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Open Pits
Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow. This form of mining differs from extractive methods that require tunnelling into the earth, such as long wall mining. Open-pit mines are used when deposits of commercially useful ore or rocks are found near the surface. It is applied to ore or rocks found at the surface because the overburden is relatively thin or the material of interest is structurally unsuitable for tunnelling (as would be the case for cinder, sand, and gravel). In contrast, minerals that have been found underground but are difficult to retrieve due to hard rock, can be reached using a form of underground mining. To create an open-pit mine, the miners must determine the information of the ore that is underground. This is done through drilling of probe holes in the ground, then plotting ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central German Lake District
The Central German Lake District (''German:'' Mitteldeutsches Seenland) is a group of artificial lakes that are the result of extensive open pit lignite mining. The area around Leipzig is sometimes separately marketed as the "Leipzig Lake District" (''German:'' Leipziger Seenland) or the Neuseenland. The Lausitzer und Mitteldeutsche Bergbauverwaltungsgesellschaft is in charge of the technological side of the area. List of lakes See also * Leipzig River Network * Lusatian Lake District The Lusatian Lake District (german: Lausitzer Seenland, dsb, Łužyska jazorina, hsb, Łužiska jězorina) is a chain of artificial lakes under construction in Germany across the north-eastern part of Saxony and the southern part of Brandenburg ... - of similar origins References {{reflist Artificial lakes of Germany Regions of Saxony Mining in Germany Mining in Saxony ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haulage
Haulage is the business of transporting goods by road or rail between suppliers and large consumer outlets, factories, warehouses, or depots. This includes everything humans might wish to move in bulk - from vegetables and other foodstuffs, to clothes, ore, coal, and other supply (economics), supplies. Haulage also involves the transportation of chemicals in large sealed containers, and the removal of waste. As the word implies, goods are loaded into large trailers or carriages and hauled between different locations. Traditionally, this was by large animals such as horses or oxen - where the practice may also be called cartage or drayage. However, in the modern age, this act is mostly performed by trains or trucks - with large shipping vessels acting as intermediaries for crossing oceans. Truck driver, Truck drivers on haulage shifts are typically male, and often work long and difficult hours with few breaks - regularly sleeping in their vehicles overnight and eating/showering at rest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drilling
Drilling is a cutting process where a drill bit is spun to cut a hole of circular cross-section in solid materials. The drill bit is usually a rotary cutting tool, often multi-point. The bit is pressed against the work-piece and rotated at rates from hundreds to thousands of revolutions per minute. This forces the cutting edge against the work-piece, cutting off chips (swarf) from the hole as it is drilled. In rock drilling, the hole is usually not made through a circular cutting motion, though the bit is usually rotated. Instead, the hole is usually made by hammering a drill bit into the hole with quickly repeated short movements. The hammering action can be performed from outside the hole ( top-hammer drill) or within the hole (down-the-hole drill, DTH). Drills used for horizontal drilling are called drifter drills. In rare cases, specially-shaped bits are used to cut holes of non-circular cross-section; a square cross-section is possible. Process Drilled holes are char ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Truck
A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction, with a cabin that is independent of the payload portion of the vehicle. Smaller varieties may be mechanically similar to some automobiles. Commercial trucks can be very large and powerful and may be configured to be mounted with specialized equipment, such as in the case of refuse trucks, fire trucks, concrete mixers, and suction excavators. In American English, a commercial vehicle without a trailer or other articulation is formally a "straight truck" while one designed specifically to pull a trailer is not a truck but a "Tractor unit, tractor". The majority of trucks currently in use are still powered by diesel engines, although small- to medium-size trucks with gasoline engines exist in the US, Canada, and Mexico. The market-share of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shotcrete
Shotcrete, gunite (), or sprayed concrete is concrete or mortar conveyed through a hose and pneumatically projected at high velocity onto a surface, as a construction technique, first used in 1907 invented by Carl Akeley. It is typically reinforced by conventional steel rods, steel mesh, or fibers. Shotcrete is usually an all-inclusive term for both the wet-mix and dry-mix versions invented by Akeley. In pool construction, however, ''shotcrete'' refers to wet mix and ''gunite'' to dry mix. In this context, these terms are not interchangeable. Shotcrete is placed and compacted/consolidated at the same time, due to the force with which it is ejected from the nozzle. It can be sprayed onto any type or shape of surface, including vertical or overhead areas. Shotcrete has the characteristics of high compressive strength, good durability, water tightness and frost resistance. History Shotcrete, then known as gunite, was invented in 1907 by American taxidermist Carl Akeley to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rock Bolt
