Large-Scale Consumption and Zero-Waste Recycling Method of Red Mud in Steel Making Process

To release the environmental pressure from the massive discharge of bauxite residue (red mud), a novel recycling method of red mud in steel making process was investigated through high-temperature experiments and thermodynamic analysis. The results showed that after the reduction roasting of the carbon-bearing red mud pellets at 1100-1200 degrees C for 12-20 min, the metallic pellets were obtained with the metallization ratio of >= 88%. Then, the separation of slag and iron achieved from the metallic pellets at 1550 degrees C, after composition adjustment targeting the primary crystal region of the 12CaO center dot 7Al(2)O(3) phase. After iron removal and composition adjustment, the smelting-separation slag had good smelting performance and desulfurization capability, which meets the demand of sulfurization flux in steel making process. The pig iron quality meets the requirements of the high-quality raw material for steel making. In virtue of the huge scale and output of steel industry, the large-scale consumption and zero-waste recycling method of red mud was proposed, which comprised of the carbon-bearing red mud pellets roasting in the rotary hearth furnace and smelting separation in the electric arc furnace after composition adjustment.