Study on high efficient desulfurization of new type synthetic refining slag

One type of premelted refining slag was developed in this article. This new type refining slag has the characteristics of high basicity and low melting point. Under laboratory conditions, the average desulfurization rate reached to 84.5%. During the industrial experiment, the charging schemes of steel grades were distinct. The experimental results indicated that using the new type refining slag the slag-melting rate was 100% at the end of tapping and the refining time was shortened by 11 min. By comparison with original refining slag, oxygen content and nitrogen content in steel reduced respectively by 7×10^-6 and 12×10^-6 before VD refining and by 5×10^-6 and 15×10^-6 after VD refining. The desulfurization rate was also increased sharply. The results showed that the desulfurization rate was 92% from EAF tapping to craning ladle of VD, and the lowest sulphur content in steel was 30×10^-6.