Antimony

Antimony is a chemical element with the symbol Sb (from Latin stibium) and atomic number 51. A lustrous grey metal or metalloid, it occurs in nature mainly in the form of the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient history and were powdered for use as cosmetics (often known by the Arabic name kohl) and as medicine. China is the largest producer of antimony and its compounds, with most production coming from the Xikuangshan Mine in Hunan. The industrial methods for refining antimony from stibnite are roasting followed by reduction with carbon, or direct reduction of stibnite with iron. The most common applications for metallic antimony are in alloys with lead and tin, which have improved properties for solders, bullets, and plain bearings. It improves the rigidity of lead-alloy plates in lead–acid batteries. Antimony trioxide is a prominent additive for halogen-containing flame retardants. Antimony is used as a dopant in semiconductor devices.