Titanium

Name:Titanium
Symbol:Ti
Atomic Number:22
Atomic Mass:47.867
Density:10.64 g/cm^3
Melting Point:1668 °C
Boiling Point:3287 °C
Group Number:4
Group Name:(none)
Standard State:Solid at room temperature
Color:silvery metallic
Classification:Metallic
Availability:Titanium is available in many forms including foil, sheet, wire, granules, sponge, nanosized activated powder, powder, mesh and rod.
Titanium, when pure, is a lustrous, white metal.
Titanium minerals are quite common. The metal has a low density, good strength, is easily fabricated, and has excellent corrosion resistance. The metal burns in air and is the only element that burns in nitrogen. It is marvelous in fireworks.
Titanium is resistant to dilute sulphuric and hydrochloric acid, most organic acids, damp chlorine gas, and chloride solutions. Titanium metal is considered to be physiologically inert.
Titanium is present in meteorites and in the sun. Some lunar rocks contain high concentrations of the dioxide, TiO₂. Titanium oxide bands are prominent in the spectra of M-type stars.

Isolation

Titanium is readily available from commercial sources so preparation in the laboratory is not normally required. In industry, reduction of ores with carbon is not a useful option as intractable carbides are produced. The Kroll method is used on large scales and involves the action of chlorine and carbon upon ilmenite (TiFeO₃) or rutile (TiO₂). The resultant titanium tetrachloride, TiCl₄, is separated from the iron trichloride, FeCl₃, by fractional distillation. Finally TiCl₄ is reduced to metallic titanium by reduction with magnesium, Mg. Air is excluded so as to prevent contamination of the product with oxygen or nitrogen.

2TiFeO₃ + 7Cl₂ + 6C (900°C) → 2TiCl₄ + 2FeCl₃ + 6CO

TiCl₄ + 2Mg (1100°C) → 2MgCl₂ + Ti

Excess magnesium and magnesium dichloride is removed from the product by treatment with water and hydrochloric acid to leave a titanium "sponge". This can be melted under a helium or argon atmosphere to allow casting as bars.