Metallothermic reduction using aluminum for metal and alloy production

Metallothermic reduction using aluminum (aluminothermic) is a versatile and potentially energy-efficient metallurgical process to produce metals and alloys from the oxides and compounds, leveraging the exothermic nature of the reaction. Importantly, when powered by low-carbon aluminum production using renewable electricity, aluminothermic reduction offers a near-zero-carbon reduction route, eliminating direct fossil fuel use and associated CO ₂ emissions from the reduction step. This paper examines the thermodynamic principles, kinetic mechanisms, and practical applications of aluminothermic reduction across diverse systems, including for production of iron, magnesium, titanium, rare earth metals, and processing of waste materials. Key factors such as stoichiometry composition, flux additives, and reaction conditions (temperature, pressure) are analyzed to optimize metal recovery and slag separation. Reaction mechanisms, process parameters, reactor innovations, and challenges of exothermic control, slag viscosity, impurity management, and aluminum reductant cost relative to metal product value are discussed. Secondary aluminum materials as the reductant are also reviewed as a significant alternative to reduce the cost and minimize the lifecycle emissions. The paper concludes with suggestions for future directions towards scaling aluminothermic reduction, emphasizing hybrid processes and circularity integration.