BS ISO 302-2015 Pulps Determination of Kappa number《纸浆 卡伯(KAPPA)值的测定》.pdf

1、BSI Standards PublicationBS ISO 302:2015Pulps Determination ofKappa numberBS ISO 302:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 302:2015. Itsupersedes BS ISO 302:2004 which is withdrawn.The UK participation in its preparation was entrusted to Technica

2、lCommittee PAI/11, Methods of test for paper, board and pulps.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

3、 British Standards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 86892 4ICS 85.040Compliance 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 July

4、2015.Amendments issued since publicationDate Text affectedBS ISO 302:2015 ISO 2015Pulps Determination of Kappa numberPtes Dtermination de lindice KappaINTERNATIONAL STANDARDISO302Third edition2015-08-01Reference numberISO 302:2015(E)BS ISO 302:2015ISO 302:2015(E)ii ISO 2015 All rights reservedCOPYRI

5、GHT PROTECTED DOCUMENT ISO 2015, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, with

6、out prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS

7、ISO 302:2015ISO 302:2015(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Reagents and materials . 26 Apparatus and equipment 27 Sampling and preparation of sample 37.1 Sampling . 37.2 Sample preparation 38 Procedure. 38.1 General . 38.2 Blank 48.3 Determinat

8、ion . 48.3.1 General 48.3.2 Kappa number range 5 to 100 . 58.3.3 Kappa number range 1 to 5 58.4 Reference pulp . 69 Calculations 69.1 Kappa number 5 to 100 . 69.2 Kappa number 1 to 5 . 79.3 Expression of results 89.4 Example of calculation . 810 Test report . 8Annex A (informative) Precision 10Bibli

9、ography .12 ISO 2015 All rights reserved iiiContents PageBS ISO 302:2015ISO 302:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out th

10、rough ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collab

11、orates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval

12、 criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subje

13、ct of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade

14、name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Techn

15、ical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 6, Paper, board and pulps.This third edition cancels and replaces the second edition (ISO 302:2004), which has been technically revised.iv ISO 2015 All rights

16、 reservedBS ISO 302:2015INTERNATIONAL STANDARD ISO 302:2015(E)Pulps Determination of Kappa number1 ScopeThis International Standard specifies a method for the determination of the Kappa number of pulp. The Kappa number is an indication of the lignin content or bleachability of pulp.This Internationa

17、l Standard is applicable to all kinds of chemical pulps and semi-chemical pulps within the Kappa number range 1 to 100. For pulps with a Kappa number exceeding 100, use the chlorine-consumption procedure (ISO 3260) to describe the degree of delignification.To achieve the greatest precision and accur

18、acy, the sample size has to be adjusted so that the consumption of permanganate falls between 20 % and 60 % of the amount added.NOTE There is no general and unambiguous relationship between the Kappa number and the lignin content of pulp. The relationship varies according to the wood species and del

19、ignification procedure. All compounds oxidized by KMnO4, not only lignin, will increase the consumption of KMnO4, and thereby increase the Kappa number.8If the Kappa number is to be used to derive an index of pulp lignin content, specific relationships will have to be developed for each pulp type.2

20、Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendmen

21、ts) applies.ISO 638, Paper, board and pulps Determination of dry matter content Oven-drying methodISO 7213, Pulps Sampling for testing3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1oxidation capacityrelative amount of potassium permanganate red

22、uced (expressed as MnO2) of the total oxidation capacity3.2total oxidation capacityoxidation capacity (permanganate consumption) when all permanganate is reduced into Mn2+3.3Kappa number of pulpnumber of millilitres of 0,02 mol/l potassium permanganate solution consumed under the specified condition

23、s by one gram of pulp (calculated on an oven-dry basis)Note 1 to entry: The results are corrected to a value corresponding to that obtained when 50 % of the total oxidation capacity of the permanganate is consumed in the test at a temperature of 25 C.4 PrincipleDisintegrated pulp is allowed to react

