Calcium oxide material for clean steel smelting and preparation method thereof

Abstract

The invention relates to a calcium oxide material for clean steel smelting and a preparation method thereof. The technical scheme is as follows: the preparation method comprises the following steps: mixing 35-40 wt% of limestone particle, 30-35 wt% of limestone fine powder, 8-22 wt% of magnesium aluminum sol and 5-20 wt% of mixture, stirring uniformly, and painting or casting to form, thereby obtaining the calcium oxide material for clean steel smelting. The mixture is formed by mixing alumina micropowder, magnesite fine powder and calcium lignosulphonate in a mass ratio of 10:(3-5):(0.7-1.5); the particle size of the limestone particle is 7-0.1mm, the particle size of the limestone fine powder is 0.05-100 mu m, and the CaCO3 content of the limestone particle and limestone fine powder is greater than or equal to 92 wt%; and the mole ratio of magnesium to aluminum in the magnesium aluminum sol is 1:(0.4-2.2). The calcium oxide material has the advantages of low impurity content, proper strength and almost no influence on total oxygen content of molten steel, can adsorb oxide inclusions in the steel, and is suitable for preparing the working line of a tundish for clean steel smelting.

Description

technical field [0001] The invention belongs to the technical field of calcium oxide materials. In particular, it relates to a calcium oxide material for clean steel smelting and a preparation method thereof. Background technique [0002] According to the requirements of innovation and development in the "12th Five-Year Plan" of the iron and steel industry, the state will increase the intensity of upgrading and development of special steel products, and strive to replace imports and meet the new market demand for the improvement of the domestic equipment manufacturing industry. Therefore, it is particularly important to strictly control the quality of molten steel in the process of iron and steel smelting. The tundish is the last container for molten steel before continuous casting of molten steel. The composition, structure and performance of the refractory material in its working layer are of great significance to ensure the quality of molten steel. [0003] Most of the ...

AI Technical Summary

Problems solved by technology

Since the amount of water added during construction is about 20wt%, cracks and spalling often occur in the early stages of use, thereby increasing the amount of oxide inclusions in the steel

At the same time, in the continuous casting process, since mineral materials such as soft clay, silicon oxide powder, and sodium silicate are acidic oxides, they have a high oxygen supply potential to molten steel and will continue to increase the total oxygen content in molten steel; Phosphate minerals such as sodium tripolyphosphate used in the process of contacting molten steel will increase the content of phosphorus in steel, which is not conducive to the improvement of steel quality; moreover, the main chemical component of magnesia is magnesium oxide, which can affect the inclusion of molten steel The adsorption capacity is not strong

In short, the mineral composition and preparation process of existing tundish coatings can no longer meet the increasingly demanding needs of clean steel smelting