1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 13971:2012Carbonate and silicate limingmaterials Determination ofreactivity Potentiometrictitration method withhydrochloric acidCopyright European Committee for Standardiza
2、tion Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 13971:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 13971:2012. Itsupersedes BS EN 13971:2008 which is withdrawn.BSI, as a
3、member of CEN, is obliged to publish EN 13971:2012 as aBritish Standard. However, attention is drawn to the fact that duringthe development of this European Standard, the UK committee votedagainst its approval as a European Standard.The UK committee submitted a negative vote with respect to thisstan
4、dard due to concerns over reproducibility limits as described inTable 1. In two cases out of eight the reproducibility limit was 60 % andin all but three cases it exceeded 30 %. The UK committee advises thatusers validate their performance.The UK participation in its preparation was entrusted to Tec
5、hnicalCommittee CII/37, Fertilisers and related chemicals.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The Bri
6、tish Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 72251 6ICS 65.080; 91.100.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 3
7、1 January 2013.Amendments issued since publicationDate Text affectedBS EN 13971:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 13971:2012. Itsupersedes BS EN 13971:2008 which is withdrawn.BSI, as a member of CEN, is obliged to publish EN 13971:2012 as aBri
8、tish Standard. However, attention is drawn to the fact that duringthe development of this European Standard, the UK committee votedagainst its approval as a European Standard.The UK committee submitted a negative vote with respect to thisstandard due to concerns over reproducibility limits as descri
9、bed inTable 1. In two cases out of eight the reproducibility limit was 60 % andin all but three cases it exceeded 30 %. The UK committee advises thatusers validate their performance.The UK participation in its preparation was entrusted to TechnicalCommittee CII/37, Fertilisers and related chemicals.
10、A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI Standard
11、sLimited 2013ISBN 978 0 580 72251 6ICS 65.080; 91.100.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 January 2013.Amendments issued since publicationDate Tex
12、t affectedBritish Standard. However, attention is drawn to the fact that during the development of this European Standard, the UK committee voted against its approval as a European Standard.standard due to concerns over reproducibility limits as described in Table 1. In two cases out of eight the re
13、producibility limit was 60 % and in all but three cases it exceeded 30 %. The UK committee advises that users validate their performance.Amendments/corrigenda issued since publicationCopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction
14、or networking permitted without license from IHS-,-,-BS EN 13971:2012EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13971 December 2012 ICS 65.080 Supersedes EN 13971:2008English Version Carbonate and silicate liming materials - Determination of reactivity - Potentiometric titration method wit
15、h hydrochloric acidAmendements minraux basiques carbonats et silicats -Dtermination de la ractivit - Mthode par titrage potentiomtrique lacide chlorhydrique Carbonatische und silikatische Kalke - Bestimmung der Reaktivitt - Potentiometrisches Titrationsverfahren mit Salzsure This European Standard w
16、as approved by CEN on 3 November 2012. 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
17、national standards may be obtained on application to the CEN-CENELEC 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 l
18、anguage and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Gre
19、ece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG
20、 Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13971:2012: ECopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reprodu
21、ction or networking permitted without license from IHS-,-,-BS EN 13971:2012EN 13971:2012 (E) 2 Contents Page Foreword 3Introduction .41 Scope 52 Normative references 53 Principle 54 Apparatus .55 Reagents .66 Preparation of the test sample .67 Procedure .78 Expression of results 99 Precision 1010 Te
22、st report . 12Annex A (normative) Preparation of the test portion of liming materials coarser than 1 mm . 13Annex B (normative) Arrangement of the test apparatus 14Bibliography . 16Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or
23、 networking permitted without license from IHS-,-,-BS EN 13971:2012EN 13971:2012 (E) 3 Foreword This document (EN 13971:2012) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of which is held by DIN. This European Standard shall be given the sta
24、tus of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2013, and conflicting national standards shall be withdrawn at the latest by June 2013. Attention is drawn to the possibility that some of the elements of this document may be the subject
25、of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 13971:2008. The following has been added to the former edition of the European Standard: a) silicate liming materials added to the scope and to the title; b)
26、EN 12947 and EN 13475 added to the normative references; c) Clause 3 reaction formula for silicates added; d) subclauses 7.1.2 and 7.2.2 enlarged concerning determination of silicate liming materials; e) subclause 8.2 and formulas (2), (3) and (4) on expression of results for silicate liming materia
27、ls added; f) subclause 9.2 and Table 2 on the precision data for silicate liming materials added; g) Bibliography revised. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgiu
