The electric refining slag produced by our company's DC plasma furnace is used for external desulfurization of steel ladles. This electric melting refining slag is based on the principles of metallurgy and the physical and chemical laws of the reaction between slag and molten steel. It compares the desulfurization characteristics of desulfurization processes outside the furnace at home and abroad, and adopts a new scientific formula for different basic components of molten steel. It is composed of * * enhanced desulfurizer, reaction promoter, gas generator, cosolvent additive and other materials.