Preparation of Diatomite-Based Porous Ceramics

Porous ceramics have been attracted attention extensively because of their excellent chemical and thermal stability, excellent permeability, high specific surface area, extremely low electrical and thermal conductivity, energy saving, heat resistance and corrosion resistance. In this paper, diatomite-based porous ceramics were prepared using diatomite as main raw material and calcite as pore-forming agent. The effect of calcite were studied by thermal analysis, XRD, SEM, and porosity. The calcite decomposed at 600–800 °C and CaSiO3 was synthesized in situ though the reaction of CaO from the calcite and SiO2 from the diatomite. At sintering temperature of 1050 °C, the porous ceramic with 20% calcite addition reserved sub-micrometer pore structure of raw material diatomite as well as a relative high porosity (about 60%), which showed potential application in filtration.