SynthesisofASingle-PhaseSuperfineNa-YZeolitefromCoalFlyAsh*ZOULixiaa,DINGHuilingb,ZHENGLanpingb,HEMejuana,XUQiongaaStateKeyLaboratoryBreedingBaseofNuclearResourcesandEnvironment,EastChinaInstituteofTechnology,Nanchang,330013,Jiangxi,ChinabJiangxiscienceandtechnologynormaluniversity,Nanchang,Jiangxi,330000,Chinaaemail:lxzou1125@163.
comKeywords:superfine,zeolite-Y(FAZ),flyash(FA),crystallization,synthesisAbstract.
Theprocessforthesynthesisofflyash-basedsuperfinezeolites-Y(FAZ)werepresented,whichbasicallyincludedthealkalinefusiontreatmentofflyash(FA),thegelsformationbydissolvedandaged,followinghydrothermalcrystallization.
Adetailedinvestigationwascarriedouttodeterminetheeffectsofconditionsofsynthesissuperfinezeolite-Y.
Thecrystallizationstructureofzeolite-YwascharacterizedbyX-raydiffraction(XRD)andscanningelectronmicroscope(SEM).
Theexperimentalresultsshowthattheoptimizedconditions:Flyashbyalkalifusion(NaOH:flyashratio1.
2:1),anddissolvedof60Cusingdistilledwaterandagedof25Cfor22h.
Thefollowing,atconditionsof2.
2MNaOHsolution,liquid:solid=6.
5,theslurrywashydrothermalcrystallizedat100Cfor24h.
Synthesisofparticlesexhibitscompletelygrowncrystalsofzeolites-Yandcubicmorphologywithapproximatedimensionsof400mm.
Thecrystalinityofzeolite-Ywas88.
7%.
AttheadvantageofthispaperwastosynthesizesuperfineYzeolitethatusingonlyflyashasarawmateriaandwithoutusinganyothersiliconandaluminumsourceandanytemplateadditionundermildconditions.
IntroductionCoalashisgeneratedbycombustionofcoalinapowerstationasawasteproduct.
IthasbeenestablishedthatFAismainlycomposedofamorphousmaterial(aluminosilicateglasses)canbeconvertedtozeolitesinalkalisolutionsbyhydrothermaltreatment.
TherearemanyreportsforsynthesisofzeolitefromFA,forexample,faujasite,Na-Azeolite,phillipsiteandhydroxysodalite.
Thezeolite-Yhasbeusedinreceivedmuchattention.
Itisalsoreportedthatuseofzeolite-Ycanimprovecatalyticcrackingselectivity,reducecokeformation,increasetheyieldofdieseloilandpromotegasolinequality;itcanalsobeusedinthefinechemicalindustry.
Inthesynthesesofzeolite-Y,silicasourcesuchassodiumsilicatesolutionandSourceofaluminumarecurrentlyusedandthisrequirestheadditionofseedsorinitialsolutiontoprovidenuclei[1~4].
Theaimofthispaperwastosynthesizeasingle-phasesuperfinezeolite-YfromFA.
Andanysourceofsiliconandaluminumsourceandanyorganictemplatewithoutadditional.
TheproductsthusobtainedwerecharacterizedbyXRDandSEM.
Theformationconditionandprocessofasingle-phasezeolite-Yarediscussedinthisarticle.
ExperimentZeolitesynthesisAhomogenousmixturewaspreparedbypropergrindingandmixingofflyashandcausticsodain1:1.
2ratio.
Thismixturewasheatedatabout750Cforabout2h.
Then,thefusionsamplewascooled,milledandmixedthoroughlyusingdistilledwaterinabreaker.
Thebreakerwaskeptinawaterbathandstirredconstantlyforafewhours.
Theslurrywassubjectedtoultrasonicandagingforafewhours.
Thisamorphousalumino-silicategelwasformed.
Thisgelwasthensubjectedtocrystallizationbetween40C~100Cforabout10~30hinspeciallydesignedstainlessalloyautoclaveswiththinwallswhichallowafastheattransfer.
