《工业分析 Industrial Analysis》课件-煤中全硫的测定（双语）

项目五:煤质分析任务三：煤的元素分析煤中全硫的测定课程：工业分析中文Scenario5:QualityanalysisofcoalsTaskThree:ElementalanalysisofcoalDeterminationoftotalsulfurincoalCourse:IndustrialAnalysisEglish1、硫的存在形式存在形态不同无机硫有机硫可燃性不同可燃硫：有机硫、单质硫、硫铁矿不可燃硫：硫酸盐中文1、TheexistenceformofsulfurDifferentformsofexistenceinorganicsulfurorganicsulfurDifferentflammabilityCombustiblesulfur:organicsulfur,elementalsulfur,pyriteNoncombustiblesulfur:sulfateEglish高温燃烧中和法全硫测定方法库仑法艾士卡法2、测定方法

硫是煤中的有害元素之一，燃料用煤中的硫在煤燃烧过程中形成SO2。SO2不仅腐蚀金属设备，而且还会造成空气污染。炼焦用煤中的硫直接影响钢铁质量，钢铁含硫大于0.07%，就会使钢铁热脆而成为废品，故需测定煤中含硫量。中文HightemperaturecombustionneutralizationmethoddeterminetotalsulfurcoulometryEscarmethod2、Measurementmethod

Sulfurisoneoftheharmfulelementsincoal,andthesulfurincoalusedasfuelformsSO2duringcoalcombustion.SO2notonlycorrodesmetalequipment,butalsocausesairpollution.Thesulfurincokingcoaldirectlyaffectsthequalityofsteel.Ifthesulfurcontentinsteelexceeds0.07%,itwillmakethesteelbrittleandbecomewaste.Therefore,itisnecessarytodeterminethesulfurcontentincoal.Eglish3、硫的测定-艾氏卡法（1）测定原理用艾士卡试剂（Na2CO3和MgO以质量比1+2的混和物）作为熔剂，使煤中硫转变为硫酸盐。方法包括煤样的半熔反应、用水浸取、硫酸钡的沉淀、过滤、洗涤、干燥、灰化和灼烧等过程。中文3、Determinationofsulfur-Escarmethod（1）Measurementprinciple

UsingEscarreagent(amixtureofNa2CO3andMgOinamassratioof1+2)asaflux,convertsulfurincoalintosulfate.

Themethodsincludesemimeltingreactionofcoalsamples,waterextraction,precipitationofbariumsulfate,filtration,washing,drying,ashing,andcalcination.Eglish称取煤样(粒度应小干0.2mm)1g于30mL瓷坩埚中，加艾士卡试剂2g，混匀，置于高温炉中。在2h内从室温升到850℃，在850℃下加热2h，取出冷却到室温。用玻璃棒把熔块搅碎，熔块中应无残炭颗粒。（2）实验操作升温过快，结果偏低中文

Weigh1gofcoalsample(particlesizeshouldbesmallanddry0.2

mm)intoa30mLceramiccrucible,add2

gofEscarreagent,mixwell,andplaceinahigh-temperaturefurnace.Raisethefurnacetemperaturefromroomtemperatureto850℃within2hours,heatat850℃for2hours,removetheporcelaincruciblefromthehigh-temperaturefurnace,andcooltoroomtemperature.Useaglassrodtocrushthemeltingblocksinthecrucible,andthereshouldbenoresidualcarbonparticlesinthemeltingblocks.（2）ExperimentaloperationHeatinguptooquicklywillresultinlowermeasurementresultsEglish熔块转入烧杯注意用水洗坩埚，保证转移完全加100-150mL热水搅拌使熔块溶解，加热煮沸5min过滤滤液用HCl调酸度煮沸后滴加BaCl2溶液所得沉淀放置过夜过滤沉淀，沉淀在850℃灼烧至恒重，称重中文meltingblocktransfertobeakerPayattentiontowashingthecruciblewithwatertoensurecompletetransferAdd100-150mLofhotwaterstirtodissolvethefrit,heatandboilfor5minutesfilteratefiltrateadjustingaciditywithHCladdBaCl2solutiondropwiseafterboilingtheprecipitateobtainedisleftovernightFilterthegeneratedprecipitate,burnitat850℃toaconstantweight,andweighitEglish（3）艾士卡试剂的作用Na2CO3作用：艾士卡试剂中的MgO能疏松反应物，使空气能进入煤样，同时也能与SO2和SO3发生反应。MgO作用：中文（3）ThefunctionofEskareagentTheroleofNa2CO3：TheMgOintheElskarreagentcanloosenthereactants,allowingairtoenterthecoalsampleandalsoreactwithSO2andSO3.TheroleofMgO：coal+airEglish（4）结果计算煤样质量硫酸钡质量空白实验中硫酸钡质量中文（4）resultcalculationThequalityofcoalMassofbariumsulfateThemassofbariumsulfateinblankexperimentsEglish4、硫的测定-高温燃烧中和法煤样氧气流中燃烧SO2用H2O2溶液吸收H2SO4H2SO4用NaOH滴定甲基红-亚甲基蓝指示剂Na2SO4计算依据：中文4、Determinationofsulfur-HightemperaturecombustionneutralizationmethodcoalburninginoxygenflowSO2absorbwithH2O2solutionH2SO4H2SO4titrationwithNaOHmethylred-methyleneblueindicatorNa2SO4calculationbasis：Eglish高温燃烧-H2O2吸收中和法测定煤中全硫量的分析结果与艾士卡法相比，引起偏低的原因是：中文Thereasonforthelowertotalsulfurcontentincoaldeterminedbythehigh-temperaturecombustionH2O2absorptionneutralizationmethodcomparedtotheEscarmethodis:(1)Interferenceofnitrogen-containingorganiccompoundsincoal:coalAmmoniawillconsumesulfuricacidEglish中文(2)Theinfluenceofmoistureincoal:Inpipelines,H2O+SO3=H2SO4,theacidmistgeneratedduringthereactioncausessulfuricacidtoremaininthepipelineandcannotreactwithsodiumhydroxide.(3)Theeffectoffillerzincoxideinrubberstoppers:(4)Theconversionrateoforganicsulfurincoalisrelativelylow.Eglish煤样在空气流中燃烧分解，煤中的硫生成SO2并被净化空气带到电解池中，立即被电解池中的I2氧化为H2SO4，溶液中的I2和I-浓度发生变化，指示电极的电位改变，从而启动电解，产生新的I2，使SO2全部被氧化，并使电解液重新回到平衡状态。根据电解所耗电量的积分及法拉第定律，可计算出试样中全硫的含量。5、库仑滴定法中文Thecoalsampleburnsanddecomposesintheairflow,andthesulfurinthecoalgeneratesSO2whichiscarriedbytheairtotheelectrolysiscell.ItisimmediatelyoxidizedtoH2SO4byI2intheelectrolysiscell.TheconcentrationofI2andI-intheelectrolytechanges,causingachangeintheindicatorelectrodepotential,whichinitiateselectrolysistogenera