- 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 formula used for calculating the thickness of tubbing: t = hdF/2C + A, where: t is the required thickness of tubbing in inches; h is the pressure of water in pounds per square inch; d is the diameter of the shaft in inches; C is the crushing strength of cast iron in pounds per square inch, which may be taken as 95,000; F is the factor of safety adopted between 5 and 10; and A is the allowance for possible flaws and corrosion and may vary from 1/4 to 1 in (6.4 to 25.4 mm), averaging 1/2 in (12.7 mm).
Industry:Mining
A formula used in the calculation of earthwork quantities. It states that the volume of any prismoid is equal to one-sixth its length multiplied by the sum of the two end-areas plus four times the mid-area.
Industry:Mining
A forward-and-reversing transmission that is shifted by a pair of friction clutches.
Industry:Mining
A fossil bone or tooth colored deep blue by iron phosphate (vivianite), and rarely green by copper compounds, and resembling turquoise, such as that from the tusks of mammoths found in Siberia. It is cut and polished for jewelry.
Industry:Mining
A fossil bone or tooth colored deep blue by iron phosphate (vivianite), and rarely green by copper compounds, and resembling turquoise, such as that from the tusks of mammoths found in Siberia. It is cut and polished for jewelry.
Industry:Mining
A fossil bone or tooth colored deep blue by iron phosphate (vivianite), and rarely green by copper compounds, and resembling turquoise, such as that from the tusks of mammoths found in Siberia. It is cut and polished for jewelry.
Industry:Mining
A fossil plant found in coalbeds or contributing its substance to the formation of coalbeds. Any plant species, the residue of which has entered into the composition of coal under natural geological conditions.
Industry:Mining
A fossil resin from the brown coal near Bonn, Germany; it ranges in color from golden yellow to brownish red, and is partly soluble in alcohol and ether.
Industry:Mining
A fossil resin resembling amber and found in small yellowish grains disseminated in brown coal.
Industry:Mining
