Antimony is a chemical element with the symbol Sb and atomic number 51. Its name comes from the Greek words ‘anti’ and ‘monos’, which when put together mean ‘not alone’. Its chemical symbol comes from its historic name Stibium.
Antimony is a silvery-grey, lustrous metalloid. It is found in nature mainly as the sulfide mineral stibnite. Antimony compounds have been used for many years – in ancient time it was a popular addition to cosmetics. In this setting you might be more familiar with its Arabic name, kohl – a popular addition to eye shadows. Today Antimony is primarily used as alloying material for lead and tin. This improves the properties of the alloys and enables them to be used in solders, bullets and plain bearings. Antimony alloys are also commonly used in batteries and cable sheathings. Antimony compounds are often used to make flame-proof materials, paints, ceramic enamels, glass and pottery.
Antinomy is in the nitrogen group (15) and is more electronegative than tin or bismuth, but less than tellurium or arsenic. It reacts with oxygen if heated and becomes antimony trioxide, however, it is stable at room temperature. It has a ranking of 3 on the Mohs scale which makes it too soft to make hard objects. In 1931 coins made of antimony were put into use in the Guizhou province of China, however, because of their rapid wear their use was quickly discontinued. Antimony is found occurring naturally in the Earth’s crust and is estimated at 0.2 to 0.5 parts per million. Even though the element is not abundant it can be found in over 100 mineral species.
Around 60% of all antimony produced is used in flame retardants with it being used mainly as a trioxide in making flame proofing compounds. The applications for this include children’s clothing, toys, aircraft and automobile seat covers. Antimony also forms a very useful alloy with lead, increasing its hardness and mechanical strength.
In 2005, the British Geological Survey reported that the People’s Republic of China was the top producer of antimony in the world. They had a staggeringly large 84% share, followed by South Africa, Bolivia and Tajikistan. In 2010 this figure rose to 88.9% according to the US Geological Survey. Due to its lack of supply outside China, antimony was identified as 1 of 12 critical raw materials for the EU in 2011. Since 2010 the reported production of antimony in China has fallen with no significant antimony deposits developed for the past 10 years. This means the remaining reserves are being rapidly depleted.