Application And Studies On The Synthesis Of Cordierite Material

The hot blast stove is one of the most important subsidiary equipments of the blast furnace, and it is a kind of heat exchanger of recuperator. Therefore, the refractory where they are used for construction of linings of hot blast stove must have high properties, especially good thermal-shock resistance. The temperature of hot blast stove unusually worked is 1000-1100℃ in China. The clay brick, the high alumina brick, mullite brick and silica brick etc. are used for construction of linings of hot blast stove. Recent years, the cordierite's thermal-shock resistance is better than the high aluminum refractory, because of the properties of high alumina brick composition and thermal shock is not very superiority, and it used in hot blast stove has been developed quickly. But the quantity of the natural mineral of the cordierite is a little, not only the cordierite content is very low, but also the impurity content is more. So the cordierite is usually synthesized.This text utilized kaolin, talcum, high pure magnesia, industrial alumina as main raw material to synthesize cordierite. And the influences of different additives were prepared. At the same time, the mixture in the hot blast was studied.The mineral phase was characterized by X-ray diffraction (XRD). The results show that: cordierite phase is all above 95% in the all samples which were synthesized by kaolin, talcum, high pure magnesia and sintered in 1340℃, and the bulk density is 2.02g/cm³ the thermal expansion coefficient is 2.04×10^-6/℃(20⁸00℃). The sintering temperature of the samples which were synthesized by kaolin, talcum, high pure magnesia, is lower than the samples which were synthesized by kaolin, talcum, industrial alumina. Besides, in the same sintering temperature, the content cordierite phase in the more silicon dioxide composition sample is more than theoretical chemical composition. The additive, especially BaCO₃, enhance the cordierite phase. BaCO₃ and Li₂CO₃reduce thermal expansion coefficient of cordierite a=l.84><10 /°C, a=l.86><10 /°C (20⁸00°C) .