Synthesis and Characterization of Iron-Rich Glass Ceramic Materials: A Model for Steel Industry Waste Reuse

Wastes deriving from steel industry, containing large amounts of iron oxides and heavy metals, when collected in landfills are subjected to atmospheric agents, with consequent release of toxic substances in the soil and groundwater. The reuse of these wastes as raw materials for the production of advanced materials is a viable way both to overcome the environmental impact and to reduce the disposal costs, proposing new technologically advanced materials. This work aims to simulate these interesting glass-ceramics by using glass cullet coming from recycled municipal waste and high amount of iron(III) oxide (from 25 wt% to 50 wt%), the prevalent component of steel waste. The oxide was mixed with glass cullet and vitrified. The samples composition and the microstructure were investigated by scanning electron microscopy (SEM), and X-ray diffraction (XRD) was used to evaluate the nature of the crystalline phases. The chemical stability of the materials, in terms of ionic release into saline solution, was assessed. The electrical behavior of the samples was also investigated by varying the iron ions content and controlling the crystallization process. It is possible to obtain chemically stable materials with a nearly semiconducting behavior.