- strip mining
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mining in an open pit after removal of the overburden.
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Technique for the surface mining of coal by removing the soil and rock overburden above a seam and extracting the exposed mineral.The method is used to best advantage where the coal seam is thin and not deeply buried. (Thicker and deeper seams would be extracted by open-pit or underground mining.) Strip mining is most economical where flat terrain and horizontal seams permit a large area to be stripped. Where deposits occur in rolling or mountainous terrain, a contour method is used that creates a shelf with a slope on one side and an almost vertical wall on the other. A variety of equipment is used, including dozers, scrapers, hydraulic shovels, draglines, and bucket-wheel excavators. Concern over the environmental effects of strip mining have resulted in numerous requirements for the reclamation of excavated land.* * *
removal of soil and rock (overburden) above a layer or seam (particularly coal), followed by the removal of the exposed mineral.The common strip-mining techniques are classified as area mining or contour mining on the basis of the deposit geometry and type. The cycle of operations for both techniques consists of vegetation clearing, soil removal, drilling and blasting of overburden (if needed), stripping, removal of the coal or other mineral commodity, and reclamation.Area mining is appropriate for the extraction of near-surface, relatively flat-lying, and thin deposits of coal, phosphate, and similar minerals. Area mining usually progresses in a series of parallel deep trenches referred to as furrows or strips. The length of these strips may be hundreds of metres. Contour mining progresses in a narrow zone following the outcrop of a mineral seam in mountainous terrain.In the past, strip-mined mineral deposits that became exhausted or uneconomical to mine often were simply abandoned. The result was a barren sawtooth, lunarlike landscape of spoil piles hostile to natural vegetation and generally unsuitable for any immediate land use. Such spoil areas are now routinely reclaimed and permanent vegetation reestablished as an integral part of surface-mining operations. Generally, reclamation is performed concurrently with mining. See mining and coal mining.William Andrew Hustrulid* * *
Universalium. 2010.