- 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 mobile downwarping of the crust of the Earth, either elongate or basinlike, measured in scores of kilometers, in which sedimentary and volcanic rocks accumulate to thicknesses of thousands of meters. A geosyncline may form in part of a tectonic cycle, in which orogeny follows. Recognition of the plate structure of the lithosphere has led to appreciation that nearly all geosynclinal phenomena are related to ocean opening and closing. Compare: mobile belt geanticline.
Industry:Mining
A mobile electric, hydraulic, four-drill rig for boring blasting holes in quarries and opencast pits. All drills, percussive and rotary, can be simultaneously or independently raised, lowered, or slewed, enabling the rig to serve a working face 32 ft (9.8 m) high and 24 ft (7.3 m) wide.
Industry:Mining
A mobile loader that uses a series of small buckets on a roller chain to elevate spoil to the dumping point.
Industry:Mining
A mobile loader that uses a series of small buckets on a roller chain to elevate spoil to the dumping point.
Industry:Mining
A mobile-type rotary drill used on opencast sites with no hard rock for drilling vertical blasting holes. It can drill a hole of 5 in or 6 in (12.7 cm or 15.2 cm) in diameter to depths of about 30 ft (9.1 m). Drilling is by means of a rotary cutting head with interchangeable cutting bits, the auger removing the cuttings from the hole. An overall speed of 30 ft/h (9.1 m/h) can be obtained.
Industry:Mining
A mobilized portion of an autochthonous granite that has moved higher in the crust or, more usually, into tectonic domains of lower pressure. It shows variable marginal relations, in some places migmatitic in others characterized by a thermal aureole.
Industry:Mining
A mode of arranging diamonds set in the face of a bit in such a manner as to have rows of diamonds forming eccentric circles so that the path cut by each diamond slightly overlaps that of the adjacent stones. Compare: concentric pattern
Industry:Mining
A mode of radioactive decay in which an orbital electron is captured by the nucleus. The resulting nuclear transformation is identical with that in beta<sub>+</sub>emission.
Industry:Mining
A mode of sediment transport in which the particles are moved progressively forward in a series of short intermittent leaps, hops, or bounces from a bottom surface; e.g., sand particles skipping downwind by impact and rebound along a desert surface, or bounding 2742 downstream under the influence of eddy currents that are not turbulent enough to retain the particles in suspension and thereby return them to the streambed at some distance downstream. It is intermediate in character between suspension and the rolling or sliding of traction. Etymol: Latin saltare, to jump, leap.
Industry:Mining
A mode of treatment of iron castings that are allowed to remain in storage, or to stand out in the open, for a more or less extended period, e.g., 6 months, to effect a reduction in the residual stresses and consequently in the degree of distortion during subsequent machining. A very similar result can often be obtained by a comparatively short period, e.g., 30 min, of tumbling. Since stress relieving by heat treatment is a more certain process, and seasoning involves much delay and the use of considerable space for storage, stress relieving is more usually employed.
Industry:Mining
