The effects of sintering temperature on the pore characteristics and strength of porous corundum-mullite ceramics made from Al(OH)(3), kaolinite gangue and MgCO(3) were investigated through an X-ray diffractometer (XRD), scanning electron microscopy (SEM), mercury porosimetry measurement, etc. It was found that the sintering temperature strongly affects the formation of secondary mullite, and then changes the pore characteristics and strength. The formation of secondary mullite takes place extremely quickly at 1500 degrees C. The pore size distributions are bimodal in samples sintered at 1300 degrees C and 1400 degrees C, and mono-modal in samples sintered at 1500 degrees C and 1600 degrees C. The strength are the same and low when the sintering temperatures are 1300 degrees C and 1400 degrees C, and increase sharply when the sintering temperature is increased to 1500 degrees C. The most apposite mode is a sample sintered at 1500 degrees C which has a high mullite content (86.6 wt%), high apparent porosity (42%), high crushing strength (52 MPa) and a homogeneous pore size distribution.

Keywords: porous ceramic; corundum-mullite; pore characterization; strength; sintering temperature