Synthesis of Zeolitic Material from Coal Fly Ash in Seawater

Zeolitic materials were prepared from coal fly ash in seawater and compared with those prepared in distilled water in order to evaluate the effect of seawater on the characteristics of the products. Zeolitic materials were prepared at 80°C for 24 hours in activated solutions, which themselves were prepared by dissolving NaOH in the seawater or distilled water. Using 2-3 M NaOH in seawater, zeolite-A, hydroxysodalite and herchelite were produced, as same as those prepared in distilled water. The study found that the mixture products have high cation exchange capacity (CEC=250-300 cmol/kg), which is higher than that of commercial natural zeolite. The CEC of the product prepared from 4 M NaOH in seawater is lower than that from 4 M NaOH in distilled water.