a. To resharpen and restore to size the worn teeth on a roller or diamond
bit. See also:face
b. To restore a tool to its original shape and sharpness by forging or
grinding. Crispin
c. To clean ore by breaking off fragments of the gangue from the valuable
mineral. See also:ore dressing
d. To shape dimension stone.
a. A general term for the processes of milling and concentration of ores.
Syn:ore dressing
b. The shaping of dimension stone.
c. Separating rock from lumps of coal by chipping with a hammer or similar
means.
d. Can. Developing claims to take them out of wildcat class.
Hoffman
A method of fraud carried out by a representative of the seller, by
systematically mining out all the low-grade or barren spots in the vein,
leaving only the high-grade spots exposed. Hoover
Material that adheres to the conveying medium and, being carried beyond
the discharge point, drops off along the return run.
In underground excavation, fall of small stone and debris from roof,
warning that a heavy fall may be imminent. Pryor, 3
See:burnt alum
A device used for removing water from damp material by evaporation,
supplemented usually with forced circulation of air.
In salt production, one who tends operations of rotary driers through
which crushed salt is run to drive off contained moisture prior to
grinding, examining the salt discharged from the driers to see that
evaporation of moisture is complete. DOT
Seams in the rock, which are usually invisible in the freshly quarried
material, but which may open up in cutting or on exposure to the weather.
See also:dry
See:drift
a. An entry, generally on the slope of a hill, usually driven horizontally
into a coal seam. Syn:surface
b. The deviation of a borehole from its intended direction or target.
CF:walk
c. A general term, used esp. in Great Britain, for all surficial,
unconsolidated rock debris transported from one place and deposited in
another, and distinguished from solid bedrock; e.g., specif. for glacial
deposits. Any surface movement of loose incoherent material by the wind;
accumulated in a mass or piled up in heaps by the action of wind or water.
See also:fill
d. Apparent offset of aerial photographs with respect to the true flight
line, caused by the displacement of the aircraft owing to cross winds, and
by failure to orient the camera to compensate for the angle between the
flight line and the direction of the aircraft's heading. The photograph
edges remain parallel to the intended flight line, but the aircraft itself
drifts farther and farther from that line. AGI
e. A time variation common to nearly all sensitive gravimeters, due to
slow changes occurring in the springs or mountings of the instrumental
systems; this variation is corrected by repeated observations at a base
station and in other ways. AGI
f. A horizontal opening in or near an orebody and parallel to the course
of the vein or the long dimension of the orebody. Beerman
g. A passageway driven in the coal from the surface, usually above
drainage, following the inclination of the bed. Hudson
h. Forest of Dean. A hard shale.
i. To make a drift; to drive. Webster 3rd
j. A horizontal gallery in mining and civil engineering driven from one
underground working place to another and parallel to the strike of the
ore. It is usually of a relatively small cross section. Larger sections
are usually called tunnels. Fraenkel
k. A heading driven obliquely through a coal seam. CTD
l. A heading in a coal mine for exploration or ventilation. CTD
m. An inclined haulage road to the surface. CTD
n. In oil well surveying, the angle from a drill hole to the vertical.
See also:inclination
o. A flat piece of steel of tapering width used to remove taper shank
drills and other tools from their holders. ASM, 1
p. A tapered rod used to force mismated holes in line for riveting or
bolting. Sometimes called a driftpin. ASM, 1
q. A gradual change in a reference that is supposed to remain constant. An
instrument such as a gravimeter may show drift as a result of elastic
aging, long-term creep, hysteresis, or other factors. AGI
r. A general term applied to all rock material (clay, silt, sand, gravel,
boulders) transported by a glacier and deposited directly by or from the
ice, or by running water emanating from a glacier. Drift includes
unstratified material (till) that forms moraines, and stratified deposits
that form outwash plains, eskers, kames, varves, glaciofluvial sediments,
etc. The term is generally applied to Pleistocene glacial deposits in
areas (as large parts of North America and Europe) that no longer contain
glaciers. The term drift was introduced by Murchison in 1839 for material,
then called diluvium, that he regarded as having drifted in marine
currents and accumulated under the sea in comparatively recent times; this
material is now known to be a product of glacial activity.
CF:glacial drift
s. One of the wide, slower movements of surface oceanic circulation under
the influence of, and subject to diversion or reversal by, prevailing
winds; e.g., the easterly drift of the North Pacific.
Syn:drift current
ocean currents and wind stress. The speed of an ocean current or ice floe,
usually given in nautical miles per day or in knots. Sometimes used as a
short form of littoral drift. See:current
t. In South Africa, a ford in a river. The term is used in many parts of
Africa to indicate a ford or a sudden dip in a road over which water may
flow at times. Syn:drif
N. Staff. A system of working coal similar to the room and pillar system.
Fay
The angular deviation of a borehole from vertical and/or its intended
course. See also:deflection angle
The rate of the increase in the drift angle that is generally expressed as
the number of degrees increase for a specific drilled footage; e.g., 2
degrees per 100 ft (30.5 m). Long
a. A bolt for driving out other bolts or pins. Webster 3rd
b. A metal rod, for securing timbers, resembling a spike but with or
without point or head. Webster 3rd
Coalfields formed by forests on higher ground being carried away by floods
into lakes. Mason
Native copper transported from its source by a glacier. AGI
See:drift
Graph of a series of gravity values read at the same station at different
times and plotted in terms of instrument reading versus time. AGI
In metal mining, one who operates a heavy, mounted, compressed-air,
rock-drilling machine in driving drifts (horizontal passages running
parallel to the vein opened up to facilitate mining of the ore).
DOT