- 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 ...
In the quarry industry, a laborer who loads barges with crushed rock by operating a hand winch to lower a chute through which crushed rock flows from a bin.
Industry:Mining
In the reflection seismic methods applied to dipping reflectors, the travel time curves may not be straight lines; i.e., the apparent velocity observed varies with the spread from shot point to detectors. The time gradient is the reciprocal of the apparent velocity. In seismic prospecting, also the rate of change of travel time with depth.
Industry:Mining
In the room-and-pillar method, the part of the coal that is won from the rooms, as distinguished from the second part, which is the extraction of the remaining pillars.
Industry:Mining
In the seismic reflection method, a special type of multiple reflection. This is the reflection that takes place when the energy traveling upward from the shot is reflected downward by the base of the weathered zone or by the Earth's surface. The reflected pulse follows the primary downgoing pulse by a time interval determined by the depth of the shot below the weathering (or the free surface) and the velocity of the material above the shot. For normal shooting depths this interval will range from 0.010 to 0.020 s.
Industry:Mining
In the so-called perfect-discharge elevator, there is an extra set of traction or sprocket wheels on the discharge side, so set that they bend the chains back under the head wheels. As a consequence, the discharging chute may be placed directly under the buckets. This elevator will also handle material that packs, and both types of gravitydischarge elevators may be run much slower than the centrifugal type.
Industry:Mining
In the steel industry, refractory used for the transfer of steel from furnace to ingot. Refractories include ladle brick, nozzles, sleeves, stopper heads, mold plugs, hot tops, and mortars used for the brickwork involved.
Industry:Mining
In the stonework industry, a foreperson who supervises the removal of waste stone, loading and unloading of finished and semifinished stone, and the moving and piling of stone slabs and blocks at a stoneworking mill.
Industry:Mining
In the stonework industry, one who attaches and detaches crane slings or hooks to and from blocks or slabs of granite, marble, and stone in loading the stone on gang saw cars or trucks and pulling them under the gang saws.
Industry:Mining
In the stonework industry, one who operates an upright drilling machine to drill holes into slate so that the slabs may be fastened in place with wires or rods when installed in a building.
Industry:Mining
