Columbite-tantalite (COLTAN)
The Engineer posted on October 17, 2006 | 54875 views

COLTAN (Columbite-Tantalite)
is a dull metallic ore found in major quantities in the eastern areas of Congo. When refined, COLTAN becomes metallic Tantalum, a heat-resistant powder that can hold a high electrical charge.
Columbite ((Fe, Mn, Mg)(Nb, Ta)2O6 : Iron Manganese Magnesium Niobium Tantalum Oxide) is the most abundant niobium mineral and is used in alloys for improved strength. Also known as Niobium, it also has shown potential superconductive properties and is being used in studies with other metals for possible breakthroughs in the manufacturing of superconductive alloys.

Tantalite ((Fe, Mn)(Ta, Nb)2O6 : Iron Manganese Tantalum Niobium Oxide) is the most widespread tantalum mineral and makes for an important ore of the industrially useful metal. Tantalum (Ta) is a gray, heavy, and extremely hard metal. When pure, it is ductile and can be drawn into fine wire, which is used as a filament for evaporating metals such as aluminum. Tantalum is almost completely immune to chemical reaction at temperatures low temperatures (sub-150 degrees C), and is reactive only with hydrofluoric acid, acidic solutions containing the fluoride ion, and free sulfur trioxide. At higher temperatures, Tantalum becomes much more reactive though it has a melting point exceeded only by Tungsten and Rhenium. Tantalum is used to make a variety of alloys with desirable properties such as extremely high melting points, extreme strength, good ductility, etc. Tantalum has good "gettering" ability at high temperatures, and tantalum oxide films are stable with good rectifying and dielectric properties.

Tantalum is used mainly in the manufacture of condensers and micro-electronic technology (chips and processors), cell phones and nuclear reactors. It is also used in the production of steel varieties having a high heat tolerances, like those used in the engines of aircraft. Whereas it was formerly only one secondary product of the exploitation of Tin, Tantalum became today, under the terms of its specific characteristics, a very required element.

Besides Congo, COLTAN is mainly extracted in Australia, Brazil, Canada, and China. The principal modern extraction takes place in Australia, in the Wodgina mine, where the annual production of Ta2O5 reaches approximately 150,000 tons. In 2000, the ore typically sold on world markets for approximately $330.00 USD per kilogram. The recent technology boom and low availability of COLTAN caused a substantial increase in the price to almost $400 USD per kilogram at one point, as supply struggled to meet the demands of companies such as Nokia and Sony.

Little information is currently available regarding the amount of radiation absorbed by the body via the inhalation of dust during the treatment and extraction of COLTAN. It is known however that the radioactivity is found almost entirely in the residue of the ore, and not in its finished products (GSM, computers, etc.).

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