Preparation, microstructure and properties of cordierite-mullite-corundum porous ceramics for high-temperature gas-solid separation

Abstract

In order to obtain ceramic materials for high-temperature gas-solid separation, the cordierite-mullite-corundum porous ceramics were prepared by particle stacking and pore-forming agent method, with bauxite as aggregate and in-situ synthesized cordierite as binder. Designed four-factor four-level orthogonal experiments for the first time to improve the porosity of the samples. The phase composition and microstructure of the samples were studied by XRD, SEM and other testing methods. The results show that: X6 sample (firing temperature of 1340 °C, 50 wt% binder, aggregate coarse, medium and fine mass percentage 30:50:20, plus 20 wt% charcoal powder, 10 wt% graphite) has the best comprehensive performance, with porosity of 41.51 % and bending strength of 17.88 MPa. Pore size distribution range from 10 to 40 μm. Corundum and mullite, with excellent high-temperature properties formed by the aggregate, are tightly bonded together by cordierite, contributing to the strength of the porous ceramics. The addition of pore-forming agent improves the porosity and forms a stable and uniform pore structure in the porous ceramics. The high porosity and large connected pore size reduce the viscous resistance of the porous ceramics to the gas, improve the filtration performance of the material, and make it expected to be applied in the field of hot gas clean-up.