Currently, approximately 1.4 billion tons per year of iron ore tailing wastes (IOT) are generated, mainly in Australia, Brazil, and China. This work describes the characterization and application of two typical IOT, i.e., fine and coarse wastes. The physicochemical characterization of these IOT by different techniques such as XRF (X-ray fluorescence), XRD (X-ray diffraction), Mössbauer spectroscopy, and granulometry, indicates for the fine tailing a composition of Fe2O3/FeOOH (10-55%), SiO2 (18-65%) and Al2O3 (up to 15%) with particles of 6-40 μm, whereas the coarse tailing presents 40-150 μm particles with the composition of 8-48% Fe2O3/FeOOH, 30-90% SiO2 and Al2O3 (up to 20%). The main IOT applications discussed in this review are related to civil construction (aggregates for concrete, mortar, Portland cement additives), ceramic industry, geopolymer, synthesis of new materials such as zeolites, mesoporous silica, carbon nanotubes, adsorbents, catalysts for different reactions, in batteries and in fuel cells. It was also carried out an analysis of patents related to IOT applications and the main technological and market barriers that hinder the industrial and commercial uses of these wastes.
Substrate Integrated Waveguide Cavity Filters: Miniaturization and New Materials for IoT Applications