- 行业: Mining
- Number of terms: 33118
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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 ...
When there are two fans at a mine it is necessary to install isolation doors for each drift leading to a fan in order to prevent the working fan from drawing air from the outside atmosphere. With modern fan layouts, the fan drift may be 5 m or more square and pass 300 m<sub>3</sub>/s of air and sometimes more. Modern fan drift doors can be fixed in any position from fully open to fully closed and can be manipulated by one person from outside the fan drift. Doors of the butterfly type are often used and can be opened manually or by power.
Industry:Mining
When track is not adequately drained and water enters the ballast and roadbed, tie pumping occurs. Under the action of the rolling stock, pressure on the tie discharges water to the surface, washing the ballast from beneath and around the tie.
Industry:Mining
When used in connection with galvanic corrosion, it may refer to corrosion of the anodic metal when there is no contact with the dissimilar metal.
Industry:Mining
Where a broad vein apexes so that the boundary line between two claims splits the apex, the extralateral rights go to the senior locator, who takes the entire width of the vein on the dip; i.e., a broad lode that is bisected by the division side line between two mining claims belongs to the claim having the prior location.
Industry:Mining
Where a vein narrows, as if the walls had been squeezed in. Where the walls meet, the vein is said to be pinched out.
Industry:Mining
Where coal seams are worked by the longwall method it is necessary to maintain roadways leading to the face. These roadways should be of sufficient height to permit the easy passage of workers and materials, and this invariably means that some of the stone above the coal must be removed. This operation is known as ripping, and, unless the roof strata are very soft, blasting will be required. The main considerations in ripping blasting are to keep the sides of the roadway square, and to obtain good fragmentation of the stone so that it can be removed easily.
Industry:Mining
Where on a small scale, beds are much wrinkled, folded, or crumpled, they are said to be corrugated. On a larger scale, they are said to be contorted.
Industry:Mining
Where the dip of the coal seam is about 1 in 10 or less, the opencast method of working usually employed is to excavate along lines parallel to the outcrop. This is termed the strike or opencast method.
Industry:Mining
Where two or more mining claims longitudinally bisect or divide the apex of a vein, the senior claim takes the entire width of the vein on its dip, if it is in other respects so located as to give the right to pursue the vein downward outside of the sideline. In other words, a broad lode bisected by the division sidelines between two mining claims belongs to the claim having the prior location. The term lode has become extensively used in the classification of ore deposits that are not comprehended by the definition of a vein. Such an occurrence is called a broad lode or zone.
Industry:Mining
