1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 6043-1.13:2000 ISO 102
2、38:1999 ICS 71.100.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Methods of sampling and test for carbonaceous materials used in aluminium manufacture Part 1: Electrode pitch Section 1.13: Determination of sulfur contentThis British Standard, having been prepared under th
3、e direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 March 2000 BSI 03-2000 ISBN 0 580 34511 4 BS 6043-1.13:2000 Amendments issued since publication Amd. No. Date Comments National foreword This Brit
4、ish Standard reproduces ISO 10238:1999 and implements it as the UK national standard. It supersedes BS 6043-1.13:1994 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee CII/24, Raw materials for the aluminium industry, which has the responsibility to: ai
5、d enquirers to understand the text; present to the responsible international/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. A list of organizat
6、ions represented on this committee can be obtained on request to its secretary. Cross-references 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 C
7、orrespondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. 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 doe
8、s not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii and iii, a blank page, pages 1 to 6, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicate
9、s when the document was last issued.Referencenumber ISO10238:1999(E) INTERNATIONAL STANDARD ISO 10238 Firstedition 1999-12-15 Carbonaceousmaterialsusedinthe productionofaluminiumPitchfor electrodesDeterminationofsulfur contentbyaninstrumentalmethod Produits carbons utiliss pour la production de lalu
10、minium Brai pour lectrodes Dosage du soufre par une mthode instrumentale BS 6043-1.13:2000ii BS 6043-1.13:2000 iii Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO memberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedou
11、tthroughISOtechnical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnon-governmental,in liaisonwithISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalElect
12、rotechnical Commission(IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtothememberbodiesforvoting. PublicationasanInternationalStandard
13、requiresapprovalbyatleast75%ofthememberbodiescastingavote. AttentionisdrawntothepossibilitythatsomeoftheelementsofthisInternationalStandardmaybethesubjectof patentrights.ISOshallnotbeheldresponsibleforidentifyinganyorallsuchpatentrights. InternationalStandardISO10238waspreparedbyTechnicalCommitteeIS
14、O/TC47, Chemistry, Subcommittee SC7, Aluminium oxide, cryolite, aluminium fluoride, sodium fluoride, carbonaceous products for the aluminium industry. BS 6043-1.13:2000BS 6043-1.13:2000INTENRATIONALTSADNADR ISO1:8320(9991)E1 Carbonaceousmaterialsusedintheproductionofaluminium PitchforelectrodesDeter
15、minationofsulfurcontentbyan instrumentalmethod 1 Scope ThisInternationalStandarddescribesamethodfordeterminingthesulfurcontentofpitchusedintheproductionof aluminium.Themethodisapplicabletopitchesofbothcoaltarandpetroleumorigin,providedthattheycontain between0,1%and4,0%bymassofsulfur. 2 Normativerefe
