- Industry: Mining
- Number of terms: 33118
- Number of blossaries: 0
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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 ...
In crystallography, two forms combined geometrically to produce a form having higher symmetry; e.g., two equally developed rhombohedra of quartz resembling a hexagonal bipyramid.
Industry:Mining
In crystallography, two forms that may each be derived from the other by rotation about an axis of symmetry.
Industry:Mining
In cutting out blocks of stone, the cut that follows a line at right angles to the strike.
Industry:Mining
In cylinder cuts the blasting is performed toward an empty hole in such a way that, as the charges in the first, second, and subsequent holes detonate, the broken rock is thrown out of the cut. The opening is successively and uniformly (cylindrically) enlarged in its entire length.
Industry:Mining
In damped seismographs, this term is by definition equal to one-half the ratio of the damping resistance (force per unit velocity) to the moving mass. It has the dimensions of a frequency.
Industry:Mining
In deep mining fields, shear bursts are the most common type. By the occurrence of a single shear crack parallel to the face in one of the walls, the wall rock behind the shear plane is able to expand freely into the stope, heavily compressing those supports that until then have not taken stress, throwing still more stress on those that have, and causing the wall rock between the nearest supports and the face to disrupt and fill the place with debris. Shear bursts frequently occur at the working face of a pillar, remnant, or promontory. In such cases, they should not be mistaken for true pillar bursts.
Industry:Mining
In deep mining, relief of pressure concentrations induced by mining or caused by geological factors. Performed by drilling and blasting to loosen the zones of peak stress. The peak load surrounding the excavation walls is thus transferred deeper into the undisturbed rock, and a protective barrier is formed.
Industry:Mining
In determining the assay value of an orebody, the multiplication of its assay grade by the number of feet along which the sample was taken. Compare: assay inch; assay value.
Industry:Mining
In determining the assay value of an orebody, the multiplication of its assay grade by the number of inches along which the sample was taken. Compare: assay foot; assay value.
Industry:Mining
In diamond drilling, using a bit that grinds the whole face, without preserving a core for sampling.
Industry:Mining
