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Long hole stoping is a highly selective and productive method of mining and can cater for varying ore thicknesses and dips (0 – 90 degree). It differs from manual methods such as timbered and shrinkage as once the stope has begun blasting phase it cannot be accessed by personnel.
Shrinkage stoping is a short-hole mining method which is suitable for steeply dipping orebodies. This method is similar to cut and fill mining with the exception that after being blasted, broken ore is left in the stope where it is used to support the surrounding rock and as a platform from which to work.
Other methods include shrinkage stope mining, which is mining upward, creating a sloping underground room, long wall mining, which is grinding a long ore surface underground, and room and pillar mining, which is removing ore from rooms while leaving pillars in place to support the roof of the room.
Three methods of stope mining are commonly used. In the "cut and fill" or "open stoping" method, the space remaining following removal of ore after blasting is filled with waste rock and cement. In the "shrinkage" method, only sufficient broken ore is removed via the chutes below to allow miners working from the top of the pile to drill and ...
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 ]
Exploration in 1965 and 1966 was successful in locating new ore, and a new mill was in operation in August 1966. Ore reserves at that time were 49,103 tons averaging 14.19% zinc, 7.01% lead, and 2.93 oz/ton silver, (17% mining dilution and 10% stope wall dilution included). Ore was mined by open stoping and shrinkage methods. Production to the ...
Weller doesn’t dispute that Trump can order Treasury to stop making the penny. It stopped making the dollar coin for general circulation in 2011 due to lack of demand. But to stop the use of ...
Stoping is a process accommodating the ascent of magmatic bodies from their sources in the mantle or lower crust to the surface. The theory was independently developed by Canadian geologist Reginald Aldworth Daly [ 1 ] and American geologist Joseph Barrell .