- 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 method of tunneling in hard rock. The heading is in the upper part of the section and is driven only a round or two in advance of the lower part or bench.
Industry:Mining
A method of tunneling through loose, running ground by driving spills (sharp-edged thick boards or steel rods) ahead and around timber or steel frames.
Industry:Mining
A method of tunneling using loaders mounted on crawler tracks, and a diesel- or batterypowered dump-truck haulage system.
Industry:Mining
A method of tunneling whereby the center is left to the last for excavation.
Industry:Mining
A method of underground haulage sometimes adopted in steep workings, where the gradient is 1:2 to 1:1.5. There are two kinds: (1) a skip carriage on which the tub is placed in a horizontal position; and (2) a self-dumping system in which the skip, which is permanently attached to the rope, is discharged automatically at the top of the incline and then returned for reloading.
Industry:Mining
A method of underland stoping in which rapid advance of the face is maintained, and by working the faces at an angle of 60 degrees to the strike, the peak travels down the dip at twice the rate of the face advance. This method was introduced on the Witwatersrand for stoping below 5,000 ft (1,524 m), where rapid face advance resulting from the closer spacing of holes reduces the incidence of rock bursts.
Industry:Mining
A method of wiring a large group of blasting charges by connecting small groups in series and connecting these series in parallel.
Industry:Mining
A method of wiring a large group of blasting charges by connecting small groups in series and connecting these series in parallel.
Industry:Mining
A method of working an orebody from the top down in successive slices. Instead of taking the full height of the slices, only the lower part is taken and the upper part is caved. After removing this portion of the ore, the cover is caved. A timber mat is used in most cases to separate the broken cover from the ore and for safety. Also known as caving system subdrifting and caving; subslicing; slicing under ore with back cave; sublevel caving; sublevel slicing.
Industry:Mining
A method of working coal seams about 30 in (76.2 cm) thick, using a small continuous miner type of machine, which is remotely controlled from the roadway and without any associated supports. The machine is used to cut and extract sections of coal about 6 ft 2043 (1.8 m) wide for a distance of 100 yd (91 m) or so from pillars alongside the roadway. Small ribs of coal, 3 to 6 ft (approx. 1 to 2 m) wide, are left between the sections extracted by the machine. The accurate steering of the machine is a critical feature of this system of mining.
Industry:Mining
