Determination of Free α-SiO2 Content in Mill Scale by X-ray Diffraction K Value Method

Abstract

At present, free α-SiO2 content is often determined by the pyrophosphate method and X-ray Diffraction (XRD) method. However, insoluble materials including FeO, Fe3O4 and Fe2O3 in mill scale cannot be decomposed by pyrophosphate, and thus the pyrophosphate method is not suitable for the determination of free α-SiO2 content in mill scale. A method for detecting free α-SiO2 content in mill scale through X-ray diffraction K value method has been developed. α-Al2O3 was used as the reference material. Diffraction peaks of crystal face (101) for α-SiO2 and crystal face (012) for α-Al2O3 were used for measured diffraction peaks. Samples for detecting K value were prepared by mixing α-SiO2 with α-Al2O3 at a mass ratio of 1:1. The acquired K value is 7.86. The measured K value has been applied to the determination of mill scale samples with known free α-SiO2 content, and the analytical results of free α-SiO2 content are in good agreement with practical values. Detection range of this method is that free α-SiO2 are equal or greater than 0.5%. This method is convenient and rapid, and has a wide detection range and can meet the need of imported mill scale inspection and supervision work.

Keywords

• mill scale
• free α-sio2 content
• x-ray diffraction
• k value method