28、m, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerl
29、and, Turkey and the United Kingdom. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 13971:2012EN 13971:2012 (E) 4 Introduction The results obtained by this method can be us
30、ed to estimate the behaviour of the liming material in the soil. The results show a good correlation with the results obtained by a soil incubation method (see 1 to 5). Regarding the precision of the method, the results are not used to declare a value, but to classify the different product groups. C
31、opyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 13971:2012EN 13971:2012 (E) 5 1 Scope This European Standard specifies a method for the determination of the speed and effect
32、iveness of the neutralising potential of calcium carbonate, calcium magnesium carbonate and calcium magnesium silicate liming materials by potentiometric titration with hydrochloric acid. This method is applicable only to liming materials with a maximum particle size of 6,3 mm. The type of liming ma
33、terial should be identified according to EN 14069 and the particle size should be determined according to EN 12948. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only t
34、he edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 1482-2, Fertilizers and liming materials Sampling and sample preparation Part 2: Sample preparation EN 12048, Solid fertilizers and liming materials Determination of
35、 moisture content Gravimetric method by drying at (105 2) C (ISO 8190:1992 modified) EN 12945, Liming materials Determination of neutralizing value Titrimetric methods EN 12947, Liming materials Determination of magnesium content Atomic absorption spectrometric method EN 12948, Liming materials Dete
36、rmination of size distribution by dry and wet sieving EN 13475, Liming materials Determination of calcium content Oxalate method 3 Principle Decomposition of carbonates and silicates with acids according to the following reactions: MeCO3+ 2 H+ Me2+ H2O + CO2 MeSiO4+ 2 H+ Me(OH)2+ SiO2Titration under
37、 stable pH conditions either with an automatic titration apparatus or a manual method. The acid consumption during a given time is a direct measure of the reaction rate of the liming materials being tested. 4 Apparatus Usual laboratory apparatus and, in particular, the following: 4.1 pH meter, with
38、electrode. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 13971:2012EN 13971:2012 (E) 6 4.2 Burette. NOTE Used only for 5,0 mol/l hydrochloric acid solution (5.2). 4.2.1 5
39、0 ml motor driven burette (for automatic titration),a pH stat function is recommended, for example Metrohm 716 DMS Titrino1). 4.2.2 50 ml burette (for manual titration). 4.3 250 ml glass beaker, with an inner diameter of 65 mm. 4.4 Magnetic stirrer, with centring mark for the 250 ml glass beaker. 4.
40、5 Magnetic stirrer rod, (9 1) mm diameter times (50 1) mm length, with central ring. 4.6 Stop-watch. 4.7 Filter paper, acid-proof, medium filtration speed, average retention capacity about 5 m to 12 m. 5 Reagents All reagents shall be of recognised analytical grade. 5.1 Hydrochloric acid solution, m
41、ass fraction, w(HCl) = 25 %. 5.2 Hydrochloric acid, standard volumetric solution, c(HCl) = 5,0 mol/l. 5.3 Calcium carbonate, precipitated, mass fraction, w(CaCO3) = of at least 99 %. Precipitated calcium carbonate is from crystalline origin. Commercial PCC for analysis is granted for its chemical ch
42、aracteristics. However, physical characteristics are not granted. The use of a highly reactive PCC, such as commercial PCC from VWR / Prolabo / BDH, reference GPR, Rectapur, Ref 22296.294, Molar mass 100,092)which will consume 15 ml after 15 min, is recommended. 5.4 Silicone defoamer. 5.5 Standard b
43、uffer solution, pH = 2,0 (commercial solution). NOTE This has a limited life. 5.6 Standard buffer solution, pH = 4,0, (commercial solution). NOTE This has a limited life. 6 Preparation of the test sample 6.1 Prepare the sample of the liming material in accordance with EN 1482-2. 1) Metrohm 716 DMS T
44、itrino is an example of a suitable product available commercially. This information is given for the convenience of users of this European Standard and does not constitute an endorsement by CEN of this product. Equivalent products may be used if they can be shown to lead to the same results. 2) This
45、 substance is an example of a suitable product available commercially. This information is given for the convenience of users of this document and does not constitute an endorsement by CEN of this product.Copyright European Committee for Standardization Provided by IHS under license with CENNot for
46、ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 13971:2012EN 13971:2012 (E) 7 6.2 Dry the test sample in accordance with EN 12048. Record the result for information only. 6.3 Use the dried test sample without further preparation, e.g. grinding. 6.4 Weigh a 5,0 g test
47、 portion of the dried sample to the nearest 0,01 g. For liming materials coarser than 1 mm, the test portion shall be prepared in accordance with Annex A. 7 Procedure 7.1 Automatic titration 7.1.1 Calibration 7.1.1.1 Calibrate the pH meter (4.1) with two standard buffer solutions, pH 2,0 (5.5) and p
48、H 4,0 (5.6). The pH electrode shall react quickly. Check the sluggishness of the electrode and if necessary, clean it carefully with hydrochloric acid (5.1) and re-calibrate with the standard buffer solutions. Checking and cleaning is more frequently required for liming materials containing clay. It is recommended to flush the acid introduction pipe between each sample for slow reacting samples. 7.1.1.2 Adjust the motor driven burette (4.2.1) to the position “continuous working” and a standard flow rate of 35 ml/min to 38 ml/min. NOTE Wide de
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