- 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 ...
The driving of two coal headings, parallel and side by side, for development purposes. Usually a pillar 10 to 20 yd (9.14 to 18.29 m) wide is left between them. Formerly it was the practice at many coal mines to drive only one heading from which the stalls were turned off right and left. Two headings simplify ventilation and provide a second egress in an emergency.
Industry:Mining
The dry density obtained by the compaction of soil at its optimum moisture content.
Industry:Mining
The dry weight per unit volume of the sediment in place.
Industry:Mining
The drying of the sap and moisture in the woody fibers and thus reducing the timber by shrinkage. It becomes more durable and weighs less. Timber may be air-dried, i.e., dried naturally in air, or kiln-dried, which means dried in kilns under the action of artificial heat. The former is more general.
Industry:Mining
The duckbill assembly consists of five major units: (1) a shovel trough to which is attached the shovel head fitting inside the feeder trough, (2) an operating carrier that controls the connection or coupling between the feeder and shovel troughs, (3) a sliding shoe that moves to and fro on the floor of the seam, (4) a swivel trough, and (5) a pendulum jack. The function of the duckbill is to gather the coal and load it into the shaker conveyor pan column. The shovel is forced into the prepared coal by the forward motion of the pan column. As the shovel is propelled forward, the coal is conveyed back along the shovel trough and then to the pan column.
Industry:Mining
The dust deposited from the cloud raised by the explosion, which settles after the explosion has died down, only part of which may be traversed by the flame.
Industry:Mining
