Recent progress in sustainable and energy-efficient technologies for sinter production in the iron and steel industry

Large amounts of iron ore sinter are produced throughout the world. The development of sustainable and energy-efficient technologies has become increasingly important due to the huge pressure associated with energy consumption and greenhouse gases emissions by iron ore sinter plants. This review describes recent progress in the substitution of renewable alternative fuels, modifying the properties of solid fuels and reactant gases, and process control implementation, as well as addressing the limitations of these techniques and identifying opportunities for future research. Alternative fuels are examined including biomass, hydrogen-based gaseous fuel, and recycled carbon sources for coke breeze in iron ore sintering to address environmental and energy-saving considerations. The negative impacts of alternative fuel substitution on the heat pattern and sinter quality, especially at a high substitution rate, are analyzed in terms of the fuel surface area, fuel reactivity, and matching the performance of the flame front speed and heat front speed. Pre-granulation and surface modifications of solid fuels are discussed, followed by flue gas recirculation and oxygen enrichment techniques. Finally, processes comprising raw material granulation control, fuel segregation control, and in situ process control are described, which aim to satisfy the ambitious goals of maximizing the sintering performance and minimizing energy consumption and environmental impacts.