An Investigation on the fabrication and properties of ultra low cement cordierite mullite refractory castables

In this article the design and development of cordierite mullite plates based on ultra low cement refractory castables (LCC) using for kiln furniture applications were investigated. Cordierite powder was synthesized from talc، kaolin and alumina as starting materials and forming the briquettes by pressing and sintering at 1430 oC. The synthetic cordierite aggregates were used as the main constituent of the samples in addition to the andalusite، secar 71 cement، calcined alumina and microsilica. Raw materials were mixed according to the designed formulations and the samples were shaped by casting into the steel dies by vibration method. After drying and sintering the samples at 1250، 1300، 1350 and 1400 oC، their physical and mechanical properties including porosity، density، thermal linear expansion and cold crushing strength were measured. Phase analyses were performed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) was used for microstructural analysis. Thermal expansion coefficient of the samples sintered at 1300 and 1400 oC was determined by dilatometery and had average values of 3. 95×10−6 and 3. 51×10−6 (1/K)، which indicates an excellent thermal shock resistant.