Novel Aerogel Absorbent Derived from Iron Tailings Via Atmospheric Drying

Silica-based aerogel composite was prepared adopting sol–gel technique combined with atmospheric drying method utilizing waste environmentally hazardous iron tailings. High-temperature alkali fusion was applied to extract the Si, Al and Fe in the tailings so as to maximize recovery of valuable elements. The SiO₂-Al₂O₃ (SA) and SiO₂-Al₂O₃-Fe₂O₃ (SAF) aerogel composites were subjected to assess its adsorption capacity for macromolecules, utilizing methylene blue (MB) as the adsorbate. The specific surface areas of the SA and SAF aerogel were estimated to be 922.03 m²/g and 683.84 m²/g. The equilibrium adsorption capacity for MB was estimated to be 318.47 mg/g and 334.44 mg/g, respectively. Although the specific surface area of SAF was lower than SA, it offered higher MB adsorption capacity which could be attributed to the presence of iron oxide. The results promised utilization of iron tailing generated aerogel composite as a potential adsorbent for separation of high molecular weight compounds.