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More modern room and pillar mines use a more "continuous" method, that uses machinery to simultaneously grind off rock and move it to the surface. [12] Other processes, such as backfill, where discarded tailings are unloaded into mined-out areas, [9] can be used, but are not required. Retreat mining (below) is an example of a process like this.
Longwall mining is a form of underground coal mining where a long wall of coal is mined in a single slice (typically 0.6–6.0 m (2 ft 0 in – 19 ft 8 in) thick). The section of rock that is being mined, known as the longwall panel, is typically 3–4 km (1.9–2.5 mi) long, but can be up to 7.5 km (4.7 mi) long and 250–400 m (820–1,310 ft) wide.
Continuous mining utilizes a continuous miner machine with a large rotating steel drum equipped with tungsten carbide picks that scrape coal from the seam. Operating in a "room and pillar", also known as "bord and pillar" system, where the mine is divided into a series of 20-to-30-foot (5–10 m) "rooms" or work areas cut into the coalbed—it ...
Shortwall mining – A coal mining method that accounts for less than 1% of deep coal production, shortwall involves the use of a continuous mining machine with moveable roof supports, similar to longwall. The continuous miner shears coal panels 150–200 feet wide and more than a half-mile long, depending on other things like the strata of the ...
Continuous production is a flow production method used to manufacture, produce, or process materials without interruption.Continuous production is called a continuous process or a continuous flow process because the materials, either dry bulk or fluids that are being processed are continuously in motion, undergoing chemical reactions or subject to mechanical or heat treatment.
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 ...
A drum hoist (steel wire rope visible) and motor. In underground mining a hoist or winder [1] is used to raise and lower conveyances within the mine shaft.Modern hoists are normally powered using electric motors, historically with direct current drives utilizing Ward Leonard control machines and later solid-state converters (), although modern large hoists use alternating current drives that ...
Example Bjerrum plot: Change in carbonate system of seawater from ocean acidification.. A Bjerrum plot (named after Niels Bjerrum), sometimes also known as a Sillén diagram (after Lars Gunnar Sillén), or a Hägg diagram (after Gunnar Hägg) [1] is a graph of the concentrations of the different species of a polyprotic acid in a solution, as a function of pH, [2] when the solution is at ...