24、 with a specified amount of potassium permanganate solution for a given time. The amount of pulp is chosen so that about 50 % of the total oxidation capacity of the permanganate is left unconsumed at the end of the reaction time. ISO 2015 All rights reserved 1BS ISO 302:2015ISO 302:2015(E)The main r

25、eactions are as follows:Residual lignin + other oxidizable compounds + MnO4+ 4H+ oxidized lignin + other oxidized compounds + excess MnO4+ MnO2+ 2H2O2MnO4+ 10I+ 16H+ 2Mn2+ 5I2+ 8H2OMnO2+ 4H+ 2I Mn2+ 2H2O + I22S2O32+ I2 S4O62+ 2INOTE By theoretical calculation and experimental observation, a consumpt

26、ion of 60 % (mass/mass) is actually the end point of the consumption for the permanganate ions, at which point the ions have been reduced to MnO2. Further oxidation, performed by means of MnO2should be considered as “out of range”. By adding potassium iodide solution, the reaction is terminated and

27、the free iodine is titrated with sodium thiosulfate solution. The value so obtained is corrected to 50 % consumption of the total oxidation capacity of permanganate.5 Reagents and materialsUse only chemicals of recognized analytical grade and only distilled water or water of equivalent purity.5.1 Su

28、lfuric acid, c(H2SO4) = 2,0 mol/l.Add with caution 112 ml of sulfuric acid, H2SO4, of density 1,84 g/ml, to about 600 ml of water. Allow to cool and dilute to 1 litre with water.5.2 Potassium iodide, c(KI) = 1 mol/l.Dissolve 166 g of potassium iodide, KI, in a 1 000 ml volumetric flask and fill up t

29、o the mark with water.5.3 Potassium permanganate, c(KMnO4) = (0,020 0,001) mol/l.Dissolve 3,161 g of potassium permanganate, KMnO4, in a 1 000 ml volumetric flask and fill up to the mark with water.NOTE Fresh solution is stable for at least 6 months if stored in a dark bottle.5.4 Sodium thiosulfate,

30、 c(Na2S2O3) = (0,200 0 0,000 5 ) mol/l.Dissolve 49,65 g of sodium thiosulfate, Na2S2O3 5H2O, in a 1 000 ml volumetric flask and fill up to the mark with water.5.5 Starch indicator, 2 g/l solution.NOTE Commercially available standard solutions may be used.6 Apparatus and equipmentOrdinary laboratory

31、equipment and the following.6.1 Agitator, of the propeller type, made of glass or other noncorrosive material (a plastic- or glass-covered magnetic stirrer may be used instead).6.2 Wet-disintegration apparatus or blender, high-speed mixer, capable of disintegrating the pulp completely with minimum d

32、amage to the fibres.6.3 Water bath, capable of maintaining a temperature of (25,0 0,2) C in the reaction vessel (see 8.3 regarding temperature correction).2 ISO 2015 All rights reservedBS ISO 302:2015ISO 302:2015(E)6.4 Timing device, capable of measuring 10 min to the nearest 1 s.NOTE Automatic Kapp

33、a number analysers can be used if they follow this International Standard and give the same results.7 Sampling and preparation of sample7.1 SamplingIf the test is being made to evaluate a pulp lot, the sample shall be selected in accordance with ISO 7213. If the test is made on another type of sampl

34、e, report the source of the sample and if possible the sampling procedure used.Make sure that the test portions taken are representative of the pulp.As the presence of small amounts of spent cooking liquor affects the Kappa number, ensure that the sample is well washed.7.2 Sample preparationPrepare

35、the test material according to one of the following procedures.7.2.1 Air-dry pulp. Tear or cut the pulp into small pieces.7.2.2 Screened slush pulp. Dewater the pulp sample by filtering on a Bchner funnel or by centrifuging, avoiding any loss of fibres or fines. Air-dry the pulp sample, or dry it at

36、 a temperature not exceeding 105 C, and tear it into small pieces.7.2.3 Unscreened pulp. If the sample is taken from unscreened pulp, which is normally screened before bleaching or other processing, remove the shives and knots from the sample by screening. Choose a procedure that gives results simil

