- 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 ...
An open crystal form consisting of nonparallel faces that intersect the c crystallographic axis and consist of three (trigonal), four (tetragonal), six (ditrigonal, hexagonal), or eight (ditetragonal) faces meeting at a point. Compare: bipyramid; hemipyramid; dome.
Industry:Mining
An open crystal form of four sides parallel to the clinoaxis a in the monoclinic system. Compare: dome; orthodome.
Industry:Mining
An open crystal form of two nonparallel faces which intersect two or three crystallographic axes. Compare: dome; disphenoid.
Industry:Mining
An open girder, beam, or column in timber, steel, or aluminum alloy, built up from structural members joined and braced together by intersecting diagonal bars.
Industry:Mining
An open guard of sheet metal, expanded metal, or similar construction around a chain drive.
Industry:Mining
An open pit quarry where the ledge of stone forms a hill and the floor of the quarry worked on a hillside may be little, if any, lower than the surrounding country. In such openings, both transportation and drainage are favorable.
Industry:Mining
An open wirework shovel used for taking salt crystals from an evaporating brine.
Industry:Mining
An open wooden channel or flume for conveying placer sand. The gold or heavy minerals settle at the bottom. The method is cleaner and requires less water than ground sluicing.
Industry:Mining
