- المجال: 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 jet black igneous rock consisting essentially of biotite. Near Libby, MT, such a rock has been altered to vermiculite by hot waters.
Industry:Mining
A jet black to brownish pitchlike material carrying from 12.12% to 84.22% CuO and found in the oxidized zone. It has a conchoidal fracture, and where it occurs in large enough pieces may resemble obsidian or anthracite coal. It apparently may be a mixture of the hydrous oxides of copper and iron, oxide and carbonate of copper, oxide and silicate of copper, or more or less hydrated oxides of copper and manganese. All the varieties may have more or less chalcedony mixed with them.
Industry:Mining
A jib crane in which the inclination of the jib, and hence the radius of action, can be varied by shortening or lengthening the tie ropes between the post and the jib.
Industry:Mining
A jib of a coal cutter or cutter loader that makes a vertical or shear cut in the coal, ore, or rock.
Industry:Mining
A jig fitted with a flexible rubber diaphragm that is worked by an eccentric motion, thus producing a jigging cycle (pulsion suction).
Industry:Mining
A jig in which pulsion is given intermittently with suction; the periods devoted to them are about equal.
Industry:Mining
A jig used chiefly on tin dredges to treat the undersize from the main revolving screen. It differs from the Harz jig in that there is no longitudinal division and the screening compartment extends over the whole surface of the jig; the plungers are located in the hutch below the screen are set in a vertical plane and reciprocate horizontally.
Industry:Mining
A jig used to handle the larger sizes and heavier grades of ore or metal.
Industry:Mining
