Research status and future prospects of CO₂ application mechanisms in steelmaking-continuous casting

To address the steel industry′s emission reduction pressure under global "carbon neutrality" goals, CO₂ resource utilization in the steelmaking-continuous casting process has become a key low-carbon pathway. CO₂ ′s application mechanisms as a reaction medium, stirring gas, coolant and protective atmosphere are systematically explored, focuses on its industrial effects in converter blowing, electric arc furnace steelmaking, secondary refining and continuous casting, including covering dust/temperature control, energy/nitrogen reduction, inclusion removal and billet quality improvement. However, it yet notes three bottlenecks for its large-scale, high-quality promotion, namely unclear reaction kinetics and mass transfer under multiphase/multi-field coupling（mechanism）, poor economy due to high capture and equipment transformation costs（economy）, and severe equipment lifespan/safety impacts from CO₂′s corrosion on furnace linings and transportation systems（material）. To achieve this, it is pro‑posed that future efforts require coordinated breakthroughs across three dimensions, that are basic research, techno‑logical development, and industrial application. By integrating in-situ observation and digital twin technologies, a full-process reaction kinetics database is established. Efforts focus on developing low-cost hydrogen injection tech‑nology, targeting less than 150 yuan/t, as well as combined utilization technologies for carbon dioxide, green hydro‑gen, and renewable energy, alongside durable corrosion-resistant materials. This ultimately advances the transition from single-point demonstration to full-process integration, establishes a standardized system and economic model, and delivers replicable, scalable integrated technical solutions for the green and low-carbon transformation of the steel industry.