Solvent-free synthesis of FAU zeolite from coal fly ash

FAU zeolite is successfully synthesized from coal fly ash (CFA) as the sole silicon and aluminum sources under solvent-free conditions. CO2 adsorption and ion-exchange tests show that the product possesses excellent CO2 adsorption capacity and even better Ca2+ and Mg2+ ion exchange capacity, which is particularly important for its wide application in industrial processes.