a. A fan supplying air under pressure. Webster 3rd
b. A fan that forces fresh air into a mine as distinguished from one that
exhausts air from the mine. Fay
The indistinct six-rayed star produced on a mica plate after pressing with
a dull point. CF:percussion figure
a. A machine for removing solids from tailings; the effluent can be reused
in the washery or plant. The tailings are pumped into the filter under
pressure; filtration takes place and solids are deposited in the chambers.
Gradually the resistance increases until a pressure of 100 psi (690 kPa)
is necessary to force more tailings into the press. At this stage, the
chambers are almost full of solids. The feed is cut off and the press
opened to allow the cakes to fall onto the conveyor beneath the chambers.
The output of the pressure filter is low. Nelson
b. A filter in which pressure is applied to increase the rate of
filtration. BS, 5
c. A filter in which the liquid to be filtered is forced through filtering
material by a pressure greater than its own weight in the filter.
Forging done by a steady pressure, as in a hydraulic press.
Standard, 2
An instrument used to measure the force per unit area exerted by a
confined fluid or gas. Long
a. The act or process of injecting, at high pressures, a thin cement
slurry or grout through a pipeline or borehole to seal the pores or voids
in rock or to cement fragmented rocks together. Long
b. Forcing a slurry of cement and sand into subgrade or an embankment
either by use of compressed air or by hydraulic pressure. Urquhart
The height of a column of liquid supported, or capable of being supported,
by the pressure at a point in the liquid. See also:static head;
total head. AGI
In chemical extraction of valuable ore constituents, use of an autoclave
to speed processing by means of increased temperatures and pressures.
Pryor, 3
The feed pressure or load applied per diamond in a bit. The total load
supported by the bit divided by the number of stones set in the bit face
expresses the pressure per stone in numerical values. Also called diamond
pressure; stone pressure. Long
In a clutch, a plate driven by the flywheel or rotating housing, which can
be slid toward the flywheel to engage the lined disk or disks between
them. Nichols, 1
Treatment of mine timber to prevent decay by forcing a preservative, such
as creosote, zinc chloride, sodium fluoride, and other chemicals, into the
cells of the wood. See also:timber preservation
A ring about a large excavated area, evidenced by distortion of the
openings near the main excavation. Shear cracks appear and minor slabbing
of the rock takes place. Lewis
The name sometimes applied to a fringe or halo differing from the
groundmass that often accompanies a porphyroblast in a schistose rock.
Hess
The predominant means of extracting precious metal values from loaded
activated carbon in the cyanidation process. Loaded carbon is placed in a
pressure column along with a solution containing about 1% NaOH. This
solution is circulated through the column at 150 degrees C until the
precious metal values have been removed from the carbon absorbant. The
loaded strip solution serves as the electrolyte for a subsequent
electrowinning step for recovery of the precious metals. Van Zyl
An investigation to determine the pressure distribution or pressure losses
along consecutive lengths or sections of a ventilation circuit.
See also:ventilation planning; ventilation survey. Nelson
An indirect method of testing porosity and permeability of formations at
elevations of proposed structures.
A cartridge loader in which compressed water, rather than compressed air,
is used for loading underwater. Langefors
A pressure produced by expanding gases moving at high velocity, the side
component of which, equivalent to static pressure, may be recorded by a
manometer at the side of the entry or mine passage. Syn:P wave;
compressional wave. Rice, 2
Wire leading from any of various points of an electric system to a central
station, where a voltmeter indicates the potential of the system at the
point. Webster 2nd