Investigation on Mechanism of Cordierite Formation from Nano Silica-Magnesium chloride-Reactive Alumina

Cordierite ceramics are used as refractory materials and kiln furnaces tools due to their very low coefficient of thermal expansion, high corrosion resistance and excellent thermal shock resistance. The aim of the present work was to synthesis of cordierite with raw materials including nano silica, magnesium chloride and reactive alumina. The synthesis procedure is done at solid state. Mechanism of cordierite formation was studied by simultaneous thermal analysis (STA) and x-ray diffraction (XRD). Microstructure of synthesized powder at various temperatures were observed by a scanning electron microscope (SEM). The results showed that the mechanism of cordierite formation from the mentioned materials was different from mechanisms for the formation of cordierite using other raw materials. Probable reactions on the way to form the cordierite were proposed at various temperatures. Cordierite formation temperature from raw materials including nano silica, magnesium chloride and reactive alumina determined as 1330°C. The synthesized cordierite was not pure and alumina, cristobalite, spinel and forsterite were present as impurities.