Cobalt - MANTRA

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Cobalt

Cobalt is used in most modern batteries such as the lithium-ion battery or the nickel-metal hydride batteries that have been known for years. Cobalt is important for the human organism because vitamin B12 contains cobalt. Like many other metals, cobalt has a shiny grey metallic appearance. It is a heavy metal due to its high density.

How could I come in contact with it?

As cobalt is used in some everyday applications, you may also come into frequent contact with it. Guitar strings and permanent magnets can contain cobalt. Tools that have to withstand particularly high loads also often contain cobalt (as tungsten carbide-cobalt). Cobalt improves the mechanical properties of prostheses, so you can have cobalt in your own body. Deep blue glass objects often contain cobalt as a colour pigment.

How dangerous is the material for humans and the environment?

Cobalt is not dangerous to humans or animals in low doses. As it is used in steel, glass or comparable solid materials, it normally remains firmly bound and no large quantities of cobalt or its compounds are released. If larger quantities of cobalt are ingested, this can lead to poisoning. As with nickel, cobalt can also trigger a contact allergy.

In small quantities, cobalt is vital for most living organisms, including humans. It is contained in the vitamin B12 group. A deficiency of this vitamin can lead to changes in the blood count, damage to the central nervous system and other diseases.

Conclusion

Cobalt is a good example of Paracelsus‘ still valid saying “The dose makes the poison”: small amounts are vital, larger amounts can be harmful to health. Under normal living conditions, a high uptake of cobalt is unlikely.

By th way…

Vegans should have the vitamin B12 level in their blood checked occasionally, as there is no vitamin B12 in a purely plant-based diet. However, it can be supplemented vegan via freely available preparations.

Material Information

Properties and Applications

Cobalt is a shiny, silvery metal that is used in many metal alloys and other compounds such as ceramics (see also our article on tungsten carbide cobalt, a hard metal compound that is particularly hard in keeping with its name). Cobalt can be used to improve the temperature properties and corrosion resistance of steel, making it suitable for use in aircraft or gas turbines. In addition, cobalt itself is ferromagnetic and can be used as a component of permanent magnets (samarium-cobalt magnet). Guitar strings can also be made of cobalt alloys.
Cobalt-alloyed steel is used in apparatus in the chemical industry. There are also a number of cobalt catalysts that can be used to control chemical processes such as desulphurisation and the production of synthetic fuels. Cobalt compounds also play a role as colourants in ceramics and glass (cobalt blue).

With more than 45% and thus the largest part of the cobalt production (as of 2017, and rising), cobalt now plays a decisive role as a component of the electrode material in nickel-metal hydride, nickel-cadmium and lithium-ion batteries. While the first lithium-ion batteries consisted of lithium-cobalt dioxide (LiCoO₂), today so-called NMC (nickel-manganese-cobalt) lithium composite oxides are used. Efforts are increasingly being made to move away from cobalt, as it is sometimes mined under very questionable working conditions (child labour, slave labour). Nickel-cadmium and nickel-metal hydride batteries, which also contain cobalt, are on the market since a long time.
For humans and animals, cobalt is a key component of vitamin B12 (more precisely, cobalamins). Vitamin B12 is important for the nervous system, cell reproduction and haematopoiesis. The body needs small amounts of cobalt, which is therefore an essential element. The human body cannot produce vitamin B12 for itself; it must be obtained from food. A number of other enzymes also contain cobalt.
Cobalt is often used in orthopaedic implants because it is inherently stable as an element in alloys under physiological conditions. Gamma radiation from the radioactive ⁶⁰Co nuclide is used in the treatment of cancer as well as for the disinfection of medical devices and for the preservation of food. Due to the wide range of applications of this radionuclide, it is one of the most important of all.

Natural occurence

Cobalt occurs naturally as an ore and must be mined and processed until it is available as a metal. Cobalt-containing ores often also contain other metals such as copper, nickel and chromium, meaning that the ores are mined for all of these metals. Cobalt has not yet been mined from the manganese nodules found on the seabed, which contain cobalt and other valuable metals in addition to the name-giving metal. If such mining were to begin, unexplored ecosystems could be severely damaged.

The world’s largest producer of cobalt is the state of Congo. The mining of cobalt ore is viewed particularly critically in this country because numerous uncontrolled mines lead to frequent deaths, including those of children working there illegally. Other, far less important mining areas are located in Russia, Australia and Cuba.

Production

The extraction of cobalt depends heavily on the type of ore available. Many different industrial processes are used, which always involve considerable energy input, as cobalt is often present as cobalt oxide, sulphide or arsenide in mixtures with other metal oxides or salts. Cobalt can only be separated from other substances from this mixture by using auxiliary agents such as coal, silicates or electric current. It is then obtained as metallic cobalt or pure cobalt oxide. The metals with which cobalt is mixed are often also valuable, so that several other valuable materials, e.g. copper or nickel, can be recovered at the same time during the processing procedures.