ČSN EN ISO 21068-1 (726076) Nové vydání

Anotace obsahu normy

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).