What is Niobium?

About Niobium:

• It is a rare, soft, malleable, ductile, gray-white metal.
• Atomic symbol: Nb
• It has a body-cantered cubic crystalline structure.
• It must be placed in a protective atmosphere when processed at even moderate temperatures because it tends to react with oxygen, carbon, the halogens, nitrogen, and sulphur.
• Melting point: 2,477 degrees Celsius
• Boiling point: 4,744 degrees Celsius
• In air, an oxide layer forms over it, whose colour depends on its thickness. Shades of blue, green, and yellow are typical.
• Niobium resists corrosion due to the oxide film.
• The metal starts to oxidise rapidly in the air at 200 degrees Celsius.
• The metal is inert to acids, even to aqua regia at room temperature, but is attacked by hot, concentrated acids, and especially by alkalis and oxidizing agents.
• It is one of the five major refractory metals (metals with very high resistance to heat and wear).
• It has the property of becoming superconducting at low temperatures.
• Sources:
  • It is not found free in nature but in minerals such as columbite and tantalite. 
  • Commercially, niobium is extracted by first forming the oxide (Nb2O5). The oxide is then reduced using carbon or hydrogen.
• Major Producers: Brazil is the world's largest supplier, with Canada a distant second.
• Applications:
  • It is used for the production of high-temperature-resistant alloys and special stainless steels.
  • It is also used in its pure form to make superconducting accelerating structures for particle accelerators.
  • Niobium alloys are used in surgical implants because they do not react with human tissue.
  • Niobium carbide is used in cutting tools.
  • Niobium-tin and niobium-titanium alloys are used as wires for superconducting magnets capable of producing exceedingly strong magnetic fields.