ISO 23071:2021

Refractory products — Determination of reduced species in carbon containing refractories by XRD

This document describes methods for the determination of mineralogical phases often present as additives or reaction products in carbon containing or graphitic refractory products by X-ray Diffraction (XRD) using a Bragg-Brentano diffractometer. It includes details of sample preparation and general principles for qualitative and quantitative analysis of mineralogical phase composition. Quantitative determination of a-Si₃N₄, ?-Si₃N₄, AlN, aluminium metal, Al₄C₃, silicon metal, boron carbide and BN are described. The problems encountered with some determinations are highlighted.

Additional reduced species present in some refractories could include Al₂O₃·AlN solid solutions (so called Alons), Si₃N₄·SiO₂ solid solutions and Si₃N₄·Al₂O₃ solid solutions (Sialons). The presence of some of these solid solution components will cause problems with both identification and quantification as they are not well-defined structures.

NOTE????? For rationalisation of nitrogen containing phases, the total nitrogen content, analysed in accordance with EN?12698-1 is used.

Edition	2021
Published Date	2021
Published By	International Standardization Organisation
Page Count	7