Fluoride-free slagging medium for use in converter and preparation method thereof

Abstract

The invention relates to a fluoride-free slagging medium for use in a converter and a preparation method thereof. The fluoride-free slagging medium comprises metal aluminum, aluminum sesquioxide, iron and oxides thereof, silicon dioxide, calcium oxide, magnesium oxide and other inevitable impurities, and is suitable for slagging during steelmaking in the converter. Used raw materials are ordinary, a pelletizing process is advanced and reliable, and the fluoride-free slagging medium is convenient to use. The fluoride-free slagging medium has the advantages that: the reaction dynamics condition of a melting bath can be improved remarkably, a good slagging effect is achieved, and the problems of steel adhesion to an oxygen lance, melting spraying and poor capability of removing S and P from slag caused by 'return to dryness' of slag are solved; the TFe content of slag is lowered, the metal yield of molten steel is increased, and the tonnage consumption cost of molten steel is lowered; furnace lining erosion is reduced, and a good slag splashing effect is achieved; and F<-> is not contained, so that environmental protection is facilitated, fluoride-free steelmaking is realized, and the slagging medium is suitable for the requirement of cleanliness in a steelmaking production process of the converter.

Description

technical field [0001] The invention relates to a converter slag flux for steelmaking, in particular to a fluoride-free slag flux for a converter and a preparation method thereof. Background technique [0002] The process of steelmaking is the process of smelting slag. Making good slag is an important link in the steelmaking process. For example, the physical and chemical properties and amount of slag in converter steelmaking slag are related to the removal of impurities in steel, the absorption of floating non-metallic inclusions in metal, and the size of splash and metal yield rate. Lime is a commonly used slagging material, and CaO is easily combined with SiO in the smelting process. 2 The reaction produces high melting point C 2 S (2050°C) will cause the slag to become viscous, which will affect the slag forming speed and the phenomenon of "reverse drying", which will lead to a series of problems such as oxygen lance sticking to steel, metal splashing, and slag remova...

AI Technical Summary

Problems solved by technology

However, the use of fluorite slag has the following disadvantages: the furnace lining is highly corrosive, pollutes the environment, endangers human health, the grade and quality of fluorite are unstable, and it is facing the situation of being gradually eliminated.

[0005] Chinese patent CN101082072A discloses "A Novel Slagging Agent for Steelmaking Slag" which solves the above technical problems to a certain extent, but the product has the following problems: (1) Melting heat absorption is high, which is not conducive to slag melting; (2) TFe content is as high as 60-85%, which is prone to reactions: (FeO)+C=(Fe)+CO, which erodes the furnace lining and affects the furnace life

If only Al2O3 is used to dissolve the slag, the effect will not be obvious due to the high melting point of Al2O3

It has been reported that the combination of TFe and Al2O3 will meet the production needs, but in actual application, it is found that the slag removal effect is caused by the unsatisfied kinetic conditions of the molten pool reaction. deviation