Low-temperature sintering of porous SiC ceramic membrane with industrial-grade sodium meta-aluminate as a sintering additive

Silicon carbide (SiC) ceramic membranes require high sintering temperatures (greater than 1800 °C), which consume substantial energy and increase the production costs. In this study, we report the successful preparation of a low-cost, high-performance SiC ceramic membrane at a low temperature of 800 °C using industrial-grade sodium meta-aluminate (NaAlO2) as a sintering agent. The effects of sintering temperature and NaAlO2 content on the microstructure, porosity, bending strength, pore size, and pure water permeability of the SiC membranes were investigated systematically. The results indicate that the optimal sintering temperature and NaAlO2 content are 800 °C and 10 wt%, respectively. The SiC membrane prepared under these conditions exhibited an average pore size of 2.57 μm, a porosity of 52.07%, a bending strength of 50.2 ± 0.41 MPa, and a very high pure water permeability of 103.3 m3 m−2 h−1 bar−1. Additionally, the SiC membrane prepared in this study also exhibited good chemical stability and could be used in acid and alkali environments for long periods. These results highlight the potential of SiC membranes in various applications, particularly in water treatment and filtration application. The findings of this study are useful to enrich membrane technology knowledge and guide future research and development of related technologies.