A rock bolt is a long anchor bolt, for stabilizing rock excavations, which may be used in tunnels or rock cuts. It transfers load from the unstable exterior to the confined (and much stronger) interior of the rock mass. Rock bolts were first used in mining in the 1890s, with systematic use documented at the St Joseph Lead Mine in the U.S. in the 1920s. Rock bolts were applied to civil tunneling support in the U.S. and in Australia starting in the late 1940s. Rock bolts were used and further developed starting in 1947 by Australian engineers who began experimenting with four-meter-long expanding anchor rock bolts while working on the Snowy Mountains Scheme. As shown in the figure, rock bolts are almost always installed in a pattern, the design of which depends on the rock quality designation and the type of excavation. Rock bolts are an essential component of the New Austrian Tunneling method. As with anchor bolts, there are many proprietary rock bolt designs, with either a mec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foliation (geology)
Foliation in geology refers to repetitive layering in metamorphic rocks.Marshak, Stephen, ''Essentials of Geology,'' W. W. Norton 3rd Ed, 2009 Each layer can be as thin as a sheet of paper, or over a meter in thickness. The word comes from the Latin ''folium'', meaning "leaf", and refers to the sheet-like planar structure. It is caused by shearing forces (pressures pushing different sections of the rock in different directions), or differential pressure (higher pressure from one direction than in others). The layers form parallel to the direction of the shear, or perpendicular to the direction of higher pressure. Nonfoliated metamorphic rocks are typically formed in the absence of significant differential pressure or shear. Foliation is common in rocks affected by the regional metamorphic compression typical of areas of mountain belt formation (orogenic belts). More technically, foliation is any penetrative planar fabric present in metamorphic rocks. Rocks exhibiting foliat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear (geology)
Boudinaged quartz vein (with strain fringe) showing ''Fault (geology)">sinistral shear sense'', Starlight Pit, Fortnum Gold Mine, Western Australia In geology, shear is the response of a rock to deformation usually by compressive stress and forms particular textures. Shear can be homogeneous or non-homogeneous, and may be pure shear or simple shear. Study of geological shear is related to the study of structural geology, rock microstructure or rock texture and fault mechanics. The process of shearing occurs within brittle, brittle-ductile, and ductile rocks. Within purely brittle rocks, compressive stress results in fracturing and simple faulting. Rocks Rocks typical of shear zones include mylonite, cataclasite, S-tectonite and L-tectonite, pseudotachylite, certain breccias and highly foliated versions of the wall rocks. Shear zone A shear zone is a tabular to sheetlike, planar or curviplanar zone composed of rocks that are more highly strained than rocks adjacent to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault (geology)
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the plane that represents the fracture surface of a fault. A ''fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can blur the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bench (geology)
In geomorphology, geography and geology, a bench or benchland is a long, relatively narrow strip of relatively level or gently inclined land that is bounded by distinctly steeper slopes above and below it. Benches can be of different origins and created by very different geomorphic processes.Jackson, J.A., 1997, ''Glossary of Geology.'' American Geological Institute. Alexandria, Virginia. First, the differential erosion of rocks or sediments of varying hardness and resistance to erosion can create benches. Earth scientists called such benches "structural benches." Second, other benches are narrow fluvial terraces created by the abandonment of a floodplain by a river or stream and entrenchment of the river valley into it. Finally, a bench is also the name of a narrow flat area often seen at the base of a sea cliff that was created by waves or other physical or chemical erosion near the shoreline. These benches are typically referred to as either "coastal benches," "wave-cut benche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tagebau Garzweiler Bei Otzerath Schaufelradbagger Januar2008
Surface mining, including strip mining, open-pit mining and mountaintop removal mining, is a broad category of mining in which soil and rock overlying the mineral deposit (the overburden) are removed, in contrast to underground mining, in which the overlying rock is left in place, and the mineral is removed through shafts or tunnels. In North America, where the majority of surface coal mining occurs, this method began to be used in the mid-16th century and is practiced throughout the world in the mining of many different minerals. In North America, surface mining gained popularity throughout the 20th century, and surface mines now produce most of the coal mined in the United States. In most forms of surface mining, heavy equipment, such as earthmovers, first remove the overburden. Next, large machines, such as dragline excavators or bucket-wheel excavators, extract the mineral. The pros of surface mining are that it has a lower financial cost and is a lot safer than undergrou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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