1、December 2007DEUTSCHE NORM English price group 10No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 81.080!$K#d“1400065ww
2、w.din.deDDIN EN ISO 21078-2Determination of boron(III) oxide in refractory products Part 2: Acid extraction method for the determination of boron(III) oxidein binder components (ISO 21078-2:2006)English version of DIN EN ISO 21078-2:2007-12Bestimmung des Gehaltes an Bor(III)-oxid in feuerfesten Erze
3、ugnissen Teil 2: Sureextraktionsverfahren zur Bestimmung des Bor(III)-oxid-Gehaltes inBinderkomponenten (ISO 21078-2:2006)Englische Fassung DIN EN ISO 21078-2:2007-12www.beuth.deDocument comprises 15 pagesDIN EN ISO 21078-2:2007-12 2 National foreword This standard has been prepared by Technical Com
4、mittee CEN/TC 187 “Refractory products and materials” (Secretariat: BSI, United Kingdom). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Technical Committee NA 062-02-61 AA Chemische Analyse von oxidischen Roh-
5、und Werkstoffen. The DIN Standards corresponding to the International Standards referred to in clause 2 of the EN are as follows: ISO 31-0 DIN 1313 and DIN 1338 ISO 3310-1 DIN ISO 3310-1 ISO 3696 DIN ISO 3696 National Annex NA (informative) Bibliography DIN 1313, Quantities DIN 1338, Writing and typ
6、esetting of formulae DIN ISO 3310-1, Test sieves Technical requirements and testing Part 1: Test sieves of metal wire cloth DIN ISO 3696, Water for analytical laboratory use Specification and test methods EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 21078-2 October 2007 ICS 81.060.01; 81
7、.040.01 English Version Determination of boron(III) oxide in refractory products - Part 2: Acid extraction method for the determination of boron(III) oxide in binder components (ISO 21078-2:2006) Dosage de loxyde de bore(III) dans les produits rfractaires - Partie 2: Mthode dextraction acide pour le
8、 dosage de loxyde de bore(III) dans les composants de liant (ISO 21078-2:2006) Bestimmung des Gehaltes an Bor(III)-oxid in feuerfesten Erzeugnissen - Teil 2: Sureextraktionsverfahren zur Bestimmung des Bor(III)-oxid-Gehaltes in Binderkomponenten (ISO 21078-2:2006) This European Standard was approved
9、 by CEN on 16 September 2007. 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
10、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 notif
11、ied 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, Mal
12、ta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of ex
13、ploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 21078-2:2007: EContents Page2 EN ISO 21078-2:2007 (E) Foreword 3 1 Scope . 4 2 Normative references . 4 3 Terms and definitions 4 4 Preparation of the test sample 4 5 Reagents . 5 6 Mass of test port
14、ion for extraction . 5 7 Preparation of the test solution 5 8 Blank solution . 6 9 Classification of determination methods . 6 10 Determination of boron(III) oxide by sodium hydroxide titrimetry 6 11 Determination of boron(III) oxide by inductived coupled plasma/atomic emission spectrometry . 8 12 C
15、urcumine absorption spectrophotometry (Rothocyanine method) 9 13 Quality assurance and control 12 14 Expression of test results .12 15 Test report . 13 Foreword The text of ISO 21078-2:2006 has been prepared by Technical Committee ISO/TC 33 “Refractories” of the International Organization for Standa
16、rdization (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 Standard shall be given the status of a national standard, either by publication of an identical text or by end
17、orsement, 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 standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium
18、, 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. Endorsement notice The te
19、xt of ISO 21078-2:2006 has been approved by CEN as EN ISO 21078-2:2007 without any modifications. 3 EN ISO 21078-2:2007 (E) 1ScopeThis part of ISO 21078 specifies procedures of chemical analysis for the determination of boron(III) oxide usedas a binder component added to aluminosilicate refractories
20、, using an acid extraction method.It is applicable for refractories containing less than (mass fraction) 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 undat
21、ed references, the latest edition of the referenced document(including any amendments) applies.ISO 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, Wat
22、er for analytical laboratory use Specification and test methods3 Terms and definitionsFor the purposes 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 sampl
23、e4.1 Refractory brick or its raw materialSampling is carried out in accordance with the contract between 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 s
24、ample is ground to pass through a sieve(see ISO 3310-1).4.2 Unshaped refractoriesPrepare two approximately 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 g300m4
25、EN ISO 21078-2:2007 (E) 4.3 Dry unshaped refractoriesTake one bag or of the sample from a lot and reduce 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 i
