BS ISO 3260-2015 Pulps Determination of chlorine consumption (Degree of delignification)《纸浆 耗氯量的测定 (脱木素程度)》.pdf

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1、BSI Standards PublicationBS ISO 3260:2015Pulps Determination ofchlorine consumption (Degreeof delignification)BS ISO 3260:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 3260:2015.The UK participation in its preparation was entrusted to TechnicalCommittee

2、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 British St

3、andards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 86894 8ICS 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 30 April 2015.Amend

4、ments issued since publicationDate Text affectedBS ISO 3260:2015 ISO 2015Pulps Determination of chlorine consumption (Degree of delignification)Ptes Dtermination de la consommation en chlore (Degr de dlignification)INTERNATIONAL STANDARDISO3260Third edition2015-04-01Reference numberISO 3260:2015(E)B

5、S ISO 3260:2015ISO 3260:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015All 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 po

6、sting on the internet or an intranet, without 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 officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrigh

7、tiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 3260:2015ISO 3260:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Reagents 16 Apparatus . 27 Preparation of sample 38 Procedure. 38.1 Test portion 38.2 Determination . 49 Expression of

8、results 410 Test report . 5Bibliography 6 ISO 2015 All rights reserved iiiContents PageBS ISO 3260:2015ISO 3260:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Stan

9、dards is normally carried out through 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 t

10、ake part in the work. ISO collaborates 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 p

11、articular the different approval 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 o

12、f this document may be the subject 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

13、 www.iso.org/patents).Any trade 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

14、 the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information .The committee responsible for this document is ISO/TC 6, Paper, board and pulps.This third edition cancels and replaces the second edition (ISO 3260:1982), of which it constitutes

15、 a minor revision.iv ISO 2015 All rights reservedBS ISO 3260:2015ISO 3260:2015(E)IntroductionThe method specified in this International Standard for determining the degree of delignification of pulp by measuring its chlorine consumption under specified conditions is related to that for determining t

16、he degree of delignification of pulp by measuring its potassium permanganate consumption under specified conditions, given in ISO 302, Pulps Determination of Kappa number. Unlike that method, the method for the determination of chlorine consumption has the merit of not being restricted to pulps obta

17、ined in yields under 60 %.It has been shown experimentally that there is a linear relationship between the chlorine consumption and the total lignin content of pulp. This relationship is independent of the method used in the manufacture of the pulp. ISO 2015 All rights reserved vBS ISO 3260:2015BS I

18、SO 3260:2015Pulps Determination of chlorine consumption (Degree of delignification)WARNING The method specified in this International Standard involves the use of hazardous chemicals. Appropriate precautions must be taken to ensure the proper use and disposal of these chemicals.1 ScopeThis Internati

19、onal Standard specifies a method for the determination of the degree of delignification of pulp by measuring its chlorine consumption.This method is applicable to all kinds of pulp.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For da

20、ted references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 638, Paper, board and pulps Determination of dry matter content Oven-drying method3 Terms and definitionsFor the purposes of this document, the

21、 following terms and definitions apply.3.1chlorine consumption of a pulpamount of active chlorine consumed by a pulp under the conditions specified in this International StandardNote 1 to entry: The chlorine consumption of a pulp is expressed as a percentage by mass.4 PrincipleTreatment of a test po

22、rtion of pulp for 15 min, at room temperature of 25 C 1 C, with chlorine generated by acidification of a sodium hypochlorite solution.Determination of the residual chlorine, which shall be more than 50 % of the amount added (see the note in Clause 9), by iodometric titration. Correction of the chlor

23、ine consumption so obtained to the consumption at constant concentration of available chlorine.5 Reagents5.1 Sodium hypochlorite (NaClO), solution containing about 20 g of active chlorine per litre and of total alkalinity corresponding to a pH of 12,0 0,5, measured with a glass electrode.5.2 Hydroch

24、loric acid, 4 mol/l solution, obtained by adding 100 ml of hydrochloric acid (HCl), = 1,19 g/ml, to 200 ml of water.5.3 Potassium iodide, 1 mol/l solution, containing 166 g of potassium iodide (KI) per litre.INTERNATIONAL STANDARD ISO 3260:2015(E) ISO 2015 All rights reserved 1BS ISO 3260:2015ISO 32

25、60:2015(E)5.4 Sodium thiosulfate, standard volumetric solution, (Na2S2O3) = 0,2 mol/l. The concentration shall be known to 0,000 4 mol/l.5.5 Starch, 2 g/l indicator solution.6 ApparatusOrdinary laboratory apparatus, and6.1 High-speed wet disintegration apparatus, for example a kitchen mixer or simil

26、ar apparatus which disintegrates the pulp completely with a minimum of damage to the fibres.6.2 Apparatus for the determination of chlorine consumption, as shown in Figure 1, consisting of the following.6.2.1 Thick-walled conical flask (D), of capacity 750 ml, with a standard ground joint (C).6.2.2

27、Separating funnel (E), of capacity 50 ml to 100 ml, with standard ground joints (B and C) and a glass stopper (A).6.3 Motor-driven coated magnetic stirrer, providing efficient stirring when the magnet and the motor table are approximately 40 mm apart.6.4 Water bath, capable of maintaining a temperat

28、ure of 25 C 1 C for at least 20 min and provided with a support for the flask.6.5 Vacuum-pump.6.6 Stop-watch.2 ISO 2015 All rights reservedBS ISO 3260:2015ISO 3260:2015(E)Figure 1 Apparatus for determination of the chlorine consumption of pulp7 Preparation of sample7.1 Air-dried pulp sheets.Tear 3 g

