The measurement of oxygen partial pressure and characterisation of oxidation-reduction equilibria in glass melts

The measurement of oxygen partial pressure in glass melts by the method of reference glass melt is presented. The experimental procedure completed by the wet chemical analysis of the ratio Fe2+/Fe3+ is used for the determination of equilibrium constant of iron in soda-lime-silica glass melt. Experimentally obtained values of oxygen partial pressure bring input data for the calculation procedure of redox equilibria in glass melt containing sulphate and iron. In addition, calculated temperature dependencies of oxygen partial pressure are verified by experimental values. The calculation example showing positive effect of Calumite addition in glass batch to the efficiency of bubble refining process is discussed.