Application Of Homogenized Bauxite In Al₂O₃-SiC-C Materials

This paper mainly studied the application of homogenized bauxite in Al₂O₃-SiC-C castables,the main contents are shown as follows:?1?In order to compare the difference of performances between Al₂O₃-SiC-C castables,containing different aggregates and homogenized bauxite partial replaced aggregates,a series Al₂O₃-SiC-C castables were prepared from different aggregates,including brown fused corundum,homogenized bauxite,round kiln calcined bauxite and rotary kiln calcined bauxite,respectively.?2?The influence of andalusite content on properties of homogenized bauxite based Al₂O₃-SiC-C castables and the effect of andalusite on the properties of Al₂O₃-SiC-C castables,with difference aggregates,were investigated.?3?The effect of particle size and content of SiC on the properties of homogenized bauxite based Al₂O₃-SiC castables.?4?The effects of antioxidants on the properties of Al₂O₃-SiC castables using pure Si powder,ternary intermetallic compounds Ti₃AlC₂ and B₄C as the antioxidants,respectively,were studied.The experimental results showed that:?1?Compared with the brown fused corundum based castables and two kinds of high grade bauxite based castables,homogenized bauxite based castables had higher bulk density,lower apparent porosity and higher cold strength after heat treatment.In addition,homogenized bauxite based castables had good thermal shock resistance but low bending strength at high temperature.The homogenized bauxite based samples had good slag penetration resistance,although their slag corrosion resistance was not satisfactory.?2?With the increase of andalusite content,the linear change rate of samples varies from contraction to expansion gradually.When the content of andalusite is 5?7%?wt?,the volume stability and the cold strength after heat treatment of homogenized bauxite based Al₂O₃-SiC-C castables were improved.Moreover,5%?wt?andalusite addition could increase the thermal shock resistance and slag resistance of samples and improved the volume stability and cold bending strength of different aggregates basted Al₂O₃-SiC-C castables.?3?No matter the particle size of SiC is 1-0 mm or 3-1 mm,the total content of SiC should not be too much,when the total content of SiC of each particle size was15?20%?wt?,the properties of Al₂O₃-SiC castables reach the balance.?4?With the increase of pure Si powder,the physical properties and oxidation resistance of the samples increased.The oxidization resistance of three antioxidants were B₄C>Ti₃AlC₂>Si,and the sample with B₄C as antioxidant has the higher cold strength and lower apparent porosity.