Reduction Behavior of Lump Ore and Its Applicability During Hydrogen-Based Shaft Furnace Process

Adding lump ore to burden used in hydrogen-based shaft furnace is a method to reduce carbon emission in steel production process. Therefore, the reduction performance of the lump ore in a hydrogen-based shaft furnace was tested, including low-temperature reduction experiments and reduction experiments. After adding lump ore to the burden, the low-temperature disintegration performance of the burden would significantly begin to deteriorate. When the lump ore ratio was 60%, the LTD_+6.3 decreased to 79.10%, it couldn’t achieve industrial production standards, and the LTD_− 3.2 increased to 10.53%. When the burden was all pellets, the time for the burden to reach the reduction end point was 180 min at 950 °C. When the proportion of lump ore in the burden was 100%, the reduction time was only 145 min. When the burden was all reduced pellets, the proportion of more than 6.3 mm was 98.15%, and that of less than 3.2 mm was only 0.14%. When the proportion of lump ore was 80%, the proportion of particles larger than 6.3 mm in the burden was less than 90%. When the burden was all lump ores, 85.23% of the burden was greater than 6.3 mm and 7.72% was less than 3.2 mm. Based on the experimental research results above, the proportion of lump ore in the burden should not exceed 40%.