Accuracy Improvement of the XRD-Rietveld Method for the Quantification of Crystalline Phases in Iron Sintered Ores Through the Correction of Micro-absorption Effects

Takayuki Harano, Yu Nemoto, Reiko Murao, Masao Kimura
2021 Tetsu to hagane  
The mass fraction of each crystalline phase in inorganic materials can be investigated using the Rietveld refinement of the X-ray diffraction (XRD) patterns. For quantitative analysis, differences in the values of the linear absorption coefficient, μ, among the crystalline phases must be considered when certain X-ray sources are used, because such differences often affect their mass fractions. Herein, we evaluate the effects of the differences between the Cu and Co Kα X-rays on the mass
more » ... s of the crystalline phases in iron sintered ores using the XRD-Rietveld method by performing two types of XRD measurements. Type 1 samples modeled materials with two different particle size combinations of α-Fe 2 O 3 and ZnO. Type 2 samples used powder mixtures to simulate iron sintered ores composed of α-Fe 2 O 3 , and synthesized SFCA and SFCA-I in various mass fractions. Moreover, a correction method was developed using the Taylor-Matulis (TM) correction that considers the μ of each phase and the average particle diameter of each crystalline phase determined by scanning electron microscopy with energy dispersive spectroscopy. For type 1 samples, results that were in good agreement with the initially-charged mass fractions could be obtained using the TM correction, even in the presence of significant differences in R between α-Fe 2 O 3 and ZnO. The results for type 2 samples confirmed that quantitatively accurate mass fractions could be obtained using the TM correction with an accuracy of approximately ±3 mass% for Cu and Co sources, whereas the error was greater than ±3 mass% for Cu source when the TM correction was not applied.
doi:10.2355/tetsutohagane.tetsu-2020-098 fatcat:me43nwk5gvhfnegdbxul5c5exy