- Industry: 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 ...
The refraction of a ray of light at certain points of double-refracting crystals, so that on emerging from the crystal it widens from an apex into a hollow cone (external conical refraction), or on entering diverges into a cone and issues as a hollow cylinder (internal conical refraction).
Industry:Mining
The refractory portion of a mixture used in the manufacture of firebrick, composed of calcined clay or of reground bricks.
Industry:Mining
The region immediately adjacent to the boundary of an explosion crater characterized by excessive in-place crushing and fracturing where the stresses produced by the explosion exceeded the ultimate strength of the medium. Compare: plastic zone
Industry:Mining
The relation between pressure, p, and volume, Q, in the ventilation of a mine. If the resistance, R, of the mine is known, then the mine characteristic can be expressed as p=RQ<sub>2</sub>. The curve of this equation for a particular mine may thus be plotted on the same axes as the characteristics of a fan. The point of intersection of this curve, termed the mine characteristic, with the pressure characteristic of the fan, indicates the pressure and volume at which the fan would work in ventilating that mine. Knowing the volume and pressure, the power and efficiency are obtained. The suitability of any fan to any mine can be studied, and the effect of possible changes in mine resistance may be predicted.
Industry:Mining
The relation of drilled holes to each other and any free faces as part of the blast design.
Industry:Mining
The relation of some directional feature in a rock to the horizontal plane. The attitude of planar features (bedding, foliations, joints, etc.) is described by the strike and the dip. The attitude of a linear feature (fold axis, lineation, etc.) is described by the strike of the horizontal projection of the linear feature and its plunge.
Industry:Mining
The relationship between the density of a sample of soil in a dry state and its moisture content for a given degree of compaction. Such relationship can be determined from a curve that will reveal the optimum moisture content.
Industry:Mining
The relationship between the speeds of the first and last shafts, respectively, of a train of gears. If a certain force drives a machine at a given speed and the output shaft runs at one-tenth of the speed of the input shaft, then the output force will be 10 times the input. If the gear ratio of a motor-driven machine is 10 to 1, then the turning force of the last shaft will be 10 times that of the motor, apart from force used up in friction.
Industry:Mining
