Method for smelting high-phosphorus molten iron to produce steel with converter end point P less than or equal to 0.01% by adopting slagless material

Abstract

The invention belongs to the technical field of converter steelmaking processes, and particularly relates to a method for smelting high-phosphorus molten iron to produce steel with converter end pointP less than or equal to 0.01% by adopting slagless material. The method comprises the following steps that loading low-silicon high-phosphorus molten iron and steel scrap which are not subjected to triple-removal pretreatment into a converter, a single-slag method is adopted to carry out blowing, a slagging material is added twice in a blowing process and a gun position control mode of high, low, high and low is adopted in the blowing process, and oxygen supply and nitrogen supply are carried out in the blowing process; after the blowing is completed, the steel is discharged, slag splashingis carried out after the steel is discharged, slag is reserved after the slag splashing, and is used for smelting in the next furnace. According to the method, on the premise that lime consumption ofa steel liquid is less than or equal to 30 kg/t, and the consumption of the new slag material is less than or equal to 50 kg/t, dephosphorizing of the molten iron with the following components, by weight, 0.14-0.26% and Si, 0.15-0.20% of P is carried out until P is less than or equal to 0.01%, and a dephosphorization rate is larger than or equal to 94%, so that the problem that low-phosphorus steel is smelted by a low-silicon high-phosphorus molten iron with the few slag material in the single-slag method is solved.

Description

Technical field [0001] The invention belongs to the technical field of converter steelmaking technology, and specifically relates to a method for producing converter end-point P≤0.01% steel by smelting high-phosphorus hot metal with less slag material. Background technique [0002] The blast furnace reduces the silicon content in the molten iron ≤ 0.6%, on the one hand, it can increase the output, on the other hand, it can also reduce the coke ratio, which brings huge economic benefits to the enterprise. At the same time, with the gradual decrease of high-quality low-phosphorus ore and the sharp increase in its price, companies have increased the use of high-phosphorus ore to reduce production costs, resulting in an increase in the proportion of high-phosphorus molten iron, which has seriously affected the converter’s low-phosphorus molten steel. Production restricts the production of high-quality low-phosphorus products. Under the premise of reducing production costs, improving...

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Problems solved by technology

[0003] At present, the dephosphorization process of converter mainly includes single slag method, double slag method and double-combination method. Generally speaking, for high-phosphorus molten iron with P≥0.15%, double-slag and double-combination process should be used for dephosphorization when smelting low-phosphorus steel However, due to the need for furnace and slag dumping during the smelting process, the production rhythm is slow, and sometimes the control is not good, and the metal yield will be reduced.

The single slag method can improve production efficiency, but for molten iron with low silicon content and high phosphorus content, the low silicon content leads to slow slag melting in the early stage, which cannot make good use of the good thermodynamic conditions of low temperature dephosphorization in the early stage, resulting in poor dephosphorization effect in the early stage. Increased the difficulty of dephosphorization

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