Iron in glass melts - A voltammetric investigation

Abstract

By the aid of square-wave voltammetry, a fast potentiostatic pulse method, iron oxide-doped soda-lime-silica glass melts were investigated. The iron concentration (0.1 to 2 mol% Fe2O3) and the temperature (400 to 1300 °C) were varied in a wide range. At low iron concentrations as well as at high temperatures the reduction of the Fe3+ to the Fe2+ ion is a one-step process, while at high iron concentrations and at relatively low temperatures a two-step process is observed. By comparison with thermodynamic data of solid state iron oxides, especially of Fe3O4, it is assumed that this is due to the formation of aggregated species containing Fe3+ as well as Fe2+ ions.