Cobalt was introduced at the London Metals Exchange, the February 22, 2010.
Futures contract-specific characteristics of cobalt
Contract: 99.30% pure cobalt with respect to approved LME Brand
Lot Size: 1 ton of cobalt at 99.3%
Margin per Lot: $7,000
Forms: Cathodes-Balls-Tiles-Bullion Granules
Cobalt is the chemical element with atomic number 27. Its symbol is Co.
It is a silvery-white element, magnetic and very hard. Its Curie temperature is 1388 K with 1.6 ~ 1.7 Bohr atom for magnetoni. It is often associated with nickel, and both are characteristic components of meteoric iron. Mammals require small amounts of cobalt salts in the diet. The 60Co, an artificial radioactive isotope, is used in the treatment of many types of cancers. Cobalt has a relative permeability two thirds that of iron. The metal cobalt is usually a mixture of two different crystallographic structures: hcp and fcc, with a transition temperature by hcp to fcc to 722 K. The thermodynamically stable configuration is therefore the hexagonal, even if technologically it's easy to get the cubic allotrope (e.g. making thin films of cobalt).
Oxidation States that Cobalt can take are +2, +3 and (rarely) +1.
Cobalt and its salts are used in many fields and applications:
- Metal alloys, such as
- those used in manufacturing turbines for aircraft engines
- high-alloy corrosion resistance and wear resistance
- tool steels at high speed
- Diamond tools
- Magnets and magnetic media for recording, alloyed with Fe (CoFe, magnetically hard materials with low remanence) and Al alloy and Ni (Alnico, magnetically hard materials with high remanence)
- Catalysts for petrochemical and chemical industries
- Electrodeposition coating material (electroplating), for its appearance, its resistance and its hardness.
- Desiccant compounds for paints, lacquers and inks
- Powders for coating porcelain and enamels
- Pigments: cobalt blue and cobalt Green
- Electrodes for car batteries
- For the construction of special cathode vacuum tubes for HiFi applications of the highest level, these special valves (very expensive) have the unique characteristic of emitting a greenish light instead of the usual orange glow from typical of other types of "normal" valves.
- Cobalt-60, radioactive, it is used as a gamma ray source:
- is used in radiotherapy
- do you use for food sterilization by radiation (cold pasteurization)
- industrial radiography is used for detecting structural anomalies in metal artifacts.
Its use as a radioactive tracer is popular because it is easy to produce; you get indeed exposing natural cobalt to neutrons produced by a nuclear reactor.
Cobalt was known since antiquity for its compounds, that spontaneous blue glass nice. George Brandt (1694-1768) is considered the discoverer of cobalt: the date of discovery varies depending on the source, but is between 1730 and 1737. He was able to show that Cobalt was the source of the blue color in glass, which previously had been attributed to the bismuth found with cobalt. During the 19th century, cobalt blue was produced by the Norwegian Blaafarvevaerket (70-80% of world production), followed by the production of German industrialist Benjamin Wegner. In 1938, John Livingood and Glenn Seaborg discovered cobalt-60.
The cobalt comes from the German word kobalt or kobold, meaning evil spirit (the miners named cobalt ore because it is poisonous and can contaminate other minerals such as nickel). According to others it may derive from the Greek kobalos, meaning Elf: it is possible that the words kobold, goblin and cobalt have all the same etymon.
Cobalt is not found in its pure State, but only as a metallic ore, and is not retrieved alone but as a by-product of copper and nickel mining. The most important ores of cobalt are cobaltite, erythrite, glaucodot the and skutterudite. The world's largest manufacturers of cobalt are the Congo, China, Zambia, the Russia and Australia.
Cobalt metal dust may ignite spontaneously in air. Cobalt compounds should be handled with caution, given their mild toxicity.
The 60Co, radioactive, is a powerful gamma-ray emitter, so its exposure increases the risk of cancer. Ingested, is eliminated from tissues only slowly.
The 60Co can be produced from nickel and cobalt from stable isotopes due to neutron radiation is within the nuclear reactors, both in the case of use of nuclear weapons for the neutrons emitted by these. There are nuclear weapons specifically designed to increase the amount of 60Co dispersed into the environment through the fall-out.