Abstract:Against the backdrop of China′s "Dual Carbon", CO emission reduction technologies arecrucial in the sintering process. We employed Computational Fluid Dynamics (CFD) to developseparate models for the combustion of fuel particles and for sintering machines. Numerical simulationswere conducted to study the effects of oxygen concentration on fuel particle combustion and thecombustion process within the sintering bed. For fuel particles, increasing oxygen concentrationEnergy Environmental Protectioneffectively improves conditions for complete combustion, enhances fuel combustion efficiency, andreduces CO emissions. Higher oxygen levels promote more thorough oxidation reactions, ensuring agreater proportion of fuel conversion to carbon dioxide (CO) rather than carbon monoxide (CO).However, the influence of oxygen concentration on fuel combustion behavior during sintering is morecomplex. Internal fuel combustion in the sintering bed is simultaneously affected by heat transfer andoxygen concentration within the material layer. Increasing oxygen concentration leads to a lower fuelignition point, extending the high-temperature zone and increasing oxygen consumption due toincomplete combustion. When the increase in oxygen concentration is small, the proportion ofincomplete fuel combustion increases. This is because the additional oxygen initially promotes fasterignition but does not sufficiently support complete combustion throughout the sintering bed layer.Consequently, when the oxygen concentration reaches 23%, the sintering combustion efficiencydecreases to 94.4%, the sintering temperature drops, and the CO concentration in the combustionproducts increases. This phenomenon highlights the delicate balance between oxygen availability andcombustion dynamics during sintering; insufficient oxygen results in incomplete combustion andincreased CO emissions. Further oxygen concentration increases, combined with rising layer temperature,optimize the kinetic conditions for CO secondary combustion. This indicates that excess oxygensupports initial combustion and facilitates further CO oxidation to CO in the high-temperature regionsof the sintering bed. Consequently, the sintering combustion efficiency improves, and the CO emissionconcentration decreases. When the oxygen concentration is increased to above 27%, the combustionefficiency exceeds 94.9%, significantly optimizing fuel utilization efficiency during sintering andreducing CO emission concentration in the sintering flue gas. This indicates a threshold oxygenconcentration beyond which the benefits of enhanced combustion efficiency and reduced emissionsbecome pronounced. These findings highlight the importance of carefully controlling oxygen levelsduring sintering to achieve both energy efficiency and environmental goals. This study providesvaluable insights into how oxygen concentration improves combustion efficiency and reduces emissionsduring sintering, contributing to energy efficiency and environmental protection in industrial applications. Close-