Determination of the Al2O3 Content in NaF鈥揂lF3鈥揅aF2鈥揂l2O3 Melts at 950 掳C by Raman Spectroscopy

详细信息    查看全文

• 作者：Cedric Malherbe ; Gauthier Eppe ; Bernard Gilbert
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：August 19, 2014
• 年：2014
• 卷：86
• 期：16
• 页码：8073-8081
• 全文大小：388K
• ISSN：1520-6882

文摘

The in situ control of the chemical composition of industrial aluminum smelter is a challenge mainly for physicochemical reasons: high temperature, high surrounding electromagnetic field, and the highly corrosive molten salt electrolyte to deal with. In previous works, we proposed that Raman spectroscopy is a method of choice that could be adapted to real smelters. The laboratory study presented here relies on reproducible Raman spectra recorded on molten mixtures whose compositions are identical to those used during the production of aluminum. A normalization procedure for the Raman spectra is proposed based on the equilibria taking place in the bath. In addition, we discuss two quantitative models to determine the alumina content from the Raman spectra of the molten NaF鈥揂lF₃鈥揅aF₂鈥揂l₂O₃ electrolytes. Univariate and multivariate approaches are applied to determine both the C_Ox (alumina content) and the CR (NaF/AlF₃ molar ratio) by Raman spectroscopy without referring to an additional internal reference of intensity. The procedure was successfully tested and validated on industrial samples.