Thesolidcrystallineproductwasrecoveredbyfiltrationandwashedwithdistilled-deionizedwaterthoroughlyuntilthefiltratepHwas11,anddriedat80°Cfor24hinanairoven.
Characterization.
Thematerialsobtainedwerecharacterizedbyvariousconventionalmethods.
PowderX-raydiffraction(XRD)patternsweretakenonaRigakuX-raydiffractometerusingNi-filteredCuKRradiation(30kV,16mA).
ParticlemorphologywasobservedbyanHitachiscanningelectronmicroscope(SEM).
ResultsandDiscussionInfluenceofmolarratiosSiO2/Al2O3Fig.
1.
InfluenceofFig.
2Influenceofagingtemperatures:FAzeolite-YmolarratioSiO2/Al2O3:(1)80C,(2)50Cand(3)40Cfor24h;Fig.
4SEMspectrumofzeolite-Y(a)0.
9,(b)2.
0,(c)pureFA(4)at60Cfor2hand25Cfor22hFigure1showstheXRDpatternsofthesynthesizedsampleswereinvestigatedbychangingotherSiO2/Al2O3ratiofrom0.
9to3.
5andthecrystallizationtemperatureat100C.
ThepatternsofthematerialformedatSiO2/Al2O3=0.
9possessesmanydiffractionpeaks,whichcanbeassignabletozeolite-A.
WhentheratioofSiO2/Al2O3increase,newpeaksoffaujasiteappear(pattern(b)-(c)).
ThesyntheticfaujasitetypezeolitetakesintwoformswiththesamecrystalstructureatdifferentSiO2/Al2O3molarratio.
Onewaszeolite-XwithSiO2/Al2O3=2.
0andanotherwaszeolite-Yusingonlythestartingmaterialsflyash(SiO2andAl2O3ratioof2.
5~3.
5about).
InfluenceofagingconditionsIthasbeenestablishedthattheamorphousaluminosilicateinFAiseasiertodissolvethanthecrystallineonesuchasR-quartzandmulliteinalkalisolutions.
Toclarifythedetailedformationprocessofzeolite-Y,effectonthefinalproductofcrystallizationwerecharacterizedunderdifferentagingconditions.
InFigure2,ascanbeseen,thezeolite-Ywassynthesised,butthecrystallizationstrengthreductionwithtemperaturerise.
Thisisbecausethesiliconaluminumdissolvedeasilyformationgelunderhightemperature,depositedonthesurfaceofFA,furtherinfluenceinwhichthesiliconaluminumdissolved,resultdcrystallizationdecreased.
TheintensityofXRDpeakofthesample-(4)washighestwhichthatitwasdissolvedof60Candagedof25Cfor22h.
So,itwasusedasafixedagingconditioninthefollowingsynthesisexperiments.
InfluenceoftheconditionsofcrystallizationFig.
3(1)illustratestheXRDpatternsofthreesamplessynthesizedfromFAattheconditionof1M,2.
2Mand3MNaOHsolutionandcrystallizationfor24h.
AccordingtoXRDpatternsofthreesamplesobtained,onlysample(2.
2MNaOHsolution)wasconfirmedbypure-formzeolite-Ywithouttheformationofothertypesofzeolites.
HuiandChaopointedoutthatsynthesisofzeoliteYdependsontherateofgeldissolution[5],thenumberanddistributionofnucleiinpreparedinitialgel,andthecrystalgrowthrateduringhydrothermaltreatment.
ThestructuralformationofzeoliteYmaybeexplainedinturndependonotherfactorssuchassynthesistemperature,crystallizationtime,compositionmolarratiosofinitialgel,etc.
Fig.
3XRDpatternsofFAYindifferentatcontidionsof1)alkalinityconcentration,2)crystallizationtime,3)crystallizationtemperatures,4)theratioofliquidtosolidThealumino-silicatefusedmassgelobtainedisamorphousandchangestothecrystallinestatewhensubjectedtohydrothermalcrystallization.
