An efficient and clean utilization technique for red mud based on fluidized bed carbon monoxide reduction

Abstract

In order to simulate the pre-reduction behavior of ore powder by coal gas produced by smelting reduction of coal-based electric furnace, an efficient and clean utilization technique for red mud based on fluidized bed carbon monoxide reduction was developed in the present study. Experimental results indicated that a metallization rate of 68.08 % and reduction degree of 78.72 was obtained under the optimal conditions of reduction temperature of 800 °C, CO concentration of 85 %, and reduction time of 30 min. Pre-reduced materials can be used as raw materials for electric furnace melting reduction. The order in which iron oxides were reduced is only related to temperature, and at 800 °C, iron oxides were reduced in the order of Fe2O3 to Fe3O4 to FeO to Fe. During different stages of prereduction, the surface structure of ore particles changes, which is related to the metallization rate of iron oxides in red mud.