Economical, environment-friendly and efficient desulfurization refining slag system and preparation method

Abstract

The invention belongs to the technical field of steel and iron metallurgy, and in particular, relates to an economical, environment-friendly and efficient desulfurization refining slag system and a preparation method. The slag system comprises raw materials of lime, aluminum particles for deoxidation, light-burned dolomite and bauxite; and the ratios of the raw materials are designed according tothe following refining slag composition: 55-60 wt% of CaO, 7-12 wt% of SiO2, 28-33% of Al2O3, 4-8 wt% of MgO, and 1.8 of CaO to Al2O3. The preparation method of the slag system comprises four steps ofconverter tapping and lime and aluminum particle adding, slag feeding, argon blowing in an alloy fine adjustment station and LF refining furnace slagging. In the converter tapping process, the designed slag system raw materials are fed to form the refining desulfurization slag; and through the gas supply system of top/bottom compound argon blowing of the alloy fine adjustment station, the oxygencontent and the sulfur content of molten steel before LF furnace refining and the content of FeO+MnO in top slag are reduced.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to an economical and environment-friendly high-efficiency desulfurization refining slag system and a production method. Background technique [0002] High-grade pipeline steel, bearing steel, low-alloy high-strength steel and other steels have high requirements for hydrogen-induced cracking (HIC) resistance. Sulfur is the main element that affects the ability of steel to resist hydrogen-induced cracking (HIC) and sulfur stress cracking (SSC). Therefore, the systematic study of the influence of refining slag composition on the desulfurization effect is of great significance for speeding up the slag melting time, improving the deep desulfurization rate, and controlling the shape of inclusions. [0003] At present, production practice has confirmed that when the mass fraction of sulfur in steel is >0.005%, the HIC sensitivity of steel increases signific...

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Problems solved by technology

[0006] Among the above two methods, the refining slag has a desulfurization rate of 30% to 53%, which is suitable for refined steel with low sulfur content requirements, but for high-grade steel products with sulfur content requirements 2 To reduce the melting point of refining slag, although it has a better effect of slag melting, but CaF 2 On the one hand, the erosion of the lining is faster, which shortens the service life of the ladle; on the other hand, the F volatilized by the metallurgical process 2 Will endanger the health of workers and cause air pollution

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