項(xiàng)目六：鋼鐵分析任務(wù)二：鋼鐵中碳的測(cè)定燃燒-氣體容量法測(cè)定鋼鐵中碳課程：工業(yè)分析中文Scenario6:SteelanalysisTask2:DeterminationofcarboninsteelDeterminationofcarboninsteelbycombustiongasvolumetricmethodCourse:IndustrialAnalysisEglish1、方法原理試樣在1200～1300℃的高溫O2氣流中燃燒，鋼鐵中的碳被氧化生成CO2:C+O2=CO24Fe3C+13O2=4CO2+6Fe2O3

Mn3C+3O2=CO2+Mn3O3FeS+5O2=Fe3O4+3SO23MnS+5O2=Mn3O4+3SO2中文1、Methodprinciple

ThesampleburnsinanO2airflowathightemperaturesrangingfrom1200to1300℃,andthecarboninthesteelisoxidizedtoproduceCO2:C+O2=CO24Fe3C+13O2=4CO2+6Fe2O3

Mn3C+3O2=CO2+Mn3O3FeS+5O2=Fe3O4+3SO23MnS+5O2=Mn3O4+3SO2Eglish生成的CO2與過剩的O2經(jīng)導(dǎo)管引入量氣管，測(cè)定容積，然后通過裝有KOH溶液的吸收器，吸收其中的CO2CO2十2KOH=K2CO3十H2O剩余的O2再返回量氣管中，根據(jù)吸收前后容積之差，得到CO2的容積，據(jù)此計(jì)算出試樣中碳的質(zhì)量分?jǐn)?shù)。中文

First,introducethegeneratedmixtureofCO2andexcessO2intothevolumetrictube,measurethevolumeofthemixture,andthenintroducethemixtureintoanabsorbercontainingKOHsolutiontoabsorbtheCO2inside:

CO2+2KOH=K2CO3+H2O

TheremainingO2isreturnedtothemeasuringtube,andbasedonthedifferenceinvolumebeforeandafterabsorption,thevolumeofCO2isobtained.Basedonthis,themassfractionofcarboninthesampleiscalculated.Eglish圖

氣體容量法定碳裝置1-氧氣瓶，2-氧氣表，3-緩沖瓶，4、5-洗氣瓶，6-干燥塔，7-玻璃磨口塞，8-管式爐，9-燃燒管，10-除硫管，11-容量定碳儀(包括:冷凝管a、量氣管b、水準(zhǔn)瓶c、吸收瓶d、小旋塞e、三通旋塞f），l2-球形干燥管，13-瓷舟，14-溫度自動(dòng)控制器，15-供氧旋塞2、測(cè)定儀器中文2、measuringinstrumentGasCapacityCarbonizationDevice1-Oxygencylinder,2-Oxygenmeter,3-Buffercylinder,4,5-Washingcylinder,6-Dryingtower,7-Glassgrindingplug,8-Tubefurnace,9-Combustiontube,10-Sulfurremovaltube,11-Capacitycarbonanalyzer(includingcondensertubea,measuringtubeb,levelbottlec,absorptionbottled,smallcocke,three-waycockf),12-Sphericaldryingtube,13-Porcelainboat,14-Temperatureautomaticcontroller,15-OxygensupplycockEglish3、測(cè)定試劑氫氧化鉀吸收劑溶液（400g/L）；除硫劑活性二氧化錳（粒狀）或釩酸銀；酸性氯化鈉溶液（250g/L）；助熔劑：錫粒（或錫片）、銅、氧化銅、純鐵粉；高錳酸鉀溶液（40g/L）；甲基橙指示劑（2g/L）。中文3、TestingreagentsPotassiumhydroxideabsorbentsolution(400g/L);Sulfurremovalagent:activemanganesedioxide(granular)orsilvervanadate;Acidicsodiumchloridesolution(250g/L);Fluxes:tinparticles(ortinsheets),copper,copperoxide,pureironpowder;Potassiumpermanganatesolution(40g/L);Methylorangeindicator(2g/L).Eglish4、測(cè)定步驟將爐溫升至1200～1350℃，檢查管路及活塞是否漏氣，裝置是否正常，燃燒標(biāo)準(zhǔn)樣品，檢查儀器及操作。稱取適量試樣置于瓷舟中，將適量助熔劑覆蓋于試樣上面，打開玻璃磨口塞，將瓷舟放入瓷管內(nèi)，用長(zhǎng)鉤推至高溫處，立即塞緊磨口塞。預(yù)熱lmin，按照定碳儀操作規(guī)程操作，測(cè)定其讀數(shù)(體積或含量)。打開磨口塞，用長(zhǎng)鉤將瓷舟拉出，即可進(jìn)行下一試樣分析。中文4、Measurementsteps

Raisethefurnacetemperatureto1200-1350℃,checkforleaksinthepipelinesandpistons,ensurethedeviceisfunctioningproperly,burnstandardsamples,andinspectinstrumentsandoperations.

