PROCESS FOR PREPARING CERAMIC FOAMS FROM MICRO- AND NANO-COMPOSITES WITH POLYMER GELS

摘要

The invention relates to a process for preparing ceramic foams used for depolluting gases in thermal stations. According to the invention, the process consists in dispersing ceramic oxides such as raw kaolin, alumina, silica or mixtures thereof, for 1...2 h, in demineralized water, in the presence of 15...20% ammonium polyacrylate solution, after which in the resulting aqueous suspension there are added, while stirring, acrylic acid, N,N' methylene bis-acrylamide, sodium metabisulphite aqueous solution, another aqueous solution of potassium persulphate, possibly an aqueous solution of ferrous sulphate, there resulting a final suspension having a concentration of the ceramic oxides of 40...50 % which is poured into gelling moulds and is kept for 60...80 min for structure stabilization, after which the crude product is thermally treated at a temperature of 1000...1200°C, wherefrom ceramic foams result with a total porosity of 80% and an average diameter of the pore of 0.5...1 mm.