Porous ceramics based on natural mineral sources

Abstract

Starting raw materials, clay and diatomite, from coal mine Kolubara, Serbia were purified using heat and chemical treatment. Porous silica ceramics were obtained at low forming pressure (40-80 MPa) and low sintering temperature (1000-1300 °C) in air. Boric acid as a /ow-cost additive was used. Sintered samples have average pore si:ze diameters ranging of macroporous for clay 0.1-10 μm and for diatomite 0.05-5 μm. As-received and the obtained samples were characterized by XRD, SEM and mercury porosimetry measurements. Relations between mechanical characteristics of samples formed at different temperature were studied.