High-aluminum fly ash recycling for fabrication of cost-effective ceramic membrane supports

In order to effectively utilize the industrial solid waste and produce high value-added products, a series of porous ceramic membrane supports made of waste fly ash and calcium carbonate mixtures were fabricated by in-situ reaction sintering method. The ceramic membrane supports with 15, 20, 25 wt % CaCO3 sintered at the range of 1200–1350 °C show the high open porosity over 30% and are further investigated. The investigated ceramic membrane supports give the main phase of anorthite, some of which contain a minor mullite phase. The pore sizes of ceramic membrane supports increase with increasing of the amount of CaCO3 and sintering temperature. The flexural strengths of ceramic membrane supports increase with sintering temperature. They are higher than 30 MPa and meet the requirement of application. This work provides a potential route to develop cost-effective ceramic membrane supports with controllable pore size, high porosity and good strength. •The main phase of synthesized ceramic supports was anorthite, containing little mullite.•FC-15, 20 and 25 supports sintered at 1200–1300 °C show high open porosity over 35%.•The pore sizes increase with increasing of sintering temperature and CaCO3 content.