Properties and performance of cordierite-bonded porous silicon carbide membrane prepared using waste fly ash and other oxide additives

The low-cost cordierite-bonded porous SiC ceramic membranes were successfully synthesized at 1300°C for 1 h in the air by in-situ solid-state reactions of SiC with a mixture of fly ash, α-Al2O3 and MgO (FAM). The effects of sintering temperature and FAM content on porosity, mechanical strength, phase compositions, microstructure and permeability were carefully investigated. The ceramics prepared at 1300°C with a 20 wt% FAM mixture showed a very high mechanical strength of 85.8 MPa at a porosity of 28 vol%. The addition of pore former effectively improved the porosity and permeability properties without significantly degradation of mechanical strength. The membrane exhibited 98.4% oil removal efficiency from synthetic oil–water emulsion (1000 mg l–1), which suggests that the membranes are suitable for oil–water separation and other microfiltration applications. The use of fly ash successfully reduced the sintering temperature for the fabrication of ceramic membranes and provided an efficient way of utilizing waste resources.