A jack in which the lifting head is carried on a plunger working in a
cylinder, to which oil or water is supplied under pressure from a small
hand-operated pump. See also:hydrostatic press
See:track-moving machine operator
In fluid flow, a change in flow conditions accompanied by a stationary,
abrupt turbulent rise in water level in the direction of flow. It is a
type of stationary wave. AGI
Excavating alluvial or other mineral deposits by means of high-pressure
water jets. See also:hydraulic mining; hydromechanization; monitor.
CF:ground sluicing
Lime that is combined with silica, alumina, and iron oxide and will set
and harden underwater.
An impure limestone that contains silica and alumina (usually as clay) in
varying proportions and that yields, upon calcining, a cement that will
harden underwater. See also:cement rock
A safety device developed by the U.S. Bureau of Mines for sensing pressure
changes, thereby warning in advance of bumps. The cells are embedded in
the walls and roofs of coal mines.
The flushing or slicing of coal or other material broken down by water
jets along the floor and into flumes. Coal will flow back toward the flume
if sufficient water is available and the gradient is not less than 6
degrees to 7 degrees in favor of the flow. Flexible low-pressure hoses
(150 to 200 psi or 1.0 to 1.4 MPa) are sometimes used to assist in the
flushing operations. See also:hydromechanization
A borehole-drilling machine on which the bit-feeding mechanism is
hydraulically actuated. Long
A main (pipe) for collecting and condensing the volatile matter given off
in carbonization of coal in the coking process. Mersereau, 2
The cross section of water flowing through a channel or pipe divided by
the wetted perimeter of the conduit. Syn:hydraulic radius
Hammond
Filling a mine with material transported by water. CF:silting; slush.
See:flush
In metal mining, one who tends riffles, sluices, and does other work in
connection with the hydraulic placer mining of gold. In this type of
mining, gold bearing gravel, usually in a bank, is excavated by the
erosive action of a high-pressure stream of water being directed at the
bank through a nozzle. The gravel is then forced into sluices where the
gold particles sink and are caught by riffles (cleats) along the sluice
bottom. DOT
a. Mining by washing sand and dirt away with water that leaves the desired
mineral. See also:hydraulicking
b. The process by which a bank of gold-bearing earth and rock is excavated
by a jet of water, discharged through the converging nozzle of a pipe
under great pressure, the earth or debris being carried away by the same
water, through sluices, and discharged on lower levels into the natural
streams and watercourses below; where the gravel or other material of the
bank is cemented, or where the bank is composed of masses of pipe clay, it
is shattered by blasting with powder. Also used for other ores, earth,
anthracite culm, etc. Made unlawful and prohibited in certain river
systems where it obstructs navigation and injures adjoining landowners.
See also:placer mining
c. In underground hydraulic mining, the extraction of coal by
high-velocity water jets, directed at the seam from a monitor or powerful
jet, which can withstand high water pressures. The jets are also used to
impel the broken coal along the floor to the point of collection.
See also:hydromechanization; jet-assisted cutting. Nelson
A device for directing a high-pressure jet of water in hydraulicking. It
is essentially a swivel-mounted, counterweighted nozzle attached to a
tripod or other type of stand and so designed that one person can easily
control and direct the vertical and lateral movements of the nozzle.
See also:giant; monitor.
A multicylinder reciprocating engine, generally of radial type, driven by
water under pressure. CTD
The ability of a rock or soil to transmit water under pressure. It may
vary according to direction. AGI
The conveyance of coal by means of water flowing in pipes. Coal may be
pumped to the surface in shallow mines, but beyond 150 ft (46 m) or so of
depth, there are technical difficulties. Solids handling pumps rarely
deliver against heads exceeding about 200 ft (61 m). Two such pumps,
placed in series, have been used in Trelewis Drift, Wales, to pump out
slurry. See also:hydromechanization; transport.
The use of pressure oil or soluble oil and water for operating face
machines and steel supports. The fluid is supplied by rotary pumps driven
by electricity located at points near the face. Hydraulic power has an
advantage in that the space required is considerably less than that for
conventional drives. See also:power pack
The total thrust, expressed in pounds or tons, that the hydraulic-feed
mechanism on a drill can impose on a drill string; also, the pressure of
the fluid within the hydraulic cylinders, generally expressed in pounds
per square inch. Long
A vertical section of the potentiometric surface of an aquifer.
AGI