- 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 temporary method of supporting a circular shaft sinking. It consists essentially of iron curbs or rings. Each ring consists of segments of wrought iron, 3 to 5 in (7.62 to 12.7 cm) deep, 5/8 to 7/8 in (1.59 to 2.22 cm) thick, and from 6 to 8 ft (1.82 to 2.44 m) in length. The segments are bent to the curvature of the shaft and bolted together, each ring being suspended from the ring above. Laggings or backing deals are wedged behind the rings. Every fourth ring or so is supported on steel strata bolts driven into holes drilled in the rock sides.
Industry:Mining
A temporary or permanent structure used for holding dredged material on a limited basis, not to be confused with a confined disposal facility.
Industry:Mining
A temporary screen or curtain to deflect the air upwards against the roof to disperse gas.
Industry:Mining
A temporary timber framework upon which the masonry of an arch of reinforced masonry lintel is supported until it becomes self-supporting.
Industry:Mining
A tenon, such as is used on a diagonal piece or strut, usually on heavy timbers.
Industry:Mining
A term applicable to various varieties of minerals containing numerous inclusions of cinnabar but esp. to a Mexican variety of jasper.
Industry:Mining
A term applied by quarry personnel to quarried blocks of any dimensions.
Industry:Mining
A term applied by quarrymen to a coarse granite vein from 2 in (5 cm) to 2 ft (61 cm) or more thick, intersecting granite or any other crystalline rock.
Industry:Mining
A term applied by some petrologists to rock consisting primarily of the mineral dolomite.
Industry:Mining
A term applied by some petrologists to rock consisting primarily of the mineral dolomite.
Industry:Mining
