The monazite–SiO2–NaF–Nb2O5–Fe2O3 system in the isotherm at 1200°C is characterized by a wide region of two immiscible melts: a silicate melt and a phosphate–fluoride (salt) melt. The system is reciprocal; in the salt melt, new rare-earth metal (REM) phases form: binary phosphates and fluoride phosphates of REM and Na, which contain neither Fe, nor Nb. Iron has a strong effect on the immiscibility of the melts: in the absence of iron, the segregation region occupies 50% of the area of the diagram; at 5% Fe2O3, 57%; and at 10% Fe2O3, 70%. REM, P, and Nb oxides are contrastingly distributed between the immiscible melts. Most (95%) of REM and P are concentrated in the phosphate–salt melt, and Nb is concentrated in the iron–silicate melt. If the silicate melt contains no Fe2O3, then the Nb2O5 content is 4.91%; and at a Fe2O3 content of 15.33%, the Nb2O5 content is 6.89%, i.e. is 40% higher.

中文翻译：

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TR2O3、P2O5 和 Nb2O5 在独居石-SiO2-NaF-Nb2O5-Fe2O3 体系中两种不混溶熔体之间的分布

处于 1200°C 等温线的独居石-SiO2-NaF-Nb2O5-Fe2O3 系统的特点是具有两种不混溶熔体的广阔区域：硅酸盐熔体和磷酸盐-氟化物（盐）熔体。制度是互惠的；在盐熔体中，新的稀土金属 (REM) 相形成：REM 和 Na 的二元磷酸盐和氟化物磷酸盐，不含 Fe 和 Nb。铁对熔体的不混溶性有很强的影响：在没有铁的情况下，偏析区占据了图中面积的 50%；在 5% Fe2O3 时，57%；在 10% Fe2O3 时，70%。REM、P 和 Nb 氧化物相反地分布在不混溶熔体之间。大多数 (95%) REM 和 P 集中在磷酸盐-盐熔体中，Nb 集中在铁-硅酸盐熔体中。如果硅酸盐熔体不含 Fe2O3，则 Nb2O5 含量为 4.91%；在 Fe2O3 含量为 15.33% 时，