An oscillating or vibrating screen on which the ore is thrown upward, as
well as moved forward on the screen. Liddell
Said of a rock that does not permit the passage of fluids under the
pressure conditions ordinarily found in the subsurface. Ant: permeable.
Syn:impervious
See:impermeable
Dust-sampling apparatus into which a measured volume of dusty mine air is
drawn through a jet in such a way as to strike a wetted glass plate, to
which dust particles adhere. Pryor, 3
A bursting inward; sudden collapse; opposite of explosion.
Standard, 2
a. A reservoir for impounding. Used in connection with the storage of
tailings from ore-dressing plants and hydraulic mines. Webster 3rd
b. To collect in a reservoir or sump provided near a borehole the water,
drill cuttings, etc., ejected therefrom. Long
One in which tailings are collected and settled; also, a water-storage
dam. Pryor, 3
a. Said of a mineral deposit (esp. of metals) in which the minerals are
epigenetic and diffused in the host rock. CF:interstitial
b. Said of timber that has been soaked in various fluids to enable it
better to resist the decomposing influences of the atmosphere.
Crispin
c. A metallic material in which fragments of diamond or other hard
substances (in unflocculated distribution) are intermixed and embedded.
See also:impregnated bit
A sintered, powder-metal matrix bit with fragmented bort or whole diamonds
of selected screen sizes uniformly distributed throughout the entire crown
section. As the matrix wears down, new, sharp diamond points are exposed;
hence, the bit is used until the crown is consumed entirely.
CF:multilayer bit
Timber that has been treated either to make it flame resistant or to
protect it from destruction by fungi and insects. Cover boards used with
steel arches are often vacuum-pressure impregnated with a flame-retardant
preservative for safety and to comply with the flame-proofing requirements
covering escape roadways. Nelson
A bell-shaped or hollow, tubular device filled with wax or other
water-resistant plastic materials, which is lowered onto an article
resting on the bottom of a borehole. The plastic material molds itself
about the lost article, and by inspecting the impression so formed, the
driller can determine which fishing tool is best fitted to recover the
lost article. Long
In crystallography, any element or operation of symmetry involving a
mirror or inversion resulting in a change of chirality of an asymmetric
unit. CF:chirality; proper.
A miner's dial in which a telescope replaces the usual sighting vanes.
BS, 7
Trade name for nonrotating wire rope of 18 by 4 over 3 by 24 construction.
Hammond
a. A water turbine, such as the Pelton wheel, in which the driving force
is provided more by the speed of the water than by a fall in its pressure.
See also:Pelton wheel
b. A turbine in which the steam is expanded in a series of stationary
nozzles that it leaves at a very high velocity, perhaps 4,000 ft/s (1.2
km/s), and then gives up its kinetic energy to blades or buckets attached
to the revolving disk that furnishes the power. Mason
Any undesirable substance not normally present in air, water, coal, or
other materials or present in an excessive amount. Syn:contaminant
a. Eng. Toward the working face, or interior, of the mine; away from the
shaft or entrance; from Newcastle coalfield. Also called in-over; inbye;
inbyeside. Fay
b. In a direction toward the face of the entry from the point indicated as
the base or starting point. Rice, 1
c. The direction from a haulage way to a working face. CTD
d. Opposite of outby. BCI
Made luminous by heat; white or glowing with heat. Standard, 2
See:coalification
The property of an igniting agent (e.g., spark, flame, or hot solid)
whereby the agent can cause ignition. Atlas
The height in inches of a column of water or of mercury as a measure of
hydrostatic pressure. Standard, 2