简介:Themethodconsistingofcoldtestandhotsimulatinghasbeenprovedtobereliablefordesigningpermeableele-ments.Thecarbon-magnesiamultiple-tubepermeableele-mentswhichareformedbyisostaticalpressurehavehigherdensity,highheatresistanceandgoodthermoshockresis-tance,Thebrickwork,maintenanceanderosionmeha-nismofpermeableelementswerestudied.Thetehnologyofcombinedblowingwaestablishedbasedonthepeculiari-tiesofsemi-steelrefiningatPanzhihuaIrom&SteelCo.(PZISC).Theservicelifeofpermeableelementsreahed600heats,thatmeansthepermeableelementscanworksynchronitiallywithconverterlining.
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)
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:UsingAl2O3-MgOcastableinlargeladlecanavoidcontainationofmoltensteelfromcarbon-containingrefractoriesandincreasladleservicliferemarkably,Theadditionofmagnesiaandfinepowder,theeffectofgrainsizeontheproper-tiesofthecastable,especiallylinearchangeandstructurespallinghavebeenstudied,Castablepro-duedforlargeladlewithsmallweareratehasgotgoodapplicatioresult.
简介:MoltensaltsynthesisofMgAl2O4powderfromindustrialaluminaandlightcalcinedMgOinKCl,LiCl,andKCl-LiClmedia,andtheinfluenceofKFat500-1000℃wereinvestigated.SynthesizedpowderswerecharacterizedbymeansofXRD,laserparticleanalyzer,andSEM,andthesynthesismechanismofMgAl2O4wasdiscussedaswell.Theresultsshowthat(1)themoltensaltcomposite(KCl-LiCl)ismorefavorableforthesynthesisofMgAl2O4thansinglemoltensalt(LiClorKCl),andLiClismorefavorablethanKCl;(2)KFcanacceleratetheformationofMgAl2O4anddecreaseitsformingtemperature;(3)synthesisofMgAl2O4powderinthemoltensaltswithoutKFiscontrolledby'template-growth'mechanism,butinthemoltensaltswithKF,itiscontrolledby'template-growth'and'dissolution-precipitation'mechanism.
简介:AnO'-Sialon-Al2O3compositerefractorywaspreparedbyinsitureactionofSi3N4-ZrSiO4-Al2O3mixturewithfusedaluminaaggregates.Densification,insitureactionprocedureandmicrostructureofthematerialwereinvestigatedbymeansofX-raydiffraction,opticalandscanningelectronicmicroscopesandEDAX.