作者:标准资料网 时间:2024-05-07 00:28:25   浏览:8277   来源:标准资料网

【英文标准名称】:StandardTestMethodforDeterminationoftheUnitCellDimensionofaFaujasite-TypeZeolite
【原文标准名称】:八面沸石单位晶格尺寸的试验方法
【标准号】:ASTMD3942-2003(2008)
【标准状态】:现行
【国别】:美国
【发布日期】:2003
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D32.05
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:atalyst;faujasite;unitcell;X-raydiffraction;zeolite;Faujasitecrystalzeolites;Unitcelldimension;X-raydiffractionanalysis;Zeolitecatalysts
【摘要】:ZeolitesYandX,particularlyforcatalystandadsorbentapplications,areamajorarticleofmanufactureandcommerce.Catalystsandadsorbentscomprisingthesezeolitesinvariousformsplusbinderandothercomponentshavelikewisebecomeimportant.Y-basedcatalystsareusedforfluidcatalyticcracking(FCC)andhydrocrackingofpetroleum,whileX-basedadsorbentsareusedfordesiccation,sulfurcompoundremoval,andairseparation.Theunitcelldimensionofafreshlysynthesizedfaujasite-typezeoliteisasensitivemeasureofcompositionwhich,amongotheruses,distinguishesbetweenthetwosyntheticfaujasite-typezeolites,XandY.ThepresenceofamatrixinaY-containingcatalystprecludesdeterminationofthezeoliteframeworkcompositionbydirectelementalanalysis.Usersofthetestmethodshouldbeawarethatthecorrelationbetweenframeworkcompositionandunitcelldimensionisspecifictoagivencationformofthezeolite.Steamorthermaltreatments,forexample,mayalterbothcompositionandcationform.Theusermustthereforedeterminethecorrelationthatpertainstohiszeolitecontainingsamples.Inaddition,onemayusethetestmethodsolelytodeterminetheunitcelldimension,inwhichcasenocorrelationisneeded.Othercrystallinecomponentsmaybepresentinthesamplewhosediffractionpatternmaycauseinterferencewiththeselectedfaujasite-structurediffractionpeaks.Ifthereisreasontosuspectthepresenceofsuchcomponents,thenafulldiffractometerscanshouldbeobtainedandanalyzedtoselectfaujasite-structurepeaksfreeofinterference.1.1Thistestmethodcoversthedeterminationoftheunitcelldimensionofzeoliteshavingthefaujasitecrystalstructure,includingsyntheticYandXzeolites,theirmodificationssuchasthevariouscationexchangeforms,andthedealuminized,decationated,andultrastableformsofY.Thesezeoliteshavecubicsymmetrywithaunitcellparameterusuallywithinthelimitsof24.2and25.0?/span>(2.42and2.50nm).1.2Thesamplesincludezeolitepreparationinthevariousforms,andcatalystsandadsorbentscontainingthesezeolites.Thezeolitemaybepresentinamountsaslowas5%,suchasinacrackingcatalyst.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:G74
【国际标准分类号】:71_100_40
【页数】:3P.;A4
【正文语种】:英语