Research On Properties Of Mullite-Silicon Carbide Castables Used For Outlet Of Cement Rotary Kiln

With NSP cement rotary kiln becomes larger,temperature of secondary air is higher andhigher，and waste is used as fuel,so castables used in cement rotary kilneye put forward higherrequirements for thermal shock resistance,wear resistance,alkali resistance and so on.In thispaper,effects of different matrix additions and different aggregate and matrix compositions onproperties of Mullite-SiC castable were investigated respectively.The research work conclusions:（1）Withthe matrix addition from25%to40%,apparent porosity gradually increases and bulkdensity gradually decreases and cold modulus of rupture firstly increases then decreases ofsamples after heated at1200°C for3h.Apparent porosity decreases and bulk density and strengthincrease of samples after carbon embedded heated at1500°C for3h.Hot modulus of rupture ofsamples signiifcantly increases. When the matrix addition is30%,wear resistance of sample is thebest.（2）Withthe silicon carbide addition from25%to55%,apparent porosity and cold crushingstrength all gradually increase of sintered samples.Bulk density of all samples is lightly change.Wear resistance becomes betetr.Alkali resistance become ifrstly worse then better and cementclinker resistance become gradually worse.（3）Apparentporosity and bulk density are minimum and modulus of rupture is maximum，andhot modulus of rupture and thermal shock resistance are the worst of sample added M45mullite.Apparent porosity is maximum and hot modulus of rupture and thermal shock resistanceare the best of sample added M60mullite. Wear resistance and cement clinker resistance becomeworse and alkali resistance becomes better of samples with the decrease of Al₂O₃content ofdifferent mullites.（4）6%secar71cement and4%microsilica used binders for sample C，6%P-Al₂O₃and4%microsilica used binders for sample A，6%secar71cement，3%p-AbCband4%microsilica usedbinders for sample CA，3%magnesia，3%P-Al₂O₃and4%microsilica used binders for sampleMA.Afetr heated at110°C for24h，for strength,sample CA>sample C>sample MA>sample A.Forhot modulus of rupture,sample A>sample MA>sample CA>sample C.For wear resistance,sampleMA>sample C>sample CA>sample A.（5）Withthe zircon addition from3%to12%,apparent porosity of samples do not changesigniifcantly and bulk density increases.Strength slight decrease of samples after heated at1200°C for3h and strength ifrstly increase and then decrease of samples after carbon embeddedheated at1500°C for3h.Zircon added is not conducive to improve thermal shock resistance ofsamples. When zircon addition is6%,wear resistance of samples is the best. When zircon additionis3%，cement clinker resistance of samples is the best.