Abstract: Test was conducted on synthesizing zeolite A and zeolite Y by hydrothermal method and melting-hydrothermal method with the fly ash of Lueyang Power Plant. The results indicate that when fly ash is under the hydrothermal reaction and alkaline condition at 80 ℃ for 4 d, fly ash zeolite containing zeolite A and zeolite Y can be obtained. Zeolite A can be obtained by adding Al(OH)₃ and NaOH solids into fly ash, melting at 800 ℃ for one hour and hydrothermal reaction at 80 ℃for 12 h; and Zeolite Y can be obtained by adding wollastonite and NaOH solids into the fly ash, melting at 800 ℃ for one hour and hydrothermal reaction at 80 ℃ for 36 h. The three kinds of synthesizing zeolite are compared with natural zeolite and fly ash in adsorbing Cd²⁺ in the solution, and the adsorption ability is sequenced from strong to weak as: zeolite Y ＞zeolite A ＞flyash zeolite ＞natural zeolite ＞fly ash.

Key words: Fly ash, Hydrothermal method, Melting hydrothermal method, Zeolite, Cd²⁺, Adsorption