Partial Molar Liquidus Temperature Of Multivalent Elements In Multicomponent Borosilicate Glass

A multi component borosilicate glass containing several multivalent elements and precipitating (Fe, Ni, Mn, Cr) (Fe, Cr, Mn) 204 spinel as its primary phase, was equilibrated with the gas phase over the range of oxygen partial pressures, p02, from 10-13 Pa to 105 Pa and temperatures, T, from 850-1300 deg C. The oxidation-reduction equilibrium of Fe in the glass was measured with Mossbauer spectroscopy and wet colorimetry. These data were combined with oxidation-reduction equilibria for Fe, Ni and Cr in a borosilicate frit of a similar composition found in the literature to estimate concentrations of Fe(II), Fe(III), Ni(II), Cr(II), Cr(III) and Cr(VI) as functions of po2 and T.