《工业分析 Industrial Analysis》课件-煤中氮的测定（双语）

项目五:煤质分析任务三：煤的元素分析煤中氮的测定课程：工业分析中文Scenario5:QualityanalysisofcoalsTaskThree:ElementalanalysisofcoalDeterminationofnitrogenincoalCourse:IndustrialAnalysisEglish1、方法原理称取一定量的空气干燥基煤样，加入混合催化剂和硫酸，加热分解，氮转化为硫酸氢铵，加入过量NaOH溶液，把氨蒸出并吸收在硼酸溶液中，用硫酸标准溶液滴定。（一）半微量凯氏法中文1、MethodprincipleWeighacertainamountofairdriedcoalsample,addamixedcatalystandsulfuricacid,heatanddecomposethecoalsample,convertthenitrogeninthecoalintoammoniumbisulfate,thenaddanexcessNaOHsolutionfordistillation,absorbtheevaporatedammoniawithboricacidsolution,andfinallytitratewithsulfuricacidstandardsolution.（一）SemitraceKjeldahlmethodcoalcatalystEglish2、所需试剂混合催化剂：32g无水硫酸钠、5g硫酸汞、0.5g硒粉混合而成硼酸：3%水溶液混合碱溶液：37gNaOH、3gNa2S溶于100mL蒸馏水甲基红-亚甲基兰混合指示剂硫酸标准溶液：c（1/2H2SO4）=0.025mol/L中文2、RequiredreagentsMixedcatalyst:madebymixing32

ganhydroussodiumsulfate,5

gmercurysulfate,and0.5

gseleniumpowderBoricacid:3%aqueoussolutionMixedalkalinesolution:37gNaOHand3gNa2Sdissolvedin100mLdistilledwaterMethylred-methylenebluemixedindicatorSulfuricacidstandardsolution：c（1/2H2SO4）=0.025mol/LEglish3、实验步骤消解蒸馏吸收滴定煤样置于50mL凯氏瓶，加入催化剂和浓硫酸，350℃消解消解液转入250mL凯氏瓶，加入混合碱蒸馏蒸馏馏出液用硼酸吸收硼酸吸收液用硫酸标准溶液滴定消解装置示意图1-温度计；2-短颈漏斗；3-凯氏瓶；4-铝加热体；5-加热炉中文3、ProceduredigestiondistillationAbsorptiontitrationPlacethecoalsampleina50mLKjeldahlflask,addcatalystandconcentratedsulfuricacid,anddigestat350℃Transferthedigestionsolutionintoa250mLKjeldahlflask,addmixedalkali,anddistillAbsorbdistillatewithboricacidTitrateboricacidabsorptionsolutionwithsulfuricacidstandardsolutionSchematicdiagramofdigestiondevice1.thermometer;2-shortneckedfunnel;3-kjeldahlbottle;4-aluminumheatingelement;5-heatingfurnaceEglish4、结果计算硫酸标准溶液消耗体积煤样质量空白实验消耗硫酸标准溶液体积硫酸（1/2H2SO4）标准溶液浓度中文4、resultcalculationvolume