TheresultspresentedinFig.
3(2,3)revealsthatcrystallizationtemperatureandtimeinfluenceszeoliticcrystallinity.
Percentcrystallinityofzeolite-Yincreasessignificantlyuntilupto100Cfor24h.
Thecrystallizationtimeincreasesto30h,theotherpeakstoformed.
Therefore,crystallizationcontidionsidentifiedas100Cfor24hintheexperiment.
Fig.
3(4)showstheXRDpatternsofsamplesproducedusingdifferentmolarratiosofliquidtosolidunderthesamesyntheticconditions.
TheXRDpatternsindicatethatallsamplesexhibitazeolite-Ystructure.
Notably,thesamples-2(liquid:solid=6.
5)showsignificantlyhigherbroadeneddiffractionpeaks,withhigheryieldofcrystallization.
Therelativecrystalinitiescalculated[6]forsamples-1(liquid:solid=8.
5)andsamples-2arefoundtobe74.
7%and88.
7%,respectively.
MorphologicalstudiesTheSEMphotographsinFig.
3depictthesampletransformationofFAintoZeolite-Y.
Sampleszeolite-Yarefairlyuniformincrystalsize,andtheindividualaggregatesarecomposedofcloselypackednanocrystals,andhavesmalleraverageaggregatesizes.
Thisisprobablybecauselessuniformcrystallizationoccurredingel.
Forthesampletheaverageparticle(aggregate)sizewasestimatedfromatleast400nmparticlesintheSEMimages.
ConclusionsSynthesisofFAZisdirectlyrelatedtoextractionofsilicatesandaluminatesformFAusingsodiumhydroxide.
Fromtheinformationpresentedinthispaper,Si4+andAl3+ionsareelutedfromfusingFAbydissolutionofamorphousmaterialduringtheagingandcrystallizationtoformasingle-phaseYtypezeoliteintheautoclave.
TheYtypezeolitewerecharacterizationbyXRDandSEMpatterns,thefollowingconclusionscanbedrawn.
AhomogenousfusionmixturewaspreparedbypropergrindingandmixingofFAandcausticsodain1:1.
2ratio.
Thismixturewascalcinedatabout750Cforabout2h.
Thensamplewasdissolvedat60Candagedat25Cfor22h,tobegelformation.
Thegelandwaterastheratioofliquidtosolidis6.
5,in2.
2MNaOHsolutiontocrystallizationfor24hat100Cusingtheautoclave.
Themaximumpurityofzeolite-Ywasobtained,crystalinitycalculatedforsampleswas88.
7%.
SO,theSiO2andAl2O3ratioof2.
5~3.
5inFAfavoursformationofZeolite-Y.
OnmodificationoftheactualSiO2andAl2O3ratio,byincreasingsodiumsilicateorsodiumaluminatecontent,itwaspossibletosynthesisezeolite-Xorzeolite-AatSiO2/Al2O3of2.
0or0.
9respectively.
Theimportantfeatureofthisnovelprocedureistoproducesuperfinezeolite-Yandcrystalinity88.
7%inonevesselwithoutusinganyothersiliconandaluminumsourceandanytemplateaddition.
ThehighvolumeutilizationofFAforzeoliteproductiontechnologycomparedtoothermediumrlowvalueutilization,thisproductiontechnologyhasadvantagesofvalueaddition,offeringanedgeoverotherflyashutilisationtechnologiescurrentlyused.
AcknowledgmentThisstudywassupportedinpartbyJiangxiProvincialDepartmentofscienceandtechnologysupportprograminchina(20122BBG70084-2).
ThehelpandcooperationrenderedbythemanagementofFengchengThermalPowerStationincollectingflyashforthisresearchworkisgreatlyacknowledged.
References[1]RayaluS,MeshramSU,HasanMZ.
Highlycrystallinefaujasiticzeolitesfromflyash.
JournalofHazardousMaterials,B,Vol.
77(2000),P.
123–131[2]JulianaCI,DeniseAF,FernandoSS,ect.
