Abstract:Based on the target requirements of shrinkage, water absorption and rupture modulus of ceramic plates, the calcined bauxite in raw materials were replaced by the kyanite, flint clay and aciform wollastonite to solve the problem of high water absorption rate and low strength. The relationship model between preparation process conditions and secondary mullitization reaction process were established through the changes of chemical and mineral composition in production formula. The formation mechanism of low strength and high water absorption rate of large scale ceramic plates were analyzed through the performance comparison of the original ceramic plates and the new ceramic plates in which calcined bauxite in raw materials were replaced by the kyanite, flint clay and aciform wollastonite. Results show that the introduction of calcined bauxite into the ceramic plates can reduce the sintering shrinkage and cause the enhance effect of mullite phase, the incomplete secondary mullite reaction is the main cause of high water absorption rate and low strength. The temperature of secondary mullitization reaction is close to the sintering temperature of the ceramic plates after kyanite is used to replace calcined bauxite. The fracture modulus of the ceramic plates increases by 183%, the water absorption rate decreases by 562%, and the shrinkage rate of sintering line decreases by 92%.