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Birtley coal picker

An electric picker that distinguishes between good coal and slate by their
different electrical conductivities. It is said to be more accurate than
the human slate picker, who, when fatigued, may fail to remove all the
impure material. Mitchell

Birtley contraflow separator

A pneumatic table for dry cleaning coal. It consists of perforated deck
plates arranged in a series of lateral steps with a longitudinal
inclination. A centrifugal fan provides a constant upward blast of air
through the deck. The usual layering takes place, the refuse sinking to
the deck plates. The capacity of the table ranges from 6 st/h per foot
(17.8 t/h/m) of width for sizes 1-1/2 to 2 in (3.8 to 5.1 cm), down to 2
st/h/ft (5.9 t/h/m) for fines below 1/16 in. They are built in any width
up to a maximum of about 8 ft (2.4 m). Nelson

bischofite

A monoclinic mineral, MgCl2 .6H2 O .

biscuit

a. Unglazed ceramic ware that has been fired in a biscuit or bisque oven
or film.
b. A small cake of primary metal, such as uranium, made from uranium
tetrafluoride and magnesium in a bomb reduction. ASM, 1

bishop's stone

See:amethyst

bisilicate

In metallurgy, a slag with a silicate degree of 2. Newton, 2

bismite

A straw-yellow monoclinic mineral, Bi2 O3 ; earthy to
powdery; in oxidized parts of bismuth ores. Syn:bismuth ocher

bismoclite

A tetragonal mineral, BiOCl .

bismuth

A white crystalline, brittle metal with a pinkish tinge. Symbol, Bi. The
most important ores are bismuthinite or bismuth glance (Bi2 S (sub
3) ) and bismite (Bi2 O3 ). Also obtained as a byproduct in
refining lead, copper, tin, silver, and gold ores. Forms low-melting
alloys that are used in fire detection and extinguishing systems; used as
a catalyst for making acrylic fibers and as a carrier for fuel in atomic
reactors; extensively used in cosmetics and in medicine.
Handbook of Chemistry and Physics, 3

bismuth blende

See:eulytite

bismuth glance

See:bismuthinite

bismuth gold

A pinkish-white native alloy of bismuth and gold, approx. Au2 Bi ;
contains 65.5% gold. See:maldonite

bismuthine

See:bismuthinite

bismuthinite

An orthorhombic mineral, 4[Bi2 S3 ] ; metallic; lead-gray to
tin-white with an iridescent tarnish; commonly associated with other ore
minerals; a source of bismuth. Syn:bismuth glance; bismuthine.

bismuth ocher

See:bismite

bismuth selenide

Bi2 Se3 ; black; orthorhombic; and melting point, 706
degrees C. Of some interest for thermoelectric applications. Also called
bismuth triselenide. Lee

bismuth spar

See:bismutite

bismuth telluride

Bi2 Te2 S ; hexagonal rhombohedral; gray; and a
thermoelectric material. Because it loses its semiconducting properties
above 100 degrees C, it is of value chiefly in cooling devices. Also
called bismuth tritelluride. Syn:tetradymite

bismutite

A tetragonal mineral, Bi2 (CO3 )O2 ; earthy or
amorphous. Syn:bismuth spar

bismutotantalite

An orthorhombic mineral, Bi(Ta,Nb)O4 .

bisphenoid

In crystallography, a form apparently consisting of two sphenoids placed
together symmetrically. CF:disphenoid