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Bismuth, a hard, brittle metal, discovered in 1450. It occurs as
the free element as well as the oxide, Bi2O3, called bismuth
ocher, and as the sulfide, Bi2S3, called bismuth
glance. Bismuth also occurs in lead ores, therefore, its principal commercial
source is from the by-product of refining lead.
Like antimony, bismuth expands when it solidifies. So,
where sharp, well-defined edges of castings are important (i.e. in type
metals), bismuth and antimony are used as alloying agents.
The melting point of bismuth is 271 oC, but form alloys that melt
as low as 47 oC. Bismuth alloys have wide applications in automatic
sprinkler systems, electrical fuses, and safety plugs in boilers where low-melting
alloys are essential.
Bismuth is also used as medicine. The active ingredient in Pepto-Bismol is
Bismuth Subsalicylate.
In recent scientific research, bismuth-containing compounds are reported to
be promising candidates for high temperature superconducting
materials.
