- 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 long-handled, plierlike device similar to a certain type of blacksmith tongs used to handle wash or drill rods in place of a safety clamp in shallow borehole drilling.
Industry:Mining
A long-period vertical seismograph suspended system adapted to the measurement of gravity differences. Sensitivity is achieved by adjusting the system to proximity to an instability configuration.
Industry:Mining
A long-range, cable-operated machine that works between a head mast and an anchor.
Industry:Mining
A longwall conveyor face from about 80 to 200 yd (73 to 183 m) long developed between two gate roads, one serving as an intake airway and usually for coal haulage, while the other acts as a return airway and for bringing in supplies to the face.
Industry:Mining
A longwall conveyor face with two face conveyors of different capacities, one delivering on to the other--tandem fashion. The layout has the disadvantage that the whole tonnage of coal must be transported along the second conveyor, and any breakdown on the second conveyor will affect the output of the entire face.
Industry:Mining
A longwall conveyor layout from 200 to 280 yd (183 to 256 m) long, developed between two tailgates with a main gate in the center of the face. The main gate conveyor is served 968 by two face conveyors and may act as an intake or a return airway. The tailgates may serve as supply roads.
Industry:Mining
A longwall conveyor layout in which the center or main gate serves two double units, one on each side. The gate belts from each double unit deliver the coal onto cross-gate 963 belts, which in turn deliver to the main gate conveyor and then by trunk conveyor or cars to the pit bottom.
Industry:Mining
A longwall cutter loader of the plow type, with two cutting blades, one at each end, operated by a hydraulic cylinder, which can give a powerful thrust (about 42 st or 38 t) to the blades and cause them to bite into the coal. While this thrust is being exerted, the 2751 machine is anchored by means of a vertical jack that engages the roof and floor. The jack is built on sliding bars, and the machine is moved by sliding the jack along the bars to the next position for anchoring the machine. It travels alongside the conveyor but is not connected to it. A loading ramp guides the cut coal onto the conveyor. The machine is employed in seams from 4 to 5 ft (1.2 to 1.5 m) thick with a strong roof and floor.
Industry:Mining
A longwall face on which the coal is cut and brought out to the gate road mechanically, without the aid of miners on the face. The face is unsupported. In general, the coal seam is thin but of high grade, and some type of rapid plow is employed.
Industry:Mining
