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Room and pillar mining was one of the earliest methods used, [3] although with significantly more manpower. The room and pillar system is used in mining coal, gypsum, [4] iron, [5] limestone, [6] and uranium [7] ores, particularly when found as manto or blanket deposits, stone and aggregates, talc, soda ash, and potash. [8]
The Morupule Colliery is a coal mine located in Palapye, Botswana, owned and operated by Debswana, a partnership between the government of Botswana and De Beers. [1] The coalfield is composed of four main seams, only one of which, the No. 1 Seam, is currently being mined, using bord and pillar mining methods.
Retreat mining is a particularly dangerous form of mining: according to the Mine Safety and Health Administration (MSHA), pillar recovery mining has been historically responsible for 25% of American coal mining deaths caused by failures of the roof or walls, even though it represents only 10% of the coal mining industry. [1]
The mine was named Stanford Merthyr No. 2 until 1 May 1931. The mine was started in the 1920s, by the East Greta Coal Mining Company. The Greta coal seam has been mined using bord and pillar mining methods. Coal was transported from the mine via the Paxton Branch of the South Maitland Railway.
In deep mining, the room and pillar or bord and pillar method progresses along the seam, while pillars and timber are left standing to support the mine roof. Once room and pillar mines have been developed to a stopping point limited by geology, ventilation, or economics, a supplementary version of room and pillar mining, termed second mining or ...
The new sinking was connected to the existing workings of Wellington Colliery in 1922 and the two mines worked in conjunction with each other until Wellington closed in 1932. Initially Haig was operated by the Bord and pillar method, with Longwall mining taking over from the late 1930s. [2]
Room and pillar mining often leads to retreat mining, in which supporting pillars are removed as miners retreat, allowing the room to cave in, thereby loosening more ore. Additional sub-surface mining methods include hard rock mining, bore hole mining, drift and fill mining, long hole slope mining, sub level caving, and block caving.
To the end, the continuing inability to mine sufficient shale to feed the retorts was the cause of the works' losses. Plans to change the method of mining from 'bord and pillar' to 'longwall' never eventuated. [6] [21] [22] [4] [23] Government funding ceased in 1952, and Glen Davis was closed on 30 May.