The Ternary System FeO-Al2O3-SiO2
JSGT_1937_V21_T270_T280
The diagram for the system FeO–Al2O3–SiO2 has been constructed from thermal and microscopic data. A description of the molybdenum wire wound furnace and technique employed for the determination of the thermal curves is given. Four ternary combinations occur, namely: (1) ferrous oxide, spinel, fayalite; (2) fayalite, spinel, mullite; (3) fayulite, silica, mullite; (4) alumina, spinel, mullite. Three ternary eutectic points occur, (i) 62% FeO, 3% Al2O3, 35% SiO2 with melting point at 980°; (ii) 68% FeO, 3% Al2O3, 29% SiO2 with melting point 1002°; (iii) 72% FeO, 3% Al2O3, 25% SiO2 with melting point 1080°, All three eutectics are very close to the composition of fayalite. This system is characterised by anarrow deep trough which runs behind the very infusible SiO2-rich region of the FeO.SiO2 system. This indicates that a very small amount of Al2O3, about 5%, in the presence of FeO will be very effective in fluxing SiO2.
R. Hay, James White & Thomas H. Caulfield
