1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58powders Part 1: Determination of impurities in aluminaThe European Standard EN 725-1:2007 has the s
2、tatus of a British StandardICS 81.060.30Advanced technical ceramics Methods of test for ceramic BRITISH STANDARDBS EN 725-1:2007BS EN 725-1:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2007 BSI 2007ISBN 978 0 580 54527 6Amen
3、dments issued since publicationAmd. No. Date Commentscontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard is the UK implementation of EN 725-1:2007. It supersedes BS EN 725-
4、1:1997 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee RPI/13, Advanced technical ceramics.A list of organizations represented on this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
5、provisions of a EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 725-1September 2007ICS 81.060.30 Supersedes EN 725-1:1997 English VersionAdvanced technical ceramics - Methods of test for ceramicpowders - Part 1: Determination of impurities in aluminaCramiques techniques avances - Mthodes dessai de
6、spoudres cramiques - Partie 1 : Dosage des impuretsdans lalumineHochleistungskeramik - Prfverfahren fr keramischePulver - Teil 1: Bestimmung von Verunreinigungen inAluminiumoxidpulverThis European Standard was approved by CEN on 11 August 2007.CEN members are bound to comply with the CEN/CENELEC Int
7、ernal 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 memb
8、er.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 a
9、re 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, Switzer
10、land and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT 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 725
11、-1:2007: EEN 725-1:2007 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Principle4 4 Reagents.4 4.1 General4 4.2 Reagents for fusion .4 4.3 Sulphuric acid-phosphoric acid mixture for acid dissolution 5 4.4 Reagents for calibration5 5 Apparatus .5 6 Test sample 5 7 Decomposition of
12、 the test sample .6 7.1 General6 7.2 Fusion .6 7.3 Acid dissolution.6 8 Calibration graph .6 8.1 General6 8.2 Fusion .6 8.3 Acid dissolution.7 8.4 Drawing the calibration curve 7 9 Adjustment of the apparatus7 9.1 Atomic absorption spectrometer .7 9.2 Inductively coupled plasma spectrometer8 10 Meas
13、urements8 11 Expression of the results8 12 Test report 9 Annex A (informative) Repeatability and reproducibility 10 Bibliography 11 EN 725-1:2007 (E) 3 Foreword This document (EN 725-1:2007) has been prepared by Technical Committee CEN/TC 184 “Advanced technical ceramics”, the secretariat of which i
14、s 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 March 2008, and conflicting national standards shall be withdrawn at the latest by March 2008. This document supersedes EN 725-1:1997
15、. EN 725 Advanced technical ceramics Methods of test for ceramic powders was prepared in parts as follows: Part 1: Determination of impurities in alumina Part 2: Determination of impurities in barium titanate Part 3: Determination of the oxygen content of non-oxides by thermal extraction with a carr
16、ier gas Part 4: Determination of oxygen content in aluminium nitride by XRF analysis Part 5 Determination of particle size distribution Part 6: Determination of the specific surface area withdrawn Part 7: Determination of the absolute density withdrawn Part 8: Determination of tapped bulk density Pa
17、rt 9: Determination of un-tapped bulk density Part 10: Determination of compaction properties Part 11: Determination of densification on natural sintering Part 12: Chemical analysis of zirconia Parts 6 and 7 of the series were superseded in 2005 by EN ISO 18757 and EN ISO 18753 respectively. Accordi
18、ng 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, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
19、 Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 725-1:2007 (E) 4 1 Scope This Part of EN 725 specifies one fusion and one acid dissolution method for the determination of elements of sodium, potassiu
20、m, iron, silicon, calcium and magnesium present as impurities in alumina using atomic absorption spectroscopy (AAS) or inductively coupled plasma (ICP) spectroscopy. For each element present as impurities, the methods are applicable to the following ranges, calculated as oxides : Sodium oxide: 20 pp
