ISO 21068-1:2024

Alcance

This document gives definitions and specifies techniques for the preparation of samples for the chemical analysis of silicon-carbide-containing raw materials and refractory products including:a)       SiC raw materials;b)       graphite brick containing silicon carbide;c)        silicon carbide brick (includes the bricks containing silicon nitride, silicon oxynitride, sialon);d)       refractories containing carbon and/or silicon carbide mixed with clay;e)       refractories containing carbon and/or silicon carbide mixed with silica (and fused silica);f)         refractories containing carbon and/or silicon carbide mixed with high alumina material;g)       refractories containing carbon and/or silicon carbide mixed with magnesia (and dolomite);h)       refractories containing carbon and/or silicon carbide mixed with chrome mineral or magnesia-chrome materials;i)         refractories containing carbon and/or silicon carbide except those described in a) to h) above.The items of analysis described in ISO 21068-2, ISO 21068-3 and ISO 21068-4 are as follows:—     loss on drying (LOD);—     loss on ignition (LOI);—     total carbon, Ctotal;—     free carbon, Cfree;—     silicon carbide, SiC;—     free silicon (Sifree);—     free aluminium (Alfree);—     free magnesium (Mgfree);—     free iron (Fefree);—     silicon(IV) dioxide (SiO2);—     aluminium(III) oxide (Al2O3);—     iron(III) oxide (Fe2O3);—     titanium(IV) oxide (TiO2);—     calcium oxide (CaO);—     magnesium oxide (MgO);—     sodium oxide (Na2O);—     potassium oxide (K2O);—     chromium(III) oxide (Cr2O3);—     zirconium(IV) oxide (ZrO2);—     boron oxide (total boron calculated as B2O3);—     nitrogen;—     oxygen;—     nitrides (undifferentiated: Si3N4, AlN, BN, sialon, oxy-nitrides, etc.);—     mineralogical phases (XRD-methods).