Preparation method of steel ladle slag modifier for low-oxygen low-sulfur high-nitrogen steel

Abstract

A preparation method of a steel ladle slag modifier for low-oxygen low-sulfur high-nitrogen steel belongs to the technical field of steel making, and is characterized by comprising the steps of mixing 30-40% of electrolytic aluminum, 40-50% of calcium oxide and 10-15% of fluorite according to ratio, adding washer fluid, mixing uniformly, then pressing to be balled, drying to obtain the steel ladle modifier, wherein the aluminum ash comprises the following components by weight percent: 15-10% of Al, 25-35% of AlN, 35-50% of Al2O3, 2-5% of SiO2 and 10-15% of NaCl. The preparation method has the advantages that the waste, namely aluminum ash of an aluminum manufacturer plays the roles of deoxidizing, removing sulfur and increasing nitrogen for the steel ladle slag modifier in steelmaking production, so that aluminum powders do not need to be added. The modifier is added into a steel ladle after the steel tapping of molten steel, the content of FeO in the steel ladle slag is reduced to be below 5%, T[O] and [S] in steel respectively reaches to be below 20ppm and 75ppm, the content of [N] in steel is increased to be more than 77ppm, and the cleanliness of the molten steel is improved.

Description

(1) Technical field [0001] The present invention belongs to chemistry according to International Patent Classification (IPC); Ministry of Metallurgy, metallurgical division, metallurgy category of iron, processing of pig iron, such as refining, smelting of wrought iron or steel; processing of ferrous alloys in molten state category, using slag or flux as a treatment agent. (2) Background technology [0002] When the molten steel is tapped from primary furnaces such as converters or electric furnaces and enters the ladle, the molten steel needs to be deoxidized, desulfurized, and inclusions removed to improve the purity of the steel and meet the quality requirements of users. Aluminum ash slag was mixed with aluminum powder as a ladle slag modifier to achieve the purpose of deoxidation and desulfurization. As announced by the Chinese Patent Office in 2003 and declared by Jiangsu Jiangnan Ferroalloy Co., Ltd., the authorized publication number is CN1410556A, and the Chinese p...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problem of high cost of aluminum ash slag mixed with aluminum powder as a ladle slag modifier in the prior art, and to provide a ladle slag modifier that uses aluminum ash and does not need to add aluminum powder to produce a ladle slag modifier. For low-oxygen, low-sulfur, high-nitrogen steels or steels that require low nitrogen content