Rare earth oxide-containing steelmaking refining slag, and preparation method and using method thereof

The invention belongs to the technical field of steelmaking refining and relates to rare earth oxide-containing steelmaking refining slag, and a preparation method and a using method thereof. The invention is characterized in that: a refining slag system comprises the following chemical components in percentage by mass: 40 to 55 percent of calcium oxide (CaO), 6 to 25 percent of aluminum oxide (Al2O3), 3 to 16 percent of cerium trioxide (Ce2O3), 3 to 10 percent of magnesium oxide (MgO), 3 to 15 percent of silicon oxide (SiO) and 1 to 6 percent of calcium fluoride. The refining slag system hashigh melting property, melting temperature of between 1,300 and 1,370 DEG C, low viscosity value of 0.1 to 0.3 Pa.s at the steelmaking temperature of between 1,550 and 1,600 DEG C and high flowability. Molten steel refining tests in a 200-kg induction furnace, a 100-t combined blown converter and a 60-t arc furnace show that compared with the traditional refining slag system, the refining slag system provided by the invention has deoxidizing rate and impurity level reduction rate of over 15 percent and effectively improving refining efficiency.