A gantry constructed for carrying a portal crane or a similar structure.
Hammond
A power-driven hoist, having a lifting capacity ranging from 200 lb (90.7
kg) to about 2-1/2 st (2.27 t), which can be raised on a loading platform
up to 200 ft (61 m) high. Hammond
a. Twisted silver wire. Standard, 2
b. Crude native platinum. AGI
Said to be a native alloy containing 84.6% gold, 2.9% silver, 0.2% iron,
0.9% copper, and the remainder 11.4% platinum. Hess
An isometric mineral, (Ir,Pt) , with Ir 50% to 80% (atomic) of Ir + Pt;
forms silver-white grains having sp gr, 22.6 to 22.8; Mohs
hardness, 6 to 7.
To coat or combine with platinum, esp. by electroplating.
Standard, 2
a. An isometric mineral, native platinum 4[Pt] with variable Pd, Ir, Fe,
Ni; malleable; ductile; metallic; sp gr, 21.45; corrosion resistant;
occurs in ultramafic rocks, quartz veins, and in placers.
b. A malleable and ductile silvery-white metal, when pure. Symbol: Pt.
Occurs native, accompanied by small quantities of iridium, osmium,
palladium, ruthenium, and rhodium. Used in jewelry, wire, vessels for
laboratory use, and in many valuable instruments including thermocouple
elements. Handbook of Chemistry and Physics, 3
(PGM). Any of the minerals native platinum, osmium, iridium, palladium,
rhodium, ruthenium, and their alloys, such as osmiridium (Ir,Os) ,
ruthenosmiridium (Ir,Os,Ru) , rutheniridosmine (Os,Ir,Ru) , and
platiniridium (Ir,Pt) . Other alloys of PGM are exemplified by
stanopalliadinite, (Pd,Cu)3 Sn2 (?) ; and potarite, PdHg .
Other sources of PGM are sperrylite, PtAs2 ; cooperite, (Pt,Pd,Ni)S;
stibiopalladinite, Pd5 Sb2 ; braggite, (Pt,Pd,Ni)S ;
vysotskite, (Pd,Ni)S ; ruthenarsenite, (Ru,Ni)As ; cuproiridsite; CuIr
2 S4 ; cuprorhodsit, CuRh2 S4 ; malanite,
Cu(Pt,Ir)2 S4 ; and dayingite, CuCoPtS4 . Varietal
terms include plyxene and ferroplatinum for iron alloys and cuproplatinum
for copper alloys.
Metallic platinum in a gray, porous, spongy form; obtained by reducing
ammonium chloroplatinate, which occludes large volumes of oxygen,
hydrogen, and other gases. Webster 3rd
Brick laid flatwise on top of a kiln to keep in the heat. Fay
In bituminous coal mining, a colloquialism of English origin for a pusher
who pushes loaded mine cars onto a cage from a platt (an enlarged
underground opening at the shaft where cars are gathered prior to
hoisting). DOT
a. A tetragonal mineral, PbO2 ; rutile group; dimorphous with
scrutinyite; iron black; occurs in lead mines.
b. Erroneous spelling of planerite.
An igneous rock structure of tabular sheets suggesting stratification. It
is formed by contraction during cooling; the structure is parallel to the
surface of cooling and is commonly accentuated by weathering.
Syn:platy structure; planar flow structure. AGI
A trigonal mineral, PbBi2 (Se,S)3 ; metallic; iron-black;
forms thin plates like graphite; at Falun, Sweden. Also spelled platinite.
a. A term used in southwestern United States for a dry, vegetation-free,
flat area at the lowest part of an undrained desert basin, underlain by
stratified clay, silt, or sand, and commonly by soluble salts. The term is
also applied to the basin containing an expanse of playa, which may be
marked by ephemeral lakes. See also:salina; alkali flat; salt flat;
salar. Syn:dry lake
b. See:playa lake
c. A small, generally sandy land area at the mouth of a stream or along
the shore of a bay. Etymol: Spanish, beach, shore, coast. AGI
See:bolson
A shallow, intermittent lake in an arid or semiarid region, covering or
occupying a playa in the wet season but drying up in summer; an ephemeral
lake that upon evaporation leaves or forms a playa. Syn:playa
AGI
A pseudochromatic optical effect resulting in flashes of colored light
from certain minerals, such as fire opal and labradorite, as they are
turned in white light. Periodic spacings of phases with slightly differing
refractive indices act as optical diffraction gratings in these minerals.
CF:fire; opalescence; pseudochromatism. Syn:schiller
See:matildite
a. A system of ventilation in which air is forced into an inclosed space,
such as a room or a caisson, so that the outward pressure of air in the
space is slightly greater than the inward pressure from the outside, and
thus leakage is outward instead of inward.
b. A mode of ventilating a mine or a heading by forcing fresh air into it.
c. Use of compressed air to hold soil from slumping into an excavation.
Nichols, 1