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Yanacocha Mine
Yanacocha ( Cajamarca Quechua: ''yana'' = "black, dark", ''qucha'' = "lake, puddle, pond, lagoon") is a gold mine in the Cajamarca region of the Northern Highlands of Peru. Considered to be the fourth largest gold mine in the world, it produced 0.97 million ounces of gold in 2014.Vladimir Basov (16 June 2015The world’s top 10 gold minesGold mining.com The 251-square kilometer open pit mine is situated about 30 kilometers (14 km straight line) north of Cajamarca, in high pampa, straddling the watershed. The operation is a joint venture between Newmont Goldcorp (51.35% ownership), Compañia de Minas Buenaventura (43.65%) and the International Finance Corporation (5%). Mercury spilled by the mining company has poisoned hundreds of people living near the mine and contaminated local water sources. Thousands of local residents have protested the mine in an environmental conflict that also includes ongoing lawsuits against the mining companies. Environmental defenders opposing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASARCO
Asarco LLC (American Smelting and Refining Company) is a mining, smelting, and refining company based in Tucson, Arizona, which mines and processes primarily copper. The company has been a subsidiary of Grupo México since 1999. Its three largest open-pit mines are the Mission, Silver Bell and Ray mines in Arizona. Its mines produce of copper a year. Asarco conducts solvent extraction and electrowinning at the Ray and Silver Bell mines in Pima County, Arizona, and Pinal County, Arizona, and operates a smelter in Hayden, Arizona. Asarco's smelting plant in El Paso, Texas, was suspended in 1999 and then demolished on April 13, 2013. Before closing, the plant produced of anodes each year. Refining at the mines as well as at a copper refinery in Amarillo, Texas, produce of refined copper each year. Asarco's hourly workers are primarily represented by the United Steelworkers. Asarco has 20 superfund sites across the United States, and it is subject to considerable litigation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andesite
Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende. Andesite is the extrusive equivalent of plutonic diorite. Characteristic of subduction zones, andesite represents the dominant rock type in island arcs. The average composition of the continental crust is andesitic. Along with basalts, andesites are a component of the Martian crust. The name ''andesite'' is derived from the Andes mountain range, where this rock type is found in abundance. It was first applied by Christian Leopold von Buch in 1826. Description Andesite is an aphanitic (fine-grained) igneous rock that is intermediate in its content of silica and low in alkali metals. It has less than 20% quartz and 10% feldspathoid by volume, with at least 65% of the fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale million years ago. It is the second and most recent epoch of the Neogene Period in the . The Pliocene follows the Epoch and is followed by the Epoch. Prior to the 2009 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alluvial Fan
An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to semiarid climates, but are also found in more humid environments subject to intense rainfall and in areas of modern glaciation. They range in area from less than to almost . Alluvial fans typically form where flow emerges from a confined channel and is free to spread out and infiltrate the surface. This reduces the carrying capacity of the flow and results in deposition of sediments. The flow can take the form of infrequent debris flows or one or more ephemeral or perennial streams. Alluvial fans are common in the geologic record, such as in the Triassic basins of eastern North America and the New Red Sandstone of south Devon. Such fan deposits likely contain the largest accumulations of gravel in the geologic record. Alluvial fans have also been found on Mars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravel
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classified by particle size range and includes size classes from granule- to boulder-sized fragments. In the Udden-Wentworth scale gravel is categorized into granular gravel () and pebble gravel (). ISO 14688 grades gravels as fine, medium, and coarse, with ranges 2–6.3 mm to 20–63 mm. One cubic metre of gravel typically weighs about 1,800 kg (or a cubic yard weighs about 3,000 lb). Gravel is an important commercial product, with a number of applications. Almost half of all gravel production is used as aggregate for concrete. Much of the rest is used for road construction, either in the road base or as the road surface (with or without asphalt or other binders.) Naturally occurring porous gravel deposits have a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Rock Mining
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 are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outcrop
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. Features Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial deposits are covered by soil and vegetation and cannot be seen or examined closely. However, in places where the overlying cover is removed through erosion or tectonic uplift, the rock may be exposed, or ''crop out''. Such exposure will happen most frequently in areas where erosion is rapid and exceeds the weathering rate such as on steep hillsides, mountain ridges and tops, river banks, and tectonically active areas. In Finland, glacial erosion during the last glacial maximum (ca. 11000 BC), followed by scouring by sea waves, followed by isostatic uplift has produced many smooth coastal and littoral outcrops. Bedrock and superficial deposits may also be exposed at the Earth's surface due to human excavations such as quarrying and build ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfidation
Sulfidation (British spelling also sulphidation) is a process of installing sulfide ions in a material or molecule. The process is widely used to convert oxides to sulfides but is also related to corrosion and surface modification. Inorganic, materials, and organic chemistry Sulfidation is relevant to the formation of sulfide minerals. A large scale application of sulfidation is the conversion of molybdenum oxides to the corresponding sulfides. This conversion is a step in the preparation of catalysts for hydrodesulfurization wherein alumina impregnated with molybdate salts are converted to molybdenum disulfide by the action of hydrogen sulfide. In organosulfur chemistry, sulfiding is often called thiation. The preparation of thioamides from amides involves thiation. A typical reagent is phosphorus pentasulfide (P4S10). The idealized equation for this conversion is: :RC(O)NH2 + 1/4 P4S10 → RC(S)NH2 + 1/4 P4S6O4 This conversion where an oxygen atom in the amide f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