Weighanappropriateamountofsampleandplaceitinaporcelainboat.Coverthesamplewithanappropriateamountofflux,opentheglassgrindingplug,placetheporcelainboatintotheporcelaintube,usealonghooktopushittoahightemperature,andimmediatelytightenthegrindingplug.Preheatforlmin,followtheoperatingproceduresofthecarbonanalyzer,andmeasureitsreading(volumeorcontent).Openthegrindingplugandpullouttheporcelainboatwithalonghooktoproceedwiththenextsampleanalysis.Eglish5、測(cè)定注意事項(xiàng)助熔劑中含碳量一般不超過0.005%樣品的放置要均勻地鋪在燃燒舟中定碳儀應(yīng)裝置在室溫較正常的地方(距離高溫爐約300～500mm)更換水準(zhǔn)瓶所盛溶液、玻璃棉、除硫劑、氫氧化鉀溶液后，均應(yīng)作幾次高碳試樣，使二氧化碳飽和后，才可進(jìn)行試樣測(cè)定。中文5、MeasurementprecautionsThecarboncontentinthefluxgenerallydoesnotexceed0.005%ThesampleshouldbeplacedevenlyinthecombustionboatThecarbonanalyzershouldbeinstalledinaplacewithrelativelynormalroomtemperature(about300-500mmawayfromthehigh-temperaturefurnace)Afterreplacingthesolution

inthelevelingbottle,glasswool,sulfurremovalagent,andpotassiumhydroxidesolution,severalhighcarbonsamplecombustionshouldbecarriedouttosaturatecarbondioxideinthesesubstancesbeforesampledeterminationcanbecarriedout.Eglish對(duì)測(cè)定含硫量較高的試樣(大于0.2%)，應(yīng)增加除硫劑量或增加一個(gè)除硫管。吸收器、水準(zhǔn)瓶?jī)?nèi)溶液以及混合氣體三者的溫度應(yīng)基本相同，否則將產(chǎn)生正負(fù)空白值。如分析完高碳試樣后，應(yīng)空燒一次，才可以接著做低碳試樣分析。當(dāng)洗氣瓶中硫酸體積顯著增加及二氧化錳變白時(shí)，說明已失效，應(yīng)及時(shí)更換。觀察試樣是否完全燃燒，如燃燒不完全，需重新分析。中文Forsampleswithhighsulfurcontent(greaterthan0.2%),thesulfurremovaldoseshouldbeincreasedorasulfurremovaltubeshouldbeadded.Thetemperatureoftheabsorber,thesolutioninthelevelbottle,andthemixedgasshouldbebasicallythesame,otherwisepositiveandnegativeblankvalueswillbegenerated.Afteranalyzingthehighcarbonsample,itshouldbeburnedoncebeforeproceedingwiththeanalysisofthelowcarbonsample.Whenthevolumeofsulfuricacidinthegascylindersignificantlyincreasesandmanganesedioxideturnswhite,itindicatesthatithasfailedandshouldbereplacedinatimelymanner.Observewhetherthesampleiscompletelyburned.Ifthecombustionisincomplete,reanalysisisrequired.Eglish爐子升溫應(yīng)開始慢，逐步加速，以延長(zhǎng)硅碳棒壽命。分析前，應(yīng)先檢查儀器各部分是否漏氣。工作開始前及工作中，均應(yīng)燃燒標(biāo)準(zhǔn)樣品，判定工作過程中儀器的準(zhǔn)確性。吸收前后觀察刻度的時(shí)間應(yīng)一致。吸收后觀察刻度時(shí)，量氣管及水準(zhǔn)瓶?jī)?nèi)液面與視線應(yīng)處在同一水平線上。吸收器中氫氧化鉀溶液使用久后也應(yīng)進(jìn)行更換，一般在分析2000次后更換，否則吸收效率降低，使測(cè)定結(jié)果偏低。測(cè)定中應(yīng)記錄溫度與大氣壓力，以確定補(bǔ)正系數(shù)f。如附錄八所示。中文Theheatingofthefurnaceshouldstartslowlyandthengraduallyacceleratetoextendthelifespanofthesiliconcarbiderod.Beforeanalysis,eachpartoftheinstrumentshouldbecheckedforairleakage.Beforeandduringwork,standardsamplesshouldbeburnedtodeterminetheaccuracyoftheinstrumentsusedduringtheworkprocess.Whenobservingthescaleafterabsorption,theliquidlevelinthemeasuringtubeandlevelbottleshouldbeonthesamehorizontalline.T