BS EN 13475-2002 Liming materials - Determination of calcium content - Oxalate method《石灰材料 钙含量的测定 草酸酯法》.pdf

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1、BRITISH STANDARD BS EN 13475:2002 Liming materials Determination of calcium content Oxalate method The European Standard EN 13475:2001 has the status of a British Standard ICS 65.080 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 13475:2002 This British Standard, having

2、been prepared under the direction of the Materials and Chemicals Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 29 January 2002 BSI 29 January 2002 ISBN 0 580 38978 2 National foreword This British Standard is the official En

3、glish language version of EN 13475:2001. The UK participation in its preparation was entrusted to Technical Committee CII/37, Fertilizers and related chemicals, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-r

4、eferences The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic C

5、atalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the

6、 text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an ins

7、ide front cover, the EN title page, pages 2 to 9 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13475 November 2001 ICS 65.

8、080 English version Liming materials Determination of calcium content Oxalate method Amendements minraux basiques Dtermination de la teneur en calcium Mthode loxalate Calcium-/Magnesium-Bodenverbesserungsmittel Bestimmung des Calciumgehaltes Oxalatverfahren This European Standard was approved by CEN

9、 on 29 September 2001. 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 standar

10、ds may be obtained on application to the 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 notified to the

11、Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United King

12、dom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2001 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13475:2001 EEN 13

13、475:2001 (E) 2 Contents Page Foreword.3 1 Scope4 2 Normative references .4 3 Principle .4 4 Reagents 4 5A p p a r a t u s .5 6 Sampling 6 7 Procedure.6 8 Expression of results8 9 Precision 8 10 Test report9EN 13475:2001 (E) 3 Foreword This European Standard has been prepared by Technical Committee C

14、EN/TC 260, Fertilizers and liming materials, the Secretariat of which is held by DIN. 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 May 2002, and conflicting national standards shall be withdraw

15、n at the latest by May 2002. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembo

16、urg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.EN 13475:2001 (E) 4 1 Scope This European Standard specifies a method for the determination of the calcium content of silicate liming materials including slags. NOTE 1 The method has been shown to be suitable for o

17、ther liming materials too, but there are no precision data available yet. NOTE 2 The method is also applicable for the determination of the calcium content of mineral fertilizers. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publicat

18、ions. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to, or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision

19、. For undated references the latest edition of the publication referred to applies (including amendments). EN 1482, Sampling of solid fertilizers and liming materials. ISO 3310-1, Test sieves Technical requirements and testing Part 1: Test sieves of metal wire cloth. 3 Principle After dissolution of

20、 the sample in a mixture of hydrochloric acid and nitric acid, calcium is precipitated in the form of calcium oxalate at a pH between 4,4 and 4,6. The supernatant solution is removed by means of an immersion filter. The calcium oxalate precipitate is dissolved in sulfuric acid and the calcium conten

21、t is determined by titration with potassium permanganate. 4 Reagents 4.1 General Commercially available standard solutions may be used instead of standard solutions produced in the laboratory. Variations in concentration shall be taken into account for the calculation of the results. 4.2 Hydrochlori

22、c acid, 20 (HCl) = 1,19 g/ml, c(HCl) = 12,5 mol/l. 4.3 Nitric acid, 20 (HNO 3 ) = 1,40 g/ml, c(HNO 3 ) = 14,9 mol/l. 4.4 Citric acid solution Dissolve 300 g of citric acid monohydrate in water and make up to 1 l. 4.5 Ammonium chloride solution Dissolve 100 g of ammonium chloride in water and make up

23、 to 1 l. Mix well. 4.6 Bromocresol green Dissolve 5 g of bromocresol green in ethanol with a volume concentration of ethanol of 96 % and make up to 1 l.EN 13475:2001 (E) 5 4.7 Ammonium oxalate solution, saturated Dissolve sufficient ammonium oxalate monohydrate (approximately 70 g) in 1 l of water t

