Electric conductivity of hafnium-containing fluoride-chloride melts

This paper presents the results of an investigation of the specific electric conductivity of melts of the potassium, hafnium-containing fluoride-chloride ternary reciprocal system which is of practical interest because fluoride-chloride melts containing hafnium can be used as electrolytes in the preparation of metallic hafnium. Experimental results depend largely on the purity of the salts that are used, so much attention was paid to problems of preparation and storage of the pure anhydrous salts. To obtain potassium fluorides, the authors used cp KF.2H2O which was dried and then melted with continuous vacuum treatment. The specific electric conductivity was measured by a relative capillary method at a frequency of 50 kHz with an R-568 alternatingcurrent bridge. The lines of equal specific electric conductivity of the melts investigated at 10000C show that the conductivity of the melts was determined mainly by the hafnium tetrafluoride content, namely, the increase of its concentration in the melt caused a decrease of the electric-conductivity values