Electric Conductivities of Molten Salts of Some Binary Fluoride Systems

The specific electric conductivities of binary molten salts of NaF-BaF_2, NaF-CaF_2, KF-BaF_2 and KF-CaF_2 systems were measured at 1000℃. 1) In these binary molten salts, the specific electric conductivities decrease almost parabolically with the increase of barium fluoride or calcium fluoride contents. 2) The specific electric conductivities of these four binary molten salts were calculated by "Taniuchi\u27s modified formula", which is a modification of "Markov\u27s formula", and the calculated values agreed well with the measured values. 3) From above-mentioned results, we conclude that the ionic species of these molten salts which take part in the electric conduction are Na^+, K^+, Ba^, Ca^ and F^- respectively. 4) We are of the opinion that sodium fluoride cannot be replaced by potassium fluoride in the aluminum refining electrolytes, because the latter is less electrically conductible and more hygroscopic