Longwall mining is an exploitaion method used in fairly flat-lying, thin, tabular deposit in which a long face is established accros panel between sets of entries and retreated or advanced by narrow cuts, aided by the complete caving of the roof or hanging wall.
Longwall mining machines consist of multiple coal shearers mounted on a series of self-advancing hydraulic ceiling supports. Almost the entire process can be automated. Longwall mining machines are about 800 feet (240 meters) in width and 5 to 10 feet (1.5 to 3 meters) tall. Longwall miners extract "panels" - rectangular blocks of coal as wide as the mining machinery and as long as 12,000 feet (3,650 meters). Massive shearers cut coal from a wall face, which falls onto a conveyor belt for removal. As a longwall miner advances along a panel, the roof behind the miner's path is allowed to collapse.
0 komentar:
Post a Comment