consumptionofsulfuricacidstandardsolutionThequalityofcoalVolumeofsulfuricacidstandardsolutionconsumedinblankexperimentc(1/2H2SO4)Eglish（二）半微量蒸汽法1、方法原理一定量的煤样在以氧化铝作催化剂和疏松剂的条件下，于1050℃通入水蒸气，试样中的氮及其化合物全部还原成氨。生成的氨经氢氧化钠溶液蒸馏，经硼酸溶液吸收后用硫酸标准溶液滴定，根据硫酸标准溶液的消耗量计算氮的含量。中文（二）Semitracevapormethod1、MethodprincipleUsingaluminaasacatalystandlooseningagent,watervaporisintroducedat1050℃,andallnitrogenanditscompoundsinthecoalsamplearereducedtoammonia.Thegeneratedammoniaisdistilledbysodiumhydroxidesolution,andthedistillateisabsorbedbyboricacidsolution.Then,theboricacidsolutionistitratedwithsulfuricacidstandardsolution,andthenitrogencontentiscalculatedbasedontheconsumptionofsulfuricacidstandardsolution.Eglish2、仪器设备蒸汽定氮装置示意图1-气体干燥塔；2-氦气流量计；3,5-橡皮塞；4-T形玻璃管；6-高温炉；7-石英托盘；8-水解管；9-硅酸铝棉；10-硅橡胶管；11-缓冲球；12-蛇形冷凝管；13-吸收瓶；14-套式加热器；15-蒸馏瓶；16-硅橡胶塞；17-镍铬丝支架；18-电炉；19-平底烧瓶中文2、InstrumentsandequipmentSchematicdiagramofsteamnitrogendeterminationdevice1.Gasdryingtower;2-Heliumgasflowmeter;3,5-rubberstopper;4-T-shapedglasstube;6-Hightemperaturefurnace;7-Quartztray;8-hydrolysistube;9-Aluminumsilicatecotton;10-Siliconerubbertube;11-Bufferball;12-Snakeshapedcondensertube;13-Absorptionbottle;14setheater;15-Distillationflask;16-Siliconerubberplug;17-Nickelchromiumwirebracket;18-Electricfurnace;19-FlatbottomedflaskEglish3、实验步骤水解炉通电升温，塞紧橡皮塞，以50mL/min速度通入氦气。从蒸馏瓶侧管加入250g/L的NaOH溶液150mL，并用橡皮塞塞紧侧管口，接通冷凝管，套式加热器通电升温，并控制温度为（125±5）℃。当水解炉炉温升到500℃时通入水蒸气，继续升温到1050℃。在此温度下空蒸30min或待馏出物体积达（100~200）mL后再进行样品测定，每天都要如此操作。取空气干燥煤样（0.1±0.01）g，称准至0.0002g，与0.5g氧化铝充分混合后转入瓷舟。对挥发分较高的烟煤，在混合后的试样上覆盖一层氧化铝（约为0.3g~0.5g）。中文3、ProcedureConnectthepowersupplytoheatupthehydrolysisfurnace,tightentherubberstopper,andintroduceheliumgasataspeedof50mL/min.Add150mLof250g/LNaOHsolutionfromthesidetubeofthedistillationflask,andplugthesidetubewitharubberstopper.Connectthecondensertube,turnonthesleeveheater,andcontrolthetemperatureto(125±5)℃.Whenthetemperatureofthehydrolysisfurnacerisesto500℃,steamisintroducedandthetemperaturecontinuestoriseto1050℃.Distillatthistemperaturefor30minutesorwaitforthevolumeofthedistillatetoreach(100-200)mLbeforeconductingsampledetermination,anddothiseveryday.Takeanairdriedcoalsample(0.1±0.01)g,mixitthoroughlywith0.5gofalumina,andtransferittoaporcelainboat.Forbituminouscoalwithhighvolatilecontent,coverthemixedsamplewithalayerofalumina(about0.3g~0.5g).Eglish在吸收瓶中加入20mL硼酸溶液和3滴甲基红-亚甲基蓝混合指示剂，连接冷凝管出口端至液面以下。将瓷舟放入燃烧管的石英托盘上，塞紧带进样杆的橡皮塞，通入水蒸气。先将试样推到（450~500）℃区域停留5min，然后推到（750~800）℃区域停留5min，最后推到1050℃区域停留25min（此时溶液体积约150mL）。取下吸收瓶，并用水冲洗硼酸溶液中的玻璃管内外，洗液并入吸收瓶。以硫酸标准溶液滴定吸收瓶中溶液由绿色变为钢灰色，根据硫酸标准溶液的消耗量计算煤中氮的含量。中文Add20mLofboricacidsolutionand3dropsofmethylredmethylenebluemixedindicatortotheabsorptionbottle,andconnecttheoutletofthecondensertubebelowtheliquidlevel.Placetheporcelainboatontothequartztrayofthecombustiontube,tightentherubberstopperwiththesamplerod,andintroducewatervapor.First,pushthesamplet