A tumbling mill used in dry grinding, from which finished material is
removed by means of regulated air currents that can be so controlled as to
produce a closed circuit. Pryor, 1
A device similar to a water swivel but designed to conduct air under
compression into a rotating drill stem when air instead of a liquid is
used as an agent to flush drill cuttings out of a borehole.
CF:water swivel
A shaking table used when water is scarce to effect gravity concentration
of sands. Air is blown upward through a porous deck, over which a layer of
finely crushed ore passes. The heavy and light minerals stratify and
gravitate to separate discharge zones. Syn:pneumatic table
Pryor, 1
A heavy drilling machine for quarry or opencast blasting. It has
continuous tracks and is operated by independent air motors. It tows its
rotary compressor and drills holes 3 in or 4 in (7.6 cm or 10.2 cm) in
diameter at any angle, but it is chiefly used for vertical holes up to 80
ft (24.4 m) in depth. Nelson
A method employed in some mines in which material is transported and
stowed pneumatically through pipelines. Stoces
A large pipe or shaft for conducting air, such as for ventilation or to a
furnace. Fay
The cylinder on a blowing engine that pumps a blast of wind or air.
Fay
A lamp coupled to the compressed air mains, which may be at any pressure
between 275 kPa and 700 kPa. It consumes 0.025 m3 /s of free air.
The electrical power is produced by a small turboalternator with a
six-pole permanent magnet rotor.
The valve that controls the alternate admission and release of compressed
air to each cell of a Baum-type washbox. BS, 5
The rate of motion of air in a given direction; in mine ventilation it is
usually expressed in meters per second. This is usually measured
conducting a vane anemometer traverse over a selected cross section, the
area of which is also measured.
A small air chamber fixed to the pipeline on the discharge side of a
reciprocating pump that acts as a cushion to minimize the shock produced
by the pulsations of the pump. Nelson
A device for handling dusty materials, built on the principle of a
pneumatic cleaner. The system used is a suction system, whereby the
material (soda ash, salt cake, cement, or powdered lime) is drawn from the
car through a flexible hose into a vacuum tank designed to recover a large
percentage of the dust floating in the air. Hess
The ratio of the volume of air space to the total volume of voids in a
soil mass. ASCE
In mining, the quantity (Q) of air flowing in cubic meters per second. It
is obtained by multiplying the average velocity (V) in meters per second
by the area (A) of the airway in square meters; i.e., Q = AV.
See also:air requirements; air quantity.
Air washers make use of water sprays or cooling coils for evaporative and
sensible cooling of mine air. Their use has largely been limited to
shallow coal mines in the United States, where it is desirable to reduce
the dry-bulb temperature of the intake air during the hot summer months to
prevent slaking of the roof due to excessive expansion. An air washer is
essentially a heat exchanger and is similar to the type of unit employed
for heat transfer with refrigeration or evaporative-cooling systems.
The acoustic-energy pulse transmitted through the air as a result of a
pressure (sound) source; e.g., explosion, near-surface seismic shot, or
supersonic aircraft. AGI
Any underground gallery or passage through which a portion of the
ventilation passes; i.e., the air is carried. Syn:air course;
wind road. BCI
A concept of the mechanism of isostasy, proposed by George Bedell Airy,
that postulates an equilibrium of crustal blocks of the same density but
of different thickness; thus the topographically higher mountains would be
of the same density as other crustal blocks but would have greater mass
and deeper roots. CF:Pratt hypothesis
A high-strength, high-density, gelatinous permitted explosive having good
water resistance; used for dry and wet conditions both in rock and in the
breaking of hard coal. See also:Polar Ajax
A pale-yellow to dark reddish brown, sulfur-bearing fossil resin found in
brown coal. Also spelled ajkite. AGI
Roman term designating size of water delivery pipes and outlet spouts.
Syn:adjutage