Refractory products are materials that can withstand high temperatures, above 1500°C. They are used in a wide range of applications, including as the lining of furnaces that perform melting and heating processing of materials for metallurgical, chemical, ceramic, machine, glass industries and so on. There are many types of refractories, including shaped refractories that have been molded and fired beforehand in the form of the final products, powder granules, or paste-like monolithic refractories that are formed into a specific shape at a construction site. Furthermore, refractory products can have different chemical properties. For example, there are acidic refractories that mainly consist of acidic oxides such as SiO₂ and ZrO₂, basic refractories that mainly consist of basic oxides such as MgO and CaO, and neutral refractories. The type of refractory is chosen depending on its intended use. In order to maximize the performance of such refractories, it is necessary to precisely control their elemental composition to meet the needs of specific applications.
Analysis of refractories can be performed according to standardized methods prescribed by Japanese Industrial Standards (JIS R 2216) and ISO 12677 (2011), utilizing X-ray fluorescence (XRF) spectrometry, which is known as a rapid and accurate quantitative analysis method for elemental analysis(2). To obtain accurate analysis results, samples are prepared by the fusion bead method to eliminate grain size and mineralogical effects.
In order to meet customer needs, Rigaku was the first company to release quantitative application packages, including for refractories. These application packages have been well received for their ability to easily and accurately perform quantitative analysis without any specialized technical skills.
This paper describes an analysis example using an application package for quartzite refractory products, an acidic refractory. Quartzite refractories are effective for repeated heating and cooling cycles due to their small change in volume above 600°C. In addition, due to their excellent heat properties, they are widely used as construction furnaces for coke ovens, hot stoves, and glass melting chambers. It is necessary to add 4 to 5 mass% of Al₂O₃ or Fe₂O₃ etc. as a sintering aid to quartzite refractories. However, when used in a glass melting chamber, it is necessary to use a low-porosity Al₂O₃ or other low-alkali component to avoid attack by alkaline vapor in the atmosphere, and accurate analysis of coexisting elements is also required.