Vanadium

Category: transition metal Atomic number: 23 Colour: greyish silver Melting point: 1,910°C (3,470°F) Boiling point: 3,407°C (6,165°F) First identified: 1801

Vanadium is another metal frequently used in alloys. Eighty per cent of total production each year is added to steel, which becomes resistant to shocks and vibrations through the addition of less than 1 per cent of vanadium and a pinch of chromium. Alloys of the metal are also used in nuclear reactors, because of its low absorption of neutrons. And it has additional uses as a pigment for glass and ceramics, and in the manufacture of superconducting magnets.

The metal was first discovered in 1801 by Andrés Manuel del Rio, a Mexican professor, within a brown lead ore called vanadite. When he sent it off for further analysis, a French chemist dismissed it as being chromium (which it does resemble, due to the many colours of its salts). Then, in 1831, the Swedish chemist Nils Gabriel Sefström discovered that cast iron made from ore mined in southern Sweden also contained vanadium. The metal workers had wondered why there was so much variation in how hard their iron was: vanadium was the answer.

There were various attempts to isolate the metal over the years, and a few attempts to claim success: finally, in 1869, Sir Henry Roscoe produced a sample in Manchester, and demonstrated that the previous samples made had all actually been the compound vanadium nitride. The metal is generally produced by reducing vanadium oxide with calcium in a high-pressure environment.

Vanadium is an essential part of our nutritional needs, but only in tiny amounts – good sources are mushrooms, shellfish, spinach, whole grains, black pepper, dill seeds and parsley. It also seems that a healthy intake of vanadium is useful to diabetics, as it increases their sensitivity to insulin.