Activation Behavior and Mechanism of Sodium Sulfate for Iron Recovery from Red Mud through Magnetization Roasting–Magnetic Separation

It is a hot topic to recover iron from red mud in the research field of solid waste comprehensive utilization, but high-quality iron concentrate is always difficult to be obtained unless by high-temperature reduction roasting–magnetic separation. In this study, low-temperature magnetization roasting–magnetic separation has been conducted to recover iron from red mud, with carbon monoxide as the reducing agent, and the effect of Na2SO4 as an additive and corresponding activation mechanism has been investigated, confirming that Na2SO4 can significantly improve the quality of the iron concentrate. Under the optimum conditions, an iron concentrate with a total iron grade of 60.65