Five lightweight mullite castables were prepared using the lightweight mullite aggregate（M45A） with narrow particle size distribution and spherical shape,mullite powder（M45P）,kyanite powder,microsilica and Secar 7...Five lightweight mullite castables were prepared using the lightweight mullite aggregate（M45A） with narrow particle size distribution and spherical shape,mullite powder（M45P）,kyanite powder,microsilica and Secar 71 cement as raw materials. After the specimens fired at 1100 ℃,1200 ℃ and 1300 ℃ for 3h,respectively,the effects of kyanite contents（ 8%,10%,12%,14%,16% by mass） on the physical properties,phase composition and microstructures were investigated through an X-ray diffractometer（ XRD）,a scanning election microscopy（ SEM） and a microscopy measurement method,etc. The results show that,for the specimens fired at 1300 ℃ with the kyanite content from 8%to16%, the bulk densities and apparent porosities change little,but the cold modulus of rupture and the crushing strengths decrease significantly,and the linear change rates increase from-0.87% to 0.64%. The most apposite mode is the specimen containing 12% kyanite fired at 1300 ℃, which has a high crushing strength of 29.3 MPa,a low linear change of 0.18%,an apparent porosity of 36.8% and a bulk density of 1.73 g/cm^3.展开更多
文摘Five lightweight mullite castables were prepared using the lightweight mullite aggregate（M45A） with narrow particle size distribution and spherical shape,mullite powder（M45P）,kyanite powder,microsilica and Secar 71 cement as raw materials. After the specimens fired at 1100 ℃,1200 ℃ and 1300 ℃ for 3h,respectively,the effects of kyanite contents（ 8%,10%,12%,14%,16% by mass） on the physical properties,phase composition and microstructures were investigated through an X-ray diffractometer（ XRD）,a scanning election microscopy（ SEM） and a microscopy measurement method,etc. The results show that,for the specimens fired at 1300 ℃ with the kyanite content from 8%to16%, the bulk densities and apparent porosities change little,but the cold modulus of rupture and the crushing strengths decrease significantly,and the linear change rates increase from-0.87% to 0.64%. The most apposite mode is the specimen containing 12% kyanite fired at 1300 ℃, which has a high crushing strength of 29.3 MPa,a low linear change of 0.18%,an apparent porosity of 36.8% and a bulk density of 1.73 g/cm^3.
