Trace Elements at LLSG Niobium (Nb)

	Trace Elements Laboratory

	A Joint Venture of London Health Sciences Centre and St. Joseph's Health Care London

Niobium (Nb)

This element is not currently measured in this laboratory.

Atomic Number:	41
Atomic Symbol:	Nb
Atomic Weight:	92.9064
Electron Configuration:	[Kr]5s¹4d⁴

Niobium is a shiny, white, soft, and ductile metal, and takes on a bluish tinge when exposed to air at room temperatures for a long time. The metal starts to oxidize in air at high temperatures, and when handled hot must be done so under a protective atmosphere so as to minimize oxide production.

Isolation of niobium appears to be complicated. Niobium minerals usually contain both niobium and
tantalum. Since they are so similar chemically, it is difficult to separate them. Niobium can be extracted from the ores by first fusing the ore with alkali, and then extracting the resultant mixture into hydrofluoric acid, HF. Current methodology involves the separation of tantalum from these acid solutions using a liquid-liquid extraction technique. In this process tantalum salts are extracted into the ketone MIBK (methyl isobutyl ketone, 4-methyl pentan-2-one). The niobium remains in the HF solution. Acidification of the HF solution followed by further extraction in MIBK gives an organic solution containing niobium. After conversion to the oxide, metallic niobium can be made by reduction with sodium or carbon. Electrolysis of molten fluorides is also used.


January 31, 2012