Activated Coke Fly Ash-Aided SiC Supports: Enhanced Mechanical Strength and Durability for High-Temperature Gas Filtration

Silicon carbide (SiC) ceramic membranes are promising for high-temperature gas filtration due to their excellent thermal and chemical stability. However, the industrial deployment of conventional SiC ceramic membranes is limited by their low bending strength and high fabrication cost. This study pioneers a sustainable strategy utilizing industrial waste activated coke fly ash (ACFA), as a dual-functional sintering aid and pore-forming agent for the fabrication of high-performance SiC supports. By systematically investigating the sintering kinetics and phase evolution mechanism of the ACFA-aided SiC supports, we established a composition-property relationship that reveals the critical role of ACFA-derived mineral phases in simultaneously enhancing mechanical integrity and filtration performance. With 12 wt.% ACFA sintered at 1400 °C the SiC support achieved optimal bending strength (28.6 MPa). This bending strength was approximately 25% higher than that of conventional SiC supports (22.8 MPa). Moreover, the ACFA-aided SiC support exhibited satisfactory thermal shock resistance and corrosion resistance during 20 cycles of thermal shocking and alkali metal corrosion tests. This work provides a sustainable route for fabricating cost-effective SiC supports with enhanced mechanical strength to broaden their applications in industrial hot gas filtration.