Van Arkel Process
A purification method in which a metal is converted to a volatile iodide and then decomposed on a hot filament.
Formula / equation
Ti + 2I₂ ⇌ TiI₄
Unit
°C
In depth
The impure metal reacts with iodine at moderate temperature to form a volatile iodide that leaves the non-volatile impurities behind. The vapour then decomposes on a filament heated above 1400 °C, depositing ultrapure metal and releasing the iodine for reuse.
Examples in the real world
Producing ultrapure titanium and zirconium for nuclear and aerospace applications.