Life cycle assessment of metallurgical options for recycling high-alloy tool steels

The iron and steel sector accounts for around 8 % of global energy-related CO₂ emissions, prompting the need for sustainable approaches in steel recycling. In Denmark, steel recycling is currently insignificant without large-scale steelmaking facilities, most high-alloyed steel scrap is exported—despite local potential for alternative powder metallurgical options. To explore the potential of high-alloyed steel recycling in Denmark, this study applies ex-ante life cycle assessment (LCA) to compare the environmental impacts of current and potential alternative recycling routes, including powder metallurgy approaches like gas atomization (GA) and spray forming (SF). Results indicated that local reprocessing using SF could reduce climate impacts by approximately 50 % compared to the current export and reprocessing by electric arc furnaces (EAF). SF shows the lowest impact overall, achieving only 40 % of secondary production using EAF. Metal remelting steps are the critical process to further decrease the impacts by either avoiding and/or improving efficiency.