- 行业: Mining
- Number of terms: 33118
- Number of blossaries: 0
- Company Profile:
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 system of opening a mine by driving three parallel entries for the main entries.
Industry:Mining
A system of protection designed to cause the supply to a circuit or system to be interrupted when the leakage current to earth exceeds a predetermined value.
Industry:Mining
A system of protection designed to cause the supply to a circuit or system to be interrupted when the leakage current to earth exceeds a predetermined value.
Industry:Mining
A system of reduction of levels by working out the rise or fall of staff readings from each level point to the one following it.
Industry:Mining
A system of roof support in mines. Boreholes usually from 3 to 12 ft (1 to 4 m) long are drilled upward in the roof, and bolts of 5/8 to 1 in (2 to 2.5 cm) or more in diameter are inserted into the holes and anchored at the top by a split cone, mechanical anchor, or resin grout. The bolts are put up in a definite pattern. The idea is to clamp together the several roof beds to form a composite beam with a strength considerably greater than the sum of the individual beds acting separately. Compare: strata bolt
Industry:Mining
A system of rope haulage used for transporting material on the surface and to transfer loaded cars from one elevation to a lower one in mines. Slope must be sufficiently steep so the loaded cars will pull the empty cars up the grade.
Industry:Mining
A system of rope haulage used for transporting material on the surface and to transfer loaded cars from one elevation to a lower one in mines. Slope must be sufficiently steep so the loaded cars will pull the empty cars up the grade.
Industry:Mining
A system of seismic surveying in which the primary concern is determining the dip and position of reflecting interfaces rather than in tracing such interfaces continuously.
Industry:Mining
A system of separating masses of rock by blasting with black blasting powder in reamed drill holes, a considerable air space being left between the charge and the stemming.
Industry:Mining
A system of shaft sinking through loose ground or quicksand by piles in the form of iron tubes connected together by webs. Their downward movement is facilitated by water under pressure that is forced down the tubes to wash away the loose material from underneath their points.
Industry:Mining
