Conductivity of molten mixtures KF-NaF-AlF₃ is measured in the whole concentration range of the [NaF]/([KF] + [NaF]) ratio at the cryolite ratio CR = 1.3 and 1.5 in the temperature range from 800°C to liquidus temperature. Replacement of K⁺ cations by Na⁺ ones results in a considerable conductivity increase. Alumina solubility rises with temperature and cryolite ratio ([KF] + [NaF])/[AlF₃] in the KF-NaF-AlF₃ system, and decreases with sodium fluoride content. Regression equations obtained allow calculating alumina solubility and electrical conductivity in the KF-NaF-AlF₃ system in the CR range from 1.3 to 3.0 depending on the concentration of the components and temperature.

The silicon electrodeposition from the KF-KCl-(10 mol%) K₂SiF₆ melt at 943–1103 K has been studied. The polycrystalline continuous single-phase silicon coatings (∼99.9 wt% Si) have been obtained on the graphite, glassy carbon, silver, and tungsten substrates. The Raman spectroscopic study of the Si/C and Si/Ag interfaces has proved an absence of the intermediate phases. Two phases (Si and Ni₂Si) were formed during the silicon electrodeposition on nickel.

Although the thermal conductivity of molten salt mixtures is of interest for many potential technological applications, precise values are often hard to obtain. In this study, the thermal diffusivity of FliNaK was studied in a molten state using the laser flash method and found to be very slightly dependent on temperature. The heat capacity of FliNaK was measured using the DSC method. There was a minor difference between our results and data from the literature. From calculations based on thermal diffusivity, density and heat capacity values, thermal conductivity was shown to decrease with temperature.