The pits that remain after removing the reasonably thin coal seams of the East are usually not big enough to hold this additional volume. Consequently, most contour miners need to get rid of their extra spoil in another “valley fill” or disposal zone. 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. In a relatively new technique that originated in 1970s to early 1980s, explosives are used to move or throw the overburden into the previous pit in a process called cast blasting.

This simply means that they have to fill the removed areas with topsoil and replant them with vegetation. It is much more efficient compared to underground mining Those who advocate for strip mining believe that the recovery rate of materials is higher using the method. It is estimated that about 80 to 90% of the material can be recovered compared to the 50% recovered using tunnel mining. Throughout its history, strip mining has played a crucial role in meeting the world’s demand for minerals and energy.

The operator positions the overburden from the second cut into the ditch formed by the original cut and grades and compresses the xcritical courses scam spoil. 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. Mining companies are nowadays operating mainly in Appalachian Mountains of Kentucky (particularly eastern Kentucky) and West Virginia.

Land Restoration and Reclamation

Surface mining, method of extracting minerals near the surface of the Earth. The three most common types of surface mining are open-pit mining, strip mining, and quarrying. Compared with other mining forms, strip mining attains a much higher recovery rate of materials, which is approximately 80%-90%, whereas underground mining only offers a roughly 50% mineral recovery rate. Although open-pit mining is similar to strip mining, during open-pit mining operation, massive, vertical pits are created by using explosives, where the mineral materials are extracted through heavy machinery. Strip mining, however, normally creates horizontal strips or trenches from which mineral extraction or ore deposits are drilled and founded. Sustainable Mining Practices– Promoting sustainable mining practices is crucial.

The removal of the overlying rock and soil layers can result in changes to the topography and drainage patterns of the area. One of the primary environmental impacts of area strip mining is the destruction of natural habitats. The removal of topsoil and vegetation can result in the loss of biodiversity, and the creation of new habitats that are less productive than the original ecosystems.

Coal is often processed at the mine to create uniform-size particles (“comminution”), remove noncombustible minerals, and provide other conditioning to improve performance. Increasing numbers of power plants are using this so-called “refined coal,” but if the precombustion cleaning, comminution and conditioning has to be done at the power plant site, this requires even more land. Large cooling towers might be necessary for plant operations, and sufficient land area for gathering and handling the postcombustion products is also needed. Many coal power plants are located along waterways or large rivers like the Ohio to facilitate the delivery of coal via barges or railroads. Some large surface coal mines, such as Wyodak near Gillette in eastern Wyoming have a power plant on-site to utilize the coal at the mine and sell electricity directly into the national grid. Surface mining has two design parameters that affect mine cost, which are minimizing rehandle and maximizing pit recovery.

The Process of Strip Mining

Strip mining, removal of soil and rock (overburden) above a layer or seam (particularly coal), followed by the removal of the exposed mineral. In large mines rotary drills are used to drill holes with diameters ranging from 150 to 450 mm (about 6 to 18 inches). The drill bit, made up of three cones containing either steel or tungsten carbide cutting edges, is rotated against the hole bottom under a heavy load, breaking the rock by compression and shear.

1. The top of each bench is equivalent to a working level, and access to different levels is gained through a system of xcriticals.
2. The contour method is used practically solely in the Appala­chian region of North America, where coal seams protrude from the sides of hills or mountains.
3. We can use them as an alternative to burning coal which releases loads of greenhouse gas emissions and eats up our natural resources.
4. The broken coal or minerals are removed by shovel or front-end loader, crushed if required, screened to various size fractions, and transported to the beneficiation plant.
5. Strip mining is favored for its efficiency and cost-effectiveness for near-surface deposits.

This initial, or drop, cut is then progressively widened to form the new pit bottom. The environmental impact of strip mining is significant and multifaceted. While it allows for efficient mineral extraction, it also poses several environmental challenges that need to be addressed. Strip mining is favored for its efficiency and cost-effectiveness for near-surface deposits.

Certain dumps can be treated by various solutions to extract the contained metals (a process known as heap leaching or dump leaching). As pits became deeper—the deepest pits in the world exceed 800 metres (2,600 feet)—alternate modes of transporting broken ore and waste rock became more common. One of these is the belt conveyor, but in general this method requires in-pit crushing of the run-of-mine material prior to transport.

List of Cons of Strip Mining

The lumpy stockpile heap of overburden waste is stable at 30°-35° for shale and 35°-45° for limestones and sandstones. The selection of the mining technique is dictated by the physical structure, location, and grade or value of the ore body and by the characteristics of the adjacent geological materials. Although open-pit mining and underground mining are the two most common mining techniques, placer mining and solution mining also have been used for mineral extraction. Placer mining involves excavation of river or stream sediments and separation of valuable minerals by gravity, by selective flotation, or by chemical extraction. Most solution mining is by heap leaching in which the extractant solution is trickled over broken ore on the surface or in underground workings; less common is injection into underground geological formations. The consequence of the excavation of open-pits and other mining-related disturbances is that sulfide minerals previously isolated from the atmosphere are exposed to oxygen.

A schematic view of the complete operating cycle of mining for shallow-bedded deposits like coal and lignite seams. Another simple thing you can do is use recycled resources (or renewable resources if we’re talking energy) instead of mined materials. 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. 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.

It is incumbent upon those involved in the drilling and blasting to turn this power into useful fragmentation work. To achieve the proper fragmentation, a series of blastholes is generally shot in a carefully controlled sequence. In China, coal mining has tarnished the quality of land of an estimated 3.2 million hectares, conferring to a 2004 assessment.

Strip Mining Types, Environmental Impacts and Solutions

Each type of surface mining has its own environmental impact, as laid out below. Very little soil is displaced in contrast with mountaintop removal; however, it is comparatively more expensive to own and operate a highwall miner. Although powerful machines are used to uncover the overburden, this method of mining only touches the surface. The object of blasting is to fragment the rock and then displace it into a pile that will facilitate its loading and transport. In large open pits the main implements for loading are electric, diesel-electric, or hydraulic shovels, while electric or mechanical-drive trucks are used for transport. The size of the shovels is generally specified by dipper, or bucket, size; those in common use have dipper capacities ranging from 15 to 50 cubic metres (20 to 65 cubic yards).

There is the extraction of ornamental stone blocks of specific colour, size, shape, and quality—an operation requiring special and expensive production procedures. In addition, the term quarrying has been applied to the recovery of sand, gravel, and crushed stone for the production of road base, cement, concrete, and macadam. However, since the practices followed in these operations are similar to those of open-pit mines, the discussion of quarrying here is limited to the excavation of ornamental stone. Though many nations need recovery plans for coal mining locations; undoing all the environmental harms to water supplies, devastated habitats, and poor air quality is a lengthy and tricky task. The contour method is used practically solely in the xcritical reviews Appala­chian region of North America, where coal seams protrude from the sides of hills or mountains.

However, it also comes with significant environmental impacts, which will be discussed in detail later in this guide. Surface mine design principles emanate from the operational characteristics of surface mining, which are drilling and blasting, spoil handling, coal removal, and haulage. Except in a few circumstances, overburden in surface mining requires the rock to be fractured by explosives to allow it to be excavated. The goal of drill and blast design is to optimize rock fracturing, which optimizes digging productivity.