Search results
Results from the WOW.Com Content Network
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. In contrast, deeper mineral ...
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.
As such they tend to be tabular, flat and really large, covering many square kilometres of the Earth's surface. However, at any one time the area of a deposit being worked for the nickel ore is much smaller, usually only a few hectares. The typical nickel laterite mine often operates as either an open cut mine or a strip mine. [citation needed]
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 ...
Fort Knox mine – gold mine in the Fairbanks mining district of Alaska; Hull–Rust–Mahoning Open Pit Iron Mine – largest open pit iron mine in the world, near Hibbing, Minnesota [7] Lavender Pit – copper mine in Cochise County, Arizona; Morenci Mine – copper mine in Greenlee County, Arizona; Mountain Iron Mine – iron mine in ...
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.
Nitrogen and potassium are also needed in substantial amounts. For this reason these three elements are always identified on a commercial fertilizer analysis. For example, a 10-10-15 fertilizer has 10 percent nitrogen, 10 percent available phosphorus (P 2 O 5) and 15 percent water-soluble potassium (K 2 O). Sulfur is the fourth element that may ...
When coal seams are near the surface, it may be economical to extract the coal using open-cut, also referred to as open-cast, open-pit, mountaintop removal or strip, mining methods. Opencast coal mining recovers a greater proportion of the coal deposit than underground methods, as more of the coal seams in the strata may be exploited. This ...