Preparation and characterization of microfi ltration membranes and their supports using kaolin (DD2) and CaCO3

Abstract

In this work, the supports for microfi ltration and ultrafi ltration were prepared with local kaolin (DD2) and calcite mixtures. The choice of these raw materials is based on their natural abundance (lowprice). These supports were made by extrusion technique in order to obtain tubular supports which were afterwards sintered at 1250°C for 2 h. It has been found that supports had interesting characteristics; an average pore size of about 4 µm, a porosity ratio around 52% and a tensile strength ˜ 23 MPa. Moreover, the pore size distribution is almost homogeneous (mono-modal type). The surface and the cross-section morphologies observed through a scanning electron microscope (SEM) are also homogeneous and do not present any macro defects (cracks, etc.). These supports were selected as substrates for the membrane layers used in microfi ltration (MF). The membrane layers were elaborated from zirconium oxide, using slip casting technique. The specimens were subsequently sintered at 1150°C. The microstructure and...