EN ISO 21068-3:2008

SLOVENSKI STANDARD
01-december-2008
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Chemical analysis of silicon-carbide-containing raw materials and refractory products -
Part 3: Determination of nitrogen, oxygen and metallic and oxidic constituents (ISO21068
-3:2008)
Chemische Analyse von Siliciumcarbid enthaltenden Rohstoffen und feuerfesten
Erzeugnissen - Teil 3: Bestimmung des Gehaltes an Stickstoff, Sauerstoff sowie
metallenen und oxidischen Bestandteilen (ISO 21068-3:2008)
Analyse chimique des matières premières et des produits réfractaires contenant du
carbure de silicium - Partie 3: Dosage de l'azote, de l'oxygène et des constituants
métalliques et oxydés (ISO 21068-3:2008)
Ta slovenski standard je istoveten z: EN ISO 21068-3:2008
ICS:
81.080 Ognjevzdržni materiali Refractories
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 21068-3
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2008
ICS 81.080
English Version
Chemical analysis of silicon-carbide-containing raw materials
and refractory products - Part 3: Determination of nitrogen,
oxygen and metallic and oxidic constituents (ISO 21068-3:2008)
Analyse chimique des matières premières et des produits Chemische Analyse von Siliciumcarbid enthaltenden
réfractaires contenant du carbure de silicium - Partie 3: Rohstoffen und feuerfesten Erzeugnissen - Teil 3:
Dosage de l'azote, de l'oxygène et des constituants Bestimmung des Gehaltes an Stickstoff, Sauerstoff sowie
métalliques et oxydés (ISO 21068-3:2008) metallischen und oxidischen Bestandteilen (ISO 21068-
3:2008)
This European Standard was approved by CEN on 11 July 2008.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 21068-3:2008: E
worldwide for CEN national Members.

Contents Page
Foreword.3

Foreword
This document (EN ISO 21068-3:2008) 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 February 2009, and conflicting national standards shall be withdrawn
at the latest by February 2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 21068-3:2008 has been approved by CEN as a EN ISO 21068-3:2008 without any
modification.
INTERNATIONAL ISO
STANDARD 21068-3
First edition
2008-08-01
Chemical analysis of silicon-carbide-
containing raw materials and refractory
products —
Part 3:
Determination of nitrogen, oxygen
and metallic and oxidic constituents
Analyse chimique des matières premières et des produits réfractaires
contenant du carbure de silicium —
Partie 3: Dosage de l'azote, de l'oxygène et des constituants
métalliques et oxydés
Reference number
ISO 21068-3:2008(E)
©
ISO 2008
ISO 21068-3:2008(E)
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ii © ISO 2008 – All rights reserved

ISO 21068-3:2008(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .2
4 Determination of nitrogen and oxygen .2
4.1 General .2
4.2 Combined determination of nitrogen and oxygen by an analyser with thermal
conductivity (CR) and infrared absorption (IR) detection.2
5 Determination of nitrogen calculated as Si N .4
3 4
5.1 General .4
5.2 Acid decomposition — Titration method.5
5.3 Acid decomposition — Photometry method .9
5.4 Inert-gas fusion — Thermal conductivity method .12
5.5 Determination of total nitrogen.17
6 Determination of free Iron by Inductively Coupled Plasma Atomic Emission Spectrometry
(ICP-AES).17
6.1 General .17
6.2 Copper sulfate method .18
6.3 Bromine/methanol method.19
7 Determination of free aluminium and free magnesium.22
7.1 General .22
7.2 Acid decomposition — Inductively coupled plasma atomic emission spectroscopy
(ICP-AES).22
7.3 Acid decomposition — Flame Atomic Absorption Spectrometry (FAAS).24
7.4 Hydrogen generating method .25
8 Analysis of oxides .26
8.1 General .26
8.2 Wet methods .26
8.3 Flame atomic absorption and/or inductively coupled plasma atomic emission
spectrometer.26
8.4 XRF fusion method after ignition of the sample .27
8.5 Determination of silicon(IV) oxide, aluminium oxide, iron(III) oxide, titanium(IV) oxide,
calcium oxide, magnesium oxide, sodium oxide, potassium oxide, chromium(III) oxide,
zirconium oxide, and boron oxide .29
9 Expression of results.31
10 Test report.31
Annex A (informative) Statistical results obtained with analysis of refractories containing carbon
and/or silicon carbide .32
Bibliography.37

ISO 21068-3:2008(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 21068-3 was prepared by Technical Committee ISO/TC 33, Refractories.
ISO 21068 consists of the following parts, under the general title Chemical analysis of silicon-carbide-
containing raw materials and refractory products:
⎯ Part 1: General information and sample preparation
⎯ Part 2: Determination of loss on ignition, total carbon, free carbon and silicon carbide, total and free silica
and total and free silicon
⎯ Part 3: Determination of nitrogen, oxygen and metallic and oxidic constituents
iv © ISO 2008 – All rights reserved

ISO 21068-3:2008(E)
Introduction
[8]
ISO 21068, Parts
...