- 行业: Mining
- Number of terms: 33118
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The U.S. Bureau of Mines (USBM) was the primary United States Government agency conducting scientific research and disseminating information on the extraction, processing, use, and conservation of mineral resources.
Founded on May 16, 1910, through the Organic Act (Public Law 179), USBM's missions ...
A landform that has survived decay or disintegration, such as an erosion remnant; or one that has been left behind after the disappearance of the greater part of its substance such as a remnant island. The term is sometimes used adjectivally as a synonym of relict, but this usage is not recommended.
Industry:Mining
A lap of metal, leather, or wood used by lapidaries in polishing gems.
Industry:Mining
A large body of rock, typically porphyry, that contains disseminated chalcopyrite and other sulfide minerals. Such deposits are mined in bulk on a large scale, generally in open pits, for copper and byproduct molybdenum. Most deposits are 3 to 8 km across, and of low grade (less than 1% Cu). They are always associated with intermediate to felsic hypabyssal porphyritic intrusive rocks. Distribution of sulfide minerals changes outward from dissemination to veinlets and veins. Supergene enrichment has been very important at most deposits, as without it the grade would be too low to permit mining.
Industry:Mining
A large boulder or concretion having the rounded appearance of the bottom of an iron pot and easily detached from the roof of a coal seam. Compare: caldron bottom; bell.
Industry:Mining
A large boulder or concretion having the rounded appearance of the bottom of an iron pot and easily detached from the roof of a coal seam. Compare: caldron bottom; bell.
Industry:Mining
A large boulder or concretion having the rounded appearance of the bottom of an iron pot and easily detached from the roof of a coal seam. Compare: caldron bottom; bell.
Industry:Mining
A large brick or tile; esp., a curved firebrick used to support melting pots for zinc and retort covers.
Industry:Mining
A large bucket for raising the stones, etc., from a shaft being sunk. Sometimes called bowk; hoppett.
Industry:Mining
A large bucket used in shaft sinking for hoisting men, rock, materials, and tools. Since about 1955, hoppit sizes have increased to about 80 ft<sub>3</sub>(2.3 m<sub>3</sub>) and in some cases to 110 ft<sub>3</sub>(2.5 m<sub>3</sub>) and surface tipping facilities have been brought to a high degree of efficiency to cope with large-diameter shafts and fast sinking rates.
Industry:Mining
