|
Shaft Sinking
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. 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 mine 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 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 a vertical tunnel boring machine) have shown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auguste Victoria Mine Shafts, Marl
Auguste may refer to: People Surname * Arsène Auguste (born 1951), 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 Clot (1858–1936), French art printer * Auguste Dick (1910–1993), Austrian historian of mathematics * Georges Auguste Escoffier (1846–1935), French chef, restaurateur and culinary writer * Auguste Metz (1812–1854), Luxembourgian entrepreneur * Auguste Léopold Protet (1808–1862), French Navy admiral * Auguste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raise (mining)
In underground mining, a raise refers to a vertical or inclined excavation that leads from one level, or drift, to another. A raise may also extend to surface. There are four excavation methods for raises: #Conventional or open raise #Long-hole or drop raise # Alimak # Raise boring Raises serve a number of purposes including: #Transportation of ore and waste rock #Ventilation #Creating a free face for mining #Movement of workers via manway A manhole (utility hole, maintenance hole, or sewer hole) is an opening to a confined space such as a shaft, utility vault, or large vessel. Manholes are often used as an access point for an underground public utility, allowing inspection, m ... ladders References {{mining-stub Underground mining ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winding Tower Void Schema
An electromagnetic coil is an electrical conductor such as a wire in the shape of a coil (spiral or helix). Electromagnetic coils are used in electrical engineering, in applications where electric currents interact with magnetic fields, in devices such as electric motors, generators, inductors, electromagnets, transformers, and sensor coils. Either an electric current is passed through the wire of the coil to generate a magnetic field, or conversely, an external ''time-varying'' magnetic field through the interior of the coil generates an EMF (voltage) in the conductor. A current through any conductor creates a circular magnetic field around the conductor due to Ampere's law. The advantage of using the coil shape is that it increases the strength of the magnetic field produced by a given current. The magnetic fields generated by the separate turns of wire all pass through the center of the coil and add ( superpose) to produce a strong field there. The more turns of wire, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sump
A sump is a low space that collects often undesirable liquids such as water or chemicals. A sump can also be an infiltration basin used to manage surface runoff water and recharge underground aquifers. Sump can also refer to an area in a cave where an underground flow of water exits the cave into the earth. Examples One common example of a sump is the lowest point in a basement, into which flows water that seeps in from outside. If this is a regular problem, a sump pump that moves the water outside of the house may be used. Another example is the oil pan of an engine. The oil is used to lubricate the engine's moving parts and it pools in a reservoir known as its sump, at the bottom of the engine. Use of a sump requires the engine to be mounted slightly higher to make space for it. Often though, oil in the sump can slosh during hard cornering, starving the oil pump. For these reasons, racing motorcycles and piston aircraft engines are "dry sumped" using scavenge pumps and a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plenum Space
A plenum space is a part of a building that can facilitate air circulation for heating and air conditioning systems, by providing pathways for either heated/conditioned or return airflows, usually at greater than atmospheric pressure. Space between the structural ceiling and the dropped ceiling or under a raised floor is typically considered plenum; however, some drop-ceiling designs create a tight seal that does not allow for airflow and therefore may not be considered a plenum air-handling space.Thomas, Timothy"What is plenum? - Definition from WhatIs.com ''TechTarget'', September 21, 2005. Retrieved July 25, 2017. Maintenance Diligence is required to make sure that a non-plenum airspace stays that way. A non-plenum airspace can become a plenum airspace by accident if the ductwork is disconnected and not properly repaired and resealed. Ductwork disconnection can occur due to building damage such as earthquakes, aging, or adverse environment causing the metal to corrode a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mine Ventilation
Underground mine ventilation provides a flow of air to the underground workings of a mine of 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. 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 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 auxiliary ventilation system takes air from the flow-through system and distributes it to the mine wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reinforced Concrete
Reinforced concrete (RC), also called reinforced cement concrete (RCC) and ferroconcrete, 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 bars ( 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 of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheave
A sheave () or pulley wheel is a grooved wheel often used for holding a belt, wire rope, or rope and incorporated into a pulley. The sheave spins on an axle or bearing inside the frame of the pulley. This allows the wire or rope to move freely, minimizing friction and wear on the cable. Sheaves can be used to redirect a cable or rope, lift loads, and transmit power. The words ''sheave'' and ''pulley'' are sometimes used interchangeably. Adjustable pulley A sheave can also refer to a pulley which has an adjustable operating diameter for use with a mechanical belt. This is accomplished by constructing the pulley out of several pieces. The two main "halves" of the pulley can be moved closer together or farther apart, thus altering the operational diameter. The usual construction is some sort of locking collar or set screws to secure the components, one half with a threaded central shaft and one half with a threaded center. By rotating the components, one can "screw" the parts ... [...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), however 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 top ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Headframe
A headframe (also known as a 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 or poppethead) is the structural frame above an underground mine shaft so as to enable the hoisting of machinery, personnel, or materials. Design Modern headframes are built out of steel, concrete or a combination of both. Timber headframes are no longer used in industrialized countries, but are still used in developing nations. Conventionally steel headframes are used when a drum hoist is employed, and concrete headframes are built for friction hoists; however a steel headframe can be used with a friction hoist for shafts with a 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 (mak ... [...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 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: , colloquially ''Václavák'' ) is one of the main city squares and the centre of the business and cultural communities in the New Town of Prague, Czech Republic. Many historical events occurred there, ... [...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 Field was the world's eighth-largest producer of gold. The company owns and operates mines in South Africa, Ghana, Australia and Peru. Growth efforts are focused mainly in 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. Gold Fields' chairperson is Cheryl Carolus, and the CEO is Chris Griffith. Board of directors * Chairperson – Cheryl C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
