Zircon bonded with Iraqi Kaolin

Abstract

Clay is one of many types of raw materials that have plasticity and advantage of securing so used as a binder in refractory products. Iraqi white kaolin used as a binding material in ratio (15, 20, 25, 30)%. The samples were formed by dry pressing and left at room temperature for (24)hr then fired at (1200)˚C with socking time for (2)hr. The Study included Linear shrinkage, Apparent density, Porosity, water absorption, loss in mass, wettability and microstructure by (SEM) as physical properties, Thermal conductivity, and thermal shock resistance as thermal properties. The microstructure of the refractories consist of zirconium silicate, mullite phase, and glass binding phase. The refractory showed medium porosity. Increasing of Iraqi white kaolin percentage leads to Increasing the Linear shrinkage ratio, Apparent density, loss in mass and thermal conductivity and decreasing the Apparent Porosity and water absorption ratio , because of the Increasing of the liquid phase ratio in refractory. The effect of thermal shock on diametrical strength studied, where it is noticed the thermal shock temperatures between (400-600)˚C.