- 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 pair of blocks, each having four sheaves, reeved with rope or cable and used to increase the lifting capacity of a drill-hoisting mechanism; a four-sheave block and tackle.
Industry:Mining
A pair of floating lightweight sheaves, which give support, at a suitable point, to the ropes leading away from the winding drums. The sheaves are located at a point about one-third of the length of rope between the drum and winding pulleys, measured from the drum. A sag tower suppresses rope oscillation and dampens out the rhythmic swing of the rope.
Industry:Mining
A pair of insulated copper conductors which lead from the exploder to the detonator wires. It may be either twin-core (both conductors contained in the one cable) or singlecore (each conductor contained in a separate cable). Twin-core cables having cores of four strands, each 0.018 in (0.046 cm) in diameter (4/0.018) with a resistance of approx. 5 Omega per 100 yd (91 m), are commonly used. Actual choice of cable must depend upon conditions of use and the relevant regulations.
Industry:Mining
A pair of insulated copper conductors which lead from the exploder to the detonator wires. It may be either twin-core (both conductors contained in the one cable) or singlecore (each conductor contained in a separate cable). Twin-core cables having cores of four strands, each 0.018 in (0.046 cm) in diameter (4/0.018) with a resistance of approx. 5 Omega per 100 yd (91 m), are commonly used. Actual choice of cable must depend upon conditions of use and the relevant regulations.
Industry:Mining
A pair of parallel entries, one of which is an intake air course and the other a return air course. Rooms can be worked from both entries. Often called double entry.
Industry:Mining
A pair of reversible conveyors, entry and exit, which provide for repeat feeding of metal being processed through a rolling mill.
Industry:Mining
A pair of similar coaxial coils with their distance apart equal to their radius, which permits an accurate calculation of the magnetic field between the coils. Used in calibration of magnetometers.
Industry:Mining
A pair of vertical plates of sheet iron or steel arranged with a ladle between them, which can be moved longitudinally along the front of a furnace; it is mainly used to protect laborers from furnace heat.
Industry:Mining
A pale greenish variety of sillimanite having fibrous inclusions; when cut, produces a chatoyant effect, but not a well-defined cat's-eye.
Industry:Mining