29、 to 10 g of pulp into small pieces.7.2 Screened slush pulps.Make a 3 g to 10 g air-dry pad by filtering on a Bchner funnel, avoiding any loss of fibres. Air-dry the pad and tear it into small pieces.7.3 Unscreened pulps.If the pulp sample is taken from unscreened pulp, which is normally screened bef

30、ore bleaching or other processing, then the shives and knots shall be removed from the sample by screening. The method of screening shall be stated in the test report and shall be chosen to give results similar to those obtained by the industrial screening of the pulp. Complete the preparation of th

31、e screened pulps as described in 7.2.8 Procedure8.1 Test portionBefore weighing the test portions, condition the samples for not less than 20 min in the atmosphere near the balance.Weigh 500 mg 5 mg of the pulp. At the same time, weigh a separate test portion for the determination of the dry matter

32、content in accordance with ISO 638. ISO 2015 All rights reserved 3BS ISO 3260:2015ISO 3260:2015(E)8.2 DeterminationDisintegrate the test portion in the disintegrator (6.1) in 250 ml of water at 25 C to 26 C until free from fibre clots and large bundles. Transfer the disintegrated test portion to the

33、 reaction flask (6.2.1) using 135 ml of water to rinse the disintegrator. Place the flask on the support in the water bath (6.4) and start the stirrer (6.3).Connect the separating funnel (6.2.2) and evacuate the flask by means of the vacuum-pump (6.5). Close the stop-cock of the funnel, remove the s

34、topper and place 10 ml of the hydrochloric acid solution (5.2) in the funnel.Suck down the acid without admitting air and simultaneously start the stop-watch (6.6). Rinse the funnel with 10 ml of water and suck it down. Pipette 15,0 ml of the sodium hypochlorite solution (5.1) into the funnel and su

35、ck it down after exactly 2 min. Do not stop the watch at this stage. Rinse the funnel with 5 ml of water and suck it down.Add 20 ml of the potassium iodide solution (5.3) to the funnel and suck it down exactly 17 min after adding the hydrochloric acid solution. Rinse the funnel with 50 ml of water,

36、suck it down, and shake the flask to dissolve gaseous chlorine. Add 50 ml of water to the funnel and suck it down; leave the stop-cock open and remove the funnel. Titrate with the sodium thiosulfate solution (5.4) using the starch solution (5.5) as indicator. Record the consumption as V1ml.Perform a

37、 blank test using the same procedure and record the consumption as V2ml.For pulps with very low chlorine consumptions, use a smaller volume of sodium hypochlorite solution (5.1) and increase the volume of water in proportion. Carry out the blank test with the same volumes of sodium hypochlorite and

38、water. For titrations, use a standard volumetric sodium thiosulfate solution of lower concentration than that stated in 5.4.Carry out two determinations.9 Expression of results9.1 Calculate the fraction r of added chlorine not consumed in the determination by means of the Formula (1):rVV=12(1)whereV

39、1is the volume, in millilitres, of standard volumetric sodium thiosulfate solution (5.4) con-sumed in the titration of the test portion;V2is the volume, in millilitres, of standard volumetric sodium thiosulfate solution (5.4) con-sumed in the titration in the blank test.If r is less than 0,5, repeat

40、 the determination with a smaller test portion. If r is greater than 0,5, obtain the correction factor f from Table 1.Table 1 Factor f for correction of the chlorine consumptionr 0,00 0,01 0,02 0,03 0,04 0,05 0,06 0,07 0,08 0,090,5 1,193 1,187 1,181 1,175 1,170 1,164 1,159 1,154 1,148 1,1430,6 1,139

41、 1,134 1,129 1,124 1,120 1,115 1,111 1,107 1,103 1,0980,7 1,094 1,091 1,087 1,083 1,079 1,075 1,072 1,068 1,065 1,0610,8 1,058 1,055 1,051 1,048 1,045 1,042 1,039 1,036 1,033 1,0304 ISO 2015 All rights reservedBS ISO 3260:2015ISO 3260:2015(E)r 0,00 0,01 0,02 0,03 0,04 0,05 0,06 0,07 0,08 0,090,9 1,0

42、27 1,024 1,021 1,018 1,016 1,013 1,010 1,008 1,005 1,0039.2 The chlorine consumption X, expressed as a percentage by mass, is given by the Formula (2):XfV Vcm=3 54621,( )(2)wherec is the concentration, in moles per litre, of the standard volumetric sodium thiosulfate solution;m is the mass, in grams

43、, of the test portion, calculated on an oven-dry basis.NOTE For calculating the chlorine consumption X, the expressionfVVVVV=+12122121lnhas been used. It has been derived on the basis of certain assumptions that are generally accepted in the theory of pulp chlorination. It has been proved experiment

44、ally and is valid only if r is greater than 0,5.Report the result as the mean of the two determinations to three significant figures.10 Test reportThe test report shall include the following particulars:a) all the information necessary for the complete identification of the sample;b) a reference to

45、this International Standard, i.e. ISO 3260;c) the results and the form in which they are expressed;d) in the case of unscreened pulp (7.3), the method of screening;e) any unusual features noted during the determination;f) any operations not specified in the International Standard, or regarded as opt

46、ional, which might have affected the results.Table 1 (continued) ISO 2015 All rights reserved 5BS ISO 3260:2015ISO 3260:2015(E)Bibliography1 Kyrklund B., & Strandell G. Paperi ja Puu Papper och Tr (Paper and Timber) 49 (1968):3,992 Kyrklund B., & Strandell G. Paperi ja Puu Papper och Tr (Paper and T

47、imber) 51 (1969):4a,2996 ISO 2015 All rights reservedBS ISO 3260:2015BS ISO 3260:2015ISO 3260:2015(E) ISO 2015 All rights reservedICS 85.040Price based on 6 pagesThis page deliberately left blankBSI is the national body responsible for preparing British Standards and other standards-related publicat

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