NBN ISO 23071:2021

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-Si3
N4
, ß-Si3
N4
, AlN, aluminium metal, Al4
C3
, 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 Al2
O3
·AlN solid solutions (so
called Alons), Si3
N4
·SiO2
solid solutions and Si3
N4
·Al2
O3
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.