Ladle refining slag modifier, preparation method and slag modifying method

Abstract

The invention belongs to the technical field of steelmaking and refining, and discloses a ladle refining slag modifier, a preparation method and a slag modifying method. The slag modifier comprises the following chemical components in percentage by mass: 30 to 60 percent of CaO, 30 to 60 percent of Al2O3, 2 to 10 percent of MgO2, 2 to 10 percent of B2O3, and less than 8 percent of impurities. The slag modifying method using the slag modifier comprises that: the slag modifier is hoisted to the front of a refining furnace after a steelmaking furnace discharges steels, and then is directly fed into ladles, or the slag modifier can also be fed into the furnace along with other slags at a refining station; the components of modifying slag are determined according to the ladle residue amount and components, desulfuration amount and steel deoxidation product amount; and the modifying slag for controlling the ladle slag comprises the following components according to the adding amount: 48 to 54 percent of CaO, 26 to 32 percent of Al2O3, 6 to 8 percent of MgO, 2 to 4 percent of B2O3, and 0 to 8 percent of SiO2, wherein the modifying slag is better if the content of the SiO2 is lower. The slag modifier has the capabilities of quickly manufacturing the slag, improving desulfuration and deoxidation of the refining slag and accommodating and absorbing deoxidation products, and is simple to prepare and convenient to store, transport and use.

Description

technical field [0001] The present invention relates to a ladle refining slag adjusting agent and its preparation method and slag adjusting method, in particular to a refining slag adjusting agent for quenching and tempering the residue in the ladle after tapping out of the steelmaking furnace and adding in the refining process, belonging to The field of steelmaking and refining technology. Background technique [0002] With the development of social economy, users have put forward higher and higher requirements for the quality of steel. At the beginning of the century, my country also proposed the development of "super steel plan". One of the means of realizing super steel is the high purity of steel, namely The requirements for the content of sulfur, phosphorus, oxygen and inclusions in steel are very strict. For example, high-grade pipeline steel requires S<0.005% in steel, and total oxygen T[O]<0.0007 in bearing steel. Therefore, traditional converter steelmaking It...

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Problems solved by technology

The deficiencies of the above-mentioned slagging process mainly include: (1) Fluorite is used as a fluxing agent. Because of its general fluxing effect, its addition is relatively large. The pyrolysis of fluorite and the reaction with other oxides will cause serious fluorine pollution. (2) The speed of slagging is slow, the smelting efficiency is low, and the refining time is prolonged; (3), lime, aluminum slag and fluorite must be baked before use, and a large amount of smoke and dust are generated during use, resulting in loss of raw materials and serious deterioration The environment of the operation site, and the composition of the slag is uneven, which reduces the refining efficiency

In view of the above problems, Chinese invention patent: CN 1224722C (invention name: aluminum-calcium slag and its preparation method) proposes to use lime, aluminum slag and other raw materials to make pre-melting refining slag adjustment agent, which can improve the slag adjustment without using fluorite. The onset speed of the slag adjusting agent is worth learning; but the main disadvantage of this invention is that there is no fluxing component in the pre-melted slag, and the melting point is above 1350°C, so the melting time is longer and the onset speed is slow when it is added into the furnace. In addition, in terms of the preparation process of pre-melted slag, since the slag contains calcium silicate components, if the special rapid cooling method is not adopted after the slag is pre-melted, natural pulverization will occur after solidification, which will affect the use effect

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