21、m to 6000 ppm Potassium oxide: 20 ppm to 100 ppm Ferric oxide: 20 ppm to 300 ppm Silica: 50 ppm to 2000 ppm Calcium oxide: 20 ppm to 700 ppm Magnesium oxide: 5 ppm to 1000 ppm 2 Normative references The following referenced documents are indispensable for the application of this document. For dated
22、references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696:1987) EN ISO/IEC 17025, General requirements for the compe
23、tence of testing and calibration laboratories (ISO/IEC 17025:2005) 3 Principle A test sample is decomposed by using either a fusion method or an acid dissolution method. NOTE The acid dissolution method cannot be used for the determination of silicon. The solution is transferred to a volumetric flas
24、k and diluted to a known volume, and the elements are determined by AAS or ICP. 4 Reagents 4.1 General During the analysis, use only reagents and calibration solutions of at least 99,99 % purity and water conforming to EN ISO 3696, Grade 3, or better. 4.2 Reagents for fusion 4.2.1 Lithium metaborate
25、 - LiBO24.2.2 Nitric acid HNO3- (20= 1,33 g/ml) EN 725-1:2007 (E) 5 4.3 Sulphuric acid-phosphoric acid mixture for acid dissolution Pour 700 ml of phosphoric acid (20= 1,78 g/ml) into 300 ml of sulphuric acid (20= 1,84 g/ml). 4.4 Reagents for calibration 4.4.1 Pure alumina, of very low and known imp
26、urity levels, 99,99% purity. 4.4.2 Sodium - commercial solution or solution obtained by dissolution of pure chemical compound, of concentration 1 g/l. 4.4.3 Potassium - commercial solution or solution obtained by dissolution of pure chemical compound, of concentration 1 g/l. 4.4.4 Iron (ferric) - co
27、mmercial solution or solution obtained by dissolution of pure chemical compound, of concentration 1 g/l. 4.4.5 Silicon - commercial solution or solution obtained by dissolution of pure chemical compound, of concentration 1 g/l. 4.4.6 Calcium - commercial solution or solution obtained by dissolution
28、of pure chemical compound, of concentration 1 g/l. 4.4.7 Magnesium - commercial solution or solution obtained by dissolution of pure chemical compound, of concentration 1 g/l. 5 Apparatus 5.1 Platinum or platinum-gold crucible with a capacity of at least 50 ml 5.2 Muffle furnace, suitable for operat
29、ion in the range of (1 000 50) C to (1 200 50) C 5.3 Hot plate with magnetic stirrer 5.4 Atomic absorption spectrometer and/or inductively coupled plasma spectrometer 5.5 Laboratory glassware 5.6 Platinum spatula 6 Test sample Use samples of approximately: 1 g for decomposition by fusion; 1 g for de
30、composition by acid dissolution. Weigh them to 0,0001 g. EN 725-1:2007 (E) 6 7 Decomposition of the test sample 7.1 General Dissolve either by a fusion method (see 7.2) or an acid dissolution method (see 7.3) 7.2 Fusion Weigh 4 g of LiBO2(4.2.1) and 1 g of test sample into a platinum or platinum-gol
31、d crucible (5.1). Mix intimately using a platinum spatula, put on lid. Place the crucible and contents into the muffle furnace (5.2) maintained at 1150 C 50 C for 30 min (after the first 15 min, swirl the contents of the crucible for a few seconds and put back in the muffle). Remove the crucible fro
32、m the furnace, remove lid and rinse with distilled water, pouring the residue into a 400 ml beaker containing 80 ml of water and 20 ml of nitric acid (4.2.2). Dip its base in water at ambient temperature (this procedure allows easy removal of the bead from the crucible). To prevent sticking of melt
33、in the crucible, either use a new crucible or, with an old one, immerse it in the solution. Pour the bead, carefully, into the 400 ml beaker that contains 80 ml of water and 20 ml of nitric acid (4.2.2). Place the beaker, covered with a watch glass on a hot plate (5.3) with magnetic stirring and mai
34、ntain the agitation at approximately 80 C 10 C until complete dissolution. Remove the beaker from the stirrer and allow it to cool down. Transfer the solution quantitatively into a 200 ml volumetric flask. Allow it to cool down to room temperature and make up to the mark. 7.3 Acid dissolution Weigh
35、the test sample (see Clause 6) into a platinum or gold-platinum crucible (5.1). Add carefully 12 ml of sulphuric acid-phosphoric acid mixture (4.3) and cover with a lid. Put the crucible with the lid on to the hot plate (5.3) and maintain it at boiling for 12 min. Remove the crucible from the heatin
