EN 12698-1:2007

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Chemical analysis of nitride bonded silicon carbide refractories - Part 1: Chemical methodsKemijska analiza nitrid silicijevega karbida - 1.del: Kemijske metodeAnalyse chimique des produits réfractaires contenant du carbure de silicium a liaison nitrure - Partie 1: Méthodes chimiquesChemische Analyse von feuerfesten Erzeugnissen aus nitridgebundenem Siliciumcarbid - Teil 1: Chemische VerfahrenTa slovenski standard je istoveten z:EN 12698-1:2007SIST EN 12698-1:2007en;de71.040.40Kemijska analizaChemical analysisICS:SLOVENSKI
STANDARDSIST EN 12698-1:200701-julij-2007

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12698-1March 2007ICS 71.040.40 English VersionChemical analysis of nitride bonded silicon carbide refractories -Part 1: Chemical methodsAnalyse chimique des produits réfractaires contenant ducarbure de silicium à liaison nitrure - Partie 1: MéthodeschimiquesChemische Analyse von feuerfesten Erzeugnissen ausnitridgebundenem Siliciumcarbid - Teil 1: ChemischeVerfahrenThis European Standard was approved by CEN on 15 February 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial 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 STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2007 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12698-1:2007: E

Page Foreword.3 1 Scope.4 2 Normative references.4 3 Terms and Definitions.4 4 Methods for determination.4 5 Sampling.5 6 Determination of free aluminium.5 6.1 Principle.5 6.2 Reagents.6 6.3 Apparatus.6 6.4 Sample preparation.6 6.5 Procedure.6 6.6 Calculation and expression of results.6 7 Determination of total nitrogen.7 7.1 General.7 7.2 Determination of total nitrogen by carrier gas fusion (CGF).7 7.3 Determination of total nitrogen content by fusion decomposition.10 7.4 Determination of total nitrogen content by Kjeldahl distillation.14 7.5 Determination of total nitrogen by microwave digestion.16 8 Determination of free silicon.18 9 Determination of free silica.18 9.1 Principle.18 9.2 Reagents.18 9.3 Apparatus.19 9.4 Sample preparation.19 9.5 Procedure.19 9.6 Determination.21 9.7 Calculation and expression of SiO2 content.21 9.8 Precision.21 10 Determination of carbon.21 10.1 Determination of the total carbon,
Ct.21 10.2 Determination of free carbon, Cfree.21 11 Calculation of silicon carbide content.25 12 Determination of free alumina (Al2O3).25 12.1 Principle.25 12.2 Reagents.25 12.3 Apparatus.26 12.4 Procedure.26 12.5 Calculation and expression of results.26 12.6 Precision.26 Annex A (informative)
Determination of free carbon using the hot chromic sulfuric iodic acid method (10.2.1): Explanation for the evaluation of the different possible detection methods.27 A.1 Coulometric detection system.27 A.2 Infrared absorption detection system.29 A.3 Conductometric detection system.30 Bibliography.32

2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12475-4:1998, Classification of dense shaped refractory products — Part:4 Special products EN 12698-2,
Chemical analysis of nitride bonded silicon carbide refractories — Part 2: XRD methods prEN ISO 21068, Chemical analysis of silicon carbide containing raw materials and refractory products ISO 836:2001, Terminology for refractories ISO 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth ISO 5022, Shaped refractory products — Sampling and acceptance testing ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results — Part 1: General principles and definitions
ISO 8656-1, Refractory products — Sampling of raw materials and unshaped products — Part 1: Sampling scheme 3 Terms and Definitions For the purposes of this document the terms and definitions given in ISO 836:2001, EN 12475-4:1998 and the following apply.
3.1 nitride and oxynitride bonded silicon carbide refractories
refractory products predominantly consisting of silicon carbide with minor amounts of nitride phases as a matrix component NOTE In general, metallic silicon is used as precursor material which undergoes a phase transformation in an oxygen-free nitrogen atmosphere. 4 Methods for determination A list of methods and the relevant European Standards are given in Table 1.
Carbon is determined by the evolution of carbon dioxide on combustion in a stream of oxygen at defined temperatures. Silicon carbide is calculated by the difference of total carbon (Ctotal) and free carbon (Cfree). NOTE 1 The carbon dioxide evolved can be conveniently measured coulometrically, gravimetrically by absorbtion onto soda lime, or by infrared detection.

The free aluminium con
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