Abstract
The procedure of A type zeolite synthesis from fly ash was studied. A small amount of hydroxysodalite was formed from fly ash by hydrothermal reaction with 2N or 6N NaOH solution at 90°C. In the case of adding sodium aluminate content to above reaction mixture, the yield of hydroxysodalite increased but A type zeolite was not formed at all. A powder of reactive sodium silicate compound was obtained by heating the fly ash and solid sodium hydroxide at 90-130°C for 2-20 hours. A type zeolite was easily synthesized by hydrothermal reaction of the pretreated fly ash and an admixture of sodium hydroxide, sodium aluminate, water and seed of A type zeolite at 90°C for 2 hours. The yield of A type zeolite increased lineally with the reaction ratio between the fly ash and solid sodium hydroxide. The yield of A type zeolite was about 65% at the optimum condition. CEC of A type zeolite from the fly ash was about 300 meq/ 100 g.
