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The Siilinjärvi carbonatite complex, [1] an open-pit mine owned by Yara International, in Siilinjärvi, Finland Coal strip mine in Wyoming. 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 ...
Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, [1] is a surface mining technique that extracts rock or minerals from the earth. Open-pit mines are used when deposits of commercially useful ore or rocks are found near the surface where the overburden is relatively thin.
Acceptable post-mining land uses include commercial, residential, recreational, agricultural or public facility improvements. In open cut mines rocky material is used for backfilling the excavation. [4] A layer of soil that was stored in the premining is placed on top of the rocky material. On top of this layer is placed a layer of topsoil.
A box cut (box pit) is a small open cut built to supply a secure and safe entrance as access to a slope to an underground mine. Generally the box cut is sunk until sufficiently unweathered rock is found to permit the development of the decline. [ 1 ]
The open pit is then surrounded with a fence, to prevent access, and it generally eventually fills up with groundwater. Tailings dams are left to evaporate, then covered with waste rock, clay if need be, and soil, which is planted to stabilize it. For underground mines, rehabilitation is not always a significant problem or cost.
In Australia, bauxite is mined using an open-cut method. [4] This is possible because most bauxite in Australia can be found at or relatively close to the surface and is easily accessible by this method. [2] Open cut mining involves first removing the area above the bauxite ore called the overburden.
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Open-pit mining of silver oxide ores was the norm from 1885 to 1898, with local smelting. From 1898 until 1915, the leadzinc-silver sulfide minerals were developed with the concentrates treated overseas. Starting in 1915, the concentrates were treated entirely in Australia.