Method for two-step desulfurization of molten iron

Abstract

The invention relates to a method for two-step desulfurization of molten iron, which comprises the following steps: adding active lime into a molten iron ladle during reladling and tapping, then tapping, performing mixed flushing, and further entering a desulfurization station for blowing magnesium powder for pretreatment of the molten iron and desulfurization. In the method, no equipment is added, no fixed investment is involved, only a part of the bagged active lime needs to be artificially added into the bottom of the iron ladle, therefore, the method is simple and easy to operate, occupies no time of an overhead travelling crane and can ensure continuous production.

Description

technical field [0001] The invention belongs to the field of steelmaking, in particular to a method for two-step desulfurization of molten iron. Background technique [0002] Since some domestic steel mills use titanium ore to protect the blast furnace, the titanium content in the hot metal has increased significantly (Ti<0.02% in the original hot metal, Ti>0.12% in the hot metal after the furnace), and the pure blowing magnesium in the steelmaking plant The desulfurization process of molten iron pretreatment with fine powder caused a huge impact. The sulfur in the molten iron was once difficult to remove, and even the phenomenon of molten iron resulfurization appeared, which brought great difficulties to the desulfurization of the converter. The amount of lime increased and the sticking gun was serious. , the sulfur is still difficult to remove, and finally the sulfur in the finished steel product exceeds the standard, which brings great difficulties to the stable pro...

AI Technical Summary

Problems solved by technology

[0002] Since some domestic steel mills use titanium ore to protect the blast furnace, the titanium content in the hot metal has increased significantly (Ti0.12% in the hot metal after the furnace), and the pure blowing magnesium in the steelmaking plant The desulfurization process of molten iron pretreatment with fine powder caused a huge impact. The sulfur in the molten iron was once difficult to remove, and even the phenomenon of molten iron resulfurization appeared, which brought great difficulties to the desulfurization of the converter. The amount of lime increased and the sticking gun was serious. , the sulfur is still difficult to remove, and finally the sulfur in the finished steel product exceeds the standard, which brings great difficulties to the stable production of the steelmaking plant

If the desulfurization process is to be changed, the continuous production of the company will be interrupted, and the modification amount is very large, and the effect cannot be guaranteed. After demonstration, it is not feasible in terms of production and economics

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