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everything about >>mining

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  1. [1]
    الصورة الرمزية احمد عباس الخطيب
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    everything about >>mining

    Mining
    is the extraction of valuable minerals or other geological materials from the earth, usually (but not always) from an ore body, vein, or (coal) seam. Materials commonly recovered by mining include bauxite, coal, copper, diamonds, iron, gold, lead, manganese, magnesium, nickel, phosphate, platinum, rock salt, silver, tin, titanium, uranium, and zinc. Other highly useful materials that are mined include clay, sand, cinder, gravel, granite, and limestone. Any material that cannot be grown from agricultural processes must be mined. Mining in a wider sense can also include extraction of petroleum and natural ga
    .
    History

    The oldest known mine in the archaeological record is the "Lion Cave" in Swaziland. At this site, which has a radiocarbon age of 43,000 years, paleolithic humans mined for the iron-containing mineral hematite, which they presumably ground to produce the red pigment ochre.

    Sites of a similar age where Neandertals may have mined flint for weapons and tools have been found in Hungary
    Another early mining operation was the turquoise mine operated by the ancient Egyptians at Wady Maghareh on the Sinai Peninsula. Turquoise was also mined in pre-Columbian America in the Cerillos Mining District in New Mexico, where a mass of rock 200 feet (60 m) in depth and 300 feet (90 m) in width was removed with stone tools; the mine dump covers 20 acres (81,000 m²).

    Black gun powder in mining was first time used in a shift Bartolomej in mines under the town Banská ?tiavnica, Slovakia in 1627. There is 12000 kilometers of tunnels under this small town drived for a 1000 years.
    Mining techniques
    Mining techniques can be divided into two basic excavation types:
    Surface mining
    is a type of mining used to extract deposits of mineral resources that are close to the surface. In most forms of surface mining, heavy equipment, such as earthmovers, first remove the overburden (the soil and rock above the deposit). Next, huge machines such as drag line excavators extract the mineral. Surface mining generally leaves large devastated areas called spoil banks unless the land is recovered and it has a huge negative effect on the local ecosystem and the environment. There are four main forms of surface mining.
    Types of surface mining
    Strip Mining

    Strip mining is the practice of mining a seam of mineral ore by first removing all of the soil and rock that lies on top of it (the overburden). It is similar to open-pit mining in many regards. Strip mining is also used to extract the oil-impregnated sand in the Athabasca Tar Sands.
    Strip mining is only practical when the ore body to be excavated is relatively near the surface. Since colossal quantities of material often need to be removed, the excavating machinery used in strip mining is often among the largest such equipment ever constructed; drag line excavators and bucket-wheel excavators are common examples.
    There are two forms of strip mining - area strip mining, which is used on fairly flat terrain, to extract deposits over a large area. Contour strip mining, usually used in hilly terrain, involves cutting terraces in mountainsides following the contour of the land.
    Open-pit mining

    Open-pit mining refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow. The term is used to differentiate this form of mining from extractive methods that require tunneling into the earth. Open-pit mines are used when deposits of commercially useful minerals or rock are found near the surface; that is, where the overburden (surface material covering the valuable deposit) is relatively thin or the material of interest is structurally unsuitable for tunneling (as would be the case for sand, cinder, and gravel). Where minerals occur deep below the surface—where the overburden is thick or the mineral occurs as veins in hard rock— underground mining methods are used to extract the valued material. Open-pit mines are typically enlarged until the mineral reserve is exhausted.
    Mountaintop removal

    Mountaintop removal (MTR) is a relatively new form of coal mining that involves the mass restructuring of earth in order to reach sediment as deep as 1,000 feet below the surface. Mountaintop removal requires that the targeted land be first clear-cut and then leveled by dynamite. The debris created is typically scraped into a valley fill - a practice that has twice been ruled illegal by a federal judge in accordance with the Clean Water Act.
    Dredging

    Dredging is a method often used to bring up underwater mineral deposits. Although dredging is usually employed to clear or enlarge waterways for boats, it can also recover significant amounts of underwater minerals relatively efficiently and cheaply.


