New perspectives for coal ash utilization: synthesis of zeolitic materials☆

Abstract An alternative use for coal ash was investigated, based on the metakaolin-type material present in the ash. In this study, fly ash from Amaga coal (Colombia) was used. The ash was treated with sodium hydroxide at different concentrations and various times and temperatures of crystallization. The zeolite produced contained 50–75% of a faujasite type material, and had an adsorption capacity ≈70–80% of that of the commercial zeolite 13X.