Abstract

This study was made with the aim of developing a process for liquation fusion of rare earth–rare metal ocherous ores of carbonatite weathering crust deposits. The formation of two immiscible melts, silicate and phosphate–salt, in the monazite–SiO₂–NaF–Nb₂O₅ system was studied. The melt liquation field in the isotherm occupies 50% of the diagram area at 1200°C, 39.0% at 1100°C, 20.0% at 1000°C, and <5% at 900°C. The silicate melt can be readily quenched into a glass containing fine spherical droplets of the phosphate–salt melt. The phosphate–salt melt is always in the crystalline state. The phosphate–salt melt and phosphate–salt spheres contain double phosphates and fluoride phosphates of rare earth elements (REEs) and sodium. Nb₂O₅ concentrates in the silicate melt. REE oxides, Nb₂O₅, and other components are distributed between the two coexisting melts in the contrast fashion. Rare earth oxalate and hydroxide concentrates were obtained from the phosphate–salt melt, and commercial niobium product containing ≤0.50% Р₂О₅, from the silicate melt.

中文翻译：

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稀土元素、Р2О5 和 Nb2O5 在独居石-SiO2-NaF-Nb2O5 体系中不混溶熔体之间的熔体不混溶性和分布的实验研究

摘要

本研究旨在开发一种用于碳酸岩风化壳沉积物稀土-稀有金属赭石矿石的液化熔合工艺。研究了在独居石-SiO ₂ -NaF-Nb ₂ O ₅系统中形成两种不混溶的熔体，硅酸盐和磷酸盐-盐。等温线中的熔体液化场在 1200°C 时占图中面积的 50%，在 1100°C 时为 39.0%，在 1000°C 时为 20.0%，在 900°C 时 <5%。硅酸盐熔体可以很容易地淬火成含有磷酸盐 - 盐熔体的细球形液滴的玻璃。磷酸盐-盐熔体始终处于结晶状态。磷酸盐-盐熔体和磷酸盐-盐球含有稀土元素 (REE) 和钠的双磷酸盐和氟化物磷酸盐。铌₂ O₅集中在硅酸盐熔体中。REE 氧化物、Nb ₂ O ₅和其他组分以对比方式分布在两种共存熔体之间。稀土草酸盐和氢氧化物精矿是从磷酸盐-盐熔体中获得的，商业铌产品含有 ≤0.50% Р ₂ О ₅，来自硅酸盐熔体。