Combined electrochemical and Mössbauer studies of the Sb3+/Sb5+ equilibrium in a silicate glass-forming melt

Abstract

The antimony redox equilibrium in an oxide glass-forming melt has been studied quantitatively. Oxygen fugacities at various concentrations and temperatures have been measured electrochemically, and Sb3+/Sb5+ concentration ratios were determined by Mössbauer spectroscopy. Equilibrium constants K(T) and thermodynamie standard values are given for the redox reaction in the melt at temperatures between 1000 and 1500 °C. If K{T) is known, the progress of redox fining can be followed by measuring only the oxygen fugacity.