Durable Solid Products Prepared by Calcining Fe₃O₄-Rich Ash and Glass Waste

Abstract

Solidified ash products were obtained by mixing and heating of powdered bottom Fe₃O₄-rich ash and glass waste paste in an inclined rotary incinerator. The chemical composition and structure of the product were analyzed by X-ray diffraction (XRD), scanning electron microscope/energy dispersive X-ray spectrometer (SEM/EDX), Fourier transformation infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The bulk sample mainly consisted of Fe₃O₄ and NaAlSiO₄, and glassy grain boundaries, which strongly bonded the ash to form a solid product. On the other hand, the surface of the product was covered by a Fe-free glassy layer of -10μm in thickness. The glassy surface layer was effective in preventing the dissolution of heavy metals (Pb, Cr) into aqueous acid solutions (2<pH<7).