Development of a Novel Hot Metal Pretreatment Process with Magnesium Vapor Produced In Situ by Reduction of Wasted MgO-containing Refractory

摘要

A novel desulfurization processes in hot metal pretreatment has been developed using magnesium vapor produced in-situ by aluminothermic reduction of MgO, the source of which can be wasted MgO-containing refractories in ironmaking and steelmaking processes. MgO-Al pellets are charged into a graphite tube, which is immersed into the molten iron. Magnesium oxide is reduced by aluminium to produce magnesium vapor, which is injected directly into the molten iron together with argon carrier gas to react with sulfur dissolved in it. It is found that desulfurization with magnesium vapor takes place mainly on the bubble surface. The desulfurization efficiency of magnesium can be greatly improved by adjusting the initial magnesium partial pressure to the optimum value through changing the argon carrier gas flow rate. The prevention of resulfurization during Mg desulfurization process can be achieved by adding CaO or C powders onto the melt surface.