Activities of FeO in the Ternary System SiO₂-MgO-FeO and Constitution of SiO₂

Abstract

Activities of FeO in the ternary system MgO-SiO₂-FeO are measured by means of the levitation method in an induction furnace.
Activities of MgO in the binary system MgO-SiO₂ are calculated from the activities of FeO in this ternary system MgO-SiO₂-FeO.
Theoretical expressions derived for molecular size distributions in multichain polymers (polymer theory) are applied to this binary system Mg-O-SiO₂, and the theoretical curve from the polymer theory fits the calculated values of activities of MgO in the system MgO-SiO₂ when the equilibrium constant of the polymer theory (K₁₁) is 0.01.
Application of the polymer theory to the ternary system MgO-SiO₂-FeO seems to be possible with several assumptions.