Influence of La2O3 on preparation and performance of porous cordierite from rice husk

A porous cordierite was synthesized at 1350 °C using rice husk as silica source and pore forming agent, and La2O3 as fluxing agent. The crystal phases of the cordierite were analyzed by X-ray diffraction (XRD) and their microstructures were observed by scanning electronic microscopy (SEM). The flexural strength, porosity and thermal expansion coefficient of the porous cordierite samples were investigated in detail. Results showed that when 5 wt.% La2O3 was added, the flexural strength, porosity and thermal expansion coefficient of the porous cordierite (named L5) reached 11.38 MPa, 45.02%, 3.03×10−6 °C−1, respectively. Compared with that of the cordierite without La2O3, the flexural strength of L5 increased about 9 MPa, the porosity exhibited a slightly increase and the thermal expansion coefficient had no significant change. It was significant that the cordierite formation temperature was greatly decreased with the addition of La2O3.