- 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 arc melting in which a carbon or tungsten electrode is used and the sponge metal to be melted is fed into the arc at the proper rate.
Industry:Mining
A method of arc melting in which the electrode itself serves to supply the metal; this method is commonly employed for melting titanium and zirconium.
Industry:Mining
A method of assessing the efficiency of a mine fan by comparing the temperature rise in an ideal isentropic fan for a given fan pressure with the measured temperature rise actually occurring in the fan under consideration when producing the same fan pressure. The ratio of isentropic temperature rise to the actual temperature rise across the fan gives the fan efficiency. The method gives an accuracy of + or -5%.
Industry:Mining
A method of assigning a sample value to a point in space. The value assigned is equal to the value of the spatially nearest sample data point. This method is sometimes used as a computer equivalent of the polygonal method of interpolation.
Industry:Mining
A method of binding mine roadway dust by spraying the area with salt and water. The salt is subjected to wetting and drying cycles. The deposited dust is bound at first by surface tension and then in the recrystallization of the dissolved salt.
Industry:Mining
A method of blasting coal that has been undercut, topcut, or sheared. Into one end of a seamless high-grade molybdenum-steel cylinder 2 to 3 in (5.08 to 7.62 cm) in diameter and 36 to 60 in (91.44 to 152.4 cm) long is put a cartridge containing a mixture of potassium perchlorate and charcoal with an electric match. The other end is sealed by a metal disk weaker than the shell and held in place by a cap that has holes at about 45 degrees to the axis of the cylinder. The cylinder is filled with liquid carbon dioxide at a pressure of 1,000 psi (6.9 MPa) and inserted in a borehole with the cap holes pointing outward. The heating mixture is lit and raises the gas pressure so that the disk is sheared; the carbon dioxide escaping through the angular holes tends to hold the cylinder in place, and break and push the coal forward. If the gas pressure is not enough to break the coal, the cylinder, if not properly set, will be blown from the borehole. The cylinder can be used over and over. It is claimed that a greater portion of lump coal is obtained than with ordinary explosives. Some smelters loosen slag in the same way.
Industry:Mining
A method of blasting in tunnels, drifts, and raises, designed to minimize overbreak and leave clean-cut solid walls. Holes in the outside row are loaded with very light, continuous explosive charges and are fired simultaneously, so that they shear from one hole to the other.
Industry:Mining
A method of blasting in which an airspace is left between the explosive charge and the stemming, or in which the shothole is of substantially larger diameter than the cartridge.
Industry:Mining
A method of blasting in which compressed air at very high pressure is piped to a steel shell in a shot hole and discharged.
Industry:Mining
A method of blasting using a number of relatively large concentrated charges of explosives placed in one or more small tunnels driven in a rock formation.
Industry:Mining
