- 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 ...
Track brakes, similar to those used on surface tramcars, may be installed on heavy downgrades underground to supplement other braking systems; they apply blocks to the rails by mechanical, pneumatic, or electromagnetic power. The normal shoe brake must be designed to work in conjunction with the track brakes so that the wheels are not skidded when the track brakes utilize part of the weight of the locomotive. Electromagnetic track brakes may utilize the braking currents produced in rheostatic braking to excite the electromagnets, which are then pulled down onto the rails and produce a strong retarding pull.
Industry:Mining
Trade name for a coal-cutter chain designed for use with curved jibs. It is short pitch and of high flexibility.
Industry:Mining
Trade name for a colloidal bentonite (jelly rock) used in papermaking. Also spelled Wilconite.
Industry:Mining
Trade name for a cutter loader incorporating a special variety of shearer head. The Mark II model consists of section plates welded together to form a composite whole spiral. The disk is made in different sizes to give cutting diameters of from 31 to 72 in (79 to 183 cm) with a maximum web depth of 30 in (76 cm). A single spiral is used for softer coals and a double spiral for hard coals. A plow attached to the machine throws the coal onto the conveyor.
Industry:Mining
Trade name for a cutting machine provided with a conveyor for gobbing the unusable cuttings formed during the cutting operation.
Industry:Mining
Trade name for a dense-medium washer for treating coal lump size down to about 1/8 in (3.2 mm). It comprises a shallow circular tank with a flat base and a conical inner shell containing the driving mechanism. The clean coal floats and passes over a weir while the shale sinks to the bottom and is conveyed to an outlet chute. Its capacity ranges from 2141 about 50 st/h (45.4 t/h) to over 500 st/h (454 t/h), depending on the size of the vessel.
Industry:Mining
Trade name for a heavy track-mounted continuous miner for operation in thick seams. The front end contains two cutter arms that rotate in opposite directions to sweep the coal it cuts inwards toward the center. The broken coal is taken back through the machine to a chain conveyor. Two cutter chains are arranged at roof and floor level behind the arms to cut down the coal left between the rotating arms. The machine cuts an area 12 ft (3.7 m) wide and 7 ft (2.1 m) high. Power is supplied by two motors, one of 70 hp (52.2 kW) and the other of 25 hp (17.4 kW). It has a continuous capacity from 3 to 3-1/2 st/min (2.7 to 3.2 t/min). This machine has been subject to several modifications.
Industry:Mining
