1、BRITISH STANDARDBS EN ISO 21078-2:2007Determination of boron(III) oxide in refractory products Part 2: Acid extraction method for the determination of boron(III) oxide in binder componentsThe European Standard EN ISO 21078-2:2007 has the status of a British StandardICS 81.040.01; 81.060.01g49g50g3g3
2、8g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 21078-2:2007This British Standard was published under the authority of the Standards Policy and Stra
3、tegy Committee on 31 October 2007 BSI 2007ISBN 978 0 580 57877 9National forewordThis British Standard is the UK implementation of EN ISO 21078-2:2007. It is identical to ISO 21078-2:2006.The UK participation in its preparation was entrusted to Technical Committee RPI/1, Refractory products and mate
4、rials.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity
5、 from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 21078-2October 2007ICS 81.060.01; 81.040.01English VersionDetermination of boron(III) oxide in refractory products - Part 2:Acid extraction method for the determinat
6、ion of boron(III) oxidein binder components (ISO 21078-2:2006)Dosage de loxyde de bore(III) dans les produits rfractaires- Partie 2: Mthode dextraction acide pour le dosage deloxyde de bore(III) dans les composants de liant (ISO21078-2:2006)Bestimmung des Gehaltes an Bor(III)-oxid in feuerfestenErze
7、ugnissen - Teil 2: Sureextraktionsverfahren zurBestimmung des Bor(III)-oxid-Gehaltes inBinderkomponenten (ISO 21078-2:2006)This European Standard was approved by CEN on 16 September 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for givi
8、ng 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 versio
9、ns (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, Bul
10、garia, 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 STANDARDIZ
11、ATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 21078-2:2007: EForeword The text of ISO 21078-2:2006 has
12、 been prepared by Technical Committee ISO/TC 33 “Refractories” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 21078-2:2007 by Technical Committee CEN/TC 187 “Refractory products and materials“, the secretariat of which is held by BSI. This European Stan
13、dard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2008, and conflicting national standards shall be withdrawn at the latest by April 2008. According to the CEN/CENELEC Internal Regulations, the national standar
14、ds 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, Port
15、ugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 21078-2:2006 has been approved by CEN as EN ISO 21078-2:2007 without any modifications. EN ISO 21078-2:2007INTERNATIONALSTANDARDISO21078-2First edition2006-12-01Reference numberISO 21
16、078-2:2006(E)Determination of boron(III) oxide in refractory products Part 2:Acid extraction method for the determination of boron(III) oxide in binder componentsDosage de loxyde de bore(III) dans les produits rfractaires Partie 2: Mthode dextraction acide pour le dosage de loxyde de bore(III) dans
17、les composants de liantEN ISO 21078-2:2007iiiiiContents Page1 Scope 12 Normative references 13 Terms and definitions 14 Preparation of the test sample . 15 Reagents . 26 Mass of test portion for extraction . 27 Preparation of the test solution 28 Blank solution 39 Classification of determination met
18、hods 310 Determination of boron(III) oxide by sodium hydroxide titrimetry 311 Determination of boron(III) oxide by inductived coupled plasma/atomic emissionspectrometry 512 Curcumine absorption spectrophotometry (Rothocyanine method) 613 Quality assurance and control . 914 Expression of test results
19、 915 Test report 10EN ISO 21078-2:2007ivForewordISO (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 ISOtechnical committees. Each member body
20、interested in a subject for which a technical committee has beenestablished has the right to be represented on that committee. International organizations, governmental andnon-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the InternationalElectrotechnic
21、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 Standardsadopted by the tec
