Abstract:Electrical conductivity of NaF-AlF₃ melts was measured by continuously varying cell constant(CVCC) technique. Relationships between equivalent conductivity at 990−1 030 ℃ and temperature and composition, and relationship between equivalent conductivity activation energy and composition of the melts were then studied on the basis of two-step decomposition mechanism of AlF₆³⁻. According to the changes of molar fractions of different anions in NaF-AlF₃ melts, courses of dependence of equivalent conductivity and its activation energy on composition were analyzed. The results show that the influence of temperature on equivalent conductivity of the melts is small in the researched temperature range, and equivalent conductivity increases with increasing the molar fraction of AlF₃; there is a minimum point in the activation energy—composition curve when molar fraction of AlF₃ is 0.29.

Key words: equivalent conductivity; equivalent conductivity activation energy; continuously varying cell constant technique; NaF-AlF₃ melts