EN ISO 21068-2:2024

SLOVENSKI STANDARD
01-september-2024
Kemijska analiza surovin in ognjevzdržnih izdelkov, ki vsebujejo silicijev karbid,
silicijev nitrid, silicijev oksinitrid in sialon - 2. del: Določevanje hlapnih sestavin,
celotnega ogljika, prostega ogljika, silicijevega karbida, celotnega in prostega
silicija, prostega in površinskega silicija (ISO 21068-2:2024)
Chemical analysis of raw materials and refractory products containing silicon-carbide,
silicon-nitride, silicon-oxynitride and sialon - Part 2: Determination of volatile
components, total carbon, free carbon, silicon carbide, total and free silicon, free and
surface silica (ISO 21068-2:2024)
Chemische Analyse von Rohstoffen und feuerfesten Erzeugnissen, die Siliciumcarbid,
Siliciumnitrid, Siliciumoxinitrid und Sialon enthalten - Teil2: Bestimmung des Gehaltes an
flüchtigen Bestandteilen, Gesamtkohlenstoff, freiem Kohlenstoff, Siliziumcarbid,
gesamtem und freiem Silizium, freiem und anhaltendem Siliziumdioxid (ISO 21068-
2:2024)
Analyse chimique des matières premières et des produits réfractaires contenant du
carbure de silicium, du nitrure de silicium, de l’oxynitrure de silicium et du sialon - Partie
2: Dosage des composés volatils, du carbone total, du carbone libre, du carbure de
silicium, du silicium total et libre et de la silice libre et superficielle (ISO 21068-2:2024)
Ta slovenski standard je istoveten z: EN ISO 21068-2:2024
ICS:
71.040.40 Kemijska analiza Chemical analysis
81.080 Ognjevzdržni materiali Refractories
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 21068-2
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2024
EUROPÄISCHE NORM
ICS 81.080 Supersedes EN ISO 21068-2:2008
English Version
Chemical analysis of raw materials and refractory
products containing silicon-carbide, silicon-nitride, silicon-
oxynitride and sialon - Part 2: Determination of volatile
components, total carbon, free carbon, silicon carbide,
total and free silicon, free and surface silica (ISO 21068-
2:2024)
Analyse chimique des matières premières et des Chemische Analyse von Rohstoffen und feuerfesten
produits réfractaires contenant du carbure de silicium, Erzeugnissen, die Siliciumcarbid, Siliciumnitrid,
du nitrure de silicium, de l'oxynitrure de silicium et du Siliciumoxinitrid und Sialon enthalten - Teil2:
SiAlON - Partie 2: Dosage des composés volatils, du Bestimmung des Gehaltes an flüchtigen Bestandteilen,
carbone total, du carbone libre, du carbure de silicium, Gesamtkohlenstoff, freiem Kohlenstoff, Siliziumcarbid,
du silicium total et libre et de la silice libre et gesamtem und freiem Silizium, freiem und
superficielle (ISO 21068-2:2024) anhaltendem Siliziumdioxid (ISO 21068-2:2024)
This European Standard was approved by CEN on 24 May 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 21068-2:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 21068-2:2024) has been prepared by Technical Committee ISO/TC 33
"Refractories" in collaboration with Technical Committee CEN/TC 187 “Refractory products and
materials” the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by December 2024, and conflicting national standards
shall be withdrawn at the latest by December 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 21068-2:2008.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 21068-2:2024 has been approved by CEN as EN ISO 21068-2:2024 without any
modification.
International
Standard
ISO 21068-2
Second edition
Chemical analysis of raw materials
2024-06
and refractory products containing
silicon-carbide, silicon-nitride,
silicon-oxynitride and sialon —
Part 2:
Determination of volatile
components, total carbon, free
carbon, silicon carbide, total and
free silicon, free and surface silica
Analyse chimique des matières premières et des produits
réfractaires contenant du carbure de silicium, du nitrure de
silicium, de l’oxynitrure de silicium et du SiAlON —
Partie 2: Dosage des composés volatils, du carbone total, du
carbone libre, du carbure de silicium, du silicium total et libre et
de la silice libre et superficielle
Reference number
ISO 21068-2:2024(en) © ISO 2024

ISO 21068-2:2024(en)
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii
ISO 21068-2:2024(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Determination of volatile components by gravimetric methods . 1
4.1 General .1
4.2 Determination of the loss on drying at 250 °C (w ) .2
LOD250
4.2.1 Principle .2
4.2.2 Apparatus .2
4.2.3 Procedure .2
4.2.4 Calculation .2
4.3 Determination of the loss on ignition in argon (w ) .2
LOIAr
4.3.1 Principle .2
4.3.2 Apparatus .3
4.3.3 Test assembly .3
4.3.4 Reagents .3
4.3.5 Procedure .4
4.3.6 Calculation .4
5 Determination of the total carbon content . 5
5.1 Scope . .5
5.2 Combustion techniques .5
5.2.1 Combustion in a resistance furnace with lead borate or tin as decomposing agent .5
5.2.2 Combustion in an induction furnace (IF) with metallic powder as decomposing
agent .6
5.3 Detection techniques .7
5.3.1 Coulometry .7
5.3.2 Detection of the released carbon dioxide, CO , by infrared absorption (IR) .7
5.3.3 Thermal conductivity (TC) method .8
5.4 Expression of results . .8
6 Determination of free carbon content . 8
6.1 General .8
6.1.1 Direct methods .8
6.1.2 Indirect methods .
...