简介：DenseSi3N4BNcompositeceramicswerefabricatedbysparkplasmasinteringat1500,1600and1650℃under50MPafor5minusingSi3N4andBNpowdersasstartingmaterialsand2mass%Al2O3and6mass%Y2O3assinteringadditives.ThevolumefractionofBNinSi3N4BNcompositepowderswaschosenas10%,20%,and30%,respectively.TheresultsofXRDandSEMshowthatα-Si3N4completelyturnsintoβ-Si3N4whenthecompositeceramicsaresinteredat1650℃;theadditionofBNhindersthegrowthofSi3N4grains,refiningthestructure;VickershardnessandfracturetoughnessofthecompositeceramicsdecreasewiththeincreaseofBNcontent.

简介：Inthispaper,theinflucnceofchiefprocessparametersontheontinuousproductionofSi3N4powderbyrenitridationhasbeenstudied,Thesutiableprocessparametershavebeenfound,andhighqualitySi3N4powderhasbeendeveloped.

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简介：TheinfluenceofthreedifferentAl2O3powderonself-flowingaluminacastablewasstudied.MaximumcompactionofsamplewascomputedbyAndresenEquation.TheresultshowedthattheAl2O3powder,whichhasmuchsmallerparticlesize,couldimprovethemicrostructureandthemechanicalpropertiesofcastableunderroomtemperatureandhightemperature.Withthesamepowdersize,theroomtemperaturestrengthofthecastableaddedwithAl2O3powderproPertiesofwhichwerealteredbyaddingmineralizingagent,washigherthanthatofthecastableaddedwithcommonAl2O3powder,buttheflowabilityofthesethreedifferentcastablewasalmostthesame.

简介：Thestabilizationofγ-aluminiumoxyni-tridespinel(γ-AlON)hasbeeninvestigatedbyadditionofMgO,MgAl2O4,etc.,inreactionprocess.Theresultsindicatedthattherearewidersolidsolutionareasnear,Al2O3-richsideinAlN-Al2O3-MgOternarysystems,ThecontentofstabilizedAlONphaseinsamplesisrelatedtoheatingtemperatures,additives,etc.ThelatticeparametersoftheirAlONphasescouldbewelldescribedbytheequation:a0=0.7900+0.0375[MgO]+0.015[AlN](nm)

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简介：Thespecimenswerepreparedbymoldingthemixtureofsilicafume(w(SiO2)=94.5%;averageparticlesize:0.08μm)andsiliconnitride(≤0.074mm)withamassratioof11,carbonembeddedfiringat1300℃,1450℃,1500℃,1550℃and1600℃for3hinair,andthenwater-cooling,respectively.Themicrostructureandphasecompositionofthespecimenswereanalyzed.Theresultsshowthat:(1)silicafumereactsobviouslywithSi3N4formingSi2N2Oabove1550℃.TheedgesandcornersofSi3N4grainsbecomesmoothandtheSi3N4grainsdistributeinthecontinuouscementationphaseofSi2N2OformingthedensestructureofSi2N2OpackedSi3N4;(2)below1500℃,theedgesandcornersofSi3N4grainsareclear,Si2N2Odoesn'tform,andonlySiO2crystallizesfromsilicafumewhichhappensobviouslyat1300℃.

简介：Researchonnewtypesofcastables,pre-castassemblypartsandthermalinsulationmaterialswithgoodresistancetowear,thermalshockanderosion,andlowthermalconductivity,wasdonetosolveproblemsofhighsystemenergyconsumption,crackingandspallingofpartialliningandmismatchoffurnacetopmaterialandhangingmaterialandsoon,causedbyunreasonabledesignofChina'sAl(OH)3dilutephasefluidizedbedroastingfurnacelining.Severaldifficultproblemssuchasthematchingofdifferentmaterials,preservationofexpansionjointsamongdifferentzonesandreasonablemechanicaldistributionofliningweresolved.'Integratedfurnace'conceptwasestablishedincludingrefractoriesR&D,liningstructuredesign,constructionoptimization,furnacewarmingtechnology,initialoperationandliningmaintenancetechnology.Thekeytechnologiesofhigh-efficiencyandenergy-savingforfurnacesweredeveloped.TheseachievementshavebeenappliedtoChina'sAl(OH)3dilutephasefluidizedbedroastingfurnacestoreduceenergyconsumptionby1000MJpertonalumina,enhancethecapacityandreducetheexhaustgasemission.

