硅藻土多孔基板的制备与优化

以天然矿物材料硅藻土为基体、球型石墨为造孔剂、聚四氟乙烯为粘结剂，采用搅拌混料、等静压成型及高温烧结工艺，制备出新型硅藻土多孔基板。通过扫描电子显微镜、X射线衍射仪、阿基米德排水法、三点抗弯强度测试，分析了造孔剂添加量、成型压强、烧结温度对基板的微观形貌、物相组成、显气孔率及抗弯强度的影响。结果表明，在造孔剂添加量为40%、成型压强为160 MPa、烧结温度为1 000℃时，可以获得显气孔率为50.1%、体积密度为0.97 g·cm-3、抗弯强度为4.43 MPa、孔道尺寸相对均匀的硅藻土多孔基板，孔径分布约在20 μm左右。该研究拓宽了矿物材料的开发和应用领域。 

Preparation and Optimization of Diatomite-based Porous Substrates

The novel diatomite-based porous substrates were prepared via the combined processes including stirring mixing, isostatic pressing and sintering with the diatomite as the source material, carbon powder as the pore-forming material, and PTFE as the binder. The effects of pore-forming agent content, molding pressure and sintering temperature on the microstructure, phase composition, open porosity and bending strength of the substrates were investigated by the scanning electron microscope, X-ray diffractometer, Archimedes method and Three-point bending strength tests. The results indicated that the diatomite-based porous substrates with open porosity of 50.1%, apparent density of 0.97 g·cm-3, bending strength of 4.43 MPa and relatively uniform pore size of 20 μm were obtained at the optimal preparation conditions of carbon content of 40%, forming pressure of 160 MPa and the sintering temperature of 1 000℃. The results expand the new application field for the development and utilization of mineral materials.