Metallurgical Properties of Lump Ore and Practice of High-Proportion Lump Ore for Low-Carbon Smelting of Blast Furnace

The existing blast furnace burden structure in China is mainly dominated by high-alkalinity sinter and acid pellets, with a relatively small proportion of lump ore blended in. Against the backdrop of the “dual-carbon” goals, iron and steel plants are under enormous pressure to save energy and reduce carbon emissions. Lump ore is directly extracted from mines and belongs to zero-carbon-emission blast furnace burden. Therefore, adjusting and optimizing the blast furnace burden structure by partially replacing sinter and pellets with lump ore is an important approach for iron and steel plants to reduce carbon emissions. Based on the metallurgical properties and decrepitation index of different types of lump ore as well as the proportion of lump ore charged into the blast furnace, and with full consideration of the interaction of the comprehensive metallurgical properties of the blended burden charged into the furnace, the metallurgical properties of sinter are adjusted to ensure good comprehensive metallurgical properties of the blended burden. By adjusting the blast furnace operation to an appropriate regime, the proportion of comprehensive lump ore in the charged burden has been achieved to be ≥28%, and the blast furnace fuel ratio to be ≤515 kg per ton of iron.