Antimony

Antimony is a chemical element with the symbol Sb and atomic number 51. It is classified as a metalloid in group 15 of the periodic table and occurs in nature mainly as the mineral stibnite (Sb2S3). The element has a long history of use and is produced commercially from sulfide and oxide ores.

Physically, antimony is a silvery-gray, brittle solid with a relatively high density. It remains solid up to about 631°C, and its boiling point is around 1587°C. Chemically, it commonly exhibits oxidation states of +3 and +5, forming compounds such as antimony trioxide (Sb2O3) and antimony pentoxide (Sb2O5). It can also form various sulfides and halides and shows mixed metallic and nonmetallic properties typical of metalloids.

Production and uses: Antimony is extracted by roasting stibnite to antimony oxide, followed by reduction with carbon to produce the metal. The metal is used to harden alloys with lead and tin, improving strength and durability in batteries and hardware. Antimony compounds, especially Sb2O3, are widely used as flame retardants in plastics, textiles, and electronics. Sb2S3 is used as a pigment and in infrared detectors. Antimony compounds also find use in catalysts and specialty glasses.

Other applications include semiconductors and dopants for silicon and germanium, where antimony acts as a donor to produce n-type material, and in high-refractive-index glass. Safety: exposure to antimony and its compounds can be toxic, causing irritation and more serious effects with prolonged exposure. Mining and processing pose environmental risks, so handling and disposal are regulated.