22、hnical committees are circulated to the member bodies for voting. Publication as anInternational 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 patentrights. ISO sh
23、all not be held responsible for identifying any or all such patent rights.ISO 21078-2 was prepared by Technical Committee ISO/TC 33, Refractories.ISO 21078 consists of the following parts, under the general title Determination of boron(III) oxide in refractoryproducts: Part 1: Determination of total
24、 boric oxide in oxidic materials for ceramics, glass and glazes Part 2: Acid extraction method for the determination of boron(III) oxide in binder componentsEN ISO 21078-2:20071Determination of boron(III) oxide in refractory products Part 2:Acid extraction method for the determination of boron(III)
25、oxide in binder components1ScopeThis part of ISO 21078 specifies procedures of chemical analysis for the determination of boron(III) oxide usedas a binder component added to aluminosilicate refractories, using an acid extraction method.It is applicable for refractories containing less than (mass fra
26、ction) of boron(III) oxide.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenced document(including any amendments) applies.ISO
27、 31-0, Quantities and units Part 0: General principlesISO 836, Terminology for refractoriesISO 3310-1, Test sieves Technical requirements and testing Part 1: Test sieves of metal wire clothISO 3696, Water for analytical laboratory use Specification and test methods3 Terms and definitionsFor the purp
28、oses of this document, the terms and definitions given in ISO 836 and the following apply.3.1 dry unshaped refractoriesdry particles and/or powder of unshaped refractories4 Preparation of the test sample4.1 Refractory brick or its raw materialSampling is carried out in accordance with the contract b
29、etween the user and producer. A specified quantitytaken from a lot of the sample is crushed to pass through a sieve (see ISO 3310-1) and reduced toabout by riffling or quartering. Then all the reduced sample is ground to pass through a sieve(see ISO 3310-1).4.2 Unshaped refractoriesPrepare two appro
30、ximately portions of the sample for analysis (both dry and wet), and crush to passthrough a sieve (see ISO 3310-1), in accordance with the following procedure in 4.3 to 4.5.1%6,7 mm100 g 300m100 g300mEN ISO 21078-2:200724.3 Dry unshaped refractoriesTake one bag or of the sample from a lot and reduce
31、 to about as above, and crush to pass througha sieve.4.4 Laboratory sampleThe laboratory sample from 4.1 or 4.2 is reduced to approximately by quartering, and ground to passthrough a sieve. This is the test sample for analysis. It is transferred into a container e.g. a flat weighingbottle ( ) or sam
32、ple tube ( ), and dried in a desiccator with silica gel desiccantfor a minimum of .4.5 Weighing of test portionThe specified quantity of the test portion for chemical analysis shall be weighed to the nearest using ananalytical balance and recorded.Carry out the extraction process in duplicate.5Reage
33、ntsUse only reagents of known analytical purity and water conforming to the requirements of grade 2 of ISO 3696(e.g. double-distilled water).The boron and borate ion concentrations in the water and the reagents shall be negligible compared with thelowest concentration to be determined. All solutions
34、 are aqueous unless otherwise specified.NOTE The reagents below are for the extraction process only. Reagents for the determination of B2O3are listed in theappropriate clauses.5.1 Dilute hydrochloric acid ( ).Add 1 volume of hydrochloric acid (concentrated, by mass) to 1 volume of water, then mix an
35、d allow tocool.5.2 Dilute hydrochloric acid ( ).Add 1 volume of hydrochloric acid (concentrated, by mass) to 50 volumes of water.6 Mass of test portion for extractionWeigh out of the test sample.7 Preparation of the test solutionWeigh and transfer the dry sample into a plastics beaker. Using a measu
36、ring cylinder, add ofhydrochloric acid solution ( ) (5.1) and of warm water, and mix intimately. Allow to stand forapproximately while stirring, to dissolve the soluble binder components.Filter with a fine-textured filter paper and wash with warm dilute hydrochloric acid ( ) (5.2). Transfer thefiltr
