- 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 ...
The true mill-head grade of an ore-stream in percent, ounces, or parts per million of a metal or mineral, less extractive metallurgical losses; the proportion of an ore material actually recovered.
Industry:Mining
The trunk or principal intake airway of a mine. The main intake air current is usually split into two or more air currents before reaching the workings.
Industry:Mining
The tub or bucket used for containing the material conveyed by a skip hoist.
Industry:Mining
The turning of a borehole along a different course at depth. This may be achieved, but not without difficulty. The cutting bit is guided upon its new course by the curved surface of a deflecting wedge that is positioned with the aid of a modified Oehman instrument. In petroleum drilling, much use is made of holes that are deflected at a predetermined depth. The technique is known as whipstocking.
Industry:Mining
The type of machine commonly installed at a colliery today where a large volume of compressed air is required. A single unit can deliver 10,000 ft <sub>3</sub>/min (283 m<sub>3</sub>/min) or more of free air, and the floor space occupied is a minimum for these capacities. It is also ideally suited for direct drive by a steam turbine, and this combination is commonly found at collieries. The compressor consists essentially of a number of impellers keyed to a shaft and running in a fixed casing with specially shaped passages. Each impeller is in the form of a hollow wheel, the two sides being united by curved vanes.
Industry:Mining
The U.S. Bureau of Mines has applied the term "explosion proof" to motors constructed so as to prevent the ignition of gas surrounding the motor by any sparks, flashes, or explosions of gas or of gas and coal dust that may occur within the motor casing.
Industry:Mining
The U.S. Mine Safety and Health Administration and other recognized safety and health agencies recommend 19.5% as the minimum oxygen content allowable.
Industry:Mining
The ultimate strength of a material in tension, compression, or shear, respectively, is the maximum tensile, compressive, or shear stress that the material can sustain, calculated on the basis of the ultimate load and the original or unstrained dimensions. It is implied that the condition of stress represents uniaxial tension, uniaxial compression, or pure shear, as the case may be.
Industry:Mining
