Synthesis and characterization of refractory cordierite precursors from rice husk silica

Abstract

This study describes the production of refractory cordierite ceramics by mixing silica extracted from rice husk, Al2O3 and MgO powder. The mixture was sintered at different temperatures of 1050, 1110, 1170  C for 4 h. The phases formed and structure change as a result of sintering were investigated using different characterisation technique of Fourier transform infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Density, porosity, hardness and electrical resistivity were also measured. Cordierite, spinel and cristobalite were the major phases in the samples sintered at temperature range of 1050-1170 C. µ-cordierite was formed through the intermediate phases of spinel and cristobalite at 1050C. The final phase -cordierite (indialite) was produced through µ-cordierite and cristobalite from 1110 to 1170 C. The density, hardness and electrical resistivity were found to increase with increasing of sintering temperature, as they are strongly influenced by microstructure of the material