  2. [2]
    احمد عباس الخطيب
    احمد عباس الخطيب غير متواجد حالياً
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    الصورة الرمزية احمد عباس الخطيب


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    Open-pit mining
    Open-pit mining refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow. The term is used to differentiate this form of mining from extractive methods that require tunneling into the earth. Open-pit mines are used when deposits of commercially useful minerals or rock are found near the surface; that is, where the overburden (surface material covering the valuable deposit) is relatively thin or the material of interest is structurally unsuitable for tunneling (as would be the case for sand, cinder, and gravel). Where minerals occur deep below the surface—where the overburden is thick or the mineral occurs as veins in hard rock— underground mining methods are used to extract the valued material. Open-pit mines are typically enlarged until the mineral reserve is exhausted.

    Open-pit mines that produce building materials are commonly referred to as quarries. People in some English-speaking countries are not likely to make a distinction between an open-pit mine and other types of open-cast mines, such as quarries, borrows, placers, and strip mines.
    When they are no longer productive for extraction of material, open-pit mines are sometimes converted to landfills for disposal of solid wastes. However, some form of water control is usually required to keep the mine pit from becoming a lake.


    Materials typically extracted from open-pit mines include:
    Clay
    Coal
    Coquina
    Gravel and stone (stone refers to bedrock, while gravel is unconsolidated material, as found in glacial or fluvial deposits)
    Granite
    Gritstone
    Gypsum
    Limestone
    Marble
    Metal ores: such as copper, iron, gold, and molybdenum
    Sand
    Sandstone
    2_ Sub-surface mining

    Sub-surface mining or underground mining refers to a group of techniques used for the extraction of valuable minerals or other geological materials from the earth. In contrast to the other main type of excavation, surface mining, sub-surface mining requires equipment and/or manpower to operate under the surface of the earth.
    Types of sub-surface mining


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  3. [3]
    احمد عباس الخطيب
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    Extractive metallurgy
    The science of extractive metallurgy is the study of beneficiation and extraction of valuable metals and minerals from their ores. Although extractive metallurgy is all encompassing, mineral processing or mineral dressing is often the term used for the study of processing coal, industrial minerals and precious stones, as these are not metals.

    Environmental effects
    Modern mining companies in many countries are required to follow strict environmental and reclamation codes, ensuring the area mined is returned to its original state, or an even better environmental state than before mining took place. Past mining methods have had, and methods used in countries with lax environmental regulations continue to have, devastating environmental and public health effects. The result can be unnaturally high concentrations of some chemical elements over a significantly wider area of surface. Combined with the effects of water and the new 'channels' created for water to travel through, collect in, and contact with these chemicals, a situation is created where mass-scale contamination can occur.


    Mining industry

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    احمد عباس الخطيب
    احمد عباس الخطيب غير متواجد حالياً
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    الصورة الرمزية احمد عباس الخطيب


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    Extractive metallurgy
    The science of extractive metallurgy is the study of beneficiation and extraction of valuable metals and minerals from their ores. Although extractive metallurgy is all encompassing, mineral processing or mineral dressing is often the term used for the study of processing coal, industrial minerals and precious stones, as these are not metals.

    Environmental effects

    Modern mining companies in many countries are required to follow strict environmental and reclamation codes, ensuring the area mined is returned to its original state, or an even better environmental state than before mining took place. Past mining methods have had, and methods used in countries with lax environmental regulations continue to have, devastating environmental and public health effects. The result can be unnaturally high concentrations of some chemical elements over a significantly wider area of surface. Combined with the effects of water and the new 'channels' created for water to travel through, collect in, and contact with these chemicals, a situation is created where mass-scale contamination can occur

    Mining industry

    While exploration and mining can sometimes be conducted by individual entrepreneurs or small business, most modern-day mines are large enterprises requiring large amounts of capital to establish. Consequently, the industry is dominated by large, often multinational, mostly publicly-listed companies.


    Mine Planning Software
    One of the most dramatic changes in the mining industry has been the role that sophisticated three dimensional 3-D mine planning software packages have had. Initially relatively simple tasks - like rendering graphic images of drill holes - meant that it became more easy for surveyors, geologists, mine planners, mining engineers and other technical staff to manipulate and visualize data. However, in recent years the range of integrated mine planning tools have meant that massively complex models can be built to optimize the extraction and processing of mineral resources.





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    أبو حمزة السلفي
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    بسم الله والحمد لله والصلاة والسلام على رسول الله

    بارك الله فيك على هذا الجمع الطيب المبارك-بإذن الله-.

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    احمد عباس الخطيب
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