Advanced Method for Recycling Red Mud by Carbothermal Solid-Phase Reduction Using Sodium Sulfite

The paper presents the results of studying the iron grain growth mechanism during carbothermal solidphase reduction of red mud in the presence of sodium sulfate. It was shown that the main mechanism of iron grain growth involves the formation of low-melting-point surface-active iron-sulfur compounds along the grain boundaries, which significantly accelerates their agglomeration process. The obtained results confirm a positive effect of the sodium sulfate additives on the process of iron grain growth during solid-phase carbothermal reduction of red mud, which makes it possible to improve the efficiency of subsequent magnetic separation.