Zirconium(IV) Chloride - Kroll Process

Kroll Process

ZrCl₄ is an intermediate in the conversion of zirconium minerals to metallic zirconium by the Kroll process. In nature, zirconium minerals invariably exist as oxides (reflected also by the tendency of all zirconium chlorides to hydrolyze). For their conversion to bulk metal, these refractory oxides are first converted to the tetrachloride, which can be distilled at high temperatures. This conversion entails treatment of the oxide with carbon as the oxide "getter" and chlorine.

ZrO₂ + 2 C + 2 Cl₂ → ZrCl₄ + 2 CO

For a simpler procedure see: Inorg. Syn., 4, 121-126(1953).