Microstructure of porous corundum and mullite-based composite water permeable ceramics prepared with fly ash and aluminum oxide

摘要

Porous corundum and mullite-based composite water permeable ceramics were prepared with fly ash and aluminum oxide by the process of raw material mixing,molding, and sintering. The influence of the mass ratio of raw materials and moldingpressure to the properties of the samples were studied. The mineral phases, porousstructures, and mechanical properties of the samples were studied by X-ray diffraction,scanning electron microscope, and mercury injection method. The compressive strengthsof the samples varied between 28.3 MPa and 31.2 MPa, and the porosity reached up to50%. The water absorption coefficients of the samples ranged from 0.95 g cm~(−3) to 1.40 gcm~(−3) and water release parameters of all samples are about 30 h. The experimental waterpermeability coefficients of the samples are between 0.59 μm~2 Pa−1 s~(−1) and 3.00 μm~2 Pa~(−1)s−1.