Elaboration and characterisation of apatite based mineral supports for microfiltration and ultrafiltration membranes

The development and the characterisation of new supports for microfiltration and ultrafiltration membranes from apatite applied to filtration are presented. The choice of this material is based primarily on its low cost (considering its abundance in the Tunisian ores). The support, with tubular configuration, was prepared from natural apatite: apatite powders were crushed for 30 min and sieved to 200 μm. The resulting powders, mixed with organic additives and water, could be extruded to elaborate a porous structure. The firing temperature of the support is 1160 °C. The morphologies of the surface and the cross-section observed on scanning electron microscope (SEM) are homogeneous and do not present any macro defects (cracks, etc.). The mean pore diameter, measured by mercury porosimetry, is 6 μm and the pore volume is 48%.