Abstract Porous diatomite ceramics with high porosity, low thermal conductivity and reasonably high compressive strength were prepared at relatively low temperatures (773–923 K) by the direct-gelcasting method using diatomite powder as… Click to show full abstract
Abstract Porous diatomite ceramics with high porosity, low thermal conductivity and reasonably high compressive strength were prepared at relatively low temperatures (773–923 K) by the direct-gelcasting method using diatomite powder as the main starting material, and melamine and boric acid respectively as a crosslinker and a sintering agent. The sample with solid loading of 20 wt%, after being fired at 923 K, showed the highest compressive strength of 1.3 MPa, though its porosity still remained as high as 80.7%. When the firing temperature was reduced to 873 K, the fired sample exhibited porosity of 82.5%, compressive strength of 0.87 MPa and thermal conductivity of 0.163 W/(m·K) (at 473 K). Upon reducing the solid loading to 10 wt%, the thermal conductivity (at 298 K) of the sample fired at 873 K, was further reduced to as low as 0.154 W/(m·K).
               
Click one of the above tabs to view related content.