Thermophysical and Chemical Properties of NaF-AlF3-SiO2 Melts with Al2O3 Addition for Al-Si Alloy Production

This study investigated the effect of aluminum oxide (Al 2 O 3 ) additives on the properties of NaF-AlF 3 -SiO 2 melts. The liquid-phase line temperature was determined through thermal analysis, while the solubility and volatilization loss of silicon dioxide (SiO 2 ) were evaluated using the rotating quartz disk method and volatilization experiments. The dissolution mechanism of Al 2 O 3 in the melt was explored through thermodynamic analysis and experimental validation. The results indicated that Al 2 O 3 addition significantly decreased liquid-phase line temperature, enhanced SiO 2 solubility, and reduced volatilization losses. These findings provide a theoretical basis for optimizing the electrolysis process of Al–Si alloys, which contribute to improved melt performance, enhanced energy efficiency, and reduced volatilization losses, thereby promoting increased efficiency in industrial applications.