- 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 ...
Blowing chips out of a hole by means of exhaust air from the drill. (Nichols, 1976)
Industry:Mining
Boards from 1 to 4 in (2.5 to 10 cm) thick and of sufficient length to bridge the space between timber or steel sets or between rings in skeleton tubing. Usually, planks 9 to 12 in (23 to 30 cm) in width are used. Round poles, either whole or split, light steel rails, ribbed sheet metal, and reinforced concrete slabs are sometimes used in place of planks. Backing deals tighten the supports against the ground and also prevent the collapse of material between the timber or steel sets or rings.
Industry:Mining
Bobs or weighted strings hung from two or more established points to give direction to miners driving a chamber or gangway.
Industry:Mining
Bol. In alluvial mining, a thick bed of blocks of granite, schists, and quartz.
Industry:Mining
Bolts installed at intersections to measure roof sag. A sag bolt is a 12-ft (3.5-m) unit put in without a bearing plate. It is securely anchored in the 12-ft horizon with the aid of a heavy nut, and extends about 2 in (5 cm) from the hole. Three 1/2-in (1.3-cm) strips of colored pressure-sensitive tape are wrapped around the extending section of the bolt, beginning with green at the roof line, then yellow and red. The color bands provide a simple, economical means of detecting roof sag at a glance.
Industry:Mining