简介：Inordertoimprovetheservicelifeofcorundumliningforinductionfurnace,corundumdryrammingmixwaspreparedusingbrowncorundum,fusedmagnesia,andα-Al2O3micropowderasmainstartingmaterials,andtheinfluenceofα-Al2O3micropowderadditions(0,1%,2%,and3%,inmass)onpropertiesofcorundumdryrammingmixwasinvestigated.Theresultsshowthatafterheattreatingat1600℃,withtheincreaseofα-Al2O3addition,thepermanentchangeindimensionsonheatingofthespecimensdecreasesfirstlyandthenincreases,bulkdensityincreases,apparentporositydecreases,andthecrushingstrengthdeclinesfirstlyandthenenhances;whentheadditionofα-Al2O3is2mass%,thepermanentchangeindimensionsonheatingofthespecimensisrelativelysmallandthecrushingstrengthdecreasesto22.8MPa.TheXRDandSEMresultsshowthatafterfiringat1600℃for3hsmallgranularmagnesiumaluminatespinelformsandiswelldistributed,whichenhancesthedensity.

简介：TheAl2O3-SiCcompositepowderswerepreparedinargonatmosphereusingcoalgangueandcarbonaceousmaterials3-SiCcompositepowderswereinvestigated.Theresultsindicatethat:temperature,soakingtimeandchlorideadditivehavesignificantinfluenceonthesynthesizedAl2O3-SiCcompositepowders.Basedontheresults,theoptimizedAl2O3-SiCcompositepowders（Al2O358mass%andSiC42mass%）withparticlesized50≤5μmwerepreparedusingcoalgangueandcarbonblackasstartingmaterialsafter3hfiringat1550℃.andproperadditiveadditioncouldreducethetemperatureby50℃.

简介：Thekineticprocessofslagcorrosionforβ－Sialonandβ-Sialon-Al2O3compositeshasbeenstudiedbymeansofdipmethod(staticandself-rotating),Thecorrosionmodelisbuitlandtheformulaofcorrosionrateisdeduced,whichareinaccordancewithexperimentalresults.

简介：Simplethree-pointbendingtestatambienttemperaturecharacterizedthemechanicalbehaviorofburnedAl2O3-Crefractoriesbeforeandafterthermalshockinassociationwiththeprocessingparameters(graphitecontentandcokingtemperature,etc.).Theresultsshowedthatnon-linearplastic-elasticbehaviorunderloadlowerthancoldmodulusofrupture(CMOR)wasregisteredinallspecimensandreallinearelasticbehaviorcouldbeidentifiedafterthefirstload.Thetotaldeformationcouldbedividedintotwoparts,plasticandelasticareas.ThegraphitecontentandjointbondingsystemofcarbonandceramicphaseswereresponsibleformechanicalbehaviorofAl2O3-Crefractories.

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简介：TheeffectoftheadmixturesofAlandSimetalsandB4CandMgAlONcompoundsontheoxidationofMgO/Si3N4compositerefractoryhasbeenstudied,whichisapromisingcarbonfreerefractoryforsteel-makingapplicatlon.Thefourkindsofadmixturescanbeusedasanti-oxidantsforSi3N4,butthemixtureofAlandSiachievedthebestresult.Themixturecannotonlyplaytheroleasantioxidant,butalsoassistthesinteringprocessandhelpformdensesinteringlayer,improvingthepropertyofthecomposite.

简介：UsingAl2O3-MgOcastableinlargeladlecanavoidcontainationofmoltensteelfromcarbon-containingrefractoriesandincreasladleservicliferemarkably,Theadditionofmagnesiaandfinepowder,theeffectofgrainsizeontheproper-tiesofthecastable,especiallylinearchangeandstructurespallinghavebeenstudied,Castablepro-duedforlargeladlewithsmallweareratehasgotgoodapplicatioresult.

