1、May 2016 English price group 7No 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).ICS 85.040!%SM“2484229www.din.deDIN ISO 3
2、260Pulps Determination of chlorine consumption (Degree of delignification) (ISO 3260:2015),English translation of DIN ISO 3260:2016-05Zellstoff Bestimmung des Chlorverbrauchs (Delignifizierungsgrad) (ISO 3260:2015),Englische bersetzung von DIN ISO 3260:2016-05Ptes Dtermination de la consommation en
3、chlore (Degr de dlignification) (ISO 3260:2015),Traduction anglaise de DIN ISO 3260:2016-05SupersedesDIN ISO 3260:1986-01www.beuth.deDocument comprises 10 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.04.16 A comma is used as
4、 the decimal marker. National foreword 3Contents PageNational Annex (infomative) Bibliography .3Introduction 41 Scope . 52 Normative references 53 Terms and definitions . 54 Principle 55 Reagents 56 Apparatus . 67 Preparation of sample 78 Procedure. 78.1 Test portion 78.2 Determination . 89 Expressi
5、on of results 810 Test report . 9Bibliography . 10DIN ISO 3260:2016-05 2 National foreword This document (ISO 3260:2015) has been prepared by Technical Committee ISO/TC 6 “Paper, board and pulps” (Secretariat: SCC, Canada). The responsible German body involved in its preparation was DIN-Normenaussch
6、uss Papier, Pappe und Faserstoff (DIN Standards Committee Paper, Board and Pulps), Working Committee NA 074-02-01 AA Chemisch-technische Prfverfahren fr Papier, Pappe, Faserstoff und Chemiezellstoff. Attention is drawn to the possibility that some of the elements of this document may be the subject
7、of patent rights. DIN and/or DKE shall not be held responsible for identifying any or all such patent rights. The DIN Standard corresponding to the International Standard referred to in this document is as follows: ISO 638 DIN EN ISO 638 Amendments This standard differs from DIN ISO 3260:1986-01 as
8、follows: a) a warning regarding the use of hazardous chemicals and precautions to be taken has been added; b) the standard has been editorially revised. Previous editions DIN 54353: 1976-01 DIN ISO 3260: 1986-01 National Annex NA (informative) Bibliography DIN EN ISO 638, Paper, board and pulps Dete
9、rmination of dry matter content Oven-drying method DIN ISO 3260:2016-05 3 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 the degr
10、ee 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 obtained in
11、 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.DIN ISO 3260:2016-05 4 Pulps Determination of chlorine con
12、sumption (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 International Standard specifies a method for the determ
13、ination 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 dated references, only the edition cited applies.
14、 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 following terms and definitions apply.3.1chlor
15、ine 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 portion of pulp for 15 min, at room temperature o
16、f 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 chlorine consumption so obtained to the consumption
17、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 Hydrochloric acid, 4 mol/l solution, obtained by addin
18、g 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.DIN ISO 3260:2016-05 5 5.4 Sodium thiosulfate, standard volumetric solution, (Na2S2O3) = 0,2 mol/l. The concentration shall be known to 0,0
19、00 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 similar apparatus which disintegrates the pulp completely with a minimum of damage to the fibres.6.2 Apparatus for the determinatio
20、n 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 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-dr
21、iven 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 temperature 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.DIN ISO 3260:2016
22、-05 6 Figure 1 Apparatus for determination of the chlorine consumption of pulp7 Preparation of sample7.1 Air-dried pulp sheets.Tear 3 g 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
23、pad and tear it into small pieces.7.3 Unscreened pulps.If the pulp sample is taken from unscreened pulp, which is normally screened before 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 repor
24、t and shall be chosen to give results similar to those obtained by the industrial screening of the pulp. Complete the preparation of the 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 n
25、ear 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 content in accordance with ISO 638.DIN ISO 3260:2016-05 7 8.2 DeterminationDisintegrate the test portion in the disintegrator (6.1) in 250 ml of water at 25 C to 26
26、C until free from fibre clots and large bundles. Transfer the disintegrated test portion to the 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 evacua
27、te the flask by means of the vacuum-pump (6.5). Close the stop-cock of the funnel, remove the stopper 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
28、 suck it down. Pipette 15,0 ml of the sodium hypochlorite solution (5.1) into the funnel and suck 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 exa
29、ctly 17 min after adding the hydrochloric acid solution. Rinse the funnel with 50 ml of water, 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 soluti
30、on (5.4) using the starch solution (5.5) as indicator. Record the consumption as V1ml.Perform a 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
31、water in proportion. Carry out the blank test with the same volumes of sodium hypochlorite and 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
32、of added chlorine not consumed in the determination by means of the Formula (1):rVV=12(1)whereV1is 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 thiosu
33、lfate solution (5.4) con-sumed in the titration in the blank test.If r is less than 0,5, repeat 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
34、,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 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 1,030DIN ISO 3260:2016-05 8 r
35、0,00 0,01 0,02 0,03 0,04 0,05 0,06 0,07 0,08 0,090,9 1,027 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 volume
36、tric sodium thiosulfate solution;m is the mass, in grams, 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 th
37、eory of pulp chlorination. It has been proved experimentally 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
38、complete identification of the sample;b) a reference to 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 spe
39、cified in the International Standard, or regarded as optional, which might have affected the results.Table 1 (continued)DIN ISO 3260:2016-05 9 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 Timber) 51 (1969):4a,299DIN ISO 3260:2016-05 10
