Method for improving dephosphorization effect of titanium-containing high-phosphorus molten iron in converter dephosphorization period

Abstract

The invention discloses a method for improving the dephosphorization effect of titanium-containing high-phosphorus molten iron in the converter dephosphorization period. The method comprises the following steps of: (1) pouring slags and remaining slags when tapping at the converter smelting end point of the last melt; (2) after the slag splashing furnace protection of the last melt is finished, sequentially adding a first batch of lime and scrap steel, preheating, and adding molten iron; (3) after ignition, respectively adding light-burned dolomite and a second batch of lime, maintaining high oxygen supply intensity, gradually reducing the lance position from the oxygen lance position to the lowest lance position, and adding sintering return mine; and (4) when the first batch of slag charge is molten, slagging, adding the second batch of slag charge, raising the lance position, reducing the oxygen supply intensity, stopping smelting, turning down the furnace, measuring the temperature and sampling. The method solves the problems that in the converter dephosphorization period of the titanium-containing high-phosphorus molten iron, the slags are excessively sticky, the slag-steel separation effect is poor and the lime is prone to being wrapped by the slags, resulting in the low utilization rate and the poor dephosphorization effect; and the influence of generation of a large amount of TiO2 in the slags in the early stage on the slag structure and the dephosphorization effect is controlled, so that the dephosphorization rate in the dephosphorization period is improved to reach over 65%.

Description

technical field [0001] The invention belongs to the technical field of steelmaking, and in particular relates to a method for improving the dephosphorization effect of a titanium-containing high-phosphorus molten iron converter during the dephosphorization period. Background technique [0002] The viscosity of molten iron increases with the increase of its titanium content. The reason why titanium increases the viscosity of molten iron is that the atomic radius of titanium is greater than that of iron, which reduces the free space of iron melt. figure 1 is the relationship between temperature and viscosity of molten iron under different titanium contents, given by figure 1 It can be seen that when the temperature is higher than the melting temperature of the molten iron sample (the iron sample made after the molten iron is solidified to detect its melting temperature), the viscosity of the molten iron is less than 4Pa s, and the fluidity of the molten iron is better; when t...

AI Technical Summary

Problems solved by technology

It can solve the problems of over-viscosity of slag during dephosphorization of titanium-containing high-phosphorus molten iron converter, poor separation effect of slag and steel, easy lime to be wrapped by slag and thus low utilization rate and poor dephosphorization effect, and control TiO in slag 2 Effect on lime melting, increase lime slag rate, improve fluidity of dephosphorization slag

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