The method of reducing energy consumption in large blast furnace smelting by low-silicon smelting

Currently, achieving carbon peaking and neutrality poses significant challenges for China's iron and steel industry. Low-carbon smelting in large blast furnaces (BFs) is poised to be a pivotal element in attaining the "double carbon" goal. This study, grounded in the fundamental process theory of blast furnace ironmaking, employs data analysis to investigate production technology across 25 large blast furnaces in China exceeding 4000 m3 in 2021. It specifically examines the correlation between pig iron silicon content and fuel consumption, elucidating strategies and techniques for low-silicon smelting. By exemplifying the reduction of silicon content in a 5050 m3 blast furnace of a Chinese enterprise, the study systematically delineates the low-silicon smelting process, including specific parameters and standards concerning fuel consumption, raw material conditions, and operational systems. The findings demonstrate that a reduction of 0.1% in pig iron silicon content can decrease carbonaceous fuel consumption by at least 5 kg/t. Given current raw material conditions and equipment levels, it is feasible to reduce the silicon content of iron in large-scale blast furnaces exceeding 4000 m3 in China to 0.3%.