A long, 3/4-in-diameter (1.9-cm-diameter) metal pipe, connected to an air
supply; used to blow out dust and chippings from vertical blast holes at
quarries. The blowpipe is generally used for holes exceeding about 12 ft
(3.66 m) deep. A stream of water is sometimes used instead of an air jet.
Nelson
Closed casing in which air pressure is maintained equal to the pressures
of the water and soils on the outside. The deeper the caisson, the higher
the pressure that must be maintained. Carson, 1
A cartridge loader widely used for underwater blasting, for blasting
without removing the overburden, and for long-hole blasting. It is also
being used increasingly for tunneling and other sorts of rock blasting.
Langefors
Mineral cleaning by machines that utilize air currents as the primary
separating medium. The air machines can generally be divided into three
types: (1) pneumatic jigs, in which the air current is pulsated; (2)
pneumatic tables, in which the refuse is diverted from the direction of
flow of the clean mineral by a system of riffles fixed to the deck; and
(3) pneumatic launders, in which the products are flowing in the same
direction, and the clean mineral is skimmed off the top of the bed and/or
the refuse is extracted from the bottom in successive stages.
Mitchell
Gravity jig, shaking table, or other device in which suitably ground
minerals are separated by gravity during their exposure to a continuous or
pulsating current of air. Pryor, 3
Use of compressed air to move fairly fine aggregates laterally and/or
vertically. Pryor, 3
a. A pipe or tube through which granular material is transported by
airblast. It is used for pulverized coal, crushed rock (pneumatic
stowing), cement, etc. The term could also be applied to a conveyor
operated by compressed air. Nelson
b. An arrangement of tubes or ducts through which bulk material or objects
are conveyed in a pressure and/or vacuum system.
Compressed-air drill worked by reciprocating piston, hammer action, or
turbo drive. Pryor, 3
See:air-leg support
A filling method in which compressed air is utilized to blow filling
material into a mined-out stope. Stoces
Machine in which the air used to generate a mineralized froth is blown
into the cell, either through a porous septum at or near the bottom, or by
pipes that bring low-pressure air to that region. Pryor, 3
This clutch transmits power through friction shoes carried on the tube of
cord and rubber construction. The pneumatic clutch is self-adjusting for
wear owing to the natural resilience of the rubber tube. Disengagement is
complete and automatic when the air under pressure is released. The clutch
is controlled by finger pressure on a valve. The valve can be installed at
the place most convenient for the operator. Pit and Quarry
A hammer that uses compressed air for producing the impacting blow.
A device for hoisting; operated by compressed air. Standard, 2
A method for fighting underground coal fires. This air-blowing technique
involves the injection of an incombustible mineral, like rock wool or dry
sand, through 6-in (15.2-cm) boreholes drilled from the surface to
intersect underground passageways in the mines.
a. Air jig used in desert countries for concentrating ore.
Pryor, 3
b. A jigging machine in which an airblast performs the work of separation
of minerals. Standard, 2
c. See:Kirkup table; plunger jig washer.
a. Underground lighting produced by a compressed-air turbomotor driving a
small dynamo. Pryor, 3
b. The use of compressed air to generate electric light.
See also:air turbolamp
See:line oiler
In flotation, a method in which gas is introduced under slight pressure
near the bottom of the flotation vessel, the device used for introduction
being either a submerged pipe or a porous cloth, frit, or rubber surface
forming the wall of a wind box. Gaudin, 2
Mortar applied to a surface with a cement gun in the same manner as
gunite. Such mortar has a cube crushing strength of 3,000 psi (20.7 MPa)
at 7 days and of 6,000 psi (41.4 MPa) at 28 days, with a water-cement
ratio of 0.45. Hammond
A compressed-air-operated hand tool used to excavate coal, ore, and rock,
with a punching action. Without the pick steel, its length is about 18 in
(46 cm) and weight about 24 lb (10.8 kg). It delivers about 2,500
blows/min. The latest type is the water-controlled pick, so designed that
the air valve is operated by water pressure. The water assists in
suppressing the dust made during cutting. Nelson