36、g device and allow it to cool down. Transfer the content quantitatively into a 100 ml volumetric flask which contains 30 ml of water. Rinse the crucible and the lid with distilled water into the flask and after cooling, make up to the mark with water. 8 Calibration graph 8.1 General The optimum cali
37、bration graph is obtained using calibration solutions whose concentrations are compatible both with the analytical method (AAS or ICP) and with the impurity concentrations in the sample, and matrix matched. The following procedure is given as an example. 8.2 Fusion Prepare five decompositions of pur
38、e alumina (4.4.1) in accordance with 7.2. Transfer into five 200 ml volumetric flasks and dilute to 150 ml with water. Add the quantities of solutions indicated in Table 1. Make up to the mark with water. EN 725-1:2007 (E) 7 Table 1 Quantities of solutions for fusion Elements 1 2 3 4 5 Na 0 l 1 l 2
39、l 4 l 6 l K 0 l 100 l 200 l 300 l 400 l Ca 0 l 250 l 500 l 750 l 1000 l Fe 0 l 100 l 200 l 300 l 400 l Si 0 l 200 l 400 l 800 l 1600 l Mg 0 l 250 l 500 l 750 l 1000 l 8.3 Acid dissolution Prepare 5 dissolutions of pure alumina (4.4.1) in accordance with 7.3. Transfer into five 100 ml volumetric flas
40、ks and dilute to 50 ml with water. Add the quantities indicated in Table 2. Make up to the mark with water. Table 2 Quantities of solutions for acid dissolution Elements 1 2 3 4 5 Na 0 l 500 l 1000 l 2000 l 3000 l K 0 l 50 l 100 l 150 l 200 l Ca 0 l 125 l 250 l 375 l 500 l Fe 0 l 50 l 100 l 150 l 20
41、0 l Mg 0 l 125 l 250 l 375 l 1000 l 8.4 Drawing the calibration curve 8.4.1 Blank test Prepare a blank test in accordance with 8.2 or 8.3 using the same quantities of all reagents as for dissolution of the test sample, but using pure alumina (4.4.1) in place of the test sample. 8.4.2 Drawing the cal
42、ibration curve Draw a graph of the AAS or ICP intensities recorded using the calibration solutions prepared against the impurity concentrations. 9 Adjustment of the apparatus 9.1 Atomic absorption spectrometer Follow the manufacturers instructions for igniting and extinguishing the nitrous oxide-ace
43、tylene flame to avoid explosion, and ensure the safety screen is in place. Set the wavelengths for the elements to be analysed (see Table 3) and adjust the apparatus so as to obtain maximum absorbance. Fit the correct burner and, in accordance with the manufacturers instructions, light the EN 725-1:
44、2007 (E) 8 flame. After 10 min preheating of the burner, adjust fuel and burner to obtain maximum absorbance while aspirating the highest calibration solution. Aspirate water and set to give the zero absorbance. Aspirate the blank solution and then, alternately aspirate the calibration solutions and
45、 water to establish that the absorbance reading is not drifting and draw the calibration graph. 9.2 Inductively coupled plasma spectrometer Follow the manufacturers instructions for igniting the plasma. Ensure the safety screen is in place. NOTE 1 The wavelengths in Table 3 can be used for the analy
46、sis. Depending on the analytical method and element concentration, other wavelengths can also be used. NOTE 2 It should be ensured that there is no spectral interference if other lines are used. Wait until a stable signal is obtained. It is possible to use an internal standard to improve the precisi
47、on of the results. NOTE 3 It is usual to use yttrium as the internal standard. Table 3 Recommended wavelengths for analysis Elements Atomic absorption (recommendations) ICP (recommendations) Na 589,0 nm 589,0 nm K 766,5 nm 769,9 nm Ca 422,7 nm 393,3 nm Fe 248,3 nm 259,9 nm Si 251,6 nm 251,6 nm Mg 28
48、5,2 nm 279,5 nm 10 Measurements Aspirate the blank and the calibration solutions and the final test solutions in order of increasing concentrations. Aspirate water between each solution and record the readings when stable responses are obtained. Repeat the measurements at least twice more and calcul
49、ate the average of the readings for each solution. Read the concentration in the solutions from the calibration curve. 11 Expression of the results Calculate the concentration of oxide in ppm by subtracting the blank value bi(this value is the concentration read at the intersection of the calibration curve with concentration axis) from the raw result obtained in accordance with Clause 10. EN 725-1:2007 (E) 9 12 Test r
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