- 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 method of working coal seams. First bords are driven, leaving supporting pillars of coal between. Next, cross drives connect the bords, leaving supporting coal as rectangular pillars. Finally, the pillars are mined (extracted, won, robbed) and the roof is allowed to cave in. The bordroom is the space from which bord coal has been removed.
Industry:Mining
A method of working coal seams. First bords are driven, leaving supporting pillars of coal between. Next, cross drives connect the bords, leaving supporting coal as rectangular pillars. Finally, the pillars are mined (extracted, won, robbed) and the roof is allowed to cave in. The bordroom is the space from which bord coal has been removed.
Industry:Mining
A method of working coal seams. First bords are driven, leaving supporting pillars of coal between. Next, cross drives connect the bords, leaving supporting coal as rectangular pillars. Finally, the pillars are mined (extracted, won, robbed) and the roof is allowed to cave in. The bordroom is the space from which bord coal has been removed.
Industry:Mining
A method of working in which rooms are driven from adjacent headings to meet at their extremities.
Industry:Mining
A method of working moderately inclined coal seams. The first stage consists of splitting a panel of coal into pillars and as a second stage the pillars are extracted on the retreat by a longwall face.
Industry:Mining
A method of working the open-hearth furnace in the duplex process so as to reduce as much as possible the amount of manganese lost in the slag in the production of manganese steels.
Industry:Mining
A method originated in the United States for breaking down coal by compressed air. Air at a pressure of 10,000 to 12,000 psi (69 to 83 MPa) is conveyed in a steel pipe to a tubeor shell-inserted shothole. The air is admitted by opening a shooting valve and is released in the hole by the rupture of a shear pin or disk. The sudden expansion of the air in the confined hole breaks down the coal.
Industry:Mining
A method originated in the United States for breaking down coal by compressed air. Air at a pressure of 10,000 to 12,000 psi (69 to 83 MPa) is conveyed in a steel pipe to a tubeor shell-inserted shothole. The air is admitted by opening a shooting valve and is released in the hole by the rupture of a shear pin or disk. The sudden expansion of the air in the confined hole breaks down the coal.
Industry:Mining
A method similar to sandblasting for cleansing the surface of metals, using broken shot or steel grit instead of sand.
Industry:Mining
A method sometimes used to recover diamond particles 1 mm or smaller.
Industry:Mining
