How Is Cobalt Extracted?

Updated November 21, 2016

Cobalt is the chemical element Co with the atomic number of 27. A silver-grey metal, cobalt is produced by reductive smelting, a technique used to produce metal from its ore. As early as to 2250 BCE, Persians used cobalt salts to colour glass blue. The Chinese and Egyptians also used cobalt in sculpture and pottery art. Metallic cobalt was discovered by Swedish scientist George Brandt and was recognised as an element in 1780.

About Cobalt

Cobalt is an essential element for all multicellular organisms. Cobalt is an active component of coenzymes cobalamins, which includes vitamin B12. It is a transition metal and is similar to nickel in its properties. Cobalt is found in cobaltite, smaltite and erythrite as well as silver, nickel, copper and iron ores. Cobalt ore deposits have been discovered in Canada, Morocco and the bottom of the Pacific Ocean near Hawaii. It is usually mined as a by-product of copper or nickel. The ore mined usually only contains 0.1 per cent of cobalt.

Mining of Cobalt

Cobalt is found by journeying into mines to extract the ore from the earth, which contains minerals, including metal elements. Ores are mined by blasting the earth with explosives or digging into rock with shovels and picks to extract the ore from the rock. Miners then process the copper or nickel ore to find cobalt by crushing the ore in primary cone crushers, using wet magnetic separators to separate the copper or nickel, and reducing it to mesh in a ball mill, which is a mineral grinder.

Cobalt Extraction

Cobalt is then extracted in a variety of ways. Cobalt is extracted from the nickel or copper through solvent extraction, which is separating compounds based on their solubility in two immiscible liquids, such as an organic solvent and water. Hence, it extracts the cobalt substance from one liquid into another liquid phase. Or, cobalt is extracted through smelting, using heat from a blast furnace and a metal reducing agent, such as carbon, to change the ore's oxidised state. The carbon removes the ore's oxygen and leaves the metal cobalt. The cobalt is taken out to attain 99.9 per cent pure cobalt. The cobalt is then sold to a manufacturer to convert the cobalt to cobalt sulphate, carbonate or salt derivatives.

Cobalt Uses

Cobalt is used as a component of magnetic alloys. Cobalt's strong resistance to high temperatures also makes it ideal for use in surface coatings, cutting tools, high speed steel and diamond tools. Cobalt is used in the production of gas turbine and jet engines, energy generation, rechargeable batteries, drying agents for paints, pigments and steel-belted radial tires. Because of its hardness and resistance to oxidation, cobalt metal is also used in electroplating, a plating process in which an electric field moves metal ions to coat an electrode. Furthermore, cobalt salts are also used to produce blue colours in pottery, glass, and porcelain. Lastly, cobalt is fed to sheep to prevent disease and improve the quality of their wool.

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