1、April 2008DEUTSCHE NORM English price group 12No 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!$NB“1433156www.di
2、n.deDDIN EN ISO 21078-1Determination of boron (III) oxide in refractory products Part 1: Determination of total boron (III) oxide in oxidic materials forceramics, glass and glazes (ISO 21078-1:2008)English version of DIN EN ISO 21078-1:2008-04Bestimmung des Gehaltes an Bor(III)-oxid in feuerfesten E
3、rzeugnissen Teil 1: Bestimmung des Gesamtgehaltes an Bor(III)-oxid in oxidischen Werkstoffen frKeramik, Glas und Glasuren (ISO 21078-1:2008)Englische Fassung DIN EN ISO 21078-1:2008-04SupersedesDIN 51086-1:1998-04www.beuth.deDocument comprises 21 pagesDIN EN ISO 21078-1:2008-04 2 National foreword T
4、his standard has been published in accordance with a decision taken by Technical Committee CEN/TC 187 “Refractory products and materials” (Secretariat: BSI, United Kingdom) to adopt, without alteration, International Standard ISO 21078-1:2008 as a European Standard. ISO 21078-1 was prepared by Techn
5、ical Committee ISO/TC 33 “Refractories”. 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 The DIN Standards corresponding to the International Standards re
6、ferred to in 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 Amendments This standard differs from DIN 51086-1:1998-04 as follows: a) The title of the standard has been changed. b) The method using ICP OES has been deleted. The ICP-AES method and
7、 the curcumin absorption spectrophotometry (rothocyanine method) have been included. c) Clause 13 “Precision of the methods” has been deleted. d) Annex A (informative) “Interlaboratory test results” has been added. e) The standard has been editorially revised. Previous editions DIN 51086-1: 1998-04
8、National Annex NA (informative) Bibliography DIN 1313, Quantities DIN 1338, Writing and typesetting 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 oxid
9、ischen Roh- und Werkstoffen. EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 21078-1January 2008ICS 81.040.01; 81.060.01English VersionDetermination of boron (III) oxide in refractory products - Part 1:Determination of total boron (III) oxide in oxidic materials forceramics, glass and glazes (
10、ISO 21078-1:2008)Dosage de loxyde de bore (III) dans les produitsrfractaires - Partie 1: Dtermination de loxyde de bore (III)total dans les matriaux oxydants pour les cramiques, lesverres et les maux (ISO 21078-1:2008)Bestimmung des Gehaltes an Bor(III)-oxid in feuerfestenErzeugnissen - Teil 1: Best
11、immung des Gesamtgehaltes anBor(III)-oxid in oxidischen Werkstoffen fr Keramik, Glasund Glasuren (ISO 21078-1:2008)This European Standard was approved by CEN on 28 December 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this E
12、uropeanStandard 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 (Engli
13、sh, 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, Cy
14、prus, 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 STANDARDIZATIONCOMI
15、T 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 for CEN national Members.Ref. No. EN ISO 21078-1:2008: EContents Page 2 EN ISO 21078-1:2008 (E) -DIN EN IS
16、O 21078-1:2008-04 Foreword 3 1 Scope .4 2 Normative references .4 3 Terms and definitions 5 4 Preparation of the test sample 5 5 Number of determinations .5 6 Determination of boron(III) oxide by alkaline titrimetry 6 7 Determination of boron(III) oxide by azomethine H absorption spectrophotometry 8
17、 8 Determination of boron(III) oxide by curcumin absorption spectrophotometry .11 9 Determination of boron(III) oxide by inductively coupled plasma atomic emission spectrometry (ICP-AES) .15 10 Expression of test results .17 11 Test report .18 Annex A (informative) Interlaboratory test results .19 F
18、oreword This document (EN ISO 21078-1:2008) 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 nation
19、al standard, either by publication of an identical text or by endorsement, at the latest by July 2008, and conflicting national standards shall be withdrawn at the latest by July 2008. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent right
20、s. 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, Cze
21、ch 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 21078-1:2
22、008 has been approved by CEN as a EN ISO 21078-1:2008 without any modification. 3 EN ISO 21078-1:2008 (E) DIN EN ISO 21078-1:2008-04 1 Scope This part of ISO 21078 specifies methods of determining boron(III) oxide in refractory products and raw materials, in mass fractions of 0,01 % or greater. It i
23、s applicable to the determination of total boron(III) oxide in oxidic materials for ceramics, glass and glazes. The determination of boron(III) oxide is carried out using one of the following four methods: a) alkaline titrimetry, which is applied to samples containing more than 0,5 % by mass of boro
