Abstract
Abstract The phase relationship in the system 3CaO·P2O5–MgO–SiO2 was investigated by a cooling experiment in the usual manner. The system 3CaO·P2O5–MgO, a side of this triangle, is a simple binary one, its eutectic being located at the composition of 4∼7% by weight of magnesia and 1570±20°C. The system 3CaO·P2O5–2MgO·SiO2 is not binary over the temperature of about 1350°C, below which it is considered as binary. Above 1350°C, nagelschmidtite is formed over the whole composition range and crystallized primarily from liquid at a high 3CaO·P2O5 portion. The minimum liquidus temperature is 1394°C, which is located at the composition of 70% C3P and 30% M2S. The system 3CaO·P2O5–MgO–2MgO·SiO2 was considered to be complex owing to the presence of nagelschmidtite, but the eutectic among their three components is located at the composition of 70% 3CaO·P2O5, 21% MgO, and 9% SiO2, and 1362±5°C. From the results described above and from those of the author’s previous reports, the preliminary phase diagram of the system 3CaO·P2O5–MgO–SiO2 was constructed. In this diagram the problem that nagelschmidtite is formed in the composition range which is rich in 3CaO·P2O5 was not mentioned in detail. In addition to this, it was found by X-ray examination that β-tricalcium phosphate may be apparently stabilized at a higher temperature than β-α transition point, and has the appearance of dissolving magnesia component.
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