26、s the test sample for analysis. It is transferred into a container e.g. a flat weighingbottle ( ) or sample 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
27、the nearest using ananalytical balance and recorded.Carry out the extraction process in duplicate.5ReagentsUse 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 an
28、d the reagents shall be negligible compared with thelowest concentration to be determined. All solutions 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 hydrochlo
29、ric acid ( ).Add 1 volume of hydrochloric acid (concentrated, by mass) to 1 volume of water, then mix and 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
30、 Preparation of the test solutionWeigh and transfer the dry sample into a plastics beaker. Using a measuring 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 wi
31、th a fine-textured filter paper and wash with warm dilute hydrochloric acid ( ) (5.2). Transfer thefiltrate 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)
32、 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 50 ml30 min 2 min1 + 50250 ml5 EN ISO 21078-2:2007 (E) 8 Blank solutionCarry out the procedure given in Clause 7 without the sample. This solution is referred to as the “blank solution”.9 Classific
33、ation of determination methodsThe determination of boron(III) oxide is carried out using one of the following 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
34、spectrometry (ICP/AES).c) Curcumin absorption spectrophotometry (Rothocyanine method).10 Determination of boron(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
35、 off. The filtrates pH is adjusted to 6,3 and D()-mannitol is added to the filtrate. Then, theH+ions liberated 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
36、hydrochloric acid ( ) as described in 5.2.10.2.2 D()-Mannitol (C6H14O6).10.2.3 Bromocresol purple (C21H16Br2O5S) 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 standar
37、d solution, B2O3/ml.Transfer approximately of boric acid into a beaker, spread it as a thin layer and dry for 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
38、.2.5 Sodium hydroxide standard volumetric solution.Transfer of sodium hydroxide into a polyethylene bottle, add 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 solut
39、ion into a polyethylene bottle, using a automatic fillingburette with soda lime tubes to absorb the carbon dioxide 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 hy
40、droxide standard volumetricsolution until the pH is 6,5. Remove the electrode, add of D()-mannitol (10.2.2), set 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
41、ml50 g 50 ml4,0 ml2 000 ml 25 ml100 ml 0,1 mg/ml 200 ml10 g6 EN ISO 21078-2:2007 (E) Calculate the equivalent factor, , 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 hydr
42、oxide standard volumetric solution after addition ofD()-mannitol.0,01 is the concentration of the NaOH solution, in 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 th
43、e standard volumetric sodium hydroxidesolution (10.2.5) until the colour of the solution becomes blue, and add drops 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 f
44、ilter 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 a
45、dddrops of the sodium hydroxide standard volumetric solution (10.2.5) until the pH is 6,3. Remove the electrode,add of D()-mannitol (10.2.2), set the electrode again, and titrate with the sodium hydroxide standardvolumetric solution until the pH is 6,3.10.4 Blank testRepeat the process described in
46、10.3 using the blank solution (see Clause 8).10.5 Calculation and expression of resultsCalculate the mass fraction of boron(III) oxide in the sample, , as a percentage, using Equation (2):(2)whereis the volume, in ml, of titration of sodium hydroxide standard volumetric solution for test solution,af
47、ter addition of D()-mannitol;is the volume, in ml, of titration of sodium hydroxide standard volumetric solution for blank solution,after addition of D()-mannitol;is the equivalent factor, in g, of boron(III) oxide equivalent to of sodium hydroxide standardvolumetric solution;is the mass, in g, of t
48、he test portion in Clause 6.Express the result as the mean of three determinations, rounded off in accordance with ISO 31-0(see Clause 14).F 1mlF =0,01VV50 ml 200 ml1 + 5020 min1 + 50100 ml10 gwBwB=(V1V2) Fm25050 100V1V2F 1mlm7 EN ISO 21078-2:2007 (E) 11 Determination of boron(III) oxide by inductiv
49、ed coupled plasma/atomic emission spectrometry11.1 PrincipleThe sample solution is injected into the argon plasma of an inductively coupled plasma/atomic emission(ICP/AE) spectrometer and the B emission is determined at a wavelength of , or at another suitablewavelength, against reference solutions.The wavelength can suffer from a Fe overlap. If so, should be used.11.2 Reagent11.2.1 Boron(III) oxide standard solution, B2O3/ml.Transfer approximately of boric acid into a beaker, spread it as a thin layer and dry for in adesiccato
