Preparation of porous cordierite using gelcasting method and its feasibility as a filter

Various-shaped porous cordierites with different pore sizes and with constant porosity of 80% were prepared by conventional mechanical foaming method combined with gelcasting using water-soluble polymers. Foamed slurries and pore structure of the products were characterized by image analysis and SEM. Apparent bubble size was dependent on the type of surfactant and not on surfactant concentration. Mean pore diameters of anionic and cationic surfactants were 100 and 200 mum, respectively. Feasibility of porous cordierites of foam type structure as filters for dust-collection was investigated. Membrane layers of 150 mum were uniformly built up on the external surfaces of candle-shaped supports to prepare trial filters. Gas permeability was above 200 x 10(-13) m(2) and was dominantly determined by that of membrane layer. In the dust collection test, removal efficiency for particulates finer than 10 mum was above 99.99%.