- المجال: 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 drilling in which the bit is directly driven by a turbine at the bottom of the hole.
Industry:Mining
A system of drilling that provides for the continuous removal of the detritus from the well by means of a water flush or current of water.
Industry:Mining
A system of earth fault protection in which the fault current is limited by design to a low value which generally requires amplification in order to operate an earth fault relay. In the case of three-phase alternating-current systems, the limitation of the leakage current may be effected by either (1) inserting a current-limiting device between the neutral point of the system and earth (single-point earthing), or (2) connecting, in each circuit to be protected, all phases, in star, through current-limiting devices, each star point being connected to earth through an earth leakage protective device (multipoint earthing).
Industry:Mining
A system of electric traction where, instead of the running rails, a second insulated contact wire is used for the return or negative current.
Industry:Mining
A system of electrical controls for a system of conveyors that maintains a controlled relationship between the units of the system. Sometimes applied to sequence-starting controls.
Industry:Mining
A system of established monuments whose positions are accurately determined and are used in all correlated cadastral surveys.
Industry:Mining
A system of filling mined cavities in which crushed rock is carried along a pipeline by compressed air and discharged at high velocity into the space to be packed, the intense projection ensuring a very high density of packed material. For stowing shallow workings--up to 200 yd (183 m) in depth--the stowing plant may be installed on the surface. The air pressure is about 60 psi (414 kPa). For deeper workings, the plant may 2393 be installed underground, and the crushed rock taken down from the surface. The stowing pipes are about 5 to 6 in (approx. 13 to 15 cm) in diameter. The system is often employed if important surface structures require protection. The material used is from old dirt heaps, screen dirt, and washery rejects. The material is crushed to -2-1/2 in (- 6.35 cm) and preferably without the -1/2-in (-1.27-cm) material.
Industry:Mining
A system of forces or stresses that tends to decrease the volume or to shorten a substance, or the change of volume produced by such a system of forces.
Industry:Mining
A system of gears, ratchets, and friction devices, or some combination of these parts, in the swivel head of a diamond drill, which controls the rate at which a bit is made to penetrate the rock formation being drilled. When controlled by a feed gear, the bit maintains the same penetration rate per revolution regardless of drill-stem revolutions per minute.
Industry:Mining
A system of gears, ratchets, and friction devices, or some combination of these parts, in the swivel head of a diamond drill, which controls the rate at which a bit is made to penetrate the rock formation being drilled. When controlled by a feed gear, the bit maintains the same penetration rate per revolution regardless of drill-stem revolutions per minute.
Industry:Mining
