Preparation And Characterization Of Porous Alumina Ceramic Membrane Support

Circular plate-shaped porous ceramic membrane support containing alumina asaggregate, carboxymethylcellulose as pore-fomring agent,Kaolin and TitaniumDioxide as high temperature binder and sintering additive was prepared bydry-pressing and solid sintering in this paper.Based on this,Tubular porous ceramicmembrane support was prepared by rolling-pressing and meltable moulding core.Theproperties of them were characteruzed by SEM、XRD、TG-DTG and self-assemblyequipments.The main conclusions as followed:（1）The sintering curve of supports was estabilished bythermogravimetry-derivative thermogravimetry analysis：The temperature rose at2℃/min between40to200℃.CMC began to disintegrate at200to300℃and themaximum decomposition rate reached at274℃.The temperature increased at1℃/min in range from200℃to300℃and300℃for1h.The temperature rose at1℃/min between300℃to600℃and kept2hours at600℃for completedecomposition of CMC, removal of structural water kaolin.Temperature rate was2℃/min at the temperature range from600℃to1200℃.Kaolin transformed intometakaolin and produced liquid.The temperature incresaed at1℃/min between1200℃to1300℃as crystal particles were generated in this temperature range.Thesupports sintered are no no apparent structural cracks and good microstructureshowed from SEM.There are also corundum,quartz,rutile and mullite.（2）Optimal process parameters of circular plate-shaped porous ceramicmembrane support as followed:a、The12gram molding powder that containing4%moisture was pressed under32Mpa and kept the pressure for3min.The biscuit would not be spallation producedby flexibility affereffect in this situation.b、Support with porosity of34%，average pore size4.25μm，acid/alkaliresistance of98%,high mechanical strength is prepared under condition thatpore-forming agent added was3%,10%of the amount of Kaolin added,sinteringtemperature of1300℃，holding time of2hours.c、Support sintered under same conditions but added2%TiO₂as sintering additive had smooth surface microstructure,high mechanical strength.（3） Optimal process parameters of Tubular porous ceramic membrane supportas followed:a、The25gram mud that containing about10%moisture was rolling on themandrel until apparent structure was smooth.b、Support with porosity of36.97%，average pore size1.86μm，flexural strengthof19.78Mpa,pure water flux of2115.55L/m2.h under0.10Mpa,acid/alkali resistanceof99.83%/99.86%,high mechanical strength is prepared under condition thatpore-forming agent added was3%,10%of the amount of Kaolin added,2%TiO₂assintering additive,sintering temperature of1300℃，holding time of2hours.c、The mechanical strength of support was significantly affected by sinteringtemperature.There is almost no mechanical strength under1000to1100℃.As thetemperature increased,the support mechanical strength was raised as the formation ofmullite,quartz,rutile phase.The sintering temperature was set at1300℃under XRDpatterns analysis and laboratory conditions.