- Industri: 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 ...
A mining method consisting of removing the overlying strata or overburden, extracting the coal, and then replacing the overburden. When the overlying material consists of earth or clay it can be removed directly by scrapers or excavators, but where rock is encountered it is necessary to resort to blasting to prepare the material into suitable form for handling by the excavators.
Industry:Mining
A mining method often used by strip-mine operators where the overburden is too thick to be removed economically. Large-diameter, spaced holes are drilled up to 200 ft (61 m) into the coalbed by an auger. Like a bit used for boring holes in wood, this consists of a cutting head with screwlike extensions. As the auger turns, the head breaks the coal and the screw carries it back into the open and dumps it on an elevating conveyor; this, in turn, carries the coal to an overhead bin or loads it directly into a truck. Auger mining is relatively inexpensive, and it is reported to recover 60% to 65% of the coal in the part of the bed where it is used.
Industry:Mining
A mining method often used by strip-mine operators where the overburden is too thick to be removed economically. Large-diameter, spaced holes are drilled up to 200 ft (61 m) into the coalbed by an auger. Like a bit used for boring holes in wood, this consists of a cutting head with screwlike extensions. As the auger turns, the head breaks the coal and the screw carries it back into the open and dumps it on an elevating conveyor; this, in turn, carries the coal to an overhead bin or loads it directly into a truck. Auger mining is relatively inexpensive, and it is reported to recover 60% to 65% of the coal in the part of the bed where it is used.
Industry:Mining
A mining method that entails working the orebody from the top down in successive horizontal slices that may follow one another sequentially or simultaneously. The whole thickness of the slice is worked. The ore may be broken by overhand or underhand stoping in each unit. The overburden or cover is caved after mining a unit.
Industry:Mining
A mining method that entails working the orebody from the top down in successive horizontal slices that may follow one another sequentially or simultaneously. The whole thickness of the slice is worked. The ore may be broken by overhand or underhand stoping in each unit. The overburden or cover is caved after mining a unit.
Industry:Mining
A mining method that entails working the orebody from the top down in successive horizontal slices that may follow one another sequentially or simultaneously. The whole thickness of the slice is worked. The ore may be broken by overhand or underhand stoping in each unit. The overburden or cover is caved after mining a unit.
Industry:Mining
A mining method that entails working the orebody from the top down in successive horizontal slices that may follow one another sequentially or simultaneously. The whole thickness of the slice is worked. The ore may be broken by overhand or underhand stoping in each unit. The overburden or cover is caved after mining a unit.
Industry:Mining
A mining method utilizing the advantages of longwalls, but at the same time without filling. In this method, the working room in front of the working face is protected by close lines of props and cribs, which are portable and easily taken to pieces. As the face proceeds, the cribs are shifted as well as the props with the face, leaving the mined-out room to cave. This method is also called mining with self-filling.
Industry:Mining
A mining practice that represents an alternative to conventional ore beneficiation in that the mineral values are hydrometallurgically extracted rather than concentrated in solid form for further processing.
Industry:Mining
A mining system in which each shift has a specific task to complete on the conveyor face. If the task on any shift is not completed in time, the following shifts are disorganized. In general, the face is machine cut during the night shift; shot-firing and hand-filling of the coal occupy the day shift; and the afternoon shift is responsible for moving the conveyor and roof supports to the new line of face.
Industry:Mining