Method for increasing residual manganese content in molten steel at end point of converter

Abstract

The invention provides a method for increasing the residual manganese content in molten steel at the end point of a converter. According to the method, the waste steel loading amount of the converteris controlled according to the waste steel ratio of not more than 15%; at the early stage of the smelting, the iron-carbon ball slag is added while the white ash slag is added into the converter, theadding amount of the first batch of the slagging material is 50-70% of the total adding amount, the blowing starting position of the oxygen gun is 0.8-1.2 m, and the gun position is increased to 2.2-2.6 m after blowing is performed for 1-2 min; 25-40% of the remaining slag is added after blowing is performed for 3-6 min; at the middle stage of the smelting, the oxygen gun is lifted to 2.5-3.0 m, blowing is performed for 10-30 s, and then the oxygen gun is lowered to the basic gun position; and at the late stage of the smelting, the gun position is controlled at 1.0-1.2 m, and the remaining slag is added to the converter at 2-5 min before the tapping. According to the present invention, with the method, the residual manganese content in the end point molten steel can be increased, the alloyaddition amount during alloying can be reduced, the steelmaking cost can be reduced, the FeO content in the final slag can be reduced, the converter blow loss can be reduced, and the rephosphorization and the tapping slag discharge can be effectively prevented.

Description

technical field [0001] The invention belongs to the field of steelmaking technology, in particular to a method for increasing the residual manganese content of molten steel at the end point of a converter. Background technique [0002] Manganese can improve the tensile strength, machinability, toughness, hardness and wear resistance of steel, and can also reduce the adverse effects of sulfur in steel, so manganese is regarded as one of the main elements in steel. After the converter completes the task of smelting molten iron, most of the manganese in the original molten iron is oxidized. According to different steel types, it is necessary to add manganese-ferroalloy to the molten steel to meet the composition requirements of the steel type. In the actual production process, the residual manganese content in molten steel has an important impact on the amount of ferromanganese added, the higher the residual manganese content, the less the amount of alloyed ferromanganese added...

AI Technical Summary

Problems solved by technology

Although this method can improve the residual manganese content in molten steel at the end point, since the addition of manganese ore is carried out in the later stage of converter blowing, the addition of manganese ore will reduce the temperature of molten steel in the furnace, which will easily cause the tapping temperature to reach It does not meet the requirements of tapping, and the impurities in the manganese ore are also likely to pollute the molten steel, which is not conducive to the improvement of the cleanliness of the molten steel

[0005] In summary, the current method of increasing the residual manganese content in molten steel is mainly achieved by adding manganese-containing slagging material or manganese ore to the converter, and according to the oxidation characteristics of manganese in molten iron, it can be improved by adjusting the smelting method. There is no relevant report on the method of residual manganese content in molten steel

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