关键词: 废钢, 直接还原铁, 碳化铁, CO-CO2-H2混合气体, 尾气利用

Abstract: High grade scrap steel in the global market appears in the situation of demand exceeding supply with rapid development of short flow steelmaking, and iron carbide as a type of substitute for high grade scrape has some distinct advantages, its technology and production have become a focus in these years. In this work, the thermodynamic analysis was carried out to discuss the iron carbide production by using CO-CO2-H2 mixing gas, then, the reduction experiment of iron ore by using CO-CO2-H2 mixing gas was performed in a fluidized bed, and the key influential factors on iron carbide production, including temperature, system pressure, H2 content and CO/CO2 ratio, were investigated respectively. The experimental result of a kilogram-scale fluidized bed showed that the reduction grade exceeded 95% with 150 min reduction time, and after 180 min, iron carbide yield achieved about 90%.

Key words: scrap steel, direct reduction iron, iron carbide, CO-CO2-H2 mixing gas, waste gas utilization