Method for removing phosphorus by utilizing LF (Ladle Furnace)

A refining furnace and dephosphorization technology, which is applied in the field of dephosphorization using LF refining furnace, can solve the problems that the vacuum furnace does not have the dephosphorization ability and the product quality cannot be guaranteed, and achieves the effect of eliminating quality risks.

Inactive Publication Date: 2013-08-21
ANGANG STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are some steel types, such as M3A33 steel, which require the phosphorus content to be less than 0.010%. Due to the high phosphorus in molten iron or poor slag formation in the converter, the phosphorus in the argon station is often greater than 0.010%, and the vacuum furnace does not have the ability to dephosphorize, so that the product quality cannot be guaranteed. Guarantee, if the phosphorus content exceeds the standard, only the steel type can be downgraded or changed

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Take the steel type M3A33 as an example, the furnace capacity of the LF refining furnace is 250 tons, and the steel type requires P≤0.010%. If the phosphorus in the argon station exceeds the steel type requirement by 0.014%, the molten steel is moved to the LF furnace, and the temperature of the LF furnace is measured at 1610°C , add 900kg lime pellets, 250kg refining slag and 30kg fluorite, adjust the argon blowing flow rate to 25Nm 3 / h, set the heating rate of the electrode to 4°C / min, control the heating time to 9min according to the incoming temperature and the outgoing temperature of 1635°C (the specific heating time value is selected according to Table 2), after the heating is completed, the argon blowing flow rate is adjusted to 95Nm 3 / h, stir for 3min, measure the temperature, if the temperature is higher than 1630°C, take the sample out.

Embodiment 2

[0024] Taking the steel grade CSC as an example, the furnace capacity of the LF refining furnace is 250 tons, and the steel grade requirement is P≤0.010%. If the argon station phosphorus 0.016% exceeds the steel grade requirement, the molten steel is moved to the LF furnace, and the temperature of the LF furnace is measured at 1620°C. Add 825kg lime pellets, 225kg refining slag and 37.5kg fluorite, and adjust the argon blowing flow rate to 20Nm 3 / h, set the temperature rise rate of the electrode to 4.5°C / min, control the heat up time to 7min according to the temperature at the station and take out the temperature at 1635°C (the specific temperature rise time value is selected according to Table 1), after the end of the temperature rise, the argon blowing flow rate is adjusted to 95Nm 3 / h, stir for 3min, measure temperature, if the temperature is higher than 1630°C, take a sample and move it out.

Embodiment 3

[0026] Taking the steel grade M3A33 as an example, the furnace capacity of the LF refining furnace is 250 tons, and the steel grade requires P≤0.010%. If the phosphorus content of the argon station exceeds the steel grade requirement of 0.018%, the molten steel is moved to the LF furnace, and the temperature of the LF furnace is measured at 1610°C. Add 800kg of lime pellets, 200kg of refining slag and 35kg of fluorite, and adjust the argon blowing flow rate to 25Nm 3 / h, set the heating rate of the electrode to 4°C / min, control the heating time to 8 minutes according to the incoming temperature and the outgoing temperature of 1635°C (select the specific heating time value according to Table 1), after the heating is completed, adjust the argon blowing flow rate to 100Nm 3 / h, stirring for 5min, temperature measurement, if the temperature is less than 1630°C, control the second heating time according to the output temperature of 1640°C, the heating rate is 5°C / min, after the seco...

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PUM

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Abstract

The invention relates to the field of the secondary refining of an LF (Ladle Furnace), and in particular relates to a method for removing phosphorus by utilizing LF. The method is characterized in that the content of oxygen entering a station and the adding amount of lime particles and refining slags are controlled by utilizing the oxidability of molten steel, so that the temperature of the molten steel entering the station is decreased so as to meet a low-temperature condition required for removing the phosphorus. Compared with the prior art, the method has the beneficial effects that 1) by utilizing the characteristic of the high oxidability of the molten steel, the lime particles are added so as to provide the high alkalinity required for removing the phosphorus; and the slags of 1ton or so are added so as to meet the large slag quantity required for removing the phosphorus, wherein the temperature of the molten steel entering the station is normally from 1600 to 1620 DEG C, thereby meeting the low-temperature condition required for removing the phosphorus; and 2) when the content of the phosphorus in an argon station is between 0.010% and 0.015%, the phosphorus removal is performed in a one-step feeding manner, wherein the phosphorus removal rate can reach 40% to 45%; and the content of the phosphorus in the argon station is greater than 0.015%, the phosphorus removal rate can reach 46% to 51% by performing the phosphorus removal in a secondary feeding manner, so that the content of a finished phosphorus product is controlled within 0.010%. As a result, the quality risk is avoided.

Description

technical field [0001] The invention relates to the field of secondary refining of an LF refining furnace, in particular to a dephosphorization method using an LF refining furnace. Background technique [0002] The production of IF steel in steelworks generally adopts the molten iron pretreatment-converter-vacuum-continuous casting process, and is produced according to the "IF Steel Operation Guide". However, there are some steel types, such as M3A33 steel, which require the phosphorus content to be less than 0.010%. Due to the high phosphorus in molten iron or poor slag formation in the converter, the phosphorus in the argon station is often greater than 0.010%, and the vacuum furnace does not have the ability to dephosphorize, so that the product quality cannot be guaranteed. Guarantee, if the phosphorus content exceeds the standard, only the steel type can be downgraded or changed. Contents of the invention [0003] The purpose of the present invention is to provide a ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21C7/064
Inventor 王鹏飞赵晓野李树斌王小善康永弟赵志刚何芳名
Owner ANGANG STEEL CO LTD
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