1、November 2013 Translation by DIN-Sprachendienst.English price group 11No part of this translation 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).I
2、CS 65.080!%*,h“2070969www.din.deDDIN EN 16357Carbonate liming materials Determination of reactivity Automatic titration method with citric acid;English version EN 16357:2013,English translation of DIN EN 16357:2013-11Carbonatische Kalke Bestimmung der Reaktivitt Automatisches Titrationsverfahren mit
3、 Citronensure;Englische Fassung EN 16357:2013,Englische bersetzung von DIN EN 16357:2013-11Amendements minraux basiques carbonats Dtermination de la ractivit Mthode par titration automatique lacide citrique;Version anglaise EN 16357:2013,Traduction anglaise de DIN EN 16357:2013-11www.beuth.deIn case
4、 of doubt, the German-language original shall be considered authoritative.Document comprises 18 pages 10.13 DIN EN 16357:2013-11 2 A comma is used as the decimal marker. National foreword This document (EN 16357:2013) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materi
5、als” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Lebensmittel und landwirtschaftliche Produkte (Food and Agricultural Products Standards Committee), Working Committee NA 057-03-02 AA Dngemittel. The DIN Standards corresponding to the I
6、nternational Standards referred to in this document are as follows: ISO 5725-1 DIN ISO 5725-1 ISO 5725-2 DIN ISO 5725-2 ISO 9277 DIN ISO 9277 National Annex NA (informative) Bibliography DIN ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results Part 1: General principles a
7、nd definitions DIN ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method DIN ISO 9277, Determination of the specific surface area of solids by gas adsorption us
8、ing the BET method EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16357 August 2013 ICS 65.080 English Version Carbonate liming materials - Determination of reactivity - Automatic titration method with citric acid Amendements minraux basiques carbonats - Dtermination de la ractivit - Mthode pa
9、r titration automatique lacide citrique Carbonatische Kalke - Bestimmung der Reaktivitt - Automatisches Titrationsverfahren mit Citronensure This European Standard was approved by CEN on 29 June 2013. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the condi
10、tions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists
11、 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 notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national stand
12、ards bodies of Austria, Belgium, 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, Slo
13、venia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means reserved worldwide
14、for CEN national Members. Ref. No. EN 16357:2013: EEN 16357:2013 (E) 2 Contents Page Foreword . 3 Introduction 4 1 Scope 5 2 Normative references . 5 3 Principle 5 4 Apparatus . 5 5 Reagents . 6 6 Sampling and sample preparation 7 6.1 General . 7 6.2 Preparation of the test sample 8 6.3 Preparation
15、of the test portion 8 7 Procedure . 8 7.1 General . 8 7.2 Calibrations 8 7.3 Measurement 10 7.4 Determination of neutralising value 11 7.5 Determination of MgO content 11 8 Calculation and expression of the results 11 9 Precision . 12 9.1 Inter-laboratory tests . 12 9.2 Repeatability . 12 9.3 Reprod
16、ucibility . 12 10 Test report 13 Annex A (normative) Preparation of the test portion of liming materials coarser than 1 mm . 14 A.1 General . 14 A.2 Calculation of mass fractions retained on the test sieves . 14 A.3 Calculation of the test portion to be weighed . 14 Annex B (normative) Arrangement o
17、f the test apparatus . 15 Bibliography 16 DIN EN 16357:2013-11 EN 16357:2013 (E) 3 Foreword This document (EN 16357:2013) 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 status
18、of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2014, and conflicting national standards shall be withdrawn at the latest by February 2014. Attention is drawn to the possibility that some of the elements of this document may be the subj
19、ect of patent rights. 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, Bu
20、lgaria, 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, Switzerland,
21、Turkey and the United Kingdom. DIN EN 16357:2013-11 EN 16357:2013 (E) 4 Introduction This method has been prepared to improve existing agricultural reactivity methods (see 1, 2, 3, 4 and 5) for carbonate liming materials: duration, accuracy, representativeness, closer from soil conditions, automatio
22、n. Attention is drawn to the following critical steps: identification of the liming material type (influence on precision data); size distribution (influence on test portion preparation and amount); calibration of pH electrode (influence on titrators pH adjustments); pH stat programme setting (influ
23、ence on accuracy of added amounts of citric acid solution); suitability of PCC used to check calibration; stirring device (provides homogeneousness without grinding); additional uncertainty with neutralising value and MgO content determination. DIN EN 16357:2013-11 EN 16357:2013 (E) 5 1 Scope This E
24、uropean Standard specifies a method for the determination of the reactivity of calcium carbonate and calcium magnesium carbonate liming materials. It assesses the speed and effectiveness of their neutralising potential by automatic titration with citric acid. This method is applicable only to liming
25、 materials with a maximum particle size of 6,3 mm determined according to EN 12948. NOTE For marble dolomite (BET procedure according to ISO 9277 below 500 m2/kg), see EN 14984. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are i
26、ndispensable for its application. For dated references, only the 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
27、12048, Solid fertilizers and liming materials Determination of moisture content Gravimetric method by drying at (105 +/- 2) C (ISO 8190, modified) EN 12945, Liming materials Determination of neutralizing value Titrimetric methods EN 12948, Liming materials Determination of size distribution by dry a
28、nd wet sieving EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696) 3 Principle Limited decomposition of carbonates in a given time with acid according to the following reaction: 2223COOHMeH2MeCO +Titration under stable pH conditions (pH 4,5) with an automatic t
