The essentials
Here is a brief description of niobium.
- Standard state: solid at 298 K
- Colour: grey metallic
- Classification: Metallic
- Availability:
niobium is available in many forms including foil, sheet, wire, insulated wire, powder, rod, turnings, and tube.

Small and large samples of niobium wire like this, as well as foil, sheet, insulated wire and tube, can be purchased from Advent Research Materials via their web catalogue.
The name niobium was adopted officially by IUPAC in 1950, but a few commercial producers still like to refer to it as columbium.
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
Here is a brief summary of the isolation of niobium.
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.
|