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United States Bureau of Mines
Industria: 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 fine silky asbestos.
Industry:Mining
A fine spongy variety of hematite.
Industry:Mining
A fine, water-insoluble, inorganic material, used in admixture with solid or semisolid bituminous materials.
Industry:Mining
A fine-coal dewatering machine consisting of a conical rotating element with a vertical axis, built up of three rows of perforated stainless steel screen plates or stainless steel wedge or round-wire sections cut and rolled to conform to the surface of the cone. Wet feed is deposited by gravity into the top of the cone-shaped dryer onto a distributing disk that throws the material by centrifugal force onto the stepped screen or basket. The rapid circular movement of the basket forces the water through the screen, while the coal moves toward the bottom. Peripheral velocity and centrifugal force become greater for each particle, breaking down the surface tension of water film on each piece, increasing drying action directly in ratio to the cone circumference and peripheral speed. The most effective drying area is at the bottom of the cone just before the material is discharged from the machine.
Industry:Mining
A fine-coal dewatering machine consisting of two rotating elements, an outside conical screen frame, and an inside solid cone, which carries spiral hindrance flights. By a slight difference in the number of teeth in the gears, the screen element moves slightly faster, 631 in the same direction, than the solid cone. Material enters the machine from the top and falls on the solid cone where centrifugal force throws it against the screen. It slides down the screen until it meets the upper end of the hindrance flights, and, in doing so, the water begins to pass through the screen. The flights spiral downward, and, as the screen moves slowly around them in the direction of the downward pitch, the solids gradually find their way to the bottom of the screen basket and the zone of maximum centrifugal force, tending to remove all of the water.
Industry:Mining
A fine-coal dewatering machine that consists of a tank or truncated conical shell, which is revolved at the desired speed by means of a drive sheave. A screw conveyor rotates inside the cone or bowl at a slightly lower speed in the same direction of rotation. The feed entrance, in the center of the large end of the truncated cone, is high enough to allow formation of a pool of slurry. Adjustable effluent-discharge parts are so located in the large end of the bowl that the level of liquid is maintained at the desired height. The solids are steadily moved forward by the screw conveyor as fast as they are deposited, being carried above the level of the pool for an interval before leaving the bowl. Discharge of both solids and effluent is continuous.
Industry:Mining
A fine-grained calc-silicate rock of flinty appearance formed by thermal metamorphism of a calcareous mudstone, possibly with some accompanying pneumatolytic action.
Industry:Mining
A fine-grained extrusive rock with the same general composition as andesite, but having a less calcic plagioclase and more quartz; according to many, it is the extrusive equivalent of granodiorite.
Industry:Mining
A fine-grained extrusive rock with the same general composition as andesite, but having a less calcic plagioclase and more quartz; according to many, it is the extrusive equivalent of granodiorite.
Industry:Mining
A fine-grained igneous rock consisting mostly of alkali feldspar, with normative quartz between 5% and 20%; the volcanic equivalent of quartz syenite. It normally shows trachytic texture.
Industry:Mining