Low-silicon molten iron blowing method

A technology in the early stage of molten iron and blowing, which is applied in the manufacture of converters, etc., can solve the problems of complex silica composition, expensive ferrosilicon, and long melting time, and achieve simple silica composition, improved slagging effect, and short melting time.

Inactive Publication Date: 2015-06-17
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, ferrosilicon itself is expensive, and river sand and silica have complex components and long melting time, so they are not ideal as supplementary silicon sources.

Method used

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  • Low-silicon molten iron blowing method
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  • Low-silicon molten iron blowing method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] During the 150-ton converter smelting process, the temperature of the molten iron is 1312°C, the silicon content of the molten iron is 0.35% (mass fraction), and the content of phosphorus in the molten iron is 0.14% (mass fraction). The phosphorus content of the finished smelted steel is required to be <0.02% (mass fraction).

[0023] The temperature of molten iron entering the converter is relatively low, and no iron ore is added before blowing.

[0024] Add the first batch of high SiO to the converter at the early stage of blowing to 60s 2 336kg of iron ore is used to promote slag melting. After adding ore, the gun position is reduced from 2210mm to 1990mm, which is 220mm lower, so as to prevent the early splashing caused by the high FeO content of slag after adding ore.

[0025] When blowing reaches 474 seconds, add 426kg of ore to prevent the slag from being excessively dry.

[0026] 424kg and 534kg of ore were added to the blowing until 520 seconds and 572 second...

Embodiment 2

[0029] During the 150-ton converter smelting process, the temperature of the molten iron is 1362°C, the silicon content of the molten iron is 0.35% (mass fraction), and the content of phosphorus in the molten iron is 0.14% (mass fraction). The phosphorus content of the finished smelted steel is required to be <0.02% (mass fraction).

[0030] The molten iron into the converter is higher than 1350℃, 672kg iron ore is added before blowing, and the gun position is lowered by 120mm after adding iron ore.

[0031] Add the first batch of high SiO to the converter at the early stage of blowing to 70s 2 360kg of iron ore is used to promote slag melting. After adding the ore, the gun position is reduced from 2210mm to 1990mm, which is 220mm lower, so as to prevent the early splashing caused by the high FeO content of the slag after the ore is added.

[0032] When blowing reaches 467 seconds, 412kg of ore is added to prevent excessive re-drying of slag, and the gun position is lowered b...

Embodiment 3

[0036] During the 150-ton converter smelting process, the temperature of the molten iron is 1375°C, the silicon content of the molten iron is 0.36% (mass fraction), and the content of phosphorus in the molten iron is 0.15% (mass fraction). The phosphorus content of the finished smelted steel is required to be <0.02% (mass fraction).

[0037] The molten iron into the converter is higher than 1350℃, 850kg iron ore is added before blowing, and the gun position is lowered by 200mm after adding iron ore.

[0038] Add the first batch of high SiO to the converter at the early stage of blowing to 60s 2 310kg of iron ore is used to promote slag melting. After adding the ore, the gun position is reduced from 2210mm to 2080mm, which is 130mm lower, so as to prevent the early splashing caused by the high content of FeO in the slag after the ore is added.

[0039] When blowing reaches 470 seconds, 405kg of ore is added to prevent the slag from excessive re-drying, and the gun position is ...

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Abstract

The invention discloses a low-silicon molten iron blowing method, and belongs to the technical field of converter smelting. The method is especially suitable for 150t converter smelting. The method comprises the following steps: adding a proper amount of high-SiO2 iron ore after addition of molten iron to a converter and before blowing starting when the temperature of molten iron entering the converter is higher than 1350DEG C, and blowing with a lance position lower than the lance position of a melting furnace without iron ore addition; adding a proper amount of the high-SiO2 iron ore into the converter when slagging is insufficient after the blowing; and adding a proper amount of the high-SiO2 iron ore into the converter after blowing is carried out for about 300s, and reducing the lance position when the converter has a splash trend after the ore is added. The method has the advantages of dephosphorization effect improvement, early stage slagging efficiency increase, and reduction of medium stage drying and lance sticking probability.

Description

technical field [0001] The invention belongs to the technical field of converter smelting, and in particular relates to a low-silicon molten iron blowing process with high dephosphorization rate, good effect of slag removal, less mid-term counter-drying and low probability of gun sticking, and is especially suitable for 150t converter smelting. Background technique [0002] In order to meet the needs of reducing smelting costs and the development of blast furnace low-silicon hot metal smelting technology has matured, the output ratio of blast furnace low-silicon hot metal has gradually increased, resulting in a decrease in the silicon content of the converter's molten iron. At the same time, due to the rapid development of the domestic iron and steel industry in recent years, the output of high-quality low-phosphate rock has gradually decreased and the price has remained high. Affected by the pressure of product cost, blast furnace smelting is forced to use ore with higher p...

Claims

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Application Information

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IPC IPC(8): C21C5/30
Inventor 包燕平闫小柏王敏林路李翔张明军顾超蔡小锋
Owner UNIV OF SCI & TECH BEIJING
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