Abstract
The liquidus surfaces and the isothermal section at 1073 K of the pseudo-ternary CaO-Fe2O3-B2O3 system were determined in a composition range of less than 50 mol% B2O3 using the thermal analysis and X-ray diffraction. The liquidus surface which is in equilibrium with Fe3O4 spreads over a wide composition range and that in equilibrium with Fe2O3 extends long and narrow toward CaO·B2O3 and then toward B2O3 apex. Temperature of the liquidus surface in equilibrium with Fe3O4 remains above 1473 K in the composition range of less than 20 mol% B2O3 but decreases when the B2O3 content exceeds 40 mol%. The liquidus surface in equilibrium with 2CaO·Fe2O3 extends widely and its slope is steep in the region of less than 10 mol% B2O3 but gentle when the B2O3 content exceeds 15 mol%. Pseudo-ternary CaO-Fe2O3-B2O3 compounds were not found in the composition range investigated.
