A method for smelting low-phosphorus steel using a low-silicon molten iron converter

Abstract

The invention discloses a method of converter smelting of low-phosphorous-content steel by adopting hot metal containing low silicon content. The method comprises the following steps: 1) before charging is carried out for the converter smelting every time, a converter slag remaining quantity is determined according to a terminal phosphorus content requirement and hot metal components of the type of steel to be smelted, and an adding total quantity of lime is calculated; 2) lime and ore adding quantities in the double slag earlier stage are determined according to the lime adding total quantity; 3) after blowing, operating personnel determine double slag oxygen lance lifting time according to a converter interior slagging situation monitored by an audio frequency slag melting instrument and with the combination of a situation monitored by a converter mouth camera; 4) after oxygen lance lifting is carried out, nitrogen is blown to a converter for carrying out iron brake operation; 5) the blowing is carried out after deslagging is finished, the left 50% of the lime and the ore are added, and secondary slag making and phosphor removal are carried out; and 6) converter blowing is carried out to a terminal, then the oxygen lance lifting is carried out, and converter turning-down and deslagging are carried out. A double slag control process is adopted for operation, the converter terminal phosphorus content fundamentality reaches the target requirement, converter supplementary blowing phosphor removal phenomena are reduced obviously, and a converter body state is improved obviously.

Description

technical field [0001] The invention belongs to the field of converter steelmaking, and in particular relates to a method for smelting low-phosphorus steel using a low-silicon molten iron converter. Background technique [0002] At present, when the converters of major steel mills use low-silicon molten iron to smelt low-phosphorus steel, they all adopt the single-slag method, and use methods such as increasing the amount of lime added, increasing the terminal alkalinity, and reducing the tapping temperature to ensure the dephosphorization efficiency of the process and make the final phosphorus content Meet the requirements. The amount of lime added in this method is not reasonable enough, the temperature control of the process is unstable, and the slag in the process is difficult to slag, the dephosphorization effect is not ideal, the phosphorus content in the molten steel at the end of the converter is high, and the gun sticks, etc., so that the final control point of the ...

AI Technical Summary

Problems solved by technology

The amount of lime added in this method is not reasonable enough, the temperature control of the process is unstable, and the slag in the process is difficult to slag, the dephosphorization effect is not ideal, the phosphorus content in the molten steel at the end of the converter is high, and the gun sticks, etc., so that the final control point of the converter is not stable enough and cannot be Meet the continuous production requirements of low phosphorus steel

At the same time, the increase in the number of supplementary blowing will seriously erode the converter lining, reduce the life of the converter, and affect the economic and technical indicators of the converter