Low-cost Preparation of Porous Ceramic Supports Using Natural Minerals

The base application of porous ceramic membrane is ceramic support. For conventional ceramic supports (such as alumina), the expensive raw materials and high sintering cost both restrict their applications. Therefore, the low-cost preparation of ceramic support with natural minerals has attracted more attention. In this paper, a series of porous ceramic supports were fabricated with kaolin clay, talc and calcium carbonate as raw materials. The sintering characteristic of the green body was analyzed by thermal expansion instrument. The phase composition, micro-structure, pore size distribution and bending strength were characterized by X-ray diffractometer, scanning electron microscope, mercury porosimeter and universal testing machine. The acid and alkali corrosion resistances of the supports were also investigated. The results indicate that the obtained green body exhibits a superior low-temperature sintering characteristic. The porous supports were prepared via chemical reaction sintering. The suitable sintering temperatures of the supports are in the range of 1000–1200 ℃. The obtained supports have a homogeneous micro-structure and a unimodal pore size distribution. The porous supports prepared at 1000–1200 ℃ have the open porosities of 49.8%–49.4%, the average pore sizes of 1.09–1.83 μm, the bending strengths of 40.57–28.85 MPa, the nitrogen gas flux of 119–340 m³·m^–2·h^–1 under a trans-membrane pressure of 0.1 MPa and a superior alkali resistance as well.