a. A device comprised of fixed or moving bars, disks, or shaped tumblers
or rollers for the coarse screening or scalping of bulk materials.
See also:bar grizzly; grizzly chute; live roll grizzly. Syn:grisley;
gravity-bar screen.
b. A series of iron or steel bars spaced so as to size, sort, or separate
the bulk material as it falls into the ore chutes. Ricketts
c. A rugged screen for rough sizing at a comparatively large size (e.g., 6
in or 15.2 cm); it can comprise fixed or moving bars, disks, or shaped
tumblers or rollers. BS, 5
A chute with a bar grizzly which separates the fine from the coarse
material as it passes through the chute. See also:grizzly
See:grizzly worker
In metal mining, a laborer who works underground at a grizzly over a chute
or raise heading to a storage bin or haulage level, dumping ore from cars
through the grizzly, and breaking oversized lumps with a sledge hammer so
that they will pass through the grizzly. Also called draw man; grizzly
man. DOT
Raw fireclay mixed with calcined fireclay, or with broken fireclay brick,
or both, all ground to suitable fineness. ASTM
a. The long, tapered, half-round slot in the deflection wedge that acts as
a guide in directing the bit to follow a new course in deflecting a
borehole. Any of the spiral depressions on a cylindrical object, such as
the spiral depression on the surface of fluted core or the rifling in a
gun barrel. Long
b. Derb. The place where a miner is working. See also:grove
Fay
c. A mine, from the German, grube. Fay
Drum having a grooved surface to support and guide a rope. Hammond
N. of Eng. A miner. Standard, 2
See:channel sample
A nearly black earthy manganese or wad, streaked with dark red markings,
occurring in parts of Europe. Standard, 2
a. The heat produced by combustion of unit quantity of a solid or liquid
fuel when burned at constant volume in an oxygen bomb calorimeter under
specified conditions, with the resulting water condensed to a liquid.
ASTM
b. The amount of heat liberated by the complete combustion of unit weight
of coal under specified conditions; the water vapor produced during
combustion is assumed to be completely condensed. BS, 4
c. At constant pressure, the number of heat units that would be liberated
if unit quantity of coal or coke was burned in oxygen at constant pressure
in such a way that the heat release was equal to the sum of the gross
calorific value at constant volume and the heat equivalent of the work
that would have been done by the atmosphere under isothermal conditions
had the pressure remained constant. BS, 1
d. At constant volume, the number of heat units measured as being
liberated per unit quantity of coal or coke burned in oxygen saturated
with water vapor in a bomb under standard conditions, the residual
materials in the bomb being taken (suitable corrections having been made)
as gaseous oxygen, carbon dioxide, sulfur dioxide, nitrogen, liquid water
in equilibrium with its vapor and saturated with carbon dioxide, and ash.
Syn:gross heat of combustion
The total amount of excavation in a road or a road section, without regard
to fill requirements. Nichols, 1
The part of the total metal recovered multiplied by the price. The
proportion recovered varies with the ore and the method used.
See also:net unit value
The long ton of 2,240 avoirdupois pounds. Webster 3rd
An isometric mineral, 8[Ca3 Al2 Si3 O12 ] ,
rarely pure; garnet group; crystallizes in dodecahedra and trapezohedra;
varicolored; in metamorphosed calcareous rocks and skarns. Formerly called
grossularite. Syn:cinnamon stone
The weight of metal per ton (long or short ton), as determined by assay or
analysis, multiplied by the market price of the metal.
See also:net unit value
A variety of titanite containing yttrium or cerium.
See:growan
a. Rock at the side of a lode; country rock. Gordon
b. The mineralized deposit and the rocks in which it occurs, e.g.,
payground, payable reef; barren ground, rock without value. CTD
c. A ground is a conducting connection, whether intentional or accidental,
between an electrical circuit or equipment and either the Earth or some
conducting body serving in place of the Earth. Also called earth.
a. A mine foreman. Hess
b. See:mine captain