16、rences Thefollowingnormativedocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsof thisInternationalStandard.Fordatedreferences,subsequentamendmentsto,orrevisionsof,anyofthese publicationsdonotapply.However,partiestoagreementsbasedonthisInternationalStandardareencouragedto
17、 investigatethepossibilityofapplyingthemostrecenteditionsofthenormativedocumentsindicatedbelow.For undatedreferences,thelatesteditionofthenormativedocumentreferredtoapplies.MembersofISOandIEC maintainregistersofcurrentlyvalidInternationalStandards. ISO565, Test sieves Metal wire cloth, perforated me
18、tal plate and electroformed sheet Nominal sizes of openings. ISO3696, Water for analytical laboratory use Specification and test methods. ISO4793, Laboratory sintered (fritted) filters Porosity grading, classification and designation. ISO6257, Carbonaceous materials used in the production of alumini
19、um Pitch for electrodes Sampling. 3 Principle Aknownmassofthesampleisburnedinastreamofoxygenatatemperatureof1350C.Theoxidesofsulfur formed,togetherwithanychlorinepresent,areabsorbedinneutralhydrogenperoxideanddetermined volumetrically.Acorrectionismadetotakeaccountofthechlorinecontentofthesample.Alu
20、miniumoxideisadded tothesampletopreventtheretentionofsulfurintheash. 4 Reagents Unlessotherwisespecified,usereagentsofanalyticalreagentgradeandwaterconformingtograde3ofISO3696. 4.1 Disodiumtetraboratesolution,c(Na 2 B 4 O 7 10H 2 O)=0,025mol/l. 4.2 Sulfuricacidsolution,c(H 2 SO 4 )=0,025mol/l. 4.3 H
21、ydrogenperoxidesolution,consistingof3%byvolumeofH 2 0 2 and97%byvolumeofwater,neutralized withthedisodiumtetraboratesolution(4.1)tothescreenedindicator(4.4). BS 6043-1.13:2000ISO:83201(9991)E 2 4.4 Screenedindicator,consistingofequalvolumesofa)andb)preparedasfollowsandmixedimmediately beforeuse: a)
22、0,125gofmethylreddissolvedin100mlof95%byvolumeethanolsolution; b) 0,083gofmethylenebluedissolvedin100mlof95%byvolumeethanolsolution. Storeinadarkglassbottle. 4.5 Mercury(II)oxycyanidesolution,consistingofapproximately100mlofwatersaturatedwithmercury(II) oxycyanide(3Hg(CN) 2 HgO). Agitatethoroughly,f
23、ilterandneutralizethefiltratewiththesulfuricacidsolution(4.2)tothescreenedindicator.Store thesolutioninadarkglassbottle.Donotkeeplongerthan4days. WARNINGThiscompoundanditssolutionaretoxicandshouldbehandledwithappropriatecare. 4.6 Aluminiumoxide,finelydivided,particlesizeapproximately0,1mm. 4.7 Oxyge
24、n. 4.8 Sodiumhydroxideonaninertbase,preferablyofcoarsegrading,forexample1,7mmto1,2mm,and preferablyoftheself-indicatingtype. 5 Apparatus Ordinarylaboratoryapparatusandthefollowing. 5.1 Combustionfurnaceandabsorptiontrain,asshowninFigure1,andconsistingofthefollowing. 5.1.1 Furnace,electricallyheated,
25、designedtocarryatubeof28,5mmoutsidediameterandtoheatitovera lengthofabout125mmtogiveatemperatureof1350Catthecentreofthehotzoneandatemperature distributioncurvesimilartothatshowninFigure2. 5.1.2 Combustiontube,of22mminternaldiameterand28,5mmoutsidediameterand0,65mlong,madeof refractoryaluminousporcel
26、ainthatisnotpermeabletogasesat1400C. 5.1.3 Combustionboat,ofiron-freeunglazedporcelain,70mmlong,12,5mmwideand10mmdeep,thatdoes notblister,discolourorchangeinmassonheatingat1350Cinoxygenfor3h. 5.1.4 Silicapusher,comprisingasealedtubeorrodofsilica,6mmindiameterandapproximately450mmlong, flattenedatone
