Converter return molten steel processing method

Abstract

The invention discloses a converter return molten steel processing method. The converter return molten steel processing method comprises the following steps that (1) return molten steel is deoxidized and then smelted through a converter, a whole ladle of molten steel is completely added into the converter to be processed, if the charging amount of the molten steel is not enough, molten iron is added into the steel ladle till reaching the preset amount, and then the molten steel and the molten iron are added into the converter; (2) a blow gun is started at 1500-1650 mm, the initial oxygen pressure while blowing is started is controlled to be 0.30-0.35 Mpa, after the gun position is constant at 1500-1650 mm, the oxygen pressure is increased to 0.80-0.85 Mpa at the speed of 0.015-0.020 Mpa/s, and in the pressure increasing process, after the oxygen pressure is increased to 0.5 Mpa, 15-20 kg/t of lime, 5-8 kg/t of dolomite and 0-13 kg/t of sintered ore are added; (3) after blowing is conducted for 1-2 min, the oxygen gun position is declined to 1300-1400 mm; (4) TSC is measured through a sublance after blowing is conducted for 3-4 min, and the oxygen blowing amount and the adding amount of the sintered ore are dynamically controlled according to TSC measuring data; and (5) after a target component of the molten steel is obtained through blowing, the gun is lifted, and tapping is conducted. The converter return molten steel processing method is short in processing cycle and high in efficiency.

Description

Technical field [0001] The invention relates to the technical field of converter steelmaking in the iron and steel metallurgical industry, in particular to a method for treating molten steel in a converter. Background technique [0002] In the production process of the steel plant, the molten steel cannot be poured due to the failure of the continuous casting machine, or the chemical composition of the molten steel is found to be seriously exceeded before the molten steel is poured, which will cause huge economic losses. Therefore, the molten steel has to be returned to the furnace for re-smelting. Molten steel is also called reheated molten steel. There are two traditional methods for treating molten steel: [0003] The first is to mix with molten iron and then add it to the converter for smelting. Most steel plant processes require that the amount of molten steel added to the furnace should not exceed 1 / 3 of the total charge. This operation method has the following disadvantages...

AI Technical Summary

Problems solved by technology

[0003] One is to mix it with molten iron and then blend it into the converter for smelting. Most steel mills require that the amount of molten steel blended into the furnace should not exceed 1 / 3 of the total charge. This method of operation has the following disadvantages: Serious splashing accidents; ②The heat balance and oxygen balance are difficult to grasp, the operator cannot control the amount of cold material added, the end point temperature and the end point carbon hit rate are almost zero, and the blowing time is difficult to grasp, which can easily cause molten steel to peroxidize; ③Improper operation can easily cause Severe corrosion of furnace lining, ④ When molten iron and molten steel are mixed in the ladle, splashing is easy to occur

This method is time-consuming and labor-intensive, and the waste cost is high

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