- 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 coal seam that has separated into two or more layers which may, or may not, rejoin some distance away.
Industry:Mining
A coal seam that has separated into two or more layers which may, or may not, rejoin some distance away.
Industry:Mining
A coal washer of the classifier type whose agitator or rotator consists of hollow arms radiating from a central distributing manifold or center head. There may be four or more of these radiating arms, each with one or more downwardly inclined nozzles. When water is discharged from these nozzles, the impulse has the effect of rotating the agitator in a manner similar to a lawn sprinkler. This agitator is suspended in a cylindrical tank and water is pumped through it under pressure, thereby creating a controlled upward current uniform over the entire area of the tank.
Industry:Mining
A coal-cleaning method that involves the use of washers plus the equipment necessary to dewater and heat-dry the coal. This method is generally used when cleaning the coarser sizes of coal. It is a more expensive method than air cleaning and creates the additional problem of water pollution. Coal can, however, be cleaned more accurately by this method than by air cleaning.
Industry:Mining
A coal-cleaning method that utilizes air to remove the dust and waste from coal. Air cleaning requires that the coal contain less than 5% of surface moisture as a rule. It is effective only in the coarse sizes (plus 10 to 28 mesh) and is best suited to coals having a sharply defined line between coal and refuse material. Predrying to reduce the moisture content of the coal ahead of the air treatment is not uncommon. It is a less expensive and also a less accurate method of cleaning coal than the wet-cleaning method.
Industry:Mining
A coal-cleaning process using a heavy suspension, consisting of clay and finely ground barite (-150 or #MG200 mesh) in water. A coal containing as little as 3.3% to 3.4% ash is steadily produced, with a yield practically equal to the theoretical float-and-sink yield.
Industry:Mining
A coal-crushing machine in which the roll teeth crack downward on the lump and the roll itself compresses the coal against the breaker plates. Teeth of two or more designs are used generally on the same roll, some for the slugging, cracking, or blow action and others for a pulling and splitting force. The breakers are not easy to stall by choking, since they will pass a heavy overload, partly because of the action of a relief mechanism, with which they are all equipped.
Industry:Mining
A coal-cutter jib designed to conduct water through ducts, or other arrangement, to the back of the kerf, to suppress dust and reduce the gas-ignition hazard.
Industry:Mining
