A heavy, chain-type flexible conveyor capable of being advanced with the
face without dismantling. It is designed either to carry a coal cutter or
a cutter loader or to guide and hold a plow against the face. It may be
advanced by horizontal hydraulic rams that are fixed at about 20-ft (6-m)
intervals on the waste side of the conveyor. It is often employed on
prop-free-front faces with hand filling, and it has a capacity of about
200 to 300 st/hr. Syn:Panzer conveyor
chain conveyor; face conveyor. Nelson
An unstable relict enveloped by a crystal or by a reaction shell which
revented its reaction with the other constituents of the rock.
See also:unstable relict
Orthorhombic Cu5 (SO4 )2 (OH)6 .3H2 O ;
perhaps the mineral antlerite.
Chlorinated diphenyl materials that are useful as vehicles for pigments
used in glass decoration since they volatilize without leaving a carbon
residue. Arochlors provide a grinding and dispersing medium for nonaqueous
slurries of pigments and ceramic bodies; also, they can be used in
combination with waxes to provide moisture-proof coatings. Lee
A compound derived from the hydrocarbon benzene, C6 H6 ,
distinguished from that derived from methane, CH4 .
Standard, 2
A compound of carbon and hydrogen that contains in its molecular structure
a closed and saturated ring of carbon atoms; e.g., benzene, naphthalene,
and anthracene. Hackh
A bituminous stone resembling a fragrant gum resin in color and odor. It
was a precious stone in ancient Arabia and Egypt. AGI
A soft, malleable, silver-rich variety of amalgam containing about 87%
silver and 13% mercury; from Coquimbo, Chile.
See:arrastre
A circular rock-lined pit in which broken ore is pulverized by stones
attached to horizontal poles fastened in a central pillar and dragged
around the pit. Also spelled arrastra. Weed, 2; CTD
A stage in coal formation when biochemical action ceases.
Tomkeieff
a. Any mechanical contrivance or device used to stop or slow up motion.
Crispin
b. Mechanism for the purification of a gas stream that may contain
suspended liquids or solids. Bennett
Dealing in ores, concentrates, and metals in transit from source to
market. Pryor, 3
A monoclinic mineral, KNa4 CaMn4 Fe10 Al(PO4 )
12 (OH,F) ; dark green, forms a series with dickinsonite.
A sharp-pointed, thin metal rod about 1 to 2 ft (0.3 to 0.6 m) long with a
ring at the other end, used in surveying; a thin metal peg. Mason
a. A term applied in the arid and semiarid regions of the Southwestern
United States to the small, deep, flat-floored channel or gully of an
ephemeral stream, usually with vertical or steeply cut banks of
unconsolidated material at least 60 cm high; it is usually dry, but may be
transformed into a temporary watercourse or short-lived torrent after
heavy rainfall. CF:dry wash
b. The small intermittent stream or rivulet that occupies such a
channel.---Etymol: Spanish, stream, brook; gutter, watercourse of a
street. See also:wadi; nullah. AGI
Possibly a silver arsenide.
a. A salt or ester of an arsenic acid; a compound containing one of the
three radicals in which arsenic has a +5 valence: ortho-arsenate, AsO (sub
4) ; meta-arsenate, AsO3 ; pyro-arsenate, As2 O7 .
b. A mineral characterized by pentavalent arsenic and oxygen; e.g.,
mimetite Pb5 (AsO4 )3 Cl . CF:vanadate
A metallic, steel-gray, brittle element. Symbol, As. Found native in
realgar and orpiment, and combined with heavy metals. Used in bronzing,
pyrotechny, insecticides, and poisons, and as a doping agent in
transistors. Gallium arsenide is used as a laser material to convert
electricity directly into coherent light. Arsenic and its compounds are
poisonous. Handbook of Chemistry and Physics, 3
See:allemontite