Thermodynamics and Kinetics of Reaction of Rare Earth (La, Ce, Y) with MgO Refractories

Based on laboratory melting and theoretical calculation, the thermodynamics and kinetics of the reactions between GCr15 bearing steel melt containing lanthanum, cerium, and yttrium and MgO crucible were studied. The results show that the La-MgO reaction is the most intense, followed by the Ce–MgO reaction, and the Y–MgO reaction is the weakest. The reaction products are in the form of RE₂O₃ and RE₂O₂S, which is consistent with the thermodynamic calculation; Within 120 min after the addition of lanthanum, cerium, and yttrium, the changing trends of the Mg content in the molten steel were significantly different. These reactions all proved to be first-order reactions. The rate formula of the consumption of rare earth per unit mass of molten steel was also obtained by kinetic analysis.