High-sodium low-fluorine continuous casting mould fluxes and preparation method thereof

Abstract

The invention relates to high-sodium low-fluorine covering slag, which is prepared from raw materials of wollastonite, limestone, quartz sand, fluorite, bauxite, manganese carbonate, magnesia, hydrous borax, industrial soda, lithium carbonate, and carbonaceous materials, and the chemical components of the covering slag meets the following weight percentage: more than 30 and less than 34 percent of CaO, more than 30 and less than 38 percent of SiO2, more than 12 and less than 25 percent of Na2O, less than 4 percent of MgO, less than 8 percent of MnO, less than 4 percent of B2O3, less than 1.5 percent of Li2O, less than 4 percent of Al2O3, less than 2 percent of F, more than 4 percent and less than 10 percent of C, and the balance being impurities. In the covering slag, the ratio of sigma CaO to the SiO2 is controlled to between 0.8 and 1.15 to ensure that the fused mass of the covering slag does not separate out crystals at high temperature and liquid slag in a slag film can lubricate a casting blank. Aiming at that the content of fluorine has adverse influence on environment and equipment, the invention adopts high-sodium low-fluorine continuous casting covering slag which not only can meet the requirement of coordinated control of heat transfer and lubrification of a continuous casting covering slag for crack sensitive steel to cast casting blank with good surface quality, but also can reduce the fluorine content in air and secondary cooling water, thus the air pollution is reduced and the corrosion of fluorine-contained water to equipment is reduced.

Description

technical field [0001] The invention relates to mold mold flux for continuous casting of molten steel, in particular to a high-sodium and low-fluorine continuous casting mold flux and a preparation process thereof, belonging to the technical field of steelmaking and continuous casting. Background technique [0002] In modern continuous casting production, mold powder is a key auxiliary material. They are usually made of limestone, quartz sand, waste glass, wollastonite, cement clinker, soda ash, fluorite, sodium fluoride, lithium carbonate, Graphite, carbon black and other natural ores or chemical products are used as basic raw materials, which are pre-melted or mechanically mixed and granulated to produce finished mold powder. By adjusting CaO and SiO in mold flux 2 、Al 2 o 3 , MgO, Na 2 O, K 2 O, F, Li 2 The content of chemical components or components such as O and C is used to adjust the physical and chemical indicators such as the melting temperature, viscosity, c...

AI Technical Summary

Problems solved by technology

However, in this invention, the fluorine content is still 3-5%, the lithium oxide content is 1-5%, and the fluorine content and lithium oxide content are still relatively high, especially the lithium oxide is 1-5%, so there is a problem of high cost ; Its application object does not involve crack-sensitive steel grades

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