The preparation and characterization of porous tubular ceramic composite microfiltration membranes, using kaolins and calcium carbonates, were reported. The porous gehlenite (2CaO·Al 2 O 3 ·SiO 2 ) and anorthite (CaO·Al 2 O 3 ·2SiO 2 ) based ceramics were obtained by a solid state reaction. A ceramic support, sintered at 1250°C, within an average pore size of about 8 μm, a porosity of about 47% and a compression strength around 40 MPa, was prepared. The microfiltration active top layer was added on the support by a slip casting from clay powder suspensions. The novel microfiltration membrane layer has a thickness of 40 μm and an APS value of about 0.2 μm. This average pore size value was improved and considerably lower than those reported in the literature (0.5 μm). The performance of the novel microfiltration ceramic membrane was determined for evaluating both the water permeability and rejection. This proved the potentiality of the membrane produced in the microfiltration field. Moreover, the good adhesion, between the support and the active microfiltration layer membranes, was also proved. A correlation between microstructures of used powders and physicochemical properties was discussed. Finally, the origin of the unique two powder order membrane depositions was also proposed.

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The supports for microltration (MF) and ultraltration (UF) were prepared with local kaolin (Djebel Debagh: type 3: DD3) and calcium carbonate (CaCO3) mixtures. The choice of these materials is based on their natural abundance (low price). In this work, the tubular ceramic supports were prepared by the extrusion method. The sintering was carried out for 2 hours, at temperatures laying between 1150 and 1300 • C. They are then characterized by various techniques: mercury porosimetry, scanning electron microscopy and x-ray diraction. The obtained results revealed that the main phase formed during the sintering step was anorthite with a minor phase of mullite. Moreover, it has been found that supports sintered at temperatures less than 1300• C had interesting characteristics; an average pore size ranged between 3.918.56 µm, a porosity ratio of 42.050.4%, a exural strength ≈6777 MPa and the pore size distribution is bimodal type. According to their average pore sizes, they may be used either as supports for MF or UF membranes.

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