METHOD OF PRODUCING NANOPOROUS CERAMICS BASED ON MULLITE Russian patent published in 2020 - IPC C04B35/185 C04B35/624 B82Y40/00 C04B38/06 

FIELD: technological processes.

SUBSTANCE: invention relates to production of porous mullite materials and articles made therefrom and can be used in production of filtration elements for various fields of national economy, in particular, for purification of drinking water. Of Al(NO₃)₃⋅9H₂O salt, diluted solution with concentration of 0.1 M is prepared, from which is deposited aluminum hydroxide with aqueous solution of NH₄OH (~1 M) at temperature 0-2°C. Gel-like residue Al(OH)₃ is subjected to vacuum filtration with subsequent heat treatment at 150°C to form boehmite (AlOOH). To obtain amorphous SiO₂, silicic acid is subjected to thermal decomposition in the temperature range of 100-250°C. Mixing is performed γ-Al₂O₃ and amorphous SiO₂ in ratio Al₂O₃ : SiO₂ = 3:2 in dry grinding mode, then into mixture of 3Al₂O₃⋅2SiO₂ introducing a pore-forming component, in form of ammonium carbonate in amount of 10 or 20 wt% to total weight of powder and stirred for 10 minutes for homogeneous distribution (NH₄)₂CO₃ in whole volume of mixture, after which produced powders are compacted at pressure of 70 or 100 MPa and burnt at 1300°C for 2 hours.

EFFECT: method enables synthesis of single-phase mullite with controlled open porosity and narrow monomodal pore distribution.

1 cl, 2 tbl, 6 dwg