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Slag foaming suppression method and converter refining method

A converter refining and slag technology, applied in the direction of manufacturing converters and improving process efficiency, can solve the problems of reduced productivity and hindered productivity, and achieve the effects of suppressing foaming and suppressing post-expansion

Inactive Publication Date: 2020-03-17
NIPPON STEEL CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the overflow can be avoided by reducing the slag discharge rate or temporarily stopping the slag discharge, this will reduce the productivity, so the slag discharge pot is injected with a substance that inhibits slag foaming
[0005] The overflow of slag from the refining vessel accompanied by foaming and slag spraying is not limited to the slag discharge pot, and it is also a phenomenon that hinders productivity in mixed iron cars, molten iron pots, converters, etc.

Method used

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  • Slag foaming suppression method and converter refining method
  • Slag foaming suppression method and converter refining method
  • Slag foaming suppression method and converter refining method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0082] Hereinafter, based on Tables 1-2, the Example of this invention is demonstrated concretely. Fill the converter with molten iron for blowing, temporarily stop the blowing, and tilt the converter with the molten iron remaining in the furnace, and pour it into the slagging pot (inner volume: 70m2) installed under the furnace body. 3 ) for 5 minutes. From the beginning of slagging, continuously spray water jets to the slag in the slag pot, and visually observe the state of the slag pot. Under the condition of no water jet injection, only the discharge of slag to the slag discharge pot is carried out.

[0083] When the slag is about to overflow, temporarily stop the tilting of the converter and stop the slag discharge, and after the foaming height is lowered by the injection of the water jet, the furnace is tilted again to start the slag discharge again. When the slag is about to overflow under the condition of no water jet injection, temporarily stop the tilting of the co...

Embodiment 5

[0089] Examples 5-8 are comparative examples. In Example 5, there is no water jet, so even if the slag discharge is temporarily interrupted, the foaming in the slag discharge pot continues and the slag overflows, and the slag discharge rate stops at 20%. However, post-expansion after slagging did not occur. V in Example 6 water / V slag Compared with the present invention, the range is too small, so the foaming suppression effect is small, and even if the slag discharge is temporarily interrupted, the foaming in the slag discharge pot continues and the slag overflows. Therefore, the slag removal rate is limited to 40%. In addition, post-expansion occurred after slagging. In Example 7, V water / V slag Since the range is too large compared to the present invention, sufficient foaming suppression effect cannot be obtained, and although slag overflow does not occur, the slag removal rate is limited to 48%. But no post-expansion occurred after deslagging. In Example 8, the i...

Embodiment 13

[0097] Examples 13-16 are comparative examples. In Example 13, there is no water jet, so even if the slag discharge is temporarily interrupted, the foaming in the slag discharge pot