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. Contour mining progresses in a narrow zone following the outcrop of a mineral seam in mountainous terrain.
Area mines dig huge rectangular pits, cultivated in a succession of parallel strips or cuts which can range several hundred yards in width and more than a mile in length. Strip mining is only applicable when the ore body to be dug is somewhat close to the surface. This kind of mining requires some of the biggest machines on earth, including bucket-wheel excavators which can dig as much as 12,000 cubic meters of earth per hour.
Highwall mining
An example of such recycling is tin cans, which use salvaged tin instead of mining more tin to manufacture new cans. All of these undesirable consequences drive individuals to move to other places because the air they breathe and the water they use becomes dirty and expanding coal mines make use of more and more of their homeland. As an alternative, he might choose to create a stable water impoundment in the last cut. These last cut lakes are normal xcritical rezension in the coal areas of the Midwest but can raise environmental and land use issues.
- If caprock is encountered, expensive and time-consuming blasting is required, a frequent occurrence in the United States.
- Sustainable Mining Practices– Promoting sustainable mining practices is crucial.
- Contour stripping is often followed by auger mining into the hillside, to remove more of the mineral.
- It commenced in the mid-16th century and is practiced all over the world, even though the bulk of surface coal mining takes place in North America.
- Drill and blast damage is reduced by stopping the drill holes from touching the coal seam or by placing nonexplosive material in each drill hole, called stemming.
Strip Mining Explained: An In-Depth Guide
As expected, mining left a degraded landscape, and xcritical official site resulted in much greater runoff , sediment production, and water quality problems. By contrast, area mining in Indiana trapped vast quantities of groundwater within the loosened soil, reducing peak discharges, extending base flow, and yielding water of acceptable quality. The process is conducted in rows, creating long ridges and valleys in the countryside that resemble a washboard.
The multiple seam mining is done by operating first pair of overburden and coal bed at a time and followed by second and third pairs in sequence. Finally, the total overburden rocks, stockpiled around the mine opening, are backfilled to the abandoned mine. Spoil handling design is of critical importance, as this function is usually the most expensive cost element in surface mining.
Strip Mining: Types, Effects and Solutions
Meanwhile, acid mine drainage is created when coal and other overlying rock unearthed are mixed with water when the site is strip mined, taking on toxic levels of minerals and heavy metals. The toxic water could contaminate groundwater, streams, soil, plants, animals, and human beings. Protecting the environment from pollution, both from tailings and from the mine workings is a complex problem (ERMITE Consortium et al., 2004), and its solution takes the combined efforts of many partners. Unquestionably, the best protection of the ecosphere would be to prevent mining entirely or, alternatively, recycle all used metals, rocks or aggregates (European Innovation Partnership on Raw Materials, 2016).
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The more common method is area stripping, which is used on fairly flat terrain, to extract deposits over a large area. As each long strip is excavated, the overburden is placed in the excavation produced by the previous strip. This technique is used for near-surface, relatively flat sedimentary mineral deposits. How deeply the mining can occur is essentially determined by the combination of technological capabilities and the economics involved. The latter includes the xcritical value of the mineral, contractual arrangements with the landowner, and mining costs, including reclamation .