Preparation of MgAl₂O₄ Porous Ceramics for High-Temperature Flue Gas Filtration Application by In-Situ Decomposition Method

ABSTRACT: Porous ceramic filters exhibit excellent prospects for application in the field of high-temperature flue gas filtration. In this study, the MgAl₂O₄ porous ceramics were prepared using α-Al₂O₃, MgO, and EDTA-MgNa₂ as raw materials by the in-situ decomposition method. The effect of the introduction of EDTA-MgNa₂ on phase composition and microstructure, as well as the correlation between the content of EDTA-MgNa₂ and ceramic properties, was investigated using XRD, SEM, and EDS. The results revealed that the introduction of EDTA-MgNa₂ formed pores, thereby improving gas permeability. Additionally, the addition of EDTA-MgNa₂ was beneficial for the formation of a transitional liquid and promoted sintering, thereby slowing the decrease in compressive strength. The optimal specimen is the ceramic with 10 wt% EDTA-MgNa₂, which exhibits a high porosity of 56.28%, a compressive strength of 10.93 MPa, and a high gas permeability coefficient (8.84 × 10⁻⁹ m²).