27、endtoformadiscof12mmdiameterforpushingthecombustionboatintothefurnace. ThepusherpasseslooselythroughaglassormetalT-piece,oneendofwhichfitsintotherubberstopperthat closestheinletendofthecombustiontube,theotherbeingsealedwitharubbersleevethroughwhichthepusher slides(seeFigure1).Oxygenisadmittedthrough
28、thelimboftheT-piece. Thepusherismarkedinmillimetresfromthediscendforconvenienceinmeasuringhowfarthecombustionboatis pushedintothecombustiontube. 5.1.5 Hook,comprisingalengthofstiffnickelchromiumwirewithahookedend,toextractthecombustionboat fromthefurnaceontoapieceofrefractorytile. 5.1.6 Flowmeter,ca
29、pableofmeasuringratesofflowofoxygenofupto300ml/min. 5.1.7 Pressuregauge,tomeasurethebackpressureonthesystem,normally0,5kPato0,7kPa. BS 6043-1.13:2000ISO:83201(9991)E3 5.1.8 Heat-resistantstopper,ofacrylonitrileorchloroprenerubber,forattachingtheabsorptiontraintothe combustiontube. 5.1.9 Silicaadapte
30、r,comprisingatranslucentsilicatube,10mmoutsidediameterandapproximately250mm long,terminatingatoneendinafunnelof20mmoutsidediameter. 5.1.10Purificationtrain,comprisingatowercontainingsodiumhydroxideonaninertbase(see4.8)forremoving anyoxidesofsulfurfromtheoxygensupply. Key 1 Tovacuumpump 2 Heat-resist
31、antstopper 3 Silicaadapter 4 Furnace 5 Combustionboat 6 Combustiontube 7 Rubbersleeve 8 Silicapusher 9 Oxygeninlet 10Tubesupport 11Thermocouple 12Hydrogenperoxidesolution 1315 mto40 mporositygradeP40sintereddisc 14Gaswashingbottle 15Mercury Figure1Absorptiontrainandfurnace BS 6043-1.13:2000ISO:83201
32、(9991)E 4 Figure2Temperaturedistributioncurve 5.1.11Absorptionvessel,comprisingagaswashingtubeorbottlewithasintereddiscofporositygradeP40 conformingtotherequirementsofISO4793,ofsuchasizethata90mmsealofliquidisobtainedwith100mlof liquidinthevessel. 5.1.12Pressureregulator,comprisingabottlecontainingm
33、ercury,fittedwithinletandoutlettubesandathird tubecapableofbeingmovedupordowntoregulatethesuctiononthesystem. 5.1.13Vacuumpump,orothersuitablepump. 6 Preparationofapparatus Insertthecombustiontube(5.1.2)intothefurnace(5.1.1)sothatitprojects100mmattheexitend.Insertatthis endtheheat-resistantstopper(5
34、.1.8)carryingthesilicaadapter(5.1.9)andadjustthelattersothattheopenendof thefunnelisapproximately150mmintothecombustiontube.Inserttherubberstoppercarryingthesilicapusher (5.1.4)attheinletendofthecombustiontubeandconnecttheoxygensupplythroughthepurificationtrain(5.1.10) tothelimboftheT-piece. 7 Sampl
35、ingandpreparationofthetestsample 7.1 Sampling SamplethepitchinaccordancewithISO6257. 7.2 Preparationoftestsample Preparethetestsampleimmediatelybeforethedetermination. Inthecaseofhardpitches,grindthesamplesothatitpassesthroughasieveofnominalaperturesize212 m usingasieveconformingtotherequirementsofI
36、SO565. BS 6043-1.13:2000ISO:83201(9991)E5 Ifthepitchistoosoftforgrinding,meltandmixthesampleinacoveredvesselensuringthatitstemperaturedoes notexceed150Candthatthemeltingperioddoesnotexceed10min. Takethematerialforthetestportionfromthemoltensample. 8 Procedure Raisethetemperatureofthefurnace(5.1.1)to
37、1350Candpasstheoxygen(4.7)throughthecombustiontube (5.1.2).Weighabout0,5gofthetestsample(7.2)tothenearest0,1mg,spreaduniformlyinthecombustionboat (5.1.3)andcoverwith0,5gofthealuminiumoxide(4.6).Measure100mlofthehydrogenperoxidesolution(4.3)to thenearest1mlintotheabsorptionvessel(5.1.11)andassembleth
