Production of Pig Iron from High-Iron Red Mud by Smelting Reduction

High-iron red mud is an alkaline solid waste generated during the process of alumina production by Bayer process. At present, the annual emissions of high-iron red mud are about 50 million tons in China. Due to strong alkalinity, the comprehensive utilization of high-iron red mud is limited. In order to realize high-value utilization of such material, a new smelting reduction technology followed by production of cement clinker from reduced slag was proposed. This paper focused on the smelting reduction of high-iron red mud. The effects of temperature, mole ratio of C/O, additive ratio of CaF2, and basicity on recovery rates of iron and sodium were investigated in detail. The results showed that the recovery rates of iron and sodium were 98.36% and 38.45%, respectively. The chemical compositions of pig iron meet the national standard of pig iron for steel-making.