- 行业: Mining
- Number of terms: 33118
- Number of blossaries: 0
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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 mine car retarder, based on the principle of the dashpot, consists of individual braking units that can be fastened to the rails at spacings according to need over any desired distance. The unit offers no resistance to motion at very low car speeds, but as the speed increases, the braking force exerted upon it increases accordingly, following the usual oil dashpot characteristic.
Industry:Mining
A mine car so constructed that all the haulage motor has to do is to pull the loaded trip across the dump. A trigger trips the flaps in the bottom of the car, allowing the coal to drop out, and a second one closes the flaps as the car leaves the dump.
Industry:Mining
A mine car that can be side-tipped while in motion on a rail track. A ramp structure is fitted alongside the track opposite the spot where tipping is required. The car is fitted with a spherically contoured wheel that engages the ramp and gradually tilts the car while in motion. A chain attachment to the underframe opens the side of the car when tilted for tipping. The ramp can be retracted when not required.
Industry:Mining
A mine containing or yielding gold. It may be either in solid rock (quartz mine) or in alluvial deposits (placer mine).
Industry:Mining
A mine explosion caused by the ignition of fine coal dust. It is considered that an explosion involving coal dust alone is relatively rare. It demands the simultaneous formation of a flammable dust cloud and the means of ignition within it. The flame and force of a combustible gases explosion are the common basic causes of a coal-dust explosion. The advancing wave of the explosion stirs up the dust on the roadways and thus feeds the flame with the fuel for propagation.
Industry:Mining
A mine fan in which the air enters along the axis parallel to the shaft and is turned through a right angle by the blades and discharged radially. There are three main types with (1) backwardly inclined blades; (2) radial blades; and (3) forward curved blades. In (2) and (3) the blades are made of sheet steel, while in (1) the present tendency is to replace curved sheet-steel blades by blades of aerofoil cross section. The aerofoil bladed radial-flow fan has an efficiency of about 90%. Compare: axial-flow fan; mixed-flow fan.
Industry:Mining
A mine fan in which the flow is both radial and axial. The Schicht fan is of this type and has the advantage that it can produce a high water gage with a single stage. This fan, however, is not well suited to mines where a large change in equivalent orifice may occur. Compare: axial-flow fan; radial-flow fan.
Industry:Mining
A mine foreman who is in direct charge of workers in a specific portion of a pit or mine.
Industry:Mining
A mine foreman who is in direct charge of workers in a specific portion of a pit or mine.
Industry:Mining
