- 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 ...
Rocks that have come from the depths of the Earth; i.e., plutonic and eruptive rocks.
Industry:Mining
Rocks, minerals, and select naturally occurring and synthetic materials of economic value, exclusive of fuel and metallic ore minerals. The select materials include peat, mineral-derived materials such as lime and cement, and synthetic versions of gemstones, abrasives, graphite, and calcite. Generally, non-metallic minerals undergo no chemical or 2133 mineralogical alteration for and in their end-uses; are low-price, high-volume commodities such as construction materials; are higher-priced and large-volume commodities that are raw materials in the chemical and agricultural industry; and very high price but very low volume materials such as gemstones. A characteristic of nonmetallic minerals is that, in most cases, they maintain their form and physical properties through processing to final end use.
Industry:Mining
Rods of round iron, used in shaft construction to suspend wallplates. In concrete-lined shafts hanging rods give reinforcement, the top set being concreted into the shaft collar and others hooked on below, with periodic consolidation in strong rock strata as the shaft is deepened. Sometimes called hangers.
Industry:Mining
Rolled steel sections or other fabricated members assembled to form structural frames by riveting, welding, bolting, or a combination of all three.
Industry:Mining
Rolls in which all four boxes are moveable in position by springs to divide the thrust whenever the springs yield and thus reduce internal stresses.
Industry:Mining
Rolls with rough surfaces to facilitate the gripping of the steel in the first stages of rolling, as distinguished from the smooth-finishing rolls.
Industry:Mining
Roof and walls of underground excavations that are in danger of collapse unless suitably supported.
Industry:Mining
