Quantitative Analysis of Titanium Ions in the Equilibrium with Metallic Titanium in NaCl-KCl Equimolar Molten Salt

Abstract

The equilibrium between titanium ions (Ti²⁺, Ti³⁺) and metallic titanium (Ti) in NaCl-KCl equimolar molten salt was investigated using TiCl₃ and Ti. Equilibrium experiments were carried out in metal container of titanium or stainless-steel at 740°C. The concentrations of titanium ions were determined by chemical methods consisting of continuous three steps. Ti²⁺ and Ti were quantitated by H₂ evolution method. Ti³⁺ was quantitated with titration by Fe³⁺. As the result, the concentration of Ti²⁺ was higher than that of Ti³⁺. The concentration quotient, K_c=(x_Ti³⁺)²⁄(x_Ti²⁺)³, depends on the concentration of Ti²⁺. The value of K_c at 740°C is recommended to be 5.9 at x_Ti²⁺=0.02 and 2.6 at x_Ti²⁺=0.07 respectively.