Cobalt

Article

August 13, 2022

Cobalt is a chemical element with the symbol Co and atomic number 27. It is a silver-colored transition metal.

History

Discovery

Cobalt compounds were used to color glass by the Egyptians, Greeks and Romans. In Persia, a necklace with cobalt-colored blue glass beads dating from about 2250 BC was found. During the Tang and Ming Dynasty, the Chinese used cobalt compounds for coloring porcelain. The element itself was discovered about 1730 by Georg Brandt while researching minerals. This Swedish scientist was then able to demonstrate that cobalt was responsible for the blue color and not – as previously assumed – bismuth.

Name

The word cobalt comes from the German kobold (gnome). Cobalt ore was often confused with ores of the metals one wanted to mine, so there was great disappointment when the unwanted cobalt was obtained. Cobalt attracts the poisonous arsenic and therefore frightened the miners. So it was believed that goblins out of malice put this metal in the mines.

Prevent

Along with nickel and iron, it is often found in large quantities in meteorites. It also occurs in the human body as a component of vitamin B12, in the body of an adult there is 1 to 2 grams of cobalt. In the Earth's crust, cobalt occurs as cobaltite, erythrite, skutterudite and other minerals.

Features

The silver cobalt is ferromagnetic.

Isotopes

In nature there is one stable isotope (cobalt-59) and a large number (more than 20) radioactive, of which cobalt-60 has the longest half-life. The decay of cobalt-60 to the stable nickel-60 is the main reason for allowing a nuclear power plant to 'cool down' for about 20 to 150 years after decommissioning, before starting decommissioning.

Cobalt salts

Cobalt occurs as an inorganic substance in combination with acid residues to form cobalt salts: Cobalt(II) Acetate Cobalt(II)bromide Cobalt(II) chloride Cobalt(II) and -(III) fluoride Cobalt(II) iodide Cobalt(II) nitrate Cobalt(II)sulphate

Applications

Cobalt is used in a whole range of industrial processes: electrodes in batteries, currently one of the most important applications of cobalt worldwide in all kinds of (super) alloys, including for gas turbine engines, for corrosion- and weather-resistant alloys; cobalt-chromium alloys are used for prosthetics and implants. airbags for cars catalyst in the chemical and oil industry; carbide and diamond tools drying agents for paint, varnish and ink dyes and pigments as a primer for porcelain enamel high speed steel magnetic recording equipment as a component in strong permanent magnets; radial tires with steel carcass. Furthermore, the isotope cobalt-60 is used in radiotherapy and the irradiation of food, medical articles, packaging material for the food industry, cosmetics, cutting pots for gardeners and many other products. Cobalt salts (cobalt(II) chloride or sulfate) were used as foam stabilizer for the foam of beer. The stabilizing effect of cobalt on the head of beer was discovered in Copenhagen in 1957 and patented by the Danes. Some beer manufacturers added too many cobalt compounds to the beer to obtain a firmer foam, but this process was stopped when it turned out that cobalt was worse for the liver than alcohol. As in ancient times, cobalt(II) oxide, better known as the trivial name cobalt blue, used as a pigment for glass and porcelain.

Economic significance

Reserves

The largest amount of cobalt ore is mined in Congo. Political instability in this country affects the price of cobalt. Other countries in which cobalt ore is mined include Turkey, China, Zambia, Russia and Australia. In the past, the ore was mined in Europe,