Effect of sintering temperature in preparation of granular ceramic filter

Abstract Ceramic filters are quite an efficient component for hot gas filtration due to their high collection efficiency and high thermal durability. Among the various steps to fabricate a ceramic filter, sintering is one of the most important processes. In this study, disk-type ceramic filters were prepared at various sintering temperatures, and the effect of sintering temperature on physical/chemical properties and filtration performance were investigated. We found that the sintering temperature strongly influenced the physical and chemical properties as well as the filtration performance of a ceramic filter. The adhesive force among powders and the oxidation degree of Si species are more important parameters to determine the mechanical strength of a ceramic filter than other physical properties. Filters prepared at sintering temperatures lower than 1450°C have low mechanical strength due to insufficient binding energy among powders, and filters prepared at sintering temperatures higher than 1500°C also have low mechanical strength due to the oxidation of SiC to SiO₂. However, ceramic filters sintered at 1350°C and 1400°C achieve a better filter quality factor than other filters, even though they have lower mechanical strength. Therefore, both mechanical strength and filter quality factor should be considered to choose a better ceramic filter.