Cobalt is a hard, lustrous and a grey metal with symbol Co and atomic number 27. Cobalt is a transition metal with a close packed hexagonal (CPH) crystal structure at room temperature.The name Cobalt was derived from the German word ‘Kobold’, meaning evil spirits. The interest in cobalt’s uses goes back to 2000 B.C. when cobalt was used by Egyptian artisans as a coloring agent.
Cobalt-based colors and pigments are in use since ancient times for making jewelry and paints. Miners have long used the name ‘kobold’ ore for some minerals.
Cobalt is an essential trace element for all multi-cellular organisms as the active center of coenzymes called cobalamins. These include vitamin B12 that is essential for mammals. Cobalt is also an active nutrient for bacteria, algae, and fungi, and may be a necessary nutrient for all life.
Although Cobalt is one of the least abundant elements compared to Copper and Nickel, it is an important part of the composition of nearly all alloys developed since the 19th century and has been of considerable interest in recent years.
The use of Cobalt goes back to 2000-3000 B.C. The term ‘Kobold’ applied to spirits (gnomes) who frequented the mines causing trouble (as per “gremlins” in air force slang). The problems were due to cobalt interfering with the silver smelting causing arsenic fumes, threatening the health with the miners. The main use of cobalt remained as a colouring agent right up to the 20th Century.
Cobalt is one of the world’s essential elements. It has many strategic and irreplaceable industrial uses but it is also a central component of Vitamin B12 that it is vital. It has a high melting point and retains its strength to a high temperature. Due to this property, it is used in making Cutting tools, super alloys, surface coating, high speed steels, cemented carbides, diamond tooling.
|Name and Symbol||Copper: Co|
|Element category||Transition Metal|
|Group: Period: Block||9: 4: d|
|Standard atomic weight||58.933195(5) g·mol−1|
|Melting point||1495 °C|
|Boiling point||2927 °C|
|Electrical resistivity||(20 °C) 62.4 nΩ·m|
|Thermal conductivity||(300 K) 100 W·m−1·K−1|
Cobalt is not a particularly rare metal and it ranks 33 in abundance. Cobalt is found in various metallic-lustered ores for example cobaltite (CoAsS), but it is produced as a by-product of copper and nickel mining. It is widely scattered in the earth’s crust is found in several countries
Extraction of Cobalt
Several methods can be used to separate Cobalt from Copper and Nickel. They depend on the concentration of cobalt and the exact composition of the used ore.
Solution purification, in term of separating impurities from cobalt to produce a pure product, is achieved by means of chemical precipitation, solvent extraction, ion exchange and electro-winning. Cobalt resources can be maximized with its recovery from leaching solution, electro-winning bleed, smelting slag, sludge and residues.
Unlike Gold or Platinum, Cobalt is not a rare and precious metal at the same time it does not exist in large quantities in the earth’s crust. Cobalt has been in use for centuries to create beautiful deep blue glass, ceramics, pottery, tiles and paint pigments. In addition to traditional uses, Cobalt is used in a number of industrial applications.
When Cobalt is alloyed with other metals, very strong magnets are created. Super alloys containing Cobalt are used in the production of jet engines and gas turbine engines for energy generation. These super alloys account for nearly half of the Cobalt used each year. Cobalt is also used in making of cutting and wear-resistant materials. Cobalt’s use in rechargeable batteries is the fastest growing use. Notably in 2007, the percentage of cobalt use for rechargeable batteries rose to 25% of total cobalt demand from 22% in 2006.
The usage of Cobalt can be significantly categorized as below:
Cobalt has been in use for centuries to create beautiful deep blue glass, ceramics, pottery and tiles. In a similar way, it is being used to make paint pigments.
In addition to traditional uses, Cobalt is used in a number of industrial applications. When Cobalt is alloyed with other metals, very strong magnets are created. Super alloys containing Cobalt are used in the production of jet engines and gas turbine engines for energy generation. These super alloys account for nearly half of the Cobalt used each year. Cobalt is also used in making of cutting and wear-resistant materials.
Lithium cobalt oxide (LiCoO2) is widely used in Lithium ion battery electrodes. Nickel-cadmium (NiCd) and nickel metal hydride (NiMH) batteries also contain significant amounts of cobalt.
Cobalt alloyed with chromium and tungsten is used for making high speed cutting tools. Since cobalt has magnetic properties, it is used to make strong permanent magnets.
Cobalt is an element that has many diverse and critical uses. In most applications, substitution for cobalt yields lower product performance. Most common industry usages of Cobalt are as below:
|Usages||% of Market|
|Batteries – Cell phones, computers, hybrid vehicles, portable tools, etc.||25|
|Super Alloys – Turbine blades, mainly jet engines||22|
|Chemicals – Includes pigments and dyes||16|
|Wear Resistant Alloys – Hard facing and cobalt carbide||12|
|Catalysts – Includes Gas-to-Liquid conversions||9|
|Magnets – High performance applications||6|
Cobalt in rechargeable batteries is the fastest growing use, and notably in 2007 the percentage of cobalt use for rechargeable batteries rose to 25% of total cobalt demand from 22% in 2006.
Since 1920, D. R. of Congo has been the dominant producer of Cobalt in the World. The Copper belt in the Democratic Republic of the Congo and Zambia yields most of the worldwide-mined Cobalt. Other major producers are Russia, Zambia, Australia, Canada, Finland, Cuba, and Germany.
Today Cobalt’s market is very dynamic but rather small in comparison with other base metals. Approximately 48% of the world’s 2007 cobalt mined was byproduct of nickel from sulfide and laterite deposits. An additional 37% was produced as a byproduct of copper operations, mainly in the Democratic Republic of the Congo (DRC) and Zambia. The remaining 15% of cobalt mining came from primary producers.
Cobalt consumption in 1995 was only 24,000 tonnes, but grew to 60,800 tonnes in 2008 for a compound annual growth rate (CAGR) of 7.4% for the 13-year period.
Forecasts made by reliable International group suggest that mineral industry is estimated to reach 72,500 tonnes in demand by 2011. Global cobalt consumption by country and the increase for the four-year period ending 2006 is shown below.
|Country||2002 (Tonnes)||2006 (Tonnes)||% Change|
The table below shows approximate production of refined cobalt and reserves and resources by country.
Refined Cobalt Production in 2007 & Reserves
|Country||Mine Production||Tonnes x 1000 Reserves||Tonnes x 1000 Reserve Base*|
* includes reserves plus measured and indicated resources
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