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Factfile
Metallic element belonging to sub-group 5B in the periodic system, discovered in 1830 by Nils Gabriel Sefström in pig-iron made from ore (titanomagnetite) obtained from Taberg, Småland. Its name derives from Vanadis, epithet of the goddess Freya in Norse mythology. Vanadium is steel grey in colour and the pure metal is malleable, but micro-contaminants render it brittle. Sir Henry Enfield Roscoe in England was probably the first to produce pure vanadium metal, in 1867. His method was to reduce vanadium chloride with hydrogen gas. Vanadium together with niobium and tantalum makes up the so-called vanadium group. Of the group's elements, vanadium has the highest mean content in the Earth's crust (somewhat higher than nickel). All three elements are quite widespread but not in high concentrations. The mean concentration by mass of vanadium in rocks in the Earth's crust is 160 ppm, in the oceans 15*10-4 ppm. Average abundance in igneous rocks is 90-150 ppm V. The arithmetic mean of forest soils lies around 55-60 ppm V. A median value for 24000 analyses of regolith (mat <0.063 mm) is 57 ppm V (SGU). The most important vanadium mineral is patronite, the polysulphide VS4. Also of significance is vanadinite, an analogue of apatite with formula Pb5(VO4)3Cl. Very large quantities of vanadium, although at low concentrations, are found in iron ores, where vanadium follows titanium and phosphorus. Vanadium often substitutes for iron in mafic rocks. Content of vanadium in sedimentary rocks: limestones 2-20 ppm; sandstones 10-60 ppm; shales 50-300 ppm; black shales 50-2000 ppm; shales, Upper Cambrian, Västergötland 680 ppm; shales, Middle Cambrian, Västergötland 450 ppm; shale, anthraconite, Mount Billingen, Västergötland 200-1000 ppm; Dictyonema shales 700-2100 ppm; olenellid shales, Lower Cambrian 300-600 ppm V. Average content in living plants is 0.2 ppm V. |
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