Preparation and mechanism of cordierite by using calcined bauxite as raw material at relatively low temperature

摘要

The cordierite was synthesized at relatively low temperature by pressureless sintering method, using calcined bauxite, talcum, quartz and feldspar as raw materials in this paper. The water absorption (Wa), porosity (Pa), bulk density (Db) and bending strength of samples have been tested, and the synthetic process and mechanism have been investigated by XRD, SEM, and so on. The results showed that the cordierite could be synthesized at 1280°C and the range of synthetic temperature is 1160～1300°C, when the sample was sintered at 1280°C for 2h, its bulk density and bending strength were 2.20g/cm~3 and 72.13MPa, respectively. XRD analysis showed that the main phase of sample was cordierite, the cordierite content was about 88wt%, and the minor phases were MgAl_2O_4 spinel and corundum. SEM results showed that the samples were dense and the pore sizes were 5μm～100μm, the grains were growth and development well, the grains size were 0.5μm～6μm. High reaction activity corundum and mullite were provided by calcined bauxite, then coupled with the role of feldspar, thus reduced the synthetic temperature of cordierite.