Which method is used for refining Zr and Ti? Explain with the equation.
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
Zr(impure) + 2I2→ ZrI4
ZrI4→Zr(pure) + 2I2 (at 1800K)
Ti(impure) + 2I2→ TiI4
TiI4 → Ti(pure) + 2I2 (at 1800K)