Which following method is used for refining of impure zirconium?
Which following method is used for refining of impure zirconium?
Liquation
Zone refining
Polling
Van Arkel method
Solution
Van Arkel method is used for refining $Zr$ and $Ti$. Van Arkel process involves heating the impure metal with Iodine. It forms a volatile complex which on decomposition at high temperatures, gives back the metal but in very pure form.
Refining of $Zr$ and $Ti$ using Van Arkel method
For Zirconium,
$\mathrm{Zr}$ (impure) $+2 \mathrm{l}_{2} \rightarrow \mathrm{Zrl}_{4}$
$\mathrm{Zrl}_{4} \rightarrow \mathrm{Zr}$ (pure) $+2 \mathrm{I}_{2}$ (at 1800K)
For Titanium,
Ti(impure) $+2 \mathrm{I}_{2} \rightarrow \mathrm{Til}_{4}$
$\mathrm{Til}_{4} \rightarrow \mathrm{Ti}($ pure $)+2 \mathrm{I}_{2}($ at $1800 \mathrm{~K})$