Antimony is a bluish-white metal, symbol Sb, with a crystalline scale like structure that exhibits poor electrical and heat conductivity. It is brittle and easily reduced to powder. It is neither malleable nor ductile and is used only in alloys or in its chemical compounds. Like arsenic and bismuth, it is sometimes referred to as a metalloid, but in mineralogy it is called a semimetal. The element is available commercially in 99.999+% purity and is finding increasing use in semiconductor technology.
Antimony is produced either by roasting the sulfide with iron, or by roasting the sulfide and reducing the sublimate of Sb4O6 thus produced with carbon; high-purity antimony is produced by electrolytic refining. Antimony is one of the few elements that exhibits the unique property of expanding on solidification. Antimony is ordinarily stable and not readily attacked by air or moisture. Under controlled conditions it will react with O2 to form oxides. The chief uses of antimony are in alloys, particularly for hardening lead-base alloys.
Antimony imparts hardness and a smooth surface to soft-metal alloys, and alloys containing antimony expand on cooling, thus reproducing the fine details of the mold. This property makes it valuable for type metals. When alloyed with lead, tin, and copper, it forms the Babbitt metals used for machinery bearings. It is also much used in white alloys for pewter utensils. Its compounds are used widely for pigments.
