- 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 ...
This type of pump, often called axial-flow, develops most of its head by the propelling or lifting action of the vanes upon the liquid. These pumps are built in horizontal or vertical casings and are primarily used in handling sludge, dewatering pits, sewage pumping, and similar duties requiring large capacities and heads under 100 ft (30 m).
Industry:Mining
This type of tonstein consists almost entirely of fine-grained kaolin groundmass, showing weak aggregate polarization, containing isolated corroded crystals of kaolinite. Such bands are commonly more than 100 mm thick and light in color.
Industry:Mining
This type of tonstein contains vermicular, prismatic, or tabular kaolinite crystals and may be either light or dark in color according to the proportion of contained carbonaceous matter. Occasionally granular kaolinite may also be recognized. The crystals lie embedded in either a finely crystalline or cryptocrystalline kaolinite groundmass.
Industry:Mining
This type of turntable is used as an alternative to the shunt-back or the traverser for changing the direction of mine cars or tubs, either on the surface or underground. A pulley driven by a creeper chain bringing along the cars is on the same vertical axis as the turntable and is so disposed that when a car is on the table two of its wheels rest on its central pulley while the other two rest on the outer edge of the turntable.
Industry:Mining
This type of wire-rope capping is simple to apply. The sleeves are first threaded on the rope, a white metal bob is then formed on the end of the rope by untwisting the wires and cutting out the hemp core, if present, and white metal is run into a mold around the wires. The bob is allowed to cool. Two tapered interlocking steel wedges are then fitted on to the rope clear of the bob so that wedges can move forward toward the bob and grip the rope as the load is applied to the capping. The rope is cleaned of lubricant where the wedges will grip, and the groove in the wedges must be of such a size that a gap is left between the wedges so that they can grip the rope firmly. The edges of the wedges should come opposite a valley between the strands of the rope. The outer socket is now placed over the wedges and the sleeves are lightly tapped into position to hold the parts together.
Industry:Mining
This type table is used at the Kimberly Mines in South Africa for concentrating the - 3.33- to +0.59-mm fraction of pan concentrate and other material of +0.59-mm size. Efficiency is 99%, and the ratio of concentration 50,000:1.
Industry:Mining
This very dangerous occurrence may arise as the result of spontaneous combustion, the ignition of timbers by gob fires, electric cable defects, or the heating and ignition of conveyor belts due to friction.
Industry:Mining
This water-sampling device is messenger actuated. It is designed to allow free flow while in the cocked position on the downward traverse. When the desired sampling point has been reached, the closures are messenger actuated, resulting in isolation of the sample on the return traverse. Frautschy bottles may be attached to the hydrographic wire at intervals and in such a manner that release of a single messenger from the surface will actuate the entire series. In this way samples from several depths may be obtained in a single operation.
Industry:Mining
This winding system makes use of a coal receptacle on small rollers that fits closely in the cage. During the previous wind, it is filled near the shaft, and similarly it is emptied very quickly at the surface and returned to the pit bottom on the next wind.
Industry:Mining
