Peru. Lowering of ores from mine to mill.
Colom. Low-lying alluvial mines that have to be unwatered by artificial
means; generally deposits in present riverbeds.
A monoclinic mineral, Ca4 B4 (BO4 )(SiO4 )
3 (OH)3 .H2 O ; gadolinite group; in white compact
nodules resembling marble or unglazed porcelain; in the Mohave Desert, CA.
a. A stage in the heating of a clay when the clay particles have lost
plasticity and have formed a moderately hard mass composed of particles
adhering together, the mass remaining porous. See also:vitrifying
Nelson
b. The process of firing shaped clay articles in kilns, in order to give
the clay permanent hardness. CTD
c. Heating to a low temperature in order to remove gases. ASM, 1
d. The hardening of rock material by heat from magmatic intrusions or lava
flows. Prolonged baking leads to contact-metamorphic effects. AGI
A Cornish name for a mine; a cluster of mines.
a. The counterpoise or weight attached by cable to the drum of a winding
engine to balance the weight of the cage and hoisting cable and thus
assist the engine in lifting the load out of the shaft. Fay
b. An instrument for weighing. Fay
c. See:assay balance; balance pit.
d. A beam device specif. designed and calibrated to determine specific
gravity by weighing methods, as in determining the specific gravity of
drilling mud. Long
A counterbalance to take the excess weight of the pitwork, or timber
beams, in a shaft; used with the Cornish type of reciprocating pump.
CTD
a. A self-acting inclined plane down which the cars of coal are lowered
and the empties elevated upon a carriage or platform. Also called balance
plane; back balance.
b. Eng. An inclined roadway in which a balance is used to assist the
haulage. Also called dilly brow. SMRB
a. In quarrying, a car loaded with iron or stone and connected by means of
a steel cable with a channeling machine operating on an inclined track.
Its purpose is to counteract the force of gravity and thus enable the
channeling machine to operate with equal ease uphill and downhill.
b. A small weighted truck mounted upon a short inclined track, and
carrying a sheave around which the rope of an endless haulage system
passes as it winds off the drum. Zern
A cutter chain that has the same number of bottom and top picks. It
usually cuts more freely in hard material and is often used for cutting at
higher than floor level. See also:unbalanced cutter chain
Nelson
A modified form of direct-rope haulage, in which a power-driven reversible
pulley (surge pulley) is used instead of a drum. The full trams are hauled
up on one end of the rope while the empties go down on the other end. It
involves a double track or a bypass midway on the haulage plane. The
descent of the empty trams assists in balancing the load being hauled
upwards. Nelson
Applied to combustion units in which forced and induced drafts are
adjusted to give atmospheric pressure in the combustion chamber to avoid
the infiltration of unwanted cold air. Nelson
Arrangement of cages or skips in mine shaft in which the winding drum
raises one and at the same time lowers the other, thus reducing power
consumption. See also:balanced winding
A system of ventilation in which the districts (each with its separate
split) are so arranged with regard to length and resistance, that the use
of ventilation regulators is unnecessary. Regulators, although sometimes
unavoidable, reduce the efficiency and increase the power required to
ventilate the mine. Nelson
A vibrating conveyor in which the center of gravity of the complete
assembly is held constant by having movement of the trough offset by
opposite movement of some other element.
The conventional method of winding in a mine shaft. As the cage containing
the loaded cars ascends, the other cage containing the empties descends,
and thus the cages and cars are balanced. Balanced winding also implies
the use of a balance rope, and thus, ignoring friction, the only load to
be hoisted is the coal or mineral. See also:winding; balanced hoisting.
Nelson
Eng. A pit or shaft in which a balance (counterweight) rises and falls.
See also:balance
See:balance brow
A steel-wire rope, generally of the same weight per foot as the main
winding rope, that is attached to the bottom of the cages, and extends
down to form a loop in the shaft bottom or sump. Its function is to
balance out the difference in weight of the upgoing or downgoing main
ropes during the wind. See also:winding
A record showing the present financial obligations and resources of the
company, in terms of cost or book value. Hoover
In coal mining, a shot for which the drill hole is parallel to the face of
the coal that is to be broken by it.