24、n(III) oxide; b) azomethine H absorption spectrophotometry, which is applied to samples containing from 0,01 % by mass to 2,5 % by mass of boron(III) oxide; c) curcumin absorption spectrophotometry (rothocyanine method), which is applied to samples containing from 0,01 % by mass to 1,0 % by mass of
25、boron(III) oxide; d) inductively coupled plasma atomic emission spectrometry (ICP-AES), which is applied to samples containing from 0,01 % by mass to 15 % by mass of boron(III) oxide. NOTE 1 The method can be extended to 30 % boron(III) oxide using modified oxidic fluxes. NOTE 2 Interlaboratory test
26、 results for this part of ISO 21078 are given in Annex A. 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 (inc
27、luding any amendments) applies. ISO 31-0, Quantities and units Part 0: General principles ISO 836, Refractories Vocabulary ISO 3310-1, Test sieves Technical requirements and testing Part 1: Test sieves of metal wire cloth ISO 3696, Water for analytical laboratory use Specification and test methods I
28、SO 6353-2, Reagents for chemical analysis Part 2: Specifications First series ISO 6353-3, Reagents for chemical analysis Part 3: Specifications Second series 4 EN ISO 21078-1:2008 (E) DIN EN ISO 21078-1:2008-04 3 Terms and definitions For the purposes of this document, the terms and definitions give
29、n in ISO 836 and the following apply. 3.1 dry unshaped refractories dry particles and/or powder of unshaped refractories 3.2 wet unshaped refractories wet particles and/or powder of unshaped refractories with liquid such as mortar and a mixture of refractory-aggregate and pitch or resin 4 Preparatio
30、n of the test sample 4.1 Refractory brick or its raw material Carry out sampling in accordance with the contract between the user and producer. Take a specified quantity from a lot of the sample and crush to pass through a 6,7 mm sieve (see ISO 3310-1). Reduce to about 100 g by riffling or coning an
31、d quartering, then grind all the reduced sample to pass through a 300 m sieve (ISO 3310-1). 4.2 Unshaped refractories Prepare two portions of approximately 100 g each of the sample for analysis (both dry and wet) and crush to pass through a 300 m sieve (see ISO 3310-1) in accordance with the followi
32、ng procedure. 4.3 Dry unshaped refractories Take one bag or 5 kg of the sample from a lot, reduce to about 100 g as described in 4.1 and crush to pass through a 300 m sieve. 4.4 Wet unshaped refractories Take a specified quantity from the sample and spread on a heat-resistant plate that does not rea
33、ct with the sample (for example, a polyethylene tetrafluoride plate) to form a charge of 10 mm thickness. Dry the sample in an air-bath or oven at 110C 5C for a minimum of 10 h. Then crush to pass through a 6,7 mm sieve, reduce to about 100 g by riffling or coning and quartering, and grind to pass t
34、hrough a 300 m sieve (see ISO 3310-1). 4.5 Laboratory sample Reduce the laboratory sample from 4.1 or 4.2 to approximately 25 g by coning and quartering, and grind to pass through a 106 m sieve. This is the test sample for analysis. Transfer it into a container (e.g. a flat weighing bottle (50 mm 30
35、 mm) or sample tube (50 mm 25 mm), dry in an oven at 110C 5C for a minimum of 2 h, cool and store it in a desiccator. 4.6 Weighing of test portion Weigh the quantity of the test portion for the chemical analysis specified for the particular procedure, to the nearest 0,1 mg, using an analytical balan
36、ce and record the actual mass. 5 Number of determinations Carry out simultaneous duplicate determinations. Carry out a blank test on the reagents and make appropriate deductions from the results. 5 EN ISO 21078-1:2008 (E) DIN EN ISO 21078-1:2008-04 6 Determination of boron(III) oxide by alkaline tit
37、rimetry 6.1 Principle The sample is fused with sodium hydroxide in a dish placed in a furnace at about 600 C. After cooling, the melt is dissolved in water and the sample solution made up to about 100 ml with water. The interfering ions left in the sample solution are precipitated by adding calcium
38、carbonate. After first adjusting the pH value to 6,5 with sodium hydroxide solution, mannitol is added and the H+ ions liberated as the result are titrated with sodium hydroxide to obtain a pH value of 6,8. 6.2 Reagents Use only reagents of known analytical purity and water conforming to the require
39、ments 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 the lowest concentration to be determined. All solutions are aqueous, unless otherwise specified. 6.2.1 Sodium hydroxide (ISO 6353-2 R 3
40、4), assay, minimum mass fraction 98 %. 6.2.2 Hydrochloric acid (concentrated), (ISO 6353-2 R 13), mass fraction 35 %. 6.2.3 Hydrochloric acid (1+1), add 1 volume of hydrochloric acid (concentrated) to 1 volume of water. 6.2.4 Calcium carbonate (ISO 6353-3 R 53), assay, minimum mass fraction 99,5 %.
