Distribution of TR2O3, P2O5 and Nb2O5 between two immiscible melts in the monazite–SiO2–NaF–Nb2O5–Fe2O3 system

Monacite-SiO₂-NaF-Nb₂O₅-Fe₂O₃ system on 1200 °C isotherm is characterized by a wide area of two immiscible melts: silicate and phosphate-fluoride, salt. The system is a mutual education in molten salt a new phase of rare earth double phosphates and fluoridahospital REE and Na in the composition of which is Fe and Nb. Iron has a great influence on the immiscibility of melts: in the absence of iron, the liquation area occupies 50% of the chart area, at 5% Fe₂O₃ - 57%, at 10% Fe₂O₃ - 70%. REE, P and Nb oxides are contrast distributed between the two immiscible melts. REE and P are 95% concentrated in phosphate-salt melt. Niobium is concentrated in an iron-silicate melt. In the absence of Fe₂O₃ in the silicate melt, the content of Nb₂O₅ = 4,91%, at 15,33% it = 6,89%, i.e. increased by 40%.