简介:Usingbrownfusedaluminaandtopgradebauxiteasmainstartingmaterials,ultrafinealumina,silicafume,andpurecalciumaluminatecementasbondingsystem,theeffectsofbrownfusedaluminaandtopgradebauxiteadditionsonthepropertiesandmicrostructureofzero-cementAl2O3-SiO2castablesafterdriedat110℃andfiredat1250℃for3hwerestudied.Themicrostructurewasanalyzedanddiscussed.Theresultsshowthatthehotmodulusofruptureofzero-cementAl2O3-SiO2castablesat1250℃isupto22.1MPawhenthebauxiteadditionisoptimumat12.5wt%.Themulliteformationmechanisminthiscastablesisdissolution-precipitationmechanismandthehotmodulusofruptureofthecastablesiscloselyrelatedtoin-situmulliteformation.Comparedwithbrownfusedalumina,thetopgradebauxiteismorehelpfultoin-situmulliteformationandimprovementofhotmodulusofruptureofthecastables.