24、o produce a saturated solution. After reaching saturation, filter the solution. 4.8 Ammonia solution Dilute 400 ml of ammonia solution containing a mass fraction of NH 3of 25 % 20 (NH 3 ) = 0,91 g/ml with water to 1 l. 4.9 Ammonium oxalate solution Dissolve 10 g of ammonium oxalate monohydrate in wa

25、ter and make up to 1 l. 4.10 Sulfuric acid, 20 (H 2 SO 4 ) = 1,84 g/ml, c(H 2 SO 4 ) = 15,2 mol/l. 4.11 Sulfuric acid solution Dilute one volume of sulfuric acid (4.10) with one volume of water. 4.12 Potassium permanganate solution, c(KMnO 4 ) 0,02 mol/l. Dissolve 3,18 g of potassium permanganate in

26、 100 ml of water by boiling for 20 min. Subsequently filter the solution through a glass filter crucible (5.3) and transfer the filtrate into a light-protected 1 l volumetric flask. Rinse the filter crucible. Transfer the washing water into the 1 l volumetric flask likewise and dilute to the mark. A

27、fter a standing time of several days filter the solution through a filter crucible (5.3). Determine the exact amount-of-substance concentration (F) of the potassium permanganate solution using the sodium oxalate (4.13). 4.13 Sodium oxalate Weigh, to the nearest 1 mg, 250 mg to 300 mg of sodium oxala

28、te into a 300 ml conical flask. Dissolve the salt in approximately 100 ml of water and mix with 30 ml of sulfuric acid (4.10). Heat the solution in a boiling water bath and titrate immediately with the potassium permanganate solution until it turns to a weak pink colour. NOTE Although sodium oxalate

29、 is not very hygroscopic it is expedient to dry the salt at 130 C for 1 h prior to use to remove any moisture. Subsequently, the dried salt is cooled to ambient temperature in a desiccator for at least 30 min. 5 Apparatus Usual laboratory equipment and in particular the following: 5.1 Water bath 5.2

30、 Immersion filter, diameter 35 mm, porosity grade P 16 (10 m to 16 m). 5.3 Glass filter crucible, porosity grade P 40 (16 m to 40 m). 5.4 Electric hot plate 5.5 Pipette filler, with a rubber expansion bulb. 5.6 Vacuum pump or water jet filter pump 5.7 Test sieve with nominal aperture size of 250 m,

31、according to ISO 3310-1.EN 13475:2001 (E) 6 6 Sampling Sampling shall be carried out in accordance with EN 1482. 7 Procedure 7.1 Preparation 7.1.1 Preparation of the test sample Dry the test sample at (105 2) C to constant mass. Record the as-received and dry masses and calculate the moisture conten

32、t. Grind the sample so that it passes the 250 m sieve (5.7). Mix thoroughly and store the sample in an airtight container. 7.1.2 Preparation of the test solution Weigh to the nearest 0,001 g about 1,0 g of the test sample (prepared in accordance with 7.1.1) into a 600 ml beaker. NOTE In the case of

33、materials of low silicic acid content with low amounts of CaO (less than 5 % CaO), the mass of the test portion taken may be increased. Suspend the sample with 100 ml of water and add 25 ml of hydrochloric acid (4.2) and 5 ml of nitric acid (4.3). Cover the beaker with a watch glass. Boil gently for

34、 30 min shaking several times and replacing evaporated water. Subsequently cool and transfer the contents of the beaker to a 500 ml volumetric flask. Dilute to the mark with water and mix. Filter through a dry filter, discarding the initial portion. Store this test solution in a stoppered flask if t

35、he determination is not to be carried out immediately.EN 13475:2001 (E) 7 7.2 Determination 7.2.1 Aliquot portion Take an aliquot portion according to Table 1. Table 1 Aliquot portions Expected CaO content % Aliquot ml Volume of burette ml 10 to 30 30 200 100 100 100 10 10 25 50 7.2.2 Titration Plac

36、e the aliquot portion (7.2.1) into a 400 ml beaker, add 10 ml of citric acid solution (4.4) and 5 ml of ammonium chloride solution (4.5). Heat the solution to boiling, add 10 drops of bromocresol green (4.6) and 30 ml of hot ammonium oxalate solution (4.7), stirring slowly and continuously. Then neu

37、tralize with ammonia solution (4.8) under constant stirring until the colour of the indicator changes from yellow to blue-green (pH 4,4 to pH 4,6). Allow the beaker to stand on a boiling water bath (5.1) for at least 30 min. Cool and remove the supernatant solution through an immersion filter (5.2).

