Abstract
Abstract The phase relationship in the system 3CaO·P2O5–MgO·SiO2–SiO2 was investigated by the usual quenching method. In the partial system 3CaO·-P2O5–SiO2, the existence of solid solution and the change of the transition temperature of α–β tricalcium phosphate were not found by X-ray examinations. The partial system 3CaO·P2O5–MgO·SiO2 is pseudo-binary, whose eutectic is at 1246°C and 40% 3CaO·P2O5. In this system, β-3CaO·P2O5, always appeared in quenched samples, has a maximum solid solubility of 7±2% MgO·SiO2. The system 3CaO·P2O5–MgO-SiO2–SiO2 has two quintuple points, the one an alteration point and the other a ternary eutectic at 50.5% 3CaO·P2O5, 15.0% MgO, 34.5% SiO2 that melts at 1230±4°C. This system is of great importance to the manufacture of the fused phosphatic fertilizer and the bone ash magnesia porcelain. For instance, in this system, the lower liquidus groove lies at higher silica side along 3CaO·P2O5–MgO-SiO2, in accord with the results of cone fusion and melting point measurements already obtained by Kiyoura and Sata.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call