.
CharacteristicsofBraziliancoalflyashesandtheirsynthesizedzeolitesOriginalResearch.
Article.
FuelProcessingTechnology,Vol.
97(2012),P.
38-44[3]BelvisoC,CavalcanteF,JavierHuertasF,ect.
.
Thecrystallisationofzeolite(X-andA-type)fromflyashat25°CinartificialseawaterOriginalResearchArticle.
MicroporousandMesoporousMaterials,Vol.
162(2012),P.
115-121[4]KazemianH,NaghdaliZ,GhaffariKashaniT,ect.
.
ConversionofhighsiliconflyashtoNa-P1zeolite:AlkalinefusionfollowedbyhydrothermalcrystallizationOriginalResearchArticle.
AdvancedPowderTechnology,Vol.
21(2010),P.
279-283[5]ClaudiaB,FrancescoC,SaverioF.
SynthesisofzeolitefromItaliancoalflyash:DifferencesincrystallizationtemperatureusingseawaterinsteadofdistilledwaterOriginalResearchArticle.
WasteManagement,Vol.
30(2010),P.
839-847[6]HuiKS,ChaoCYH.
Effectsofstep-changeofsynthesistemperatureonsynthesisofzeolite4Afromcoalflyash,Micropor.
Mesopor.
Mater.
Vol.
88(2006),P.
145–151[7]FotovatF,KazemianH,KazemeiniM.
SynthesisofNa-Aandfaujasiticzeolitesfromhighsiliconflyash.
MaterialsResearchBulletin.
MaterialsResearchBulletin,Vol.
44(2009),P.
913–917
RAKsmart 商家从原本只有专注于独立服务器后看到产品线比较单薄,后来陆续有增加站群服务器、高防服务器、VPS主机,以及现在也有在新增云服务器、裸机云服务器等等。机房也有增加到拥有洛杉矶、圣何塞、日本、韩国、中国香港等多个机房。在年前也有介绍到RAKsmart商家有提供年付129元的云服务器套餐,年后我们看到居然再次刷新年付云服务器低价格。我们看到云服务器低至年79元,如果有需要便宜云服务器的...
PhotonVPS 服务商我们是不是已经很久没有见过?曾经也是相当的火爆的,我们中文习惯称作为饭桶VPS主机商。翻看之前的文章,在2015年之前也有较多商家的活动分享的,这几年由于服务商太多,乃至于有一些老牌的服务商都逐渐淡忘。这不有看到PhotonVPS商家发布促销活动。PhotonVPS 商家七月份推出首月半价Linux系统VPS主机,首月低至2.5美元,有洛杉矶、达拉斯、阿什本机房,除提供普...
如今我们网友可能较多的会选择云服务器、VPS主机,对于虚拟主机的话可能很多人不会选择。但是我们有些外贸业务用途的建站项目还是会有选择虚拟主机的。今天看到的Stablehost 商家虚拟主机在黑五期间也有四折优惠,对于这个服务商而言不是特别的喜欢,虽然他们商家和我们熟悉的老鹰主机商有些类似,且在后来老鹰主机改版和方案后,Stablehost 商家也会跟随改版,但是性价比认为不如老鹰主机。这次黑色星期...
cn163.net为你推荐
360chrome360的chrome浏览器进程有点多哦???fastreport2.5罗斯2.5 现在能卖多少啊!?!!!fastreport2.5GPA2.5相当于什么水平winrar5.0winrar压缩3种格式分别有什么区别appletv越狱apple tv越狱后能干什么?ios8.1.3iphone4s ios8.1.3 优化小说ios7应用程序安卓4步骤ios6曲目ios6
免费二级域名申请 三级域名网站 大硬盘 美国主机推荐 全球付 名片模板psd 好看的桌面背景大图 win8升级win10正式版 网站挂马检测工具 52测评网 hostloc 双十一秒杀 空间首页登陆 四川电信商城 服务器维护 php服务器 百度云空间 日本代理ip lamp是什么意思 lamp什么意思 更多