The mining of river bars, usually between low and high waters, although
the stream is sometimes deflected and the bar worked below water level.
See also:bar diggings
a. A monoclinic mineral, (Na,Ca)2 V6 O16 .3H2
O .
b. Trademark for a rare-earth oxide used in glass polishing.
A barometer that makes a continuous record of changes in atmospheric
pressure. It is usually an aneroid type. See also:barometer
AGI
An instrument that is used to measure atmospheric pressure. It may be
either a mercury barometer or an aneroid barometer. See also:barograph
AGI
In filtering system, use of a loop more than 30 ft (9.1 m) high between
receiving vessel and vacuum pump, to protect latter against carryover of
liquid. Pryor, 3
A type of indirect leveling in which differences of elevation are
determined from differences of atmospheric pressure observed with
altimeters or barometers. AGI
The barometric pressure of the air at any point is that exerted by the
weight of the atmosphere above that point. It therefore varies with the
elevation of the point above or the depth below sea level. Barometric
pressure is measured by the mercury barometer, and is of the order of 30
in (762 mm) of mercury at sea level. Spalding
a. Any pearl of very irregular form.
b. A baroque pearl; said of a pearl, or of a tumble-polished gem material,
of irregular shape.
A generic term for injury caused by pressure. Although squeeze is a
colloquialism, it is an excellent descriptive term for all of the
phenomena that occur when a rigid closed space within the body or on its
surface fails to equalize with external pressure during descent, or is for
some reason vented to lower pressure than that acting at the depth.
Hunt
A precipice; as used in some parts of Spanish America, a ravine or small
canyon. Also spelled barranco.
A mineral intermediate between strengite and variscite.
a. As used in the petroleum industry, a volumetric unit of measurement
equivalent to 42 U.S. gal (159.0 L). AGI
b. The cylindrical part of a pump from which the movement of the piston
causes a liquid or gas to be forcibly ejected. Also, the cylindrical part
of a hydraulic jack or of a hydraulic-feed mechanism on a diamond drill.
Long
c. The drum of a hoist. Long
d. A cylindrical container or drum having a capacity of 55 gal (208.2 L).
Long
e. The water passage in a culvert. Nichols, 1
f. Commonly, although incorrectly, used as a syn. for core barrel.
See also:drum
Pieces of native copper occurring in sizes large enough to be extracted
from the gangue, and of sufficient purity to be smelted without mechanical
concentration. Syn:barrel work
A volumetric unit of measurement equivalent to 42 U.S. gal (159.0 L).
AGI
A washer comprising a cylinder rotating slowly about an axis that is
slightly inclined to the horizontal, and into which the raw coal, with a
current of water or of a suspension, is fed near its upper end. The clean
coal is carried by the water or suspension to the lower end of the
cylinder over a scroll that conveys the reject to the upper end of the
cylinder. BS, 5
Syn:barrel copper
a. In leaching ores, said of a chemical solution from which valuable
solute has been removed by precipitation, ion exchange, or solvent
extraction before reuse. Pryor, 1
b. Said of rock or vein material containing no minerals of value, or of
strata without coal, or containing coal in seams too thin to be workable.
Strata containing seams of coal that are not of a workable thickness. In
metal mining, ground that does not contain ore.
See also:dead bed
See:blank hole
Coal measures without workable seams. Standard, 2
oª *¬ üPÃ ¦ DICTIONARY TERMS:barren mine A mine may be fully developed and yet,
[\B]barren mine[\N]
A solution in hydrometallurgical treatment from which all possible
valuable constituents have been removed; it is usually recycled back to
plant for reuse in process. See also:cyanide