Abstract:As a research focus in the current iron and steel metallurgy industry, blast furnace gas fine desulfurization technology employs the three-stage dry treatment process of dechlorination-hydrolysis-desulfurization as the mainstream process. Each stage is supplemented by specific reagents, and the cost of these reagents accounts for 60% to 80% of the overall operation and maintenance of the desulfurization process, making them of great significance to the desulfurization technology. This paper introduces three most common key reagents: dechlorinating agents, hydrolyzing agents, and iron oxide desulfurizing agents, systematically elaborating on their composition, preparation methods, reaction mechanisms, and deactivation mechanisms.For dechlorinating agents, the main preparation methods include mechanical mixing and loading methods. The mechanical mixing method is primarily used for preparing calcium oxide-based dechlorinating agents with lower production costs, while the loading method is mainly applied to alumina-based dechlorinating agents, resulting in more uniform dispersion of active components but higher preparation costs. Alumina-based hydrolysis catalysts dominate the blast furnace gas fine desulfurization process; most studies on their deactivation mechanisms have focused on deactivation factors such as O2, with insufficient in-depth research on the impact of acidic gases like HCl and HCN in blast furnace gas. The activity of iron oxide desulfurizing agents is significantly influenced by their crystal structure, and those with more crystal defects and hydroxyl active sites typically exhibit higher desulfurization activity.In terms of industrial fine desulfurization operating costs, source control processes currently remain at a disadvantage with higher costs compared to traditional end-of-pipe treatment methods. Looking forward, future research should focus on promoting studies on the synergistic mechanism of the three reagents based on actual operating conditions to optimize desulfurization efficiency and improve reagent utilization; advancing the establishment of reagent quality and evaluation standard systems to standardize the reagent market; and conducting research on the regeneration and resource utilization of waste reagents to reduce resource waste and lower operating costs.
