Electrical conductivity of molten fluoride-oxide melts with high addition of aluminium fluoride

Electrical conductivity of NaF-AlF₃ melts with an addition of 2 wt % Al₂O₃ and/or 5 wt % CaF₂ was measured using a pyrolytic boron nitride tube-type cell with a constant distance of electrodes. The molar cryolite ratios MR = n(NaF)/n(AlF₃) were 1.8 and 1.6, and the temperature was varied from 865 °C to 1005 °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. Experimental data were used to describe the dependence of the electrical conductivity in fluoride melts with lower temperature on the amount of various additions and temperature.