Thermochemical Route for Extraction and Recycling of Critical, Strategic and High-Value Elements from By-Products and End-of-Life Materials, Part II: Processing in Presence of Halogenated Atmosphere

Editorial for the Special Issue: "Characterization and Processing of Complex Materials"

The Special Issue aimed to provide a forum for scientists and engineers to share and discuss their pioneering/original findings or insightful reviews on the "Characterization and Processing of Complex Materials" [...].

Processing of End-of-Life Materials and Industrial Wastes

This Special Issue (SI) offered the opportunity to present the latest scientific developments and findings in the field of processing of end-of-life materials and solid industrial wastes. Due to the large quantity of wastes generated and to their complex elemental and mineralogical composition, the approaches, methods and processes proposed for their decontamination, energy beneficiation and high-added-value metal recovery are complex and diverse. Some transversal research investigations using wastes as remediation agents and for synthesis of new materials were also included in the SI. After a brief introduction, the main scientific contributions and findings of each article published in the SI are summarized.

Some Aspects of the Thermochemical Route for the Valorization of Plastic Wastes, Part I: Reduction of Iron Oxides by Polyvinyl Chloride (PVC)

The mass production of synthetic plastics began in the last century and today they have become one of the most abundant man-made materials. The disposal or the beneficiation of end-of-life plastics represent a great challenge for society especially in the case of polyvinyl chloride (PVC). This study is focused on the use of PVC waste as a useful agent for the direct reduction of hematite (Fe₂O₃) after a thermal treatment at 300 °C for removing the chlorine contained in PVC. Thermal reduction tests were conducted from 600 °C to 1100 °C with (Fe₂O₃ + PVC + clay) pellet mixtures in which clay was used as plasticizing and binder agent of the pellets. The starting samples and treatment residues were analyzed by scanning electron microscopy through energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD) to monitor the chemical behavior and reactivity of the pellet constituents during their thermal treatment. The stepwise reduction of hematite up to metallic iron was achieved at temperatures approaching 1000 °C, confirming the capability of using PVC waste for the direct reduction of iron oxides.