Quantitative chemical analysis of fluorine in the slags produced in stainless argon-oxygen decarburization process by X-ray fluorescence spectrometry

Abstract

A quantitative analysis method of fluorine in the slags produced In the stainless argon-oxygen decarburization (STS AOD) process by X-ray spectrometry was proposed employing fusion pretreatment technique. The research concerned the separate quantification of calcium fluoride and calcium oxide contained in stainless AOD slags. X-ray diffraction measurement was performed to identify the stable phase of fluorine compound, which is primarily present in the slags. Homogeneous glass discs were prepared under the following conditions: lithium borate mix as flux with sample dilution (1 :15), with the addition of one tablet of ammonium iodide as releasing agent at 1 323 K for 20 min. XRD patterns and semi-quantitative results for the STS AOD slags provided synthetic standards based on the approximate compositional range of STS AOD slags by combining highly pure compounds and oxides. These standards were employed to establish the XRF calibration curves for F, CatO, SiO2, MgO, Al 2O3 and Cr2O3. The calibration curves were used in the quantitative analysis of a synthetic standard and an pure calcium fluoride with satisfactory precision and accuracy, considering the matrix effects and line overlap corrections. The suggested method might be a useful solution to the problem with the quantitative analyses of calcium fluoride in stainless AOD slags by XRF spectrometry. © 2007 ISIJ.