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United States Bureau of Mines
Industry: 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 type of silicification in which fine-grained quartz or chalcedony is introduced into limestones, such as in the Tri-State mining district of the Mississippi Valley.
Industry:Mining
A type of skip commonly used at metal mines, but not as often at coal mines, because of increased breakage. This skip consists of a rectangular receptacle for the material and a suspending frame of bail to an upper crosspiece of which is attached a suspension gear connecting the rope to the skip. Three guide shoes are generally provided at each side of the bail to keep it vertical. The skip body turns about a horizontal shaft at the lower end of the bail. Two rollers on the upper part are mounted on a shaft and cause the skip to tilt at an angle of 35 degrees at the tipping point in the headgear, where rollers run onto the curved guides. To prevent shocks in the case of an overwind the skips are fitted with overwind guides which glide along rollers fitted to the headgear above the tipping point.
Industry:Mining
A type of spotted slate with spots suggestive of grains of wheat.
Industry:Mining
A type of static metamorphism in which pressure due to deep burial has been a controlling influence, along with high temperature. Compare: thermal metamorphism
Industry:Mining
A type of structural steel having a maximum yield point of 23 st/in<sub>2</sub>as compared with 15.25 st/in<sub>2</sub>for mild steel.
Industry:Mining
A type of surface wave that is continuously generated by another wave that has the same phase velocity.
Industry:Mining
A type of surface wave that is continuously generated by another wave that has the same phase velocity.
Industry:Mining
A type of surfacing machine employed to remove irregularities from the surface of blocks of stone.
Industry:Mining
A type of tonstein characterized by numerous pseudomorphs of kaolinite-feldspar or kaolinite-mica within a kaolinite groundmass.
Industry:Mining
A type of topography that is formed on limestone, gypsum, and other rocks by dissolution, and that is characterized by sinkholes, caves, and underground drainage. Etymol. German, from the Yugoslavian territory Krs; type locality, a limestone plateau in the Dinaric Alps of northwestern Yugoslavia and northeastern Italy. First published on a topographic map, Ducatus Carnioliae, in 1774. Adj. karstic.
Industry:Mining