Influence of blast furnace pellet proportions on environmental impact and global warming: A life cycle assessment

The utilization of a high proportion of pellets in blast furnace enhances the reducing of the emission of CO2 and other pollutants, such as SO2, NOx, dioxin, during the ironmaking process, thereby contributing to environmentally sustainable and low-carbon ironmaking. The influence of pellet proportions on the pollutants and greenhouse gas emissions from blast furnace ironmaking, examined from a life cycle perspective, necessitates further investigation. This study utilized ironmaking production data of a steel company in China to explore the influence of pellet ratio. The results showed that the primary environmental impact associated with blast furnace hot metal production is 'Global warming', followed by 'Resource depletion' and 'Non-renewable energy'. As the proportion of pellets increased from 8.47 % to 45.00 %, the contribution to 'Global warming' decreased from 1884.8 kg CO2/t to 1784.3 kg CO2/t, 'Resource depletion' declined from 1527.3 kg Fe/t to 1369.2 kg Fe/t, and 'Non-renewable energy' consumption reduced from 996.8 kg Coal/t to 827.3 kg Coal/t. The life cycle CO2 emissions for hot metal production decreased from 1765.3 kg/t to 1671.9 kg/t. Sensitivity analysis identified 'Coke' as the most sensitive factor of CO2 emission in hot metal production process. Therefore, the application of high proportion of pellet in blast furnace, which effectively reduces the coke ratio in blast furnace, represents a viable strategy for CO2 emission reduction. Actively promoting the use of a high proportion of pellets in the blast furnace ironmaking process has emerged as an effective strategy for energy conservation and carbon emission reduction.