- 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 column so short in relation to its cross section that, if overloaded, it will fail by crushing rather than by buckling. Compare: long column.
Industry:Mining
A column that fails by buckling, as distinct from crushing, when overloaded. Compare: short column.
Industry:Mining
A combination mining machine designed and built to work in entries and other narrow places, and to load coal as it is broken down. An undercutting frame and two vertical shearing frames serve to undercut and shear the sides of the coal, so that the ram equipped with bars and operated by hydraulic jacks can break down the coal. The height at which the ram operates against the coal, when the undercut and shearing are completed, is adjustable. A conveyor in the undercutting frame carries the broken-down coal back to another conveyor mounted on a turntable so that the coal can be loaded into a mine car, or slate can be deposited on the gob side of the entry. The entire machine is mounted in a pan.
Industry:Mining
A combination of a cone and a cylinder. The ascending rope is wound on the smaller diameter of the cone; as the engine reaches full speed after the period of acceleration, the rope is wound on the larger cylindrical part. For deep shafts the rope is wound back on itself for the last part of the hoisting period, thus reducing the width of the drum.
Industry:Mining
A combination of positive and negative lenses designed to obtain larger magnification of distant objects than is possible with ordinary lenses.
Industry:Mining
A combination of sheaves over which chains are arranged in the same manner as the rope in a block and tackle.
Industry:Mining
A combination of sheaves over which chains are arranged in the same manner as the rope in a block and tackle.
Industry:Mining
A combination of the duplex and the Talbot continuous process. Molten steel from the Bessemer converter, already freed of its carbon, silicon, and manganese contents, is charged into the Talbot furnace. As this molten steel is poured through the oxidized slag, the phosphorus is removed almost immediately. Sometimes pig iron is poured in afterwards, which raises the carbon content of the bath and aids in its deoxidation. A portion of the heat can usually be tapped about an hour after this addition.
Industry:Mining
A combination of the Hasenclever and O'Hara furnaces, with four hearths, and with a combination flue under the lowest hearth and one over the upper hearth. It has mechanical rabbles.
Industry:Mining
