- 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 ...
The extraction of the coal pillars formed by a pillar method of working, by a longwall face, which can be advancing or retreating. Where the crush is not excessive, this method is more efficient and often safer than extracting each pillar individually.
Industry:Mining
The extrusive equivalent of granodiorite. The principal minerals, sodic plagioclase, sanidine, quartz, and biotite or hornblende, commonly occur as phenocrysts in a finely crystalline groundmass of alkali feldspar and quartz. Accessory minerals are apatite and magnetite, and occasionally augite.
Industry:Mining
The extrusive or hypabyssal equivalent of a quartz monzonite. The principal minerals are quartz, sanidine, biotite, sodic plagioclase, and hornblende, commonly as phenocrysts in a groundmass of potash feldspar and quartz (or tridymite, cristobalite), or glass in flows. Accessory minerals are magnetite, apatite, and zircon.
Industry:Mining
The face of a roadway, usually in longwall conveyor mining. The records indicate that the roadhead is the most dangerous place in a coal mine based on accidents from falls of ground.
Industry:Mining
The face of the spoil or embankment sloping downward from the highest elevation to the toe.
Industry:Mining
The face-centered cubic form of pure iron, which is stable from 1,670 to 2,550 degrees F (910 to 1,400 degrees C).
Industry:Mining
The factor of from 1 to 2 by which the weight of a moving load is multiplied to calculate its full effect on the structural design of a floor or bridge.
Industry:Mining
