Ceramic substrates for filtration membranes based on the dispersed fly ash microspheres

A technique has been proposed for producing ceramic substrates for filtration membranes based on a narrow fraction of dispersed fly ash microspheres using cold uniaxial pressing followed by high-temperature sintering. It is shown that increasing the sintering temperature from 1000 to 1150°C leads to a decrease in open porosity from 40 to 24%, a decrease in the average pore size from 1.60 to 0.34 μm, and an increase in the compressive strength from 9.5 to 159 MPa. The obtained substrates are characterized by liquid permeability values of 1210, 310, 240, 170 l m–2 h–1 bar–1 for sintering temperatures of 1000, 1050, 1100, 1150°С, respectively. Experiments on filtration of aqueous suspensions of dispersed microspheres (dav = 2.5 µm) and microsilica (dav = 1.9 µm) through a substrate with a sintering temperature of 1150°C showed the rejection close to 100%. The proposed methodology for using ash waste in the production of membrane materials contributes to the development of technologies for the integrated processing of thermal energy waste.