29、itration apparatus. The citric acid consumption during a given time (15 min) is a direct measure for the reaction of the liming materials being tested. 4 Apparatus Usual laboratory apparatus and, in particular, the following: 4.1 pH meter with electrode. This instrument is generally included in the
30、automatic motor driven burette device. 4.2 Automatic motor driven burette, capacity 20 ml. This kind of burette is generally equipped with all necessary accessories such as pH regulation programme (pH stat), automatic refilling device, pH electrode, continuous pH measurement and propeller stirring d
31、evice. Though a propeller stirring device is preferred, a magnetic stirring device (4.7) may be used, provided the central ring of the stirrer rod is thick enough and does not lead to grind the tested material. Make sure the rotation speed of the stirrer rod is fast enough to make homogeneous disper
32、sion in the beaker. If not, increase the speed up to the necessary value. DIN EN 16357:2013-11 EN 16357:2013 (E) 6 The burette shall be able to deliver at least 0,05 ml of citric acid solution (5.3) per second. This is to ensure the first part of the reaction (pH dropping from initial pH value to ta
33、rget pH value (4,5) will not be a limiting factor for liming material dissolution speed). This figure is higher than the flow rate obtained with the fastest reaction observed in preliminary tests. The burette shall be able to deliver its whole content in at least 4 000 steps to ensure accuracy for l
34、ow amount of citric acid solution (5.3). NOTE This condition is always fulfilled with modern titrators. All contemporary (less than 10 years old) titrators allow such accuracy: i.e. minimum step amount: 0,002 5 ml for a 10 ml burette, or 0,012 5 ml for a 50 ml burette. This is sufficient, even for l
35、ow amounts. However, this accuracy is obtained only if correct (minimal) step volume in titrator setup is specified. If not, the precision of the method will be altered. Use the burette only for the citric acid solution (5.3). For liming materials coarser than 1 mm, use a 50 ml burette. For most of
36、products, a 10 ml burette is sufficient. However, a 20 ml burette is necessary for highly reactive chalks and precipitated calcium carbonate. Because refilling takes a significant time, this can bias the results. If volumes higher than 10 ml are expected, do not use the automatic refilling possibili
37、ty and use a 20 ml or a 50 ml burette. 4.3 Glass beaker, capacity 100 ml. For liming materials coarser than 1 mm, use a 200 ml beaker. Minimum diameter in case of magnetic stirring device (4.7): 50 mm. 4.4 Stop-watch. 4.5 Balance, capable of weighing 10 g to the nearest 0,01 g. 4.6 Sample changer, o
38、ptional. If occurring, a beaker of water (5.1) shall be inserted between two samples. 4.7 Magnetic stirring device, optional, see 4.2. Capable of minimum 500 min1speed rotation. Stirrer rod minimum length: 40 mm. 5 Reagents All reagents shall be of recognised analytical grade. 5.1 Water, according t
39、o EN ISO 3696, grade 2. 5.2 Mono hydrated citric acid, C6H8O7H2O, crystallised or powder, molar mass: 210,14 g. Do not use anhydrous citric acid having a different molar mass, which can partially hydrate when storing. 5.3 Citric acid solution, = 457,17 g/l. Preferably, use a fresh home-made solution
40、 as described below. Under these conditions, the solution concentration is conventionally supposed to be equal to the necessary one, ca= 457,17 g pure citric acid per litre. DIN EN 16357:2013-11 EN 16357:2013 (E) 7 The solution may be used for up to, at most, one month stored in a closed, dark glass
41、 vessel. If the solution has been stored more than one week, check its concentration by any means, for example by titration with a strong base (NaOH) solution of known concentration and report the result in the formula given in Clause 8. Weigh 500 g of mono hydrated citric acid (5.2) to the nearest
42、0,1 g. Pour it quantitatively into a 1 l measuring vessel. Rinse the weighing material and pour the rinsing water into the vessel in a way that it takes any acid stuck on the edge or on the bottom. Add about 500 ml of water (5.1) to the measuring vessel. Heat the vessel until full dissolution (tempe
43、rature about 80 C). Let the vessel cool to ambient temperature. Make up to the volume with water to 1 l. Stir to get a homogeneous solution. The pure citric acid content, ca, (C6H8O7), in grams per litre of this solution is calculated according to Formula (1) as follows. 17,45714,21014,192500=ca (1)
44、 where 500 is the added mass of mono hydrated citric acid (5.2), in grams; 192,14 is the molar mass of anhydrous citric acid, in grams; 210,14 is the molar mass of mono hydrated citric acid, in grams. 5.4 Calcium carbonate, precipitated (or PCC), mass fraction, w(CaCO3) at least 99 %. Commercial PCC
45、 for analysis is granted for its chemical characteristics. However, physical characteristics are not granted. As reactivity depends on fineness, even for PCC, it is essential to take as a reference a highly reactive PCC, such as commercial PCC from VWR / Prolabo / BDH, reference GPR, Rectapur, Ref 2
46、2296.294, Molar mass 100,09 1), which will consume 15 ml after 15 min. This PCC was used in the ring test before launching measurements. By experience, some PCC do not meet this requirement. See also the note in 7.2.6. 5.5 Silicone defoamer. 5.6 Standard buffer solution, pH 4 (commercial solution, p
47、H 4,01). NOTE This solution has a limited lifetime. 5.7 Standard buffer solution, pH 7 (commercial solution, pH 6,98). NOTE This solution has a limited lifetime. 6 Sampling and sample preparation 6.1 General Sampling is not part of the methods specified in this document. A recommended sampling metho
48、d is given in EN 1482-1. Sample preparation shall be carried out in accordance with EN 1482-2. 1) This substance 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. DIN EN 16357:2013-11 EN 16357:2013 (E) 8 This document specifies that samples are tested “as received” in order to allow immediate starting of all the necessary
