1994 Volume 80 Issue 11 Pages 825-830
The activity of iron chromite in solid FeO·Cr2O3-MgO·Cr2O3-MgO·Al2O3 spinels, saturated with (Cr, Al)2O3, was determined at 1573 K, by the equilibrium of iron dissolved into liquid silver in the spinel crucible with CO-CO2gas mixture, to clarify the thermodynamic properties of chromium ores used in ferrochromium industry.
The phase relation between (Cr, Al)2O3and FeO·Cr2O3-MgO·Cr2O3-MgO·Al2O3spinel phase was studied, and the solubility of (Cr, Al)2O3 in FeO·Cr2O3MgO·Al2O3, MgO·Cr2O3-MgO·Al2O3 and FeO·Cr2O3-MgO·Cr2O3-MgO·Al2O3 spinel phases was found to be small.
The activity of FeO·Cr2O3 in FeO·Cr2O3-MgO·Cr2O3-MgO·Al2O3spinel solid solution coexisted with (Cr, Al)2O3shows negative deviation from ideality. It was observed that the spinel solid solution took regular solution behavior, and α-function of each pseudo-binary in FeO·Cr2O3-MgO·Cr2O3-MgO·Al2O3system was determined as follows;
α FeO·Cr2O3-MgO·Al2O3=-92, 000(J),
αMgO.Cr2O3-MgO·Al2O3=-30, 000 (J)