Reduction of Zr (IV) in (KCl/NaCl) eutectic (50/50 mol%) containing KF/ZrCl4 in molar ratios of 6/1 or 4/1 at 750° C. Characterization of the dissolved species by IR spectroscopy

Infrared analysis of baths which are mixtures of (KCl/NaCl) (50/50) with KF and ZrCl₄ in the molar ratio 4 or 6, indicates that the species present at 750° C are ZrF₄ and K₃ZrF₇. Voltammetric study of these melts containing 1 wt % Zr shows that ZrF₄ reduces in three steps: ZrF₄ ZrF₂, ZrF₄ Zr, ZrF₂ Zr, whilst K₃ZrF₇ is reduced via: K₃ZrF₇ Zr or K₃ZrF₇ ZrF₂, ZrF₂ Zr. It appears that ZrF₄ vanishes completely by increasing the KF/ZrCl₄ ratio until the KF concentration is able to stabilize K₃ZrF₇ in the melt.