Search results
Results from the WOW.Com Content Network
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 ...
[1] [2] It is a number or ratio that express how much waste is mined per unit of ore. The units of a stripping ratio can vary between mine types. For example, in coal mining the stripping ratio is commonly referred to as volume/weight. [3], whereas in metal mining, stripping ratio is unitless and is expressed as weight/weight. [2]
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 ...
Surface mining and deep underground mining are the two basic methods of mining. The choice of mining method depends primarily on depth, density, overburden, and thickness of the coal seam; seams relatively close to the surface, at depths less than approximately 55 m (180 ft), are usually surface mined. [citation needed]
Underwater mining (1 C, 13 P) W. Water management in mining (3 C, 13 P) Pages in category "Mining techniques" The following 21 pages are in this category, out of 21 ...
The power required to drive such a bridle is (T 2 – T 1) ⋅ (R + h/2) ⋅ ω, i.e. (T 2 – T 1) ⋅ v. where v is the strip speed in m/sec; h is the strip thickness in meters; R is the radius of the Bridle Rolls in meters and; ω is the Bridle's angular speed in radians per second. The electrical power required by the drive motor = volts ...
The much larger type which is erected on site is commonly used in strip-mining operations to remove overburden above coal and more recently for oil sands mining. The largest heavy draglines are among the largest mobile land machines ever built, weighing up to 13,500 tons, while the smallest and most common of the site-erected type weigh around ...
Mountaintop removal mining (MTR), also known as mountaintop mining (MTM), is a form of surface mining at the summit or summit ridge of a mountain. Coal seams are extracted from a mountain by removing the land, or overburden, above the seams. This process is considered to be safer compared to underground mining because the coal seams are ...