Redox Behaviour Of Iron And Vanadium Ions In Silicate Melts At Temperatures Up To 2000 Deg C.

Two glasses, 33Na20.67Si02 and 15Na20.85Si02 (mol%), doped with Fe203 and V205 respectively, were melted under various conditions in the temperature range of 1400 to 2000 deg C. The redox states in the quenched glasses were investigated by optical absorption spectroscopy. Investigations concerning the redox equilibrium of the polyvalent ions in the glass melts were carrried out using square-wave voltammetry. The results of both methods were compared. Furthermore, equilibrium experiments were carried out to show the time dependence of redox equilibrium reached.