Synthesis of Zeolite Products from Waste Stone Cake and Aluminum Dross Using Alkali Fusion and Their Removal Ability for Ba and Sr Ions

Zeolite products, including zeolites A and X, were successfully synthesized from two types of industrial waste, crushed stone cake and aluminum dross, using alkali fusion treatment, with a high removal ability for Ba2+ and Sr2+. Waste stone cake and aluminum dross are industrial waste materials, and their effective utilization is highly anticipated. Because the main components of the two waste materials are Si, Al, and O, they can be used as starting materials for the synthesis of zeolites. In this study, industrial waste was converted into crystalline zeolite products using alkali fusion. The stone cake, dross, and a mixture of these materials were transformed into a soluble phase via alkali fusion and then agitated in distilled water at room temperature to obtain an intermediate gel-like solid, followed by synthesis at 80°C to obtain the final product. The zeolites were successfully synthesized via the alkali fusion process, and selective synthesis of zeolites A and X was achieved by controlling the mixing ratio of aluminum dross to stone cake, with different cation exchange capacities (CECs). The adsorption of Ba2+ and Sr2+ from aqueous solutions using zeolite products synthesized from industrial waste, waste stone cake, and aluminum dross was examined. The zeolite products from the mixture of stone powder and dross (3:1) exhibited higher adsorption abilities for Ba and Sr ions from aqueous solution than commercial zeolite-X and zeolite-A.