41、6.2.5 Bromocresol purple solution, C21H16Br2O5S, 1 g/l. Dissolve 0,1 g of bromocresol purple in water and dilute to approximately 100 ml. Keep this solution in the dark at low temperature. 6.2.6 Boron(III) oxide standard solution, 0,1 mg B2O3/ml. Transfer approximately 0,5 g of boric acid into a 100
42、 ml beaker, spread it as a thin layer and dry for 24 h in a desiccator. Weigh 0,177 6 g of this dry boric acid and transfer into a 200 ml plastic beaker. Dissolve in approximately 100 ml of water and dilute precisely to 1 000 ml in a volumetric flask. 6.2.7 D()-mannitol, C6H14O6. 6.2.8 Sodium hydrox
43、ide standard volumetric solution. Transfer 50 g of sodium hydroxide into a polyethylene bottle, add 50 ml of water, and dissolve with cooling. Allow to stand for several days with a cover, pipette 4,0 ml of the supernatant fraction, and dilute to 2 000 ml in a volumetric flask. Transfer this solutio
44、n into a polyethylene bottle using a 25 ml automatic filling burette with soda-lime tubes to absorb the carbon dioxide in the air. Pipette precisely 100 ml of boron(III) oxide standard solution (0,1 mg/ml) into a 200 ml beaker and stir by using a magnetic stirrer, put a pH electrode into the solutio
45、n and add drops of the sodium hydroxide standard volumetric solution until the pH is 6,5. Remove the electrode, add 10 g of D()-mannitol, set the electrode again, and titrate with the sodium hydroxide standard volumetric solution until the pH is 6,8. Calculate the equivalent factor, F, the mass in g
46、, of boron(III) oxide equivalent to 1 ml of sodium hydroxide standard volumetric solution, using Equation (1). 0,01FV= (1) where V is the volume, in ml, of titration of sodium hydroxide standard volumetric solution after addition of D()-mannitol. 6 EN ISO 21078-1:2008 (E) DIN EN ISO 21078-1:2008-04
47、6.3 Apparatus Ordinary laboratory apparatus and the following. 6.3.1 Vitreous carbon dishes, of suitable nominal capacity. 6.3.2 Vitreous carbon lids, to fit 6.3.1. 6.3.3 Muffle furnace, capable of being controlled at temperatures up to at least 700 C. 6.3.4 pH meter, with a glass electrode. NOTE Au
48、tomated titration equipment with a piston-operated burette and magnetic stirrer may be used to facilitate the analysis. 6.4 Mass of test portion Weigh out 1,00 g of the test sample. NOTE The mass of the test portion is a function of the boron mass fraction. It is usually 1,0 g. 6.5 Procedure Weigh 1
49、 g to 2 g of sodium hydroxide into a dish, cover the dish and fuse it in the furnace at approximately 600 C for about 10 min. After cooling in the desiccator, add the weighed sample, cover it with 1 g to 2 g of sodium hydroxide, cover the dish and dissolve by digestion at approximately 600 C for about 30 min until a clear melt is obtained, swirling repeatedly. After cooling, transfer the melt cake to a 250 ml beaker, dissolve any residue in the dish with water and transfer it to the beaker, repeating this procedure sever
