Electrical conductivity of low-temperature sodium-potassium cryolite melts

Electrical conductivity of NaF-KF-AlF3 melts with different ratios of sodium fluoride and potassium fluoride was measured using a pyrolytic boron nitride tube-type cell with constant distance of electrodes. Molar cryolite ratios MR = (n(NaF) + n(KF))/n(AlF₃) varied from 1.5 to 1.2 (with a step 0.1) in the temperature range of (675—900) °C. AC-techniques with a sine wave signal with small amplitude in the high frequency range were applied. Electrolyte resistance was obtained from nonlinear regression analysis according to equivalent circuit. Concentration and temperature dependency of electrical conductivity was described and defined. Experimental data were compared with literary sources and regression equations.