ČSN EN ISO 21068-1   (726076) Chemická analýza surovin a žárovzdorných výrobků obsahujících karbid křemíku, nitrid křemíku, oxynitrid křemíku a sialon - Část 1: Obecné informace a příprava vzorků

Anotace textu normy ČSN EN ISO 21068-1   (726076)

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).