Preparation and Characterization of Al₂O₃-Kaolin Composite Porous Ceramic Used as Ceramic Membrane Support

Abstract

The high sintering temperature of Al2O3 is the main reason of the high cost of the common ceramic membrane supports. To decrease the sintering temperature, kaolin and talc were chosen as sintering aid because the reaction between kaolin, talc and Al2O3 generates cordierite. The Al2O3-cordierite porous ceramic samples were sintered in the range of 1450~1510°C. The microstructure and the bending strength of the samples were characterized. The results show that the content of kaolin is no more than 8%, the bending strength of the porous ceramic sintered at 1460°C and 1510°C are 77MPa and 153MPa, respectively. The further increases of the kaolin content result in the decrease of the bending strength and the porosity. The needle-like cordierite locates in the neck of Al2O3 grains. The reaction between kaolin and Al2O3 contributes to increasing the sintering velocity. The ceramic support using cordierite as sintering aid has the acid/alkali corrosion resistance in some degree.

Research on performance optimization of Loess-based ceramic membrane supports with Bauxite-dolomite-talc as additives

“…So, it is widely used in the manufacture of ceramics, glass, etc. Qi et al [22] used kaolin as the main raw material to prepare the ceramic membrane support and added talc to improve the plasticity of the mud. In addition, the addition of talc is also helpful to reduce the sintering temperature.…”

“…In addition, studies have shown [23,24] that talc is also a sintering aid. Adding talcum to the ceramic body can reduce the firing temperature, widen the firing temperature range, and make the sintering system easier to control.…”