38、eapparatus.Adjusttherateofgasflowby meansofthevacuumpump(5.1.13)andthedepthofsealinthepressureregulator(5.1.12)tomaintainaslight suctioninthecombustiontubewithoxygenenteringat300ml/minasshownontheflowmeter(5.1.6). Removetherubberstoppercarryingthesilicapusherandinsertthechargedcombustionboatintothec
39、ombustion tubetoapositionsuchthatitscentreis240mmfromthecentreofthehottestzone.Withthesilicapusherfully withdrawn,replacetherubberstopperandcontinuetopassoxygenat300ml/min.Attheendofeachofthenext12 one-minuteperiods,pushthecombustionboatforward20mm,withdrawingthesilicapushereachtime,if necessary,top
40、reventitsdistortion.Allowthecombustionboattoremaininthehottestzoneforafurther4min. Alternatively,continuousmechanicalpushingofthecombustionboatmaybeusedprovidedthattheheating schedulespecifiedismaintained.Disconnecttheabsorptionvesselandremovethesilicaadapter.Withdrawthe combustionboatontoarefractor
41、ytileusingthehook(5.1.5). NOTE1 Ifthesamplecombuststooquicklyforthegasestobeabsorbedbythewasherbottle,thecombustionboatshould bepushedforward10mmattheendofeachof24one-minuteperiods. Washthesilicaadapterwithwater,collectingthewashingsina250mlflask.Transferthecontentsofthe absorptionvesseltotheflask,w
42、ashingthevesselwithwaterandcollectingthewashingsinthesameflask. NOTE2 Thetotalbulkofliquidshouldnotexceed150ml. Addtwoorthreedropsofthescreenedindicator(4.4)andtitratewiththedisodiumtetraboratesolution(4.1),using asuitableburette,totheneutralsteel-greycolour.Add10mlofthemercury(II)oxycyanidesolution
43、(4.5)(sufficient excessforpitchescontainingupto0,5%chlorine)andtitratewiththesulfuricacidsolution(4.2)usingasuitable burettetotheneutralsteel-greycolour. NOTE3 Titrationagainstawhitebackgroundisstronglyrecommended. 9 Determinationoftheblank Carryoutablankdeterminationunderthesameconditionsastheactua
44、ldeterminationbutomittingthesample. 10Calculationofresult Calculatethesulfurcontent,w S ,expressedasapercentagebymassusingtheequation: w m VVVV S 1234 0,0401 bg where m isthemass,ingrams,ofsampletaken; V 1 isthevolume,inmillilitres,ofdisodiumtetraboratesolution(4.1)usedinthedetermination; BS 6043-1.
45、13:2000ISO:83201(9991)E 6 V 2 isthevolume,inmillilitres,ofdisodiumtetraboratesolution(4.1)usedintheblankdetermination; V 3 isthevolume,inmillilitres,ofsulfuricacidsolution(4.2)usedinthedetermination; V 4 isthevolume,inmillilitres,ofsulfuricacidsolution(4.2)usedintheblankdetermination. Reportthevalue
46、ofw S asapercentagebymasstotwosignificantfigures. 11Precision 11.1Repeatability Theresultsofduplicatedeterminations,carriedoutinthesamelaboratorybythesameoperatorwiththesame apparatusbutatdifferenttimesonrepresentativetestportionstakenfromthetestsample,shallnotdifferbymore than0,066%bymass. 11.2Repr
47、oducibility Themeansoftheresultsofduplicatedeterminationscarriedoutineachoftwolaboratoriesonrepresentativetest portionstakenfromthesamesampleafterthelaststageofsamplepreparation,shallnotdifferbymorethan 0,09%bymass. 12Testreport Thetestreportshallincludethefollowinginformation: a)acompleteidentifica
48、tionofthetestsample; c) areferencetothisInternationalStandard,i.e.ISO10238:1999; d) thesulfurcontentofthetestsample,calculatedandexpressedinaccordancewithclause10; e) anyunusualfeaturesnotedduringthedetermination; f) anyoperationnotincludedinthisInternationalStandardorregardedasoptional. BS 6043-1.1
49、3:2000BS 6043-1.13:2000 ISO 10238:1999 BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. I
