Composite molten steel refining additive

Abstract

This invention provides a molten steel composite refining additive. The said additive by wt.% includes aluminium ash 10-50% (aluminium content at least being 15% of ash wt.), metallurgical furnace slag 10-60%, carbide 5-65%, limestone 1-10% and witherite 1-10%. This additive is used for the oxidable slag tapping process of steel smelting furnace such as electric furnace, converter, etc. and for refining furnace to make the oxidable molten steel proceed polybasic composite oxygen removal, sulphur removal and quick deoxidated impurity inclusion removal, and at the same time, it enhances quick dissolution of added slagging material and quick slag forming.

Description

Technical field: [0001] The invention relates to a composite refining additive for molten steel used in the iron and steel industry. Background technique: [0002] The main process of modern steelmaking is converter-refining furnace-continuous casting-(LD-LF-CC) and ultra-high power electric furnace-refining furnace-continuous casting (UHP-LF-CC). The application of enhanced smelting technologies such as super oxygen supply, molten iron hot charging, scrap preheating, and oxygen burner fluxing has further shortened the oxidation and refining time of molten steel, and the popularization and application of high-efficiency continuous casting has made the billet forming speed of molten steel faster than that of traditional processes. substantial improvement. So shortening the time of LF refining outside the furnace becomes the key to increasing the output of the steelmaking process, increasing the continuous casting ratio, and ensuring the smooth flow of the "three ones" proces...

AI Technical Summary

Problems solved by technology

[0003] 1. The use of a relatively single Al deoxidizer failed to truly realize the multi-component composite deoxidation of molten steel

[0004] 2. Deoxidized inclusions are difficult to fully remove

[0005] 3. The lime (or synthetic slag) added during the tapping process cannot be quickly dissolved into slag (the melting point of lime is as high as 2130°C)

[0006] 4. The LF refining furnace is slow to melt slag, and the refining effects such as desulfurization, deoxidation, and adsorption inclusions are not ideal

[0007] 5. The whole foam slag submerged arc refining cannot be realized on LF

[0008] 6. It takes longer time for LF refining and heating, which affects the smooth progress of UHP(LD)-LF-CC process, affects the increase of continuous casting ratio, and affects steel output

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