Discovered | Name | Characteristics | Uses | Minerals

Niobium is a transition metal in Group VB (Group 5) and the 5th period. It has oxidation numbers ranging from 0 to +5, with +5 being common. Other members of Group VB are vanadium (V) and tantalum (Ta).

The three Group VB elements were all discovered at the beginning of the 19th century, although, since the properties of niobium and tantalum are so similar, there was great confusion at first. In 1802 A.G. Ekberg isolated from some Finnish minerals a new element he called tantalum, after Tantalus, a king in Greek mythology. About the same time Charles Hatchett (a very wealthy man who lived in a luxurious mansion in England) examined a yet unstudied mineral, columbite, and isolated the oxide of a new element. He named it columbium in honor of the country of origin (the present United States) of the mineral. For some time it was thought that tantalum and columbium were the same substance. However, in 1844 H. Rose examined a sample of columbite and showed that in fact tantalum and columbium were two different - and new - elements. Rose, however, referred to columbium as niobium, named because Niobe was the daughter of Tantalus. The name niobium was officially adopted in 1950, but columbium is still frequently used.

Niobium metal is a steel-gray, ductile, refractory material. Its melting point (2468°C) is slightly lower than that of Mo (2617°C). It closely resembles tantalum in its chemical properties, although Ta is slightly more reactive. It is not affected by mineral acids or aqua regia at ordinary temperature, but it will dissolve in HF.

It is used extensively, in the form of ferroniobium, in the steel industry as an additive in the manufacture of high strength steels. Indeed, thousands of pounds have been used in the space program in advanced air frames. The element is superconducting at low temperatures, and superconducting magnets have been made of Zr-Nb wire.

The chief mineral of Nb and Ta, (Fe,Mn)M2O6 (where M = Nb and Ta), is called columbite or tantalite depending on which predominates, Nb or Ta. Niobium has an abundance in the earth's crust of about 20 ppm, comparable to that of N, Ga, and Li.