Thermodynamic characterization of acid cryolite systems

Measuring of the electromotive force in molten system is used to characterize thermodynamic properties of the system at equilibrium. Values of the electromotive force are very important for the determination of activity and standard electrode potential. Investigation of the electromotive force of Al + TiB₂ and Al-Al cell was the main aim of this work leading to the characterization of acid cryolite systems. The measurements were realized using a molten aluminum electrode and the electromotive force of an electrochemical cell was investigated in electrolytes at various molar ratios (NaF/AlF₃) at equilibrium. Thermodynamic properties were measured in acid cryolite melts at three different temperatures: 800 °C, 900 °C, and 1000 °C, for all experiments.