- 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 ...
Overhand stope so shaped that miners can stand on the ore they have severed, and work horizontally along the side walls of unbroken ore that confine the excavation. The stope is carried as an inverted stepped pyramid, its apex ending in a winze that leads to the tramming level, down to which ore gravitates or is moved.
Industry:Mining
Overhead stopes; stopes worked by putting in overhead holes and blasting down the ore.
Industry:Mining
Overlapping and sloping slats arranged to prevent entrance or exit of a portion of an air stream. Louvers are sometimes used as a regulator in place of a sliding or other adjustable door.
Industry:Mining
Overthrusting in which a bed, such as a coal seam, is disrupted and thrust laterally along the roof or floor parting, giving a duplication of coal.
Industry:Mining
Oxidation of finely ground ore minerals by means of upward currents of air, blown through a reaction vessel with sufficient force to cause the bed of material to become fluid. Reaction between mineral and air is maintained at a desired exothermic level by control of oxygen entry, by admission of cooling water, or by added fuel. Fluidized beds are used in the mineral industry for a number of concentrates, including copper, lead, zinc, and carbonaceous gold ores.
Industry:Mining
Oxides of a series of 15 metallic elements, from lanthanum (atomic number 57) to lutetium (71), and of two other elements; yttrium (39), and scandium (21). These elements are not esp. rare in the Earth's crust, but concentrations are. The rare earth metals resemble one another very closely in chemical and physical properties, thus making it most difficult to separate them. The rare earths are constituents of certain minerals, esp. monazite, bastnaesite, and xenotime. Abbrev: REE.
Industry:Mining
Oxidized kimberlite of yellowish color found at the surface of diamond pipes (e.g., South Africa), above the zone of blue ground.
Industry:Mining
Oxygen supply fed automatically to a rescue worker through a valve controlled by the worker's breathing action, forming part of a portable outfit.
Industry:Mining
