![]() The world's major producers of cobalt are the Democratic Republic of the Congo, the People's Republic of China, Zambia, Russia and Australia. The main ores of cobalt are cobaltite, erythrite, glaucodot, and skutterudite. Cobalt is usually not mined alone, and tends to be produced as a by-product of nickel and copper mining activities. Cobalt is a central component of the vitamin cobalamin, or vitamin B-12.Ĭobalt is not found as a free metal and is generally found in the form of ores. Having 0.13 to 0.30 mg/kg of cobalt in soils markedly improves the health of grazing animals. The word cobalt is derived from the German kobalt, from kobold meaning "goblin", a term used for the ore of cobalt by miners, who thought it worthless and who found that it was poisonous and that it polluted and degraded other mined elements, mainly due to the arsenic and sulfur also found in the ore.Ĭobalt in small amounts is essential to many living organisms, including humans. In 1938, John Livingood and Glenn Seaborg discovered cobalt-60. He was able to show that cobalt was the source of the blue colour in glass, which previously had been attributed to the bismuth found with cobalt.ĭuring the 19th century, cobalt blue was produced at the Norwegian Blaafarveværket (70-80 % of world production), led by the Prussian industrialist Benjamin Wegner. Swedish chemist Georg Brandt (1694–1768) is credited with isolating cobalt sometime between 17. Cobalt has been detected in Egyptian sculpture and Persian jewelry from the third millennium BC, in the ruins of Pompeii (destroyed AD 79), and in China dating from the Tang dynasty (AD 618–907) and the Ming dynasty (AD 1368–1644). ![]() The 60Co source is useful for about 5 years but even after this point is still very radioactive, and so cobalt machines have fallen from favour in the Western world where linacs are common.Ĭobalt compounds have been used for centuries to impart a rich blue colour to glass, glazes, and ceramics. The metal has the unfortunate habit of producing a fine dust, causing problems with radiation protection. The 60Co source is about 2 cm in diameter and as a result produces a geometric penumbra, making the edge of the radiation field fuzzy. ![]() It produces two gamma rays with energies of 1.17 MeV and 1.33 MeV.
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