Elaboration of porous gehlenite and anorthite based ceramics using low price raw materials

摘要

Porous ceramics of good quality cost a lot in the world market, which has limited their use in developing countries. This is why this work was mainly devoted to prepare low-cost and good quality ceramics, using kaolin (DD2 type) and calcite (CaC03) available in abundance in Algeria. Based on previous results, 28 wt% CaC03 ceramic was selected. The presence of CaC03 favors to achieve porous samples characterized by a high percentage of porosity due to the CO2 release and CaO formation during its calcination at about 700 °C. The choice of these raw materials is based on their natural abundance (low price). It has been found that the samples had interesting characteristics: average pore size between 2.87 and 6.50 ytra and porosity between 53 and 57%. It has also been found that the manufactured membrane supports are mainly constituted of gehlenite and anorthite phases. Moreover, the pore size distribution was mono-modal type. The surface and cross-section morphologies observed through a scanning electron microscope were also homogeneous and do not present any possible macro-defects (cracks, etc.).