Estimated crustal abundance: 2.0 milligrams per kilogram
Estimated oceanic abundance: 2×10-6 milligrams per liter
History
(Gr. Tantalos: mythological character, father of Niobe) Discovered in 1802 by Ekeberg, but many chemists thought niobium and tantalum were identical elements until Rowe in 1844, and Marignac, in 1866, showed that niobic and tantalic acids were two different acids. The early investigators only isolated the impure metal. The first relatively pure ductile tantalum was produced by von Bolton in 1903. Tantalum occurs principally in the mineral columbite-tantalite.
Sources
Tantalum ores are found in Australia, Brazil, Mozambique, Thailand, Portugal, Nigeria, Zaire, and Canada.
Properties
Tantalum is a gray, heavy, and very 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 attack at temperatures below 150oC, and is attacked only by hydrofluoric acid, acidic solutions containing the fluoride ion, and free sulfur trioxide. Alkalis attack it only slowly. At high temperatures, tantalum becomes much more reactive. The element has a melting point exceeded only by tungsten and rhenium. Tantalum is used to make a variety of alloys with desirable properties such as high melting point, high strength, good ductility, etc. Tantalum has a good "gettering" ability at high temperatures, and tantalum oxide films are stable and have good rectifying and dielectric properties.
Uses
Scientists at Los Alamos have produced a tantalum carbide graphite composite material, which is said to be one of the hardest materials ever made. The compound has a melting point of 37380C. Tantalum is used to make electrolytic capacitors and vacuum furnace parts, which account for about 60% of its use. The metal is also widely used to fabricate chemical process equipment, nuclear reactors, aircraft, and missile parts. Tantalum is completely immune to body liquids and is a nonirritating material. It has, therefore, found wide use in making surgical appliances. Tantalum oxide is used to make special glass with high index of refraction for camera lenses. The metal has many other uses.
Would you like to contact senior executives directly? Join our network on OurMetals.in
It's free and only takes 2 minutes to register.
Our company is a private firm founded in 1990 with aim to develop export and import with Russia. We do promote EU industrial and consumer goods in Russia and strongly support marketing of Russian and CIS industrial products and services.