1/17/2024 0 Comments Cobalt oxidation numberThe ideal transition temperature between the hcp and fcc structures is 450 ☌ (842 ☏), but in practice the energy difference between them is so small that random intergrowth of the two is common. Metallic cobalt occurs as two crystallographic structures: hcp and fcc. Cobalt has a relative permeability two-thirds that of iron. The Curie temperature is 1,115 ☌ (2,039 ☏) and the magnetic moment is 1.6–1.7 Bohr magnetons per atom. Cobalt in inorganic form is also a micronutrient for bacteria, algae, and fungi.Ĭharacteristics A block of electrolytically refined cobalt (99.9% purity) cut from a large plateĬobalt is a ferromagnetic metal with a specific gravity of 8.9. Vitamin B 12, the best-known example of the type, is an essential vitamin for all animals. Ĭobalt is the active center of a group of coenzymes called cobalamins. This is to purge it of sulfur, which is very polluting when burned and causes acid rain. Cobalt is also used in the petroleum industry as a catalyst when refining crude oil. Cobalt-60 is a commercially important radioisotope, used as a radioactive tracer and for the production of high-energy gamma rays. Cobalt occurs naturally as only one stable isotope, cobalt-59. The compounds cobalt silicate and cobalt(II) aluminate (CoAl 2O 4, cobalt blue) give a distinctive deep blue color to glass, ceramics, inks, paints and varnishes. Ĭobalt is primarily used in lithium-ion batteries, and in the manufacture of magnetic, wear-resistant and high-strength alloys. World production in 2016 was 116,000 tonnes (114,000 long tons 128,000 short tons) (according to Natural Resources Canada), and the DRC alone accounted for more than 50%. The Copperbelt in the Democratic Republic of the Congo (DRC) and Zambia yields most of the global cobalt production. The element is more usually produced as a by-product of copper and nickel mining. Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as cobaltite (CoAsS). In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), which was ultimately named for the kobold. They were so named because they were poor in known metals and gave off poisonous arsenic-containing fumes when smelted. Miners had long used the name kobold ore ( German for goblin ore) for some of the blue pigment-producing minerals. The color was long thought to be due to the metal bismuth. The free element, produced by reductive smelting, is a hard, lustrous, silvery metal.Ĭobalt-based blue pigments ( cobalt blue) have been used since antiquity for jewelry and paints, and to impart a distinctive blue tint to glass. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. Cobalt is a chemical element it has symbol Co and atomic number 27.
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