Physics & Chemistry

Tantalum

January 27, 2011, 5:51 pm
Content Cover Image

Tantalum milled single crystal. Source: Heinrich Pniok

caption Manganotantalite, a manganese rich variety of tantalite
Source: University of Delaware

Introduction

Tantalum is a hard, grayish-blue, metallic element, whose atomic number is 73 and its symbol is Ta. It has an extremely high melting point (2996°C), being exceeded only by that of carbon, tungsten, and rhenium. Tantalum is remarkably resistant to attack by air, water and most acids. Tantalum was discovered in the year 802 AD by the Swedish scientist Anders Ekeberg. Commercial use of tantalum began in 1903 with the production of tantalum wire.

Name 

Tantalum is mostly found with the element niobium. The two elements are so similar that they are very difficult to isolate from one another. Tantalum was named after the Greek god, Tantalus. Niobium, discovered before tantalum (1801), was named after the daughter of Tantalus, Niobe.

Sources

Tantalum is recovered from ore minerals such as columbite and tantalite. The United States has no high-grade tantalum ores. In fact, no significant tantalum ores have been extracted in the USA since 1959.

About 20% of the tantalum used in the United States comes from recycling. The rest must be imported. Recent major sources for tantalum imports were Australia, Kazakhstan, Canada, China and Thailand..

Industrial uses

The electronics industry uses most of the tantalum consumed to make electronic components (tantalum capacitors). Since tantalum is so resistant to corrosion, it is used to make surgical instruments and medical equipment such as rods to attach to broken bones, skull plates, and wire meshes to help repair nerves and muscles.

Because it has such a very high melting point, it is alloyed (that is, mixed with) other metals to create alloys that are needed for very high temperature applications. Tantalum is also used in camera lenses.

Tantalum oxide is employed to make special high refractive index glass for optical lenses.The high melting point and oxidation resistance lead to the use of the metal in the production of vacuum furnace parts. Because of  its high density, explosively formed penetrator liners have been produced from tantalum. Tantalum greatly increases the armor penetration capabilities of a shaped charge due to its high density and high melting point. It is also occasionally used in fine timepieces

Substitutes and Alternative Sources

Columbium can be used in place of tantalum to make carbides. Columbium, hafnium, iridium, molybdenum, rhenium and tungsten can be used for high-temperature situations. Aluminum and ceramics can be used in place of tantalum in electronic capacitors. The problem is, however, that most of these substitutes are not as effective as tantalum in some of these applications.

Further Reading

Disclaimer: This article contains information that was originally published by the Mineral Information Institute. Topic editors and authors for the Encyclopedia of Earth have edited the content and added new information. The use of information from the Mineral Information Institute should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

 
Glossary

Citation

Institute, M. (2011). Tantalum. Retrieved from http://www.eoearth.org/view/article/156409

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