PRODUCTION OF POROUS ZEOLITE HARDENED BODY

PROBLEM TO BE SOLVED: To obtain a zeolite hardened body having excellent adsorptivity by granulating a raw material containing a silica and/or alumina-containing material, an alkali and water and after molding, hydrothermally treating the molding. SOLUTION: The silica and/or alumina-containing material composed of a granular waste material such as coal ash is dipped into an alkali hydroxide solution such as sodium hydroxide at 0-100 deg.C for 6-48 hr to be treated with the alkali. Silica and/or alumina is converted to silicate ion and/or aluminate ion by the alkali treatment. The material after the treatment is adjusted to 20-30 wt.% in water content by adding the raw material before the treatment, granulated to have 2-30 mm average particle diameter, molded into a cylindrical state, a block like state, or the like, by centrifugally molding or vibration molding. The molding is hydrothermally treated at 180-200 deg.C for 2-24 hrs to be hardened to obtain the porous zeolite hardened body excellent in water permeability and having the surface area equal to that of charcoal.