- 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 needle, consisting of a steel magnet, similar to that in a miners' dial, but pivoted at the center so as to be free to rotate vertically. It is used to locate the presence of shallow deposits of magnetic ores. The magnetometer has now replaced the dipping needle for large-scale prospecting work.
Industry:Mining
A nepheline-rich groundmass in an igneous rock; the glassy groundmass in nepheline rocks.
Industry:Mining
A network along grain boundaries, which may originate by segregation on exsolution. A similar texture may form by the replacement of organic forms, esp. cell walls, by ore minerals.
Industry:Mining
A network of intersecting blades or plates of limonite or other iron oxide, deposited in cavities and along fracture planes from which sulfides have been dissolved by processes associated with the oxidation and leaching of sulfide ores, esp. porphyry copper deposits.
Industry:Mining
A new cutter loader devised by Maynard Davies and developed at the Central Engineering Establishment of the National Coal Board of Great Britain. A shearer drum is carried on a vertical shaft in contrast to the horizontal shaft in the Anderson shearer.
Industry:Mining
A new device to achieve short-interval delay firing with Cordtex. A relay is an aluminum tube with a delay device, and is inserted in a line of Cordtex where required. The relays are made with two delays, 15 ms and 20 ms, respectively.
Industry:Mining
A new drill hole pattern in which two overlapping holes of diameter about 2-1/4 in (5.7 cm) are drilled in the tunnel center and left uncharged. These holes form a slot roughly 4 in by 2 in (10.2 cm by 5.1 cm) to which the easers can break. All the holes in the round are parallel and in line with the tunnel. Short-delay detonators are used for the easer holes and 1/2-s delays for the rest of the round. A pull of 10 ft (3.0 m) per round has been obtained in strong rock with 10.5-ft (3.2-m) holes. Explosive consumption for the easer holes is about 0.2 lb/ft (0.3 kg/m) of hole.
Industry:Mining
A niche cut in the rib or wall of an underground mine for the storage of explosives or detonators.
Industry:Mining
