Deposição direta de ferro metálico a partir de Fe2O3 em meio alcalino e eutético

Abstract

Iron is essential for the industry, playing a crucial role in steel manufacturing and infrastructure. Traditionally, obtaining iron via blast furnaces is efficient but consumes a lot of energy and generates high CO₂ emissions, negatively impacting the environment. Blast furnace iron production is responsible for 7-9% of global CO₂ emissions. To reduce these emissions without compromising the need for metallic iron, methods are being sought to minimize these emissions. One such method is the direct reduction of iron oxide (Fe₂O₃, Hematite). According to the literature, direct reduction in a highly alkaline solution yields better results for metallic iron deposition. To achieve optimal conditions for direct reduction, tests are conducted by varying the molarity of the alkaline solution to 5, 10, and 18 mol/L, while keeping voltage, temperature, and Fe₂O₃ concentration constant. Based on the best NaOH concentration results, a new series of tests is performed to determine the optimal Fe₂O₃ concentration, aiming for the best deposition results relative to Fe₂O₃ amount in the solution. As the best deposition conditions are identified, it is necessary to determine the optimal potential for deposition. Although high current is essential for direct reduction, at a certain potential, the electric current in the solution stops depositing iron and starts producing hydrogen. A significant advantage of direct metallic iron deposition is the ability to adjust temperature to optimize iron deposition, based on temperature variation. Similar studies were conducted for the eutectic solvent solution. As it was not possible to differentiate the molar ratio of the solution, the studies focused on varying Fe₂O₃ concentration, potential, and temperature.