Process of quickly regulating alkalinity of LF (ladle furnace) slag

Abstract

The invention discloses a process of quickly regulating alkalinity of LF slag. The process comprises a molten iron desulfurization pretreatment and converter smelting process and an LF refining smelting process, wherein the molten iron desulfurization pretreatment and converter smelting process comprises the following steps: 1) end point operation, 2) slag stopping operation and 3) implementation of a system for tapping, deoxidizing and slagging; the LF refining smelting process comprises the following steps: 1) LF early-stage operation: adding a first batch of deoxidizing and slagging material; 2) implementation of an LF middle-stage deoxidization and desulfuration process: adding a second batch of deoxidizing and slagging material, alloying according to components of a steel grade; if the sulfur content of a second sample meets the component requirements of the steel grade, feed aluminum wires; if the components of the second sample fail to meet the component requirements of the steel grade, adding a third batch of deoxidizing and slagging material until the requirements are met, and then feeding the aluminum wires to supplement the aluminum content in the molten steel; 3) LF middle-later stage quick alkalinity regulation: at the end of feeding of the aluminum wires to supplement the aluminum content in the molten steel, adding an alkalinity regulator to optimize a slag system and ending the process. According to the process of quickly regulating the alkalinity of top slag of an LF steel ladle in stages, the requirements for refining furnace molten steel desulfuration and the impurity removal are both met to achieve the molten steel refining effects, so that the internal quality of continuous casting is improved.

Description

technical field [0001] The invention relates to a steelmaking process in the field of metallurgy, in particular to a process for quickly adjusting the basicity of LF slag. Background technique [0002] The level of slag basicity in the steelmaking process has an important impact on the dephosphorization, desulfurization and removal of inclusions in molten steel. With the continuous improvement of the market's requirements for steel quality, molten steel refining has become an indispensable condition for improving the purity of steel. In particular, LF ladle refining furnace has become a necessary process for smelting high-quality steel. However, in order to improve the purity of molten steel, LF refining furnace needs deep Deoxidation, sulfur and other impurity elements, high alkalinity and strong reducing desulfurization slag are quickly produced in the early stage of treatment, and the amount of lime is too large. When the oxygen and sulfur in molten steel are reduced to t...

AI Technical Summary

Problems solved by technology

Ladle top slag with such a high alkalinity has poor fluidity and poor adsorption capacity for molten steel inclusions, which is not conducive to improving the purity of molten steel

At this time, the high-basicity slag required for deoxidation and desulfurization conflicts with the good fluidity and low-basicity slag required for the removal of molten steel inclusions

In order to break through these restrictive conditions, it is an urgent problem to be solved to develop a refining furnace slagging process that adjusts the basicity of LF refining furnace ladle top slag step by step and is compatible with molten steel desulfurization and removal of inclusions, especially for smelting high value-added varieties. Steel, there will be a series of problems such as excessive oxygen and sulfur impurities in molten steel or excessive inclusions in molten steel

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