38、 Wash the precipitate with 50 ml of cold ammonium oxalate solution (4.9) and subsequently, three times with 50 ml of cold water, sucking off the wash solution each time. Add to the precipitate, without removing the immersion filter, 100 ml of water and subsequently approximately 4 ml of sulfuric aci

39、d solution (4.11) and dissolve under heating while blowing twice through the immersion filter by means of a pipette filler (5.5). Titrate the hot solution (min. 60 C) with potassium permanganate solution (4.12) while blowing air through the immersion filter several times by means of the pipette fill

40、er until a lasting pink colour is obtained. 7.2.3 Blank titration Titrate the same amount of water as used in the above titration (see 7.2.2) with the addition of 4 ml of sulfuric acid solution (4.11) but omitting the test solution.EN 13475:2001 (E) 8 8 Expression of results 1 ml of 0,02 mol/l potas

41、sium permanganate solution (4.12) corresponds to 2,002 mg Ca. The calcium content w(CaO), expressed as mass fraction calcium oxide (CaO) in percent, is given by equation (1): m F V V w 02 , 14 ) ( (CaO) 0 1 (1) where V 0 is the volume of the potassium permanganate solution (4.12), in millilitres, us

42、ed in the blank titration (7.2.3); V 1 is the volume of the potassium permanganate solution (4.12), in millilitres, used in the titration of the test solution (7.2.2); F is the amount-of-substance concentration of the potassium permanganate solution (4.12) in moles per litre; m is the mass of the te

43、st portion, in grams, contained in the aliquot portion (7.2.1); 14,02 is of the molar mass of calcium oxide. The calcium content of the product as received w(CaO) aris given by equation (2): 100 ) 100 ( (CaO) (CaO) M ar w w w (2) where w(CaO) is the calcium content, given as mass fraction calcium ox

44、ide (CaO) in percent, of dry material see equation (1); w M is the moisture content of the test sample (7.1.1), given as mass fraction in percent. To express the results in % Ca use equation (3): 7147 , 0 ) CaO ( ) Ca ( w w (3) 9 Precision 9.1 General The values derived from interlaboratory tests wi

45、th eight participating laboratories are shown in 9.2 and 9.3.EN 13475:2001 (E) 9 9.2 Repeatability The absolute difference between two single test results obtained with the same method on identical test material in the same laboratory by the same operator using the same equipment within the shortest

46、 feasible time interval will exceed the repeatability limit r in not more than 5 % of cases. The values arer = 0,64 % (mass fraction) for blast furnace slags with w (CaO) = 42,0 %;r = 1,01 % (mass fraction) for converter slags with w (CaO) = 48,6 %. NOTE w (CaO) is the mean mass fraction of calcium

47、oxide. 9.3 Reproducibility The absolute difference between two single test results, obtained with the same method on identical test material in different laboratories with different operators using different equipment, will exceed the reproducibility limit R in not more than 5 % of cases. The values

48、 are R = 1,56 % (mass fraction) for blast furnace slags with w (CaO) = 42,0 %; R = 1,56 % (mass fraction) for converter slags with w (CaO) = 48,6 %. NOTE w (CaO) is the mean mass fraction of calcium oxide. 10 Test report The test report shall contain at least the following information: a) all inform

49、ation necessary for the complete identification of the sample; b) a reference to this European Standard; c) the results and the units in which the results have been expressed; d) any particular points observed in the course of the test; e) any operations not specified in the method or regarded as optional which may have affected the results.BS EN 13475:2002 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British