Formation of Metal Fog and Dissolved Metals During Electrodeposition from Molten Salts

So-called metal fog is a visual phenomenon which is often observed in the electrolyte near the cathode during deposition of liquid metals from molten salts. Results from visual observations have been reported [1, 2, 3]. Metal solubility in molten salts leads to formation of coloured solutions suggesting that in some cases at least part of the fog is due to dissolved metal. Visual observations and studies of nucleation of magnesium during deposition from chloride melts indicated that the fog consisted of tiny Mg droplets formed by homogeneous nucleation from a supersaturated solution of dissolved Mg [4]. Fog formation was facilitated at cathodes with poor wetting properties.