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Stripping Ratio
In surface mining, stripping ratio or strip ratio refers to the amount of waste (or overburden) that must be removed to release a given ore quantity. 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., whereas in metal mining, stripping ratio is unitless and is expressed as weight/weight. A stripping ratio can be expressed as a ratio or as a number. Equations The equations for stripping ratio are, for coal: :\frac for metal: :\frac where volume is typically expressed as m3 or yd and weight is typically expressed as tonne or ton. Use It is common for the stripping ratio to be used as an indicator of economic value for an open pit mine. This is because removal of waste is a cost to the mine whereas mining ore leads to revenue. A stripping ratio is commonly used as a quick method to evaluate a mine’s or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Mining
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 overlying rock is left in place, and the mineral is removed through shafts or tunnels. In North America, where the majority of surface coal mining occurs, this method began to be used in the mid-16th century and is practiced throughout the world in the mining of many different minerals. In North America, surface mining gained popularity throughout the 20th century, and surface mines now produce most of the coal mined in the United States. In most forms of surface mining, heavy equipment, such as earthmovers, first remove the overburden. Next, large machines, such as dragline excavators or bucket-wheel excavators, extract the mineral. The pros of surface mining are that it has a lower financial cost and is a lot safer than undergrou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overburden
In mining, overburden (also called waste or spoil) is the material that lies above an area that lends itself to economical exploitation, such as the rock, soil, and ecosystem that lies above a coal seam or ore body. Overburden is distinct from tailings, the material that remains after economically valuable components have been extracted from the generally finely milled ore. Overburden is removed during surface mining, but is typically not contaminated with toxic components. Overburden may also be used to restore an exhausted mining site during reclamation. Interburden is material that lies between two areas of economic interest, such as the material separating coal seams within strata.Peng, Syd S. (1986) ''Coal Mine Ground Control'' (2nd edition), Wiley, New York, page 303, Analogous uses Overburden is also used for all soil and ancillary material above the bedrock horizon in a given area. By analogy, overburden is also used to describe the soil and other material that lies ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-pit Mining
Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow. This form of mining differs from extractive methods that require tunnelling into the earth, such as long wall mining. Open-pit mines are used when deposits of commercially useful ore or rocks are found near the surface. It is applied to ore or rocks found at the surface because the overburden is relatively thin or the material of interest is structurally unsuitable for tunnelling (as would be the case for cinder, sand, and gravel). In contrast, minerals that have been found underground but are difficult to retrieve due to hard rock, can be reached using a form of underground mining. To create an open-pit mine, the miners must determine the information of the ore that is underground. This is done through drilling of probe holes in the ground, then plotting ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
