An in-situ Raman spectroscopic study on potential-pO^(2-) phase diagram of lanthanum in LiCl-KCl eutectic melt  

作　　者：Seung Park Jong-IL Yun 

机构地区：[1]Department of Nuclear and Quantum Engineering.KAIST,Yuseong-gu,Daejeon 34141,Republic of Korea

出　　处：《Journal of Rare Earths》2020年第7期793-800,I0004,共9页稀土学报（英文版）

基　　金：Project supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(NRF-2017M2A8A5014801,NRF-2016M2B2B1945252)。

摘　　要：The oxidative reaction between lanthanum trichloride and oxide ion was studied in the molten LiCl-KCl eutectic at 773 K by in-situ Raman spectroscopy using an yttria-stabilized zirconia electrode in conjunction with electrochemical methods.The formation of lanthanum oxychloride,LaOCl(s),was confirmed by studying the vibrational properties of crystalline LaOCl and X-ray diffraction analysis.The solubility product of LaOCl in the LiCl-KCl molten eutectic at 773 K is found to be pKsp(LaOCl)=7.569±0.100,by combining the results of Raman spectroscopy and potentiometric titration with the addition of barium oxide.The use of Raman spectroscopic quantitation of dissolved lanthanum ions in the system allows faster and more accurate determination of the stable phase of lanthanum as well as the solubility product of LaOCl compared with that measured by potentiometric titration only.Based on experimentally obtained pKsp and standard equilibrium potentials,the potentialpO2- phase diagram of lanthanum in the molten LiCl-KCl eutectic was reported.

关 键 词：LANTHANUM Solubility product E-pO2-diagram Raman spectroscopy Chloride molten salt Rare earths 

分 类 号：O646[理学—物理化学] O657.37[理学—化学]