- 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 ...
Metallurgy involved in winning and refining metals in which heat is used, as in roasting and smelting. Practically all iron and steel, nickel and tin, most copper, and a large proportion of zinc, gold, and silver, as well as many of the minor metals, are won from their ores and concentrates by pyrometallurgical methods. It is the most important and oldest class of the extractive processes.
Industry:Mining
Metal-rich water, as it moves away from the source of the metal, ordinarily comes into an environment where changing conditions of some kind cause precipitation of part or all of the metal from the water. Precipitation barriers account for the more than normal decay of hydrochemical anomalies than can be accounted for by simple dilution. They characteristically occur in spring and seepage areas where groundwaters coming to the surface encounter an environment of increased availability of oxygen, sunlight, and organic activity.
Industry:Mining
Metals or alloys used in thermocouples for measuring high temperatures. Platinum, nickel, copper, rhodium, etc., are much used.
Industry:Mining
Metals or metal compounds left at, or falling from, the anode during electrolytic refining. The plural form is often used.
Industry:Mining
Metals used for electroplating. They are as pure as commercially possible, uniform in texture and composition, and have the skin removed by machining. In addition to pure single metals, various alloys are produced in anode form, such as Platers' brass and Spekwite, the latter yielding a white plate harder than nickel.
Industry:Mining
Metamorphic changes in response to a higher pressure or temperature than that to which the rock last adjusted itself. Compare: retrograde metamorphism
Industry:Mining
Metamorphic processes at the extreme upper range of temperatures and pressures, at which partial to complete fusion of the affected rocks takes place and magma is produced. The term was originated by Holmquist in 1909.
Industry:Mining
Metamorphism accompanied by intimate injection of sheets and streaks of liquid magma (usually granitic) in zones near deep-seated intrusive contacts. Compare: plutonic metamorphism; lit-par-lit.
Industry:Mining
Metamorphism caused by a local process; e.g., contact metamorphism or metasomatism near an igneous body, hydrothermal metamorphism, or dislocation metamorphism in a fault zone. Compare: regional metamorphism
Industry:Mining
Metamorphism that is accomplished under conditions of low to moderate temperature and pressure. Compare: high-rank metamorphism
Industry:Mining
