CaO・Al₂O₃・2Fe₂O₃近傍のカルシウム・フェライト固溶体の組成

鉄鉱石の焼結に関する応用鉱物学的研究 (第1報)

抄録

Ternary solid solution including CaO·Al₂O₃·2Fe₂O₃ has been synthesized, and the chemical composition has been determined by electron micro-probe analysis after quenching. The experimental runs were carried out in air. All crystals of the calciumferrite which is called the βT phase hereafter, have grown from melts during the fall of temperature. Results of electron micro-probe analysis show that the chemical composition of the βT phase distributes in a narrow belt which extends nearly parallel to the Al₂O₃-Fe₂O₃ side of the CaO-Al₂O₃-Fe₂O₃ ternary phase diagram. At 1100°C, the βT phase is stable in the region between 5CaO·xAl²O₃·(11-x) Fe₂O₃ (x=0.59-3.85) and 2CaO·xAl₂O₃·(5-x) Fe₂O₃ (x=0.33-1.84).At 1300°C, however, the βT phase is stable on the composition line of CaO·xAl₂O₃·(3-x) Fe₂O₃ (x =1.19-2.56). The melting surface and primary phase field of the βT phase have not been determined exactly in the present work. But it was found that a high-Al₂O₃ part of the βT phase melts incongruently. From the relation between the primary phase field of this solid solution and its chemical composition analyzed in the present work, the phase diagram determined by Dayal and Glasser (1964) should be rechecked.