简介：Cr2O3canbesinteredwellat1500℃incarbon-embeddedconditionorH2atmosphere.Butthehighchromebearingrefractoriescannotreachdensificationwhensinteredat1700℃for10hinweakreducingatmosphereformedbythecombustionoffuel,anditsapparentporosityisabout18%.Thehighchromebearingrefractoriesaremainlyusedincoalgasifiers.Thetemperatureinthefurnaceisabout1500℃andtheproductsareH2andCO,whicharejustthesinteringconditionsofthedensechromerefractorieswithapparentporositylessthan10%.Thehighchromebearingrefractoriesusedincoalgasifiersmaybesinteredagainandthenshrink,destroyingthegasifierlining.Thethermodynamiccalculationshowsthatitissafeaboutthehighchromebearingrefractoriesusedingasifiers.Itisalsoexplainedthatthehighchromebearingrefractoriescan’tbesintereddenselyinweakreducingatmosphereformedbythecombustionoffuel.Thenewsinteringtechnologiescanbeusedtoimprovethebulkdensityofthehighchromebearingrefractories.

简介：Inthisstudy,inordertoevaluatetheperformanceofhomogenizedbauxite,twoAl_2O_3-SiC-Ccastableswerepreparedusinghomogenizedbauxiteandbrownfusedcorundumasaggregates,respectively.5mass%andalusitewasintroducedintothetwocastablessoastoresearchtheeffectandmechanismofandalusiteinAl_2O_3-SiC-Ccastables.Theresultsshowedthat:(1)comparedwiththebrownfusedcorundumbasedcastables,thehomogenizedbauxitebasedcastableshadhighercoldstrengthafterheattreatment,butlowerhotmodulusofrupture;(2)additionof5mass%andalusitecouldenhancethecoldandhotmodulusofrupture,improvethethermalshockresistance,andoptimizethemicrostructureofspecimens;(3)themullitizationofandalusitewasnotobviousinthecastablesfiredat1100-1400℃.

简介：Inthispaper,X-raydiffractogramanalysisandSEMobservationofAl4C3formedathightemperaturefromcarbon-containingrefractorieswithAlhavebeencarriedout.Aluminumaddedtocarbon-containingrefractoriesreactswithC(s)toformAl4C3(s)graduallyduringheatingfrom600℃to1200℃.ItisconsideredthattheinterlockedstructureofAl4C3platecrystalspromotestheoutstandingincreaseofhotmodulusofruptureofcarbon-containingrefractorieswithAl.TheHMORofcarbon-containingrefractoriesaddedwithAladditivefrom0to5wt％increasesby2.8timesbeingfrom6.5MPato18.2MPa.AfterathermochemicalcalculationforhydrationreactionprocessesofAl4C3andH2O(g),theequilibriumpartialpressurechartofH2O(g)inH2O-Al4C3-Al(OH)3systemvsvarioustemperatureshasbeenattained.TheH2O(g)partialpressureintheairneededfortheAl4C3hydrationreactionisnomorethan10～18atmatthetemperaturebelow120℃.Itisconsideredthattheburnedcarbon-containingrefractorieswithAlisextremelyeasytohydrateandthecrackingofburnedcarbon-containingrefractoriesisgeneratedbecausethatthehydrationexpansionis2.11timesduringtransformingfromAl4C3toAl(OH)3.ThefundamentalmeasureagainsthydrationoftherefractoriesistoinsulatetherefractoriesfromH2O(g)byvariousmeanssuchaspitchimpregnationorothersealingmaterials.

简介：ThispapertestifiesthataluminiumandsiliconaswellastheircarbidexandnitridescanreactwithCOincarbon-containingzonetoformAl2O3andSiOgasthroughexperimentandthermodyanmicanalysis,ThegasesdiffusetooxidizedzoneandreactwithoxidizerssuchasCO2,Asaresult,Al2O3andSiO2aredepositedfromthegases,wihichblockthepores,thusreducetheamountofgasdiffusionandincreaseoxidationresistnaceofcarbon-containingmaterials.

简介：SiliconoxynitridewasaddedinshapedAl2O3-SiC-Crefractorymaterialtoimprovetheslagresistanceinthispaper.Optimumaddingquantityofsiliconoxynitridepowderwasalsostudied.TheresultsshowthattheslagresistanceofAl2O3-SiC-Cshapedrefractoryisimprovedwhen2%or3%Si2N2Oisadded.AreasonableamountofSi2N2OaddedintoAl2O3-SiC-Cshapedrefractorycanproducesiliconoxideintotheslag,whichcanimprovetheviscosityofslagandpreventtheslagerosionandpenetration.