Temperature Dependence Of The Redox State Of Iron And Sulfur In Amber Glass Melts

In industrially melted amber glass the logarithm [Fe2+]/[Fe3+] shows no linear dependence on the logarithm of oxygen partial pressure. This nonlinearity is due to the interaction between iron and sulfur which can be described by means of a simple oxygen balance model. The change of chemically dissolved oxygen as a function of the oxygen partial pressure depends on the redox state and has a minimum at intermediate oxygen partial pressures. In this region small variations of reducing additions in the batch cause large variations of oxygen partial pressure.