- 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 ...
The sighting or pointing line of a telescope, defined by the optical center of the objective and the intersection of crosshairs.
Industry:Mining
The silica, SiO<sub>2</sub>, present within various clay minerals occurring in bauxite. During the Bayer process digestion of bauxite, this silica reacts with comparable amounts of alumina to form insoluble sodium aluminum silicate, which is lost as refinery plant residue.
Industry:Mining
The siliceous cell wall of a diatom, consisting of two valves, one overlapping the other. It is ornate, microscopic, and boxlike.
Industry:Mining
The simplest form of track layout for car or trip loading. In this system, the track can merely be extended down the heading, or it can be turned right or left, and then turned back, U-fashion, in an adjacent heading. The major disadvantage is that trips must come out the same way they go in, meaning increased loss of time unless the changing track is very close.
Industry:Mining
The simplest method for determining the amount of mineral matter present in a coal is to determine the ash and sulfur contents and to make corrections for the changes taking place in these during combustion. The Parr formula for doing this is: total inorganic matter=moisture+1.08 ash+0.55 sulfur, where moisture, ash, and sulfur represent the percentages of these substances found by analysis of the coal.
Industry:Mining
The simplest method of surveying, which has the advantage that the equipment required is inexpensive and hard wearing. It is the ideal method for small areas and has been employed successfully for large surveys. Nevertheless, it has definite limitations when applied to surveys of enclosed or built-up areas.
Industry:Mining
The simplest of all separating devices and the cheapest to install and maintain. It consists of a series of fixed bars or rails spaced the required distance apart in order that the "undersize" may drop through. The use of a stationary grizzly is limited to coarse screening of dry material (aperture 2 in or 5.1 cm and larger), although it is sometimes used with openings as small as 3/4 in (1.9 cm), the efficiency dropping off in proportion. It is not satisfactory for moist or sticky material.
Industry:Mining
The simplest type of stretcher used for underground first aid. This basket-type stretcher acts as a splint for the whole body, and is constructed of tubular steel and strong wire mesh. Used for lifting or lowering injured persons in difficult places. This type of stretcher is used in metal mines or in coal mines where the coalbed has a steep pitch.
Industry:Mining
