- Industry: 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 ...
An excellent and cheap explosive in powder form, consisting of the constituents ammonium nitrate + trotyl + nitroglycerin + silicon.
Industry:Mining
An exceptionally accurate instrument for borehole surveying, designed particularly for use with the freezing and cementation methods of shaft sinking; capable of giving the slope of a borehole to within 1 min of arc.
Industry:Mining
An exceptionally coarse-grained igneous rock, with interlocking crystals, usually found as irregular dikes, lenses, or veins, esp. at the margins of batholiths. Most grains are 1 cm or more in diameter. Although pegmatites having gross compositions similar to other rock types are known, their composition is generally that of granite; the composition may be simple or complex and may include rare minerals rich in such elements as lithium, boron, fluorine, niobium, tantalum, uranium, and rare earths. Pegmatites represent the last and most hydrous portion of a magma to crystallize and hence contain high concentrations of minerals present only in trace amounts in granitic rocks. Adj: pegmatitic.
Industry:Mining
An exceptionally coarse-grained igneous rock, with interlocking crystals, usually found as irregular dikes, lenses, or veins, esp. at the margins of batholiths. Most grains are 1 cm or more in diameter. Although pegmatites having gross compositions similar to other rock types are known, their composition is generally that of granite; the composition may be simple or complex and may include rare minerals rich in such elements as lithium, boron, fluorine, niobium, tantalum, uranium, and rare earths. Pegmatites represent the last and most hydrous portion of a magma to crystallize and hence contain high concentrations of minerals present only in trace amounts in granitic rocks. Adj: pegmatitic.
Industry:Mining
An expandable device that is placed in a borehole to bar entry of water into the lower part of a hole or to separate two distinct flows of water from different strata.
Industry:Mining
An expanding bit used to enlarge the diameter of the hole below the casing to allow the casing to be lowered farther down the borehole.
Industry:Mining
An expansive clay of the smectite(?) group at Santa Lucia, near Mexico, D.F.
Industry:Mining
An exploder approved for firing six shots simultaneously in British coal mines. It contains a 67-1/2-V high-tension dry battery, used to charge a 150-mu F condenser, which in turn is discharged through the shotfiring circuit by a firing key. The test circuit and an ohmmeter are incorporated in the exploder, thc ohmmeter pointer moving over a scale to indicate whether or not the external circuit is in order. A pushbutton disconnects the test circuit from the external circuit and makes connection with the firing circuit.
Industry:Mining
An exploding charge producing an impulse that impinges upon an explosive acceptor charge.
Industry:Mining
An exploration technique utilizing the variation in the rate of propagation of shock waves in layered media. It is used primarily to delineate subsurface geologic structures of possible economic importance.
Industry:Mining
