A hollow bar attached to the top of the drill column in rotary drilling;
also called grief joint; kelly joint; kelly stem. Meyer
An intermittent, movable pressure filter. The leaves are vertical and are
set parallel with the axis of the tank. Pulp is introduced into the tank
(a boilerlike affair) under pressure, and the cake is formed. The head is
then unlocked, the leaves are run out of the tank chamber by means of a
small track, and the cake is dropped. The carriage and leaves are then run
back into the tank, and the cycle begins again. Liddell
The ashes of seaweeds, formerly the source of soda as used in glassmaking
and soapmaking; now a source of potash, iodine, and char.
Standard, 2
a. Board of Trade unit of energy (1 kW/h). Pryor, 3
b. See:Kelvin temperature scale
The absolute temperature scale in which the temperature measure is based
on the average kinetic energy per molecule of a perfect gas. The zero of
the Kelvin scale is -273.16 degrees C. The temperature scale adopted by
the International Bureau of Weights and Measures is that of the constant
volume hydrogen gas thermometer. The magnitude of the degree in both these
scales is defined as one one-hundredths the difference between the
temperature of melting ice and that of boiling water at 760 mm pressure.
See also:temperature
Handbook of Chemistry and Physics, 2
See:corona
See:corona
A term applied to the rims or borders consisting of microcrystalline
aggregates of pyroxene or amphibole occurring around olivine, where it
would otherwise be in contact with plagioclase, or around garnet, where it
would otherwise be in contact with olivine or other magnesium-rich
minerals.
See:corona
A scraper-box type of plow for use on longwall faces.
See also:scraper box plow
An orthorhombic mineral, Mn2 Cl(OH)3 ; forms minute
emerald-green prismatic crystals; at Alum Rock Park, CA.
A coal that can be ignited with a match to burn with a bright flame.
Syn:candle coal
An orthorhombic mineral, Pb2 Mn2 Si2 O9 ;
forms a series with melanotekite; massive or in sheaflike prismatic
crystals; at Laangban and Nordmark, Sweden, and Sassari, Sardinia, Italy.
A revolving steel ring with three rolls pressing against its inner face.
The rolls are supported on springs, and the rings support the roll, so
that there is some freedom of motion. The material to be crushed is held
against the ring by centrifugal force. Liddell
A local name used in the Paradox Valley, Colorado, for a black,
vanadium-bearing sandstone. Syn:vanoxite
a. One of the steel supports on which a cage rests at the pithead during
unloading or loading so that the rail track is always at the proper level.
During this period, the rope is released from the weight of the cage. The
ordinary type of kep gear consists of four steel arms, two for each end of
the cage, carried on shafts that are connected to and operated by levers.
Normally, the cage must be raised from the kep arms before the latter can
be withdrawn to allow the cage to descend the shaft.
See also:Beien kep gear; cage stop. Nelson
b. One of the retractable rests on which the mine cage is supported during
its stop at a shaft landing. Also called catch; chair; keep; landing
chair; stop. Pryor, 3
c. One of the bearing-up stops for supporting a cage or load at the
beginning or end of hoisting in a shaft. CTD
Corn. Spar or hard stone on each side of the lode.
See:cerargyrite
A name generally applied to all salic extrusive and hypabyssal rocks
characterized by the presence of albite or albite-oligoclase and chlorite,
epidote, and calcite, generally of secondary origin. Some varieties of
keratophyre contain sodic orthoclase, sodic amphiboles, and pyroxenes.
Keratophyres commonly are associated with spilitic rocks and interbedded
with marine sediments. AGI
a. The undercut usually made in the coal to facilitate its fall.
BCI
b. A horizontal cut in a block of coal, as opposed to a shearing, which is
a vertical cut. BCI
c. Undercut in a coal seam from 3 to 7 in (7.6 to 18 cm) thick and
entering the face to a depth of up to 4 ft (1.2 m), made by a mechanical
cutter. Also called kirve. Pryor, 3
d. The undercut made in a coalbed to assist the action of explosives in
blasting. Hudson
e. The annular groove cut into a rock formation by a core bit.
See also:kerve
f. The space that was occupied by the material removed during cutting.
ASM, 1
g. The thickness of the wall of the diamond-insert part of the crown of a
core bit. Long
h. Sometimes incorrectly used as a syn. for nose, as applied to a diamond
core bit. Long
One of the diamonds inset in the kerf of the crown of a diamond bit. Also
called face stone. Long