37、ate and washings into a volumetric flask, and dilute to the mark with water. Transfer into a plasticsbottle. This solution is referred to as the “test solution” for the determination of boron(III) oxide.50 kg 100 g300m25 g106m50 mm 30 mm 50 mm 25 mm8h0,1 mg1 + 135 %1 + 5035 %5,0 g200 ml 20 ml1 + 1 5
38、0 ml30 min 2 min1 + 50250 mlEN ISO 21078-2:200738 Blank solutionCarry out the procedure given in Clause 7 without the sample. This solution is referred to as the “blank solution”.9 Classification of determination methodsThe determination of boron(III) oxide is carried out using one of the following
39、three methods.a) Sodium hydroxide titrimetry.NOTE This method is applied to the sample containing more than (mass fraction) of boron(III) oxide.b) Inductively coupled plasma atomic emission spectrometry (ICP/AES).c) Curcumin absorption spectrophotometry (Rothocyanine method).10 Determination of boro
40、n(III) oxide by sodium hydroxide titrimetry10.1 PrincipleA specified volume of test solution is taken and adjusted to pH approximately 5,0. The precipitate containingsilicic acid is filtered off. The filtrates pH is adjusted to 6,3 and D()-mannitol is added to the filtrate. Then, theH+ions liberated
41、 by the mannitol in the solution are titrated with the sodium hydroxide standard solution until thesolutions pH becomes 6,3 again.10.2 Reagents10.2.1 Dilute hydrochloric acid.Prepare dilute hydrochloric acid ( ) as described in 5.2.10.2.2 D()-Mannitol (C6H14O6).10.2.3 Bromocresol purple (C21H16Br2O5
42、S) solution, .Dissolve of bromocresol purple in water and dilute to approximately . Keep this solution in the darkat a low temperature for a maximum of 7 days.10.2.4 Boron(III) oxide standard solution, B2O3/ml.Transfer approximately of boric acid into a beaker, spread it as a thin layer and dry for
43、in adesiccator with silica gel desiccant. Weigh of this dry boric acid and transfer into a plasticsbeaker. Dissolve in approximately of water and dilute precisely to in a volumetric flask.10.2.5 Sodium hydroxide standard volumetric solution.Transfer of sodium hydroxide into a polyethylene bottle, ad
44、d of water, dissolve while cooling, and puta seal on it. Keep the sealed bottle for several days, pipette of the supernatant fraction, and dilute toin a volumetric flask. Transfer this solution into a polyethylene bottle, using a automatic fillingburette with soda lime tubes to absorb the carbon dio
45、xide in the air.Pipette precisely of boron(III) oxide standard solution ( ) into a beaker and stir using amagnetic stirrer, put a pH electrode in the solution, and add drops of the sodium hydroxide standard volumetricsolution until the pH is 6,5. Remove the electrode, add of D()-mannitol (10.2.2), s
46、et the electrode again,and titrate with the sodium hydroxide standard volumetric solution until the pH is 6,8.0,5 %1 + 501 g/l0,1 g 100 ml0,1 mg0,5 g 100 ml 24 h0,177 6 g 200 ml100 ml 1 000 ml50 g 50 ml4,0 ml2 000 ml 25 ml100 ml 0,1 mg/ml 200 ml10 gEN ISO 21078-2:20074Calculate the equivalent factor
47、, , i.e. the mass, in g, of boron(III) oxide equivalent to of sodium hydroxidestandard volumetric solution, using the equation:(1)whereis the volume, in ml, of titration of sodium hydroxide standard volumetric solution after addition ofD()-mannitol.0,01 is the concentration of the NaOH solution, in
48、mol/l.10.3 ProcedurePipette precisely of both test solutions (see 4.5 and Clause 7) into two beakers and add 2 or 3drops of bromocresol purple (10.2.3) solution as an indicator. Add the standard volumetric sodium hydroxidesolution (10.2.5) until the colour of the solution becomes blue, and add drops
49、 of dilute hydrochloric acid ( )(5.2) until the colour becomes yellow.Boil for with a watch glass as a cover, wash the watch glass with water and remove it, filter with a closed-pore filter paper, and wash several times with hot water.NOTE If the yellow-green colour appears during the boiling period, keep the colour yellow by adding drops of dilutehydrochloric acid ( ) (5.2).Cool and dilute to with water. Stir by using a magnetic stirrer, put a pH electrode in the solution, and adddrops of the sodium hydroxide standard volumetric
