Oxidation‐Reduction Equilibria in Iron‐Containing Glass

Abstract

The oxidation‐reduction equilibrium between ferrous and ferric iron in Na 2 O · 2Si0 2 glass melts was studied by equilibrating melts with various oxygen partial pressures. Exceedingly long equilibration times were required to obtain meaningful results. The reaction appears to be diffusion‐controlled and may be expressed as 20 2‐ + 4Fe 3+ $4 4Fe 2+ + O 2 . Data are presented in which the valence of iron varies from predominantly +3 to predominantly +2.