Synthesis of linde F zeolite by KOH treatment of coal fly ash

Abstract

The products from KOH-treated coal fly ash (FA) was systematically examined. Only linde F zeolite was formed under the reaction conditions of the present experiments. The yield of the zeolite from 2 g of FA was highest when reaction time, temperature, KOH concentration and volume were 48 h, 95°C, 8 mol dm^-3 and 50 ml, respectively. In this case, FA spheres were completely dissolved out, and square prisms of linde F zeolite crystal with 0.5 to 2.0μm in width and 1 to a few μm in length were formed. The specific surface area and cation exchange capacity of the product were 2.02m²/g and 2.3 meq g^-1, respectively.