关键词: 钢铁制造, 流程结构, 全废钢电弧炉, 氢冶金, 低碳发展

Abstract: According to the analysis and assumption of the low-carbon development of the iron and steel industry， the future iron and steel production and manufacturing processes will gradually evolve into three categories： blast furnace-converter long process， all-scrap electric arc furnace short process and hydrogen metallurgy-electric furnace process.The key factors affecting the carbon emission level of the three types of processes include process structure， raw material structure， energy structure， product structure， equipment level， management level， technical level， etc. This paper uses the "carbon peak and carbon neutrality" analysis model （CISRI-CPCN） constructed by China Iron and Steel Research Institute to draw a carbon reduction roadmap for the three types of processes.The research results show that the carbon emission of the three types of processes decreases annually. From 2020 to 2060， the CO2 emission of the long process will be reduced from 2.0 t/t （steel） to 0.87 t/t （steel）， and carbon neutrality can be achieved through carbon sinks， carbon trading and other means. In 2050， the short process will be reduced from 0.45 t/t （steel） to close to 0， which is expected to achieve "near-zero carbon" smelting. In 2060， the hydrogen metallurgical electric arc furnace process （50% scrap steel + 50% hydrogen direct reduced iron raw material structure） will be reduced from 1.31 t/t （steel） to close to 0， basically achieving carbon neutrality. Comprehensively considering the development needs of the national economy， it is recommended that the steel industry gradually adjust the product structure of the three types of processes in the development of steel industry  reduction in the future. The product structure of the long process should gradually transform into the production of flat products， especially high-end flat products， which are mainly distributed in coastal deep-water port areas. The short process should take the long products for construction as the entry point， gradually replace the small and medium-sized blast furnace-converter process， and partially produce single varieties such as combined steel and other high-quality special steel or stainless steel， mainly in the layout around cities with rich scrap steel resources. At present， the hydrogen metallurgy-electric furnace process is still in the stage of exploration and development， and many difficulties in green hydrogen， economy， technical reliability and engineering needed to be overcome.

Key words: Steel Manufacturing, Process Structure, All-scrap Electric Furnace, Hydrogen Metallurgy, Low-carbon Development