.-Ing. Richard (1989). ''Wörterbuch der Industriellen Technik'' (5th ed.). Wiesbaden: Oscar Brandstetter, 1989. pit frame, shafthead frame, headgear, headstock, poppethead) is the structure above an underground mine shaft, built for hoisting machines, people, and materials. Design Modern headframes are made of steel, concrete, or a combination of both. Timber headframes are no longer used in industrialized countries, but are still used in developing countries. Conventionally, steel headframes are used for drum hoists, and concrete headframes are built for friction hoists; but a steel headframe can be used with a friction hoist for a shaft of smaller capacity and depth. Steel headframes A steel headframe is less expensive than a concrete headframe; the tallest steel headframe measures 87 m. Steel headframes are more adaptable to modifications (making any construction errors easier to remedy), and are conside ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muzeum Śląskie - Szyb Warszawa II 03
Muzeum () is a Prague Metro station providing the interchange between Lines A and C, and serving the National Museum. It is located at the top end of Wenceslas Square. The Line C station was opened on 9 May 1974, with the first section of the Prague Metro, between Sokolovská and Kačerov. It is a single hall station, long and only deep. Two escalators and a staircase go to the vestibule. The Line A station was opened on 12 August 1978 as part of the inaugural section of Line A, between Leninova and Náměstí Míru. It is a three-bore station with a shortened, middle tunnel. It is long and deep. The station at Line A was damaged during the 2002 floods and station at Line C was terminus. Nearby Attractions *National Museum *Wenceslas Square Wenceslas Square (Czech language, Czech: , colloquially ''Václavák'' ; German language, German: ''Wenzelsplatz'') is one of the main city squares and the centre of the business and cultural communities in the New Town, Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold Fields Limited
Gold Fields Limited (formerly The Gold Fields of South Africa) is one of the world's largest gold mining firms. Headquartered in Johannesburg, South Africa, the company is listed on both the Johannesburg Stock Exchange (JSE) and the New York Stock Exchange (NYSE). The firm was formed in 1998 with the amalgamation of the gold assets of Gold Fields of South Africa Limited and Gencor Limited. The company traces its roots back to 1887, when Cecil Rhodes founded Gold Fields of South Africa Limited. As of 2019, Gold Fields was the world's eighth-largest producer of gold. The company owns and operates mines in Australia, Chile, Ghana, Peru and South Africa, with one 50:50 JV project in Canada. Growth efforts are focused mainly on the regions where it currently operates and are mainly driven through brownfields exploration on its existing land positions and through mergers and acquisitions in the same regions. Board of directors * Chairperson – Yunus Suleman Executive directors * C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Deep Mine
The South Deep mine is one of the largest gold mines in the South Africa and in the world. The mine is located in the north-east of the country in Gauteng. The mine has estimated reserves of 81.4 million oz of gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal .... Environment, Social & Corporate Governance South Deep Mine has experienced a challenging period over recent years with various steps taken to revise its cost base in order to reduce losses (of approximately US$292m over a five-year period). In August 2019 a material restructuring of the mine was announced with the primary aim being to reduce costs by way of cutting 1,100 employees and 460 contractors. In response to the retrenchment announcements, the National Union of Mineworkers branch at South Deep started strike ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hartley Colliery Disaster
The Hartley Colliery disaster (also known as the Hartley Pit disaster or Hester Pit disaster) was a coal mining accident in Northumberland, England, that occurred on 16 January 1862 and resulted in the deaths of 204 men and children. The beam of the pit's pumping engine broke and fell down the shaft, trapping the men below. The disaster prompted a change in British law that required all collieries to have at least two independent means of escape. Collieries Hartley old pit Hartley old pit was established in the coastal village of Hartley, Northumberland, Hartley, Northumberland, (today part of Seaton Sluice) during the 13th century; the earliest existing records date from 1291. The colliery suffered increasingly from flooding as the seams were worked out under the sea and in 1760 the first atmospheric engine was installed, followed later by more powerful engines. Despite these efforts, the flooding became so severe that the old pit was abandoned in 1844. Hester pit The coal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raise Borer
A raise borer is a machine used in underground mining, to excavate a circular hole between two levels of a mine without the use of explosives. The raise borer is set up on the upper level of the two levels to be connected, on an evenly laid platform (typically a concrete pad). A small-diameter hole (pilot hole) is drilled to the level required; the diameter of this hole is typically 230mm – 445mm (9" - 17.5"), large enough to accommodate the drill string. Once the drill has broken into the opening on the target level, the bit is removed and a reamer A reamer is a type of rotary cutting tool used in metalworking. Precision reamers are designed to enlarge the size of a previously formed hole by a small amount but with a high degree of accuracy to leave smooth sides. There are also non-precisio ... head, of the required diameter of the excavation, is attached to the drill string and raised back towards the machine. The drill cuttings from the reamer head fall to the floor of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
