Redox Reactions Between Cations Of Different Polyvalent Elements In Glass Melts: An Optical Basicity Study

Redox data are currently available for each of the pairs Fe2+/Fe3+, Cr3+/Cr6+, As3+/As5+, Sn2+/Sn4+, Ce3+,/Ce4+, and Cu+/Cu2+, in equilibrium with oxygen as oxide (-II) and O2, for alkali and alkaline earth silicate melts at 1400C in air atmosphere. For each pair, an almost linerar relationship exists when upper and lower oxidation state ratio is plotted against the glass basicity. Some of these equilibria are affected only slightly by basicity, while others, change sharply over a narrow critical basicity range.