37、ar to those obtained by industrial screening. State the method of screening in the test report. Continue the sample preparation as described in 7.2.2.NOTE If the pulp sample contains a considerable amount of shives, the screening procedure may give rise to incorrect results. A more reliable value ma

38、y be obtained by defibrating the pulp sample before the determination. State the method of defibration in the test report.8 Procedure8.1 GeneralThis International Standard includes two different procedures. One is used in the Kappa number range 5 to 100 and the other in the Kappa number range 1 to 5

39、.The main difference between the procedures is the added amounts of pulp and of KMnO4,and the calculation. Due to stirring problems when determining Kappa numbers below 5, decrease the amounts of pulp and permanganate.Use 8.2 and 8.3 in both procedures. The separate procedures are described in 8.3.2

40、 and 8.3.3.Run the determination in duplicate.NOTE Experimental work in Nordic countries has shown that the Kappa number determination according to the procedure for Kappa number 5 to 100 gives results equivalent to those obtained by the procedure for Kappa number 1 to 5, within the Kappa number ran

41、ge from 4 to 6. ISO 2015 All rights reserved 3BS ISO 302:2015ISO 302:2015(E)8.2 BlankCarry out a blank determination using exactly the procedure described in 8.3, but without the pulp. Read off the volume, V1, to the nearest 0,1 ml, of the sodium thiosulfate (5.4) consumed at the inflection point. T

42、he consumption of sodium thiosulfate solution may vary by at most 1 % from its theoretical value (25,0 ml).Divide the blank value of the Kappa number determination in the range 5 to 100 by two, for use in the Kappa number determination in the 1 to 5 range.8.3 Determination8.3.1 GeneralCondition the

43、test specimens for at least 20 min, or until constant weight has been reached, in an atmosphere near the balance prior to weighing the samples for determination of Kappa number and dry matter content.Weigh, to the nearest 0,001 g, the amount of pulp which will consume approximately 50 % of the potas

44、sium permanganate (5.3). Examples of suitable amounts of pulps are given in Table 1 and Table 2. Ensure that the consumption of permanganate is between 20 % and 60 % (mass/mass) of the amount added (see Reference 11).At the same time, weigh a separate test specimen for determination of the dry matte

45、r content in accordance with ISO 638, or any other method for determination of the dry matter content giving a similar result.Table 1 Suitable amounts of oven-dry pulp in the Kappa number range 5 to 100Kappa number Amount of sample, g5 4,56 4,08 3,010 2,515 1,520 1,225 1,030 0,935 to 45 0,650 to 55

46、0,560 to 70 0,480 to 90 0,3100 0,25Table 2 Suitable amounts of oven-dry pulp in the Kappa number range 1 to 5Kappa number Amount of sample, g1 5,52 to 3 4,04 3,05 2,54 ISO 2015 All rights reservedBS ISO 302:2015ISO 302:2015(E)In order to avoid stirring problems when the Kappa number is low (i.e. fiv

47、e in the Kappa number range 5 to 100, and 1 to 2 in the Kappa number range 1 to 5), the amount of sample must be smaller than the amount corresponding to approximately 50 % of the total oxidation capacity of permanganate. However, the amount of sample should still correspond to at least 20 % of the

48、total oxidation capacity of permanganate.Disintegrate the test specimen in 300 ml of distilled water until it is free from fibre clots and from large fibre bundles. Avoid methods of disintegration which involve extensive cutting of the fibres. Rinse the disintegrator with approximately 90 ml of dist

49、illed water. If a combined disintegration and reaction beaker is used, perform the disintegration in 390 ml of distilled water.Place the beaker in a water bath (6.3) adjusted to maintain a reaction temperature of (25,0 0,2) C during the entire reaction.NOTE A constant temperature bath must be used in order to perform this test under standardized conditions. It is recognized, however, that a constant temperature bath may not be available, or a constant temperature may be difficult to maintain, as may be the