On the interaction between oxygen, iron and sulfur in industrial glass melts

Abstract

The oxidation state of iron in industrially molten glasses has been investigated in the cold glass and related to the oxygen activity in the glass melt. The prediction of the oxidation state of iron in the cold glass from the measured oxygen activity in the glass melt is disturbed in such a way that in oxidized molten glasses the Fe²⁺ content and in amber glasses the Fe³⁺ content increase during cooling. This behavior can be explained by an interaction due to the oxidation reactions of sulfur known from the literature during cooling. The reaction constants result in electrochemical standard potentials which agree with voltammetric studies.