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Bismuth,
a silver-white metal, atomic number 83, atomic weight 208.980,
is the most
metallic element in the group 15 in the periodic table. Though the principal deposits are in ores,
the primary
source of bismuth is as a by-product in refining of copper
and lead ores. Of all the metals, bismuth is the most diamagnetic and has the lowest thermal conductivity except
mercury. Bismuth has a high electrical resistance
and the highest Hall coefficient. Elemental bismuth like antimony and water
is the
substances of which the liquid phase is denser than its solid phase.
The field of application of our bismuth-based chemicals is found
in ceramic materials, pharmaceuticals, cosmetics, and automobile industry to
reduce the levels of lead. Bismuth telluride (Bi2Te3) and bismuth selenide (Bi2Se3)
are used in
thermoelectric equipment for refrigeration. Bismuth phosphomolybdate (BiPMo12O40)
is a highly
effective catalyst for the preparation of acrylonitrile, which is the raw
materials of acrylic fibres, plastics, and
paints. Bismuth chemicals
are used in cosmetics for shiny look in eye shadow, nail varnish and lipstick due
to metallic and pearlescent effect.
Salts of bismuth have astringent, antacid, and mildly germicidal properties and are used to
treat diarrhea, nausea, indigestion, and other gastrointestinal conditions,
They are used as a positive contrast agent in X-ray
examination.
Bismuth Subnitrate is a white, almost odourless
cryistalline powder, containing 71 - 75 % w/w of bismuth Bismuth Subnitrate is more astringent than other bismuth salts. It is
used pharmaceutically in wound
dressing, ointment component and as an antiacid. In cosmetics it is used as
a cosmetic white pigment. |
