Abstract
Phase relations in the system C3P-M2S (abbreviations: C=CaO, M=MgO, P=P2O5 and S=SiO2) were investigated by means of the quenching method at temperatures up to 1600°C. Primary crystals are tricalcium phosphate and forsterite, and an intermediate compound sc appeared coexisting with the above compounds and liquid. Two minima of liquidus are located at 1440°C between C3P and sc, and at 1410°C between sc and M2S. Liquid disappears below 1365°C. The original composition of sc is C3M2PS (50-50mol% of C3P-M2S) or (C0.6M0.4)5PS (60-40mol% of C5PS-M5PS), and has a solid solution range in both sides of this composition. This sc compound decomposes to both β-C3P and forsterite below 1365°C.
