High-quality iron powder made by reduction of iron oxide; used in powder
metallurgy. Bennett
a. The map of a survey in horizontal projection, such as of a mine,
townsite, etc.
b. A diagram drawn to scale showing land boundaries and subdivisions,
together with all data essential to the description of the several units.
A plat differs from a map in that it does not show additional cultural,
drainage, and relief features. Seelye, 2
c. A platform, floor, or surface in or about a mine used esp. for loading
and unloading ore, etc. Webster 3rd
a. A flat iron or steel sheet laid around a mine-shaft collar, at the
shaft bottom, or at any level station, to enable mine cars and other
equipment to be easily turned and moved about. Also, a cast-iron plate
with a circular ridge on which mine rail cars are turned at the junction
of roads.
b. A horizontal timber laid on a floor or sloping wall to receive a
framework of timbers.
c. A torsionally rigid thin segment of the Earth's lithosphere, which may
be assumed to move horizontally and adjoins other lithosopheric plates
along zones of seismic activity. See also:plate tectonics
Use of copper or copper-alloy plates coated with enough mercury to form a
soft adherent film, in order to trap gold from crushed ore pulp as it
flows over the plates. The resulting amalgam, containing up to 40%
metallic gold, is periodically scraped off and more mercury is added to
the film. Pryor, 3
A filter press consisting of plates with a gridiron surface alternating
with hollow frames, all of which are held by means of lugs, on the press
framework. The corners of both frames and plates are cored to make
continuous passages for pulp and solution; the filter cloth is placed over
the plates. The pulp passageway connects with the large, square opening in
the frame; the solution and passageways connect with the gridiron surface
of the plate. The Dehne and the Merrill are well-known types.
Liddell
An automatic arrangement by which coal or ore is fed forward on steel
plates forming segments linked together in an endless chain.
See also:plate feeder
Broadly, any comparatively flat area of great extent and elevation;
specif. an extensive land region considerably elevated (more than 150 to
300 m in altitude) above the adjacent country or above sea level; it is
commonly limited on at least one side by an abrupt descent, has a flat or
nearly smooth surface but is often dissected by deep valleys and
surmounted by high hills or mountains, and has a large part of its total
surface at or near the summit level. A plateau is usually higher and has
more noticeable relief than a plain (it often represents an elevated
plain), and it is usually higher and more extensive than a mesa; it may be
tectonic, residual, or volcanic in origin. See also:tableland
CF:mesa
A term applied to those basaltic lavas that occur as vast composite
accumulations of horizontal or subhorizontal flows, which, erupted in
rapid succession over great areas, have at times flooded sectors of the
Earth's surface on a regional scale. They are generally believed to be the
product of fissure eruptions. CF:shield basalt
AGI
A sheet, spread, or patch of surficial gravel, often compacted, occupying
a flat area on a hilltop, plateau, or other high region at a height above
that normally occupied by a stream-terrace gravel. It may represent a
formerly extensive deposit that has been raised by earth movements and
largely removed by erosion. AGI
A method by which the load bearing capacity of a soil may be estimated.
See also:ultimate bearing pressure
A device for cleaning raw coal which uses the difference in the
coefficient of resilience or friction between clean coal and an inclined
plate, commonly of steel, and that between refuse and the plate to allow
the clean coal to jump over a gap while the refuse falls through.
BS, 5
A conveyor in which the carrying medium is a series of steel plates, each
in the form of a short trough, joined together with a slight overlap to
form an articulated band. The plates are attached either to one center
chain or to two side chains. The chains connect rollers running on an
angle-iron framework and transmit the drive from the driveheads that can
be installed at intermediate points as well as at the head or tail ends. A
plate conveyor can negotiate bends down to about 20 ft (6.1 m) radius;
available in widths 400, 540, and 640 mm with running speeds from 3 to 4
ft/s (0.9 to 1.2 m/s) with a carrying capacity from 100 to 400 st/h (90.7
to 362.8 t/h). Syn:steel plate conveyor
In photographic mapping, either of two rectangular coordinates measured on
a photograph with reference to the principal point as origin.
Seelye, 2
A crystal with a conductive surface film of gold, silver, aluminum, or
other metal produced by cathode sputtering, evaporation, or chemical
methods. The films, to which lead wires may be soldered, take the place of
the conventional clamped metal electrodes. Am. Mineral., 2
The mechanical plate feeder is a device for feeding material at a fixed
and uniform rate. It is generally applied at the tail end of a conveyor or
elevator which feeds a plant, but may be applied to feeding any other
single unit. It relieves the pressure and drag, with the consequent
unnecessary wear on the belt, which is ordinarily experienced if feeding
from a hopper directly to a belt. It not only cuts maintenance costs by
eliminating uneven wear, but increased output can be obtained by steady
feeding. This type of feeder also handles wet aggregate.
See also:disk feeder; reciprocating feeder.
Pit and Quarry; ACSG, 2
Used for lining shafts, winzes, and rises; usually constructed of
comparatively thin steel sheeting, stiffened around the edges with angles.
Plates should be of such size that they can be conveniently handled in the
skips or buckets used for sinking. Spalding
A built-up riveted or welded steel girder, having a deep vertical web
plate, with a pair of angles riveted along each edge to act as compression
and tension flanges. For heavier loads, flange plates are riveted or
welded to the angles. Hammond
A smooth roll for making sheet iron or plate iron, as distinguished from
iron having grooves for rolling rails, beams, etc. Standard, 2
A theory of global tectonics in which the lithosphere is divided into a
number of plates whose pattern of horizontal movement is that of
torsionally rigid bodies that interact with one another at their
boundaries, causing seismic and tectonic activity along these boundaries.
AGI
Tongs for grasping and handling iron or steel plates. Standard, 2
a. The place on top of a breaker where the freshly mined coal is weighed
by a weigh boss just before it is dumped into the machinery.
Korson
b. A wooden floor on the side of a gangway at the bottom of an inclined
seam, to which the coal runs by gravity, and from which it is shoveled
into mine cars.
c. A plank or mesh steel-covered level area at the base of a drill tripod
or derrick, used as a working space in front of a drill machine around the
collar of the borehole. Sometimes the platform is large enough to act as a
foundation and anchor for the drill machine. Long
d. A scaffold. Fay
e. A wood mat used in sets to support machinery on soft ground. Also
called pontoon. Nichols, 1
f. An operator's station on a large machine, particularly on rollers.
Nichols, 1
g. In the breaker, a flat or slightly inclined floor covered with iron
plates onto which coal is run from the main screen bars and cleaned by
platform workers. Korson
h. Also a similar floored area in the tripod or derrick on which a laborer
stands while working in a tripod or derrick. See also:floor
Long