Thermodynamic Analysis of Phase Diagrams Simulated by FactSage in Process of Rare Earth Oxides Production by Spray Pyrolysis Method

被引：0

作者：

Guo X. ^{[1
]}

Su H. ^{[1
]}

Wu Y. ^{[1
,2
]}

Wu W. ^{[2
]}

机构：

[1] Inner Mongolia Key Laboratory of Coal Chemical Engineering & Comprehensive Utilization, Inner Mongolia University of Science & Technology, Baotou

[2] School of Metallurgy, Northeastern University, Shenyang

来源：

Wu, Yongfu (wyf07@imust.edu.cn) | 1600年 / Editorial Office of Chinese Rare Earths卷 / 38期

关键词：

FactSage software; Phase diagram; Rare earth oxides; Spray pyrolysis; Thermodynamic analysis;

D O I：

10.11785/S1000-4343.20200611

中图分类号：

学科分类号：

摘要：

The one-step production of rare earth oxides (REOx) from rare earth chlorides (RECl3) by spray pyrolysis method has attracted much attention due to its short, green and eco-friendly process. However, the further promotion of this process was impeded by the ambiguous understanding about the fundamental issue on its chemical reaction. Consequently, the phase diagrams of this process were simulated by FactSage software. The influences of temperature, carrier gas composition and pressure on reaction products were analyzed via thermodynamics. Through theoretical calculation, the conversion temperature of light rare earth chlorides like LaCl3, NdCl3, SmCl3 and EuCl3 decreases with the increase of atomic number. While CeCl3 and PrCl3 can convert at lower temperature compared with their adjacent elements, and it is due to the participation of O2 in the reaction. The valence states of Ce and Pr change from RE+3 (in chlorides) to RE+4 (in oxides) at the oxidation of O2. The formation temperature of La2O3 and Nd2O3 is higher than that of other rare earth oxides, because they are formed indirectly from LaCl3 and NdCl3 via LaOCl and NdOCl as intermediates. For all spray pyrolysis processes, lower chloride concentration and higher oxygen concentration (partial pressure) are beneficial to the formation of oxides. For LaCl3, the addition of H2O2 has little effect on the reduction of conversion temperature, which is due to the defects of the FactSage software itself. © 2020, Editorial Office of Journal of the Chinese Society of Rare Earths. All right reserved.

引用

页码：788 / 797

页数：9

共 30 条

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