IRON REDOX EQUILIBRIUM AND DIFFUSIVITY IN MIXED ALKALI-ALKALINE EARTH-SILICA GLASS MELTS

摘要

Dependence of redox behavior and diffusivity of iron on temperature and composition was studied in mixed alkali-alkalineearth-silica glass melts by means of square wave voltammetry (SWV). The voltammograms showed that irrespective ofK?O/(Na?O+K?O) the peak potential due to Fe3?/Fe2? moved toward negative direction with temperature decrease andthe peak current showed a strong dependence on frequency at constant temperature. Iron diffusion coefficient versus meltviscosity showed a good linearity. The compositional dependence showed that the peak potential shifted to the positivedirection with increase of K?O but a typical mixed alkali effect occurred in iron diffusion either at constant temperature orat constant viscosity.