An assemblage of machines and equipment, including the necessary housing,
where electrical energy is produced from some other form of energy. Steam
boilers are fed with coal or oil and the heat generated is used to produce
high-pressure steam. The steam then passes to turbines that drive the
generators and thus produce electricity. Nelson
A place in a transmission or engine to which a shaft can be attached so as
to drive an outside mechanism. Nichols, 1
A mechanically powered wrench used to make up or break out a drill rod,
casing, or pipe string. Long
All moving parts connecting an engine with the point where work is
accomplished. Nichols, 1
a. Generally applied to any device used to drive or operate machinery
around a mine. Specif., it is used for the motor-speed reducer combination
used to drive belt and chain conveyors. Jones, 1
b. That part of a mining belt conveyor that consists of a power unit base,
an electric motor, an electric controller, a speed reducer with a flexible
coupling between motor and speed reducer, a power transmission device to
power the drive pulley or pulleys, suitable covers for all moving parts
and, if the power unit is of the detachable type, a device for attaching
it to the conveyor. NEMA, 2
In coal mine ventilation, the horsepower applied is often known as the
power upon the air. This may be the power exerted by a motive column due
to the natural causes, to a furnace, or it may be the power of a
mechanical motor. The power upon the air is always measured in foot pounds
per minute. Kentucky
a. A leucitic tuff quarried near Pozzuoli, Italy, and used in the
manufacture of hydraulic cement. The term is now applied more generally to
a number of natural and manufactured materials, such as ash and slag, that
impart specific properties to cement. Pozzolanic cements have superior
strength when cured and are resistant to saline and acidic solutions. Also
spelled: pozzolan; pozzuolana; pozzuolane. See also:gaize
b. A material that is capable of reacting with lime in the presence of
water at ordinary temperature to produce a cementitious compound. Natural
pozzolanas are siliceous material of volcanic origin. They include trass
and Santorin earth. Blast furnace slag is used to produce artificial
pozzolanas. CCD, 2
A cement produced by grinding together portland cement clinker and a
pozzolana, or by mixing together a hydrated lime and a pozzolana.
Syn:Roman cement
In coal mining, a shot for which a hole has been drilled in a direction
selected with reasonable care and filled with powder and tamped with the
same degree of care. Fay
Soil transitional between a pedalfer and a pedocal. Leet, 1
a. A translucent dull green or yellow-green variety of chalcedony.
b. Crystalline quartz containing abundant hairlike crystals of actinolite.
Syn:edinite; mother-of-emerald.
A rare earth that, together with zirconia and silica, produces a
distinctive and stable yellow color for pottery decoration. Dodd
a. A green alteration product of iolite. Fay
b. A greenish foliated alteration product of cordierite.
A green chromium variety of common opal from Australia, Hungary, and
Brazil. Also spelled prase opal.
A suggested type of hydrostatic support for the Earth's solid outer crust
in which crustal density is supposed to be greater under mountains than
under oceans. CF:isostasy; Airy hypothesis.
See:N-truss
The most common phosphoric acid dihydrate process for phosphoric acid
production using sulfuric acid with naturally occurring phosphate rock.
Becker
Aeration of water or ore pulp before treatment, notably by froth flotation
where deoxygenated water is used (e.g., from under a frozen lake). Also
used to stabilize ore pulp containing unstable sulfides before
cyanidation. Pryor, 3
Anode produced by binding together crushed petroleum coke and coal-tar
pitch in a mold under pressure; subsequently baked to 1,000 to 1,200
degrees C; used in a metallurgical electrical furnace and replaced as a
unit when consumed; in the production of aluminum metal, the anode is
attached to a metal rod.
Pertaining to the time period prior to the initiation of a blast.
Documentation of the existing condition of a structure prior to exposure
to blasting vibrations.