1、BS EN ISO21068-2:2008ICS 81.080NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDChemical analysisof silicon-carbide-containing rawmaterials andrefractory productsPart 2: Determination of loss onignition, total carbon, free carbonand silicon carbide, total and fre
2、esilica and total and free silicon (ISO21068-2:2008)This British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 30 BSI 2008ISBN 978 0 580 58092 5Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 21068-2:2008National forewordThis British St
3、andard is the UK implementation of EN ISO21068-2:2008.The UK participation in its preparation was entrusted to TechnicalCommittee RPI/1, Refractory products and materials.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purpor
4、t to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.September2008EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 21068-2August 2008ICS 81.080English VersionChem
5、ical analysis of silicon-carbide-containing raw materialsand refractory products - Part 2: Determination of loss onignition, total carbon, free carbon and silicon carbide, total andfree silica and total and free silicon (ISO 21068-2:2008)Analyse chimique des matires premires et des produitsrfractair
6、es contenant du carbure de silicium - Partie 2:Dtermination de la perte au feu, du carbone total, ducarbone libre et du carbure de silicium, de la silice totale etlibre, et du silicium total et libre (ISO 21068-2:2008)Chemische Analyse von Siliciumcarbid enthaltendenRohstoffen und feuerfesten Erzeug
7、nissen - Teil 2:Bestimmung des Glhverlustes und Gehaltes anGesamtkohlenstoff, freiem Kohlenstoff und Siliciumcarbid,des Gehaltes an gesamtem und freiem Silicium(IV)-oxidsowie an gesamtem und freiem Silicium (ISO 21068-2:2008)This European Standard was approved by CEN on 11 July 2008.CEN members are
8、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
9、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 stat
10、us 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, Sl
11、ovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide
12、for CEN national Members.Ref. No. EN ISO 21068-2:2008: EBS EN ISO 21068-2:2008EN ISO 21068-2:2008 (E) 3 Foreword This document (EN ISO 21068-2:2008) has been prepared by Technical Committee ISO/TC 33 “Refractories“ in collaboration with Technical Committee CEN/TC 187 “Refractory products and materia
13、ls” 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. At
14、tention 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
15、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, Sl
16、ovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 21068-2:2008 has been approved by CEN as a EN ISO 21068-2:2008 without any modification. BS EN ISO 21068-2:2008ISO 21068-2:2008(E) ISO 2008 All rights reserved iiiContents Page Foreword .v Introdu
17、ctionvi 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Determination of change in mass2 4.1 General .2 4.2 Determination of the loss on drying at 250 C (LOD250) gravimetric method.2 4.3 Determination of the loss on calcination in argon (LOIAr) 3 4.4 Determination of the change in mass
18、 by heat pretreatment in air.5 4.5 Determination of the change in mass at 750 C (LOI750).6 4.6 Determination of loss on ignition at 850 C (LOI850)7 4.7 Determination of loss on ignition at 1 050 C (LOI1 050) 7 5 Determination of the total carbon content8 5.1 General .8 5.2 Combustion techniques9 5.3
19、 Detection techniques 12 5.4 Detection methods 17 6 Determination of free carbon content .24 6.1 General .24 6.2 Sample decomposition by combustion 24 6.3 Detection techniques 24 6.4 Direct detection methods .24 6.5 Indirect detection methods.29 6.6 Direct determination of free carbon by wet oxidati
20、on.33 7 Determination of silicon carbide content, SiC33 7.1 General .33 7.2 Determination of silicon carbide, SiC, by indirect quantitative method34 7.3 Determination of silicon carbide, SiC, by direct quantitative method .34 7.4 Determination of silicon carbide SiC by ignition method at 750 C.35 7.
21、5 Determination of silicon carbide, SiC, by chemical method.36 8 Determination of total silicon content via silica.38 8.1 Principle38 8.2 Reagents.38 8.3 Apparatus.38 8.4 Procedure.39 8.5 Blank test39 8.6 Calculation .40 9 Determination of free silicon content40 9.1 Principle40 9.2 Pretreatment with
22、 hydrochloric acid .40 9.3 Silicon determination by hydrogen evolution 40 9.4 Silicon determination by silver displacement 43 10 Determination of silica content, SiO245 10.1 General .45 10.2 Determination of free and/or combined silica content, SiO245 BS EN ISO 21068-2:2008ISO 21068-2:2008(E) iv ISO
23、 2008 All rights reserved10.3 Determination of free silica, SiO2.46 10.4 Determination of surface silicon dioxide, SiO246 11 Expression of results 46 12 Test report 46 Annex A (informative) Examples of CRMs for calibration of carbon analyser .47 Bibliography 48 BS EN ISO 21068-2:2008ISO 21068-2:2008
24、(E) ISO 2008 All rights reserved vForeword 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 int
25、erested 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 Electrotechnic
26、al 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
27、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.
28、ISO shall not be held responsible for identifying any or all such patent rights. ISO 21068-2 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 pr
29、oducts: 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 BS EN ISO 21068-2:2008I
30、SO 21068-2:2008(E) vi ISO 2008 All rights reservedIntroduction ISO 21068, Parts 1 to 3, have been developed from the combination of a Japanese standard JIS 20116and work items originally developed within CEN. Because there is a wide variety of laboratory equipment in use, the most commonly used meth
31、ods are described. This part of ISO 21068 is applicable to the analysis of all refractory products classified in ISO 100812 to 5(shaped) and ISO 19271(unshaped) and raw materials containing carbon and/or silicon carbide. Therefore, this part of ISO 21068 covers the full range of analysis from pure s
32、ilicon carbide to oxidic refractory composition with a low content of silicon carbide and/or nitrides. Primarily, this part of ISO 21068 provides methods to distinguish between different carbon-bound types like total carbon (Ctotal) and free carbon (Cfree) and derives from these two the silicon carb
33、ide content. If free carbon is present, this part of ISO 21068 includes different types of temperature treatment, in order to determine the mass changes gravimetrically. Frequently, the resulting residue is used for other determinations. The determination of other groups of analytes described in thi
34、s part of ISO 21068 are free metals, free silicon (Sifree), free aluminum (Alfree), free magnesium (Mgfree), free iron (Fefree) and the group of oxides from main to trace components. This part of ISO 21068 also describes the chemical analysis of SiO2, total Si, oxygen and nitrogen and other oxidic-b
35、ound metals which typically occur in the materials. This part of ISO 21068 represents a listing of analytical methods which is approximately structured according to material composition. However, it is still the user who should prove the applicability of the method, depending on the material and ana
36、lytical requirements. BS EN ISO 21068-2:2008INTERNATIONAL STANDARD ISO 21068-2:2008(E) ISO 2008 All rights reserved 1Chemical analysis of silicon-carbide-containing raw materials and refractory products Part 2: Determination of loss on ignition, total carbon, free carbon and silicon carbide, total a
37、nd free silica and total and free silicon 1 Scope This part of ISO 21068 specifies analytical techniques for the determination of change in mass by thermal treatment at specified temperatures, and methods for the determination of the total carbon content, free carbon, silicon carbide, silicon, total
38、 silica and free silica content of silicon-carbide-containing raw materials and refractory products. 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 lat
39、est edition of the referenced document (including any amendments) applies. ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method ISO 9286:1997, Abrasive grains
40、and crude Chemical analysis of silicon carbide ISO 10060, Dense, shaped refractory products Test methods for products containing carbon ISO 21068-1:2008, Chemical analysis of silicon-carbide-containing raw materials and refractory products Part 1: General information and sample preparation EN 12698-
41、1:2007, Chemical analysis of nitride bonded silicon carbide refractories Part 1: Chemical methods 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 21068-1 apply. BS EN ISO 21068-2:2008ISO 21068-2:2008(E) 2 ISO 2008 All rights reserved4 Determination o
42、f change in mass 4.1 General The determination of change in mass is defined as a loss or increase in mass caused by heat treatment. Several methods are distinguished based on the sample material, temperature and atmosphere. The determination of change in mass is carried out by a gravimetric method.
43、Heat treatments in air will lead to a loss of volatile matter and carbon and an increase of mass due to oxidation, whereas a heat treatment in argon will only lead to a loss of volatile matter. Normally, the residue is used for other determinations. Therefore, the change in mass is considered for th
44、e calculation of the analytical result. The analytical method which is applied to the residue depends on the matrix and the parameters to be determined. It is up to the user to select the appropriate analytical method. Table 1 gives an overview of methods of determination of change in mass by heat p
45、retreatments and their different applications. Table 1 Methods and application purpose of determination of change in mass Short title of method Temperature Subclause Application Loss on drying (LOD250) 250 C 4.2 Attached water and chemically combined water are removed, e.g. in clay containing plasti
46、c formulations Loss on calcination in argon (LOIAr) 750 C 4.3 All volatile compounds out of pitch- or resin-bondedformulations are removed 200 C 4.4 Volatile compounds are removed from resin-bondedformulations Change in mass in air 400 C 4.4 Volatile compounds are removed from pitch-bondedformulatio
47、ns Change in mass (LOI750) 750 C 4.5 Loss on ignition (LOI850) 850 C 4.6 Both procedures are suitable to remove carbon (e.g. graphite) from refractory formulations. If fine-grainedSiC is present, care should be taken because SiC may be oxidised as well. Loss on ignition (LOI1 050) 1 050 C 4.7 Loss o
48、r gain of mass; attached water, chemically combined water, carbon, organic compounds (e.g. pitch, resin), silicon carbide, and metals are removed 4.2 Determination of the loss on drying at 250 C (LOD250) gravimetric method 4.2.1 Principle The test sample is heated at 250 C 10 C and the loss of mass
49、from attached water is determined. 4.2.2 Apparatus 4.2.2.1 Heat-resistant container, for example with dimensions 200 mm 150 mm 30 mm and made from stainless steel. 4.2.3 Procedure Heat the heat-resistant container at 250 C 10 C for 30 min. Cool in a desiccator, weigh and record its empty mass , m0, to the nearest 0,01 g. Transfer the sample into the container and spread it out flat. Then weigh and record the mass, m1, of the container and sample to the nearest 0,01 g. BS EN ISO 21068-2:2008ISO 21068-2:
