Tantalum was discovered in in 1802 by Anders Ekeberg. It is resistant to corrosion and has high refractory properties.
History and Discovery
Tantalum was discovered by Anders Ekeberg in 1802 [1]. Initially, it was considered very similar to niobium but in 1864, Christian Wilhelm Blomstrand highlighted the differences between the two and categorized them as two distinct elements. The elemental form of tantalum was discovered by De Marginac in 1864, but it was impure. Tantalum was produced in pure elemental form by Werner von Bolton in 1903. In the beginning, tantalum was given the name tantalium. The name has been derived from Greek mythology villain, and father of Niobe, Tantalus.
Tantalum
| Periodic Table Classification | Group 5 Period 6 |
|---|---|
| State at 20C | Solid |
| Color | Gray blue |
| Electron Configuration | [Xe] 4f14 5d3 6s2 |
| Electron Number | 73 |
| Proton Number | 73 |
| Electron Shell | 2, 8, 18, 32, 11, 2 |
| Density | 16.65 g.cm-3 at 20°C |
| Atomic number | 73 |
| Atomic Mass | 180.95 g.mol -1 |
| Electronegativity according to Pauling | 1.50 |
Occurrence
Tantalum is not a very rare element and is present in around 1 or 2 ppm in the earth’s crust [2]. In nature, tantalum is mostly present in form of minerals. It exists in combination with niobium, that is quite similar to tantalum in various characteristics. The most common minerals of tantalum include coltan, columbite and tantalite. Tantalite (Fe, Mn) mineral is commonly used for the extraction of tantalum. Tantalum metallurgy is categorized as the most complex and demanding metal separation process from its ores. The primary reason being the profound resemblance of tantalum with niobium, and it becomes a challenge to separate the two elements from each other and obtain pure forms. Today, the most efficient method for tantalum metallurgy is hydrometallurgy [3]. The largest producers of tantalum include Australia, Ethiopia, China and Malaysia.
Physical Characteristics
Tantalum is a greyish-blue transition metal. It is hard and shiny in nature. Tantalum is ductile and can be fabricated for various purposes [4]. Tantalum is resistant to corrosion. Due to its extraordinary ability to withstand heat and physical stress, tantalum is considered a refractory metal and have been widely used along with other refractory group elements, including platinum etc. Tantalum is a dense metal, with a density of 7.98 g/cm3. It is an efficient conductor or electricity and heat. the melting and boiling points of tantalum are very high, 3017°C and 5458°C. There are two crystalline forms of tantalum, alpha and beta. Alpha phase is soft while beta phase is hard and brittle. Alpha is the predominant and stable form of tantalum.
Chemical Characteristics
Tantalum is an inert metal. There are various oxidation states of tantalum, that range from -3 to+5. Commercially, the most significant tantalum compound is tantalum pentoxide. Tantalum carbides and tantalum nitrides are widely used refractory compounds of tantalum. Tantalum forms compounds with halogens with varying oxidation state, as with fluorine it forms tantalum pentafluoride. And with lower halides, tantalum form compounds with lower oxidation states.
Significance and Uses
- Tantalum is used in various electronic devices as capacitors. These devices include video games, mobile phones, laptops, computers, cameras, and DVD players.
- Tantalum nitride is used as insulator in certain microelectronic fabricating application.
- Tantalum is used to make high power resistors in electrical devices.
- Tantalum is used to make various alloys to enhance strength, melting points, boiling point and ductility of the metals. super alloys of tantalum are used to make nuclear reactors, components of jet engine and missile parts.
- Tantalum is inert and is resistant to attack by various acids and base, so it is used to make storage vessels for corrosive liquids.
- The refractory properties of tantalum allow its use in making of parts of vacuum furnace.
Health effects
Tantalum is a nontoxic metal. it is compatible to the human body and is used in various implants and prosthetic devices. According to the standards of the National Institute for Occupational Safety and Health (NIOSH), a dose of 2500mg/m3 of tantalum can cause hazardous effects on health of humans.
Isotopes of Tantalum
There are two isotopes in naturally occurring tantalum: tantalum-180m and tantalum-181. Tantalum-180m is the metastable isotope and that is why it occurs in very low concentrations, around 0.012%.
REFERENCES
[1]. Ekeberg, Anders (1802). “Of the Properties of the Earth Yttria, compared with those of Glucine; of Fossils, in which the first of these Earths in contained; and of the Discovery of a metallic Nature (Tantalium)”. Journal of Natural Philosophy, Chemistry, and the Arts. 3: 251–255
[2]. Agulyansky, Anatoly (2004). The Chemistry of Tantalum and Niobium Fluoride Compounds. Elsevier. ISBN 978-0-444-51604-6. Retrieved 2008-09-02
[3]. Zhaowu Zhu; Chu Yong Cheng (2011). “Solvent extraction technology for the separation and purification of niobium and tantalum: A review”. Hydrometallurgy. 107: 1–12. doi:10.1016/j.hydromet.2010.12.015.
[4]. Colakis, Marianthe; Masello, Mary Joan (2007-06-30). “Tantalum”. Classical Mythology & More: A Reader Workbook. ISBN 978-0-86516-573-1.