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Val separator

A launder used for cleaning buckwheat, rice, and barley sizes of
anthracite. It has three distinguishing features: (1) a mixing tank at the
head end of the machine, (2) a baffle in the bottom of the machine next to
the mixing tank to facilitate the stratification of the solids in specific
gravity layers, and (3) the use of a screen and bed of slate in the free
discharge boxes. Mitchell

valuation

a. The act or process of valuing, or of estimating the value or worth;
appraisal. Webster 3rd
b. The value or estimated price set upon a thing. Webster 3rd

value

The valuable constituents of an ore; their percentage in an orebody, or
assay grade; their quantity in an orebody, or assay value.
See also:assay grade; assay value; unit value. AGI

valve tower

A tower built up within a reservoir to house the control valves of supply
pipes drawing off water at different levels. Hammond

vamping

The debris of a stope, which forms a hard mass under the feet of a miner.
Fay

van

a. To separate, such as ore from veinstone, by washing it on the point of
a shovel. Fay
b. A shovel used in ore dressing. Fay

vanadate

A salt or ester of vanadic acid; a compound containing the radical (VO
4 )3- (ortho) or (VO3 )- (meta).
CF:arsenate; phosphate.

vanadic ocher

A native yellow vanadium oxide found near Lake Superior.
Standard, 2

vanadinite

A hexagonal mineral, Pb5 (VO4 )3 Cl ; apatite group;
soft; varicolored; sp gr, 6.7 to 7.1; in oxidized zones of lead ore
deposits; in New Mexico, Arizona, Africa, Scotland, and Russia.
Syn:vanadite

vanadite

See:descloizite; vanadinite.

vanadium

A gray or white, malleable, ductile, metallic element. Symbol, V. Found in
about 65 different minerals, among which are carnotite, roscoelite,
vanadinite, and patronite; also found in phosphate rock, certain iron
ores, and some crude oils. About 80% of the vanadium now produced is used
as a ferrovanadium or as a steel additive; also used in ceramics, as a
catalyst, and in the production of a superconductive magnet.
Handbook of Chemistry and Physics, 3

vanadium minerals

Those most exploited for industrial use are patronite (MoS2 with
vandium sulfide) , roscoelite (vanadium mica), vanadinite, carnotite, and
chlorovanadinite. Metal is silvery and whitish; melting point is 1,720
degrees C; used in high-speed steels and shock-resistant alloys,
chemicals, ceramics, and textiles. Pryor, 3

vanadium ore

Most vanadium is obtained from vanadium-bearing magnetite (1% to 2.2% V)
in South Africa. Other sources include patronite, carnotite, roscoelite,
vanadinite, descloizite, and volborthite.

vanadium-zirconium turquoise

See:zirconium-vanadium blue

vanalite

A monoclinic mineral, NaAl8 V10 O38 .30H2 O ;
forms bright-yellow incrustations on weathered shales; in northwest
Kara-Tau, Kazakhstan.

Van Allen radiation zone

Powerful doughnut-shaped zone of radiation 1,000 to 3,000 miles above the
Earth's surface and parallel with the Equator. AGI

van Arkel and de Boer process

See:iodide process

vandenbrandeite

A triclinic mineral, Cu(UO2 )(OH)4 ; radioactive; dark green
to black; secondary; associated with kasolite, sklodowskite, malachite,
goethite, chalcocite, chalcopyrite, uraninite, curite, uranophane, and
cobalt wad; occurs at Karungwe, Katanga, Republic of the Congo. Also
spelled vandenbrandite.

vandenbrandite

A very rare, strongly radioactive, triclinic, dark green to almost black
mineral, Cu2+ (UO2 )(OH)4 ; a secondary mineral
found associated with kasolite, sklodowskite, malachite, geothite,
chalcocite, chalcopyrite, and uraninite; also found associated with
curite, uranophane and cobalt wad; from Karungwe, Katanga, Zaire. Also
spelled vandenbrandeite. Crosby; Hey, 1

vandendriesscheite

An orthorhombic mineral, Pb(UO2 )4 (OH)9 .2H2
O ; radioactive; forms small, amber-orange pseudohexagonal crystals,
commonly barrel shaped; at Katanga, Congo.

van der Kolk method

A test used in microscopy to determine the index of refraction of a
mineral grain relative to that of an immersion liquid. When transmitted
light is blocked, the grain acts as a lens and the ocular inverts the
image of the obstacle, causing a shadow to appear on the same side as the
obstacle when the grain has the higher refractive index, but on the
opposite side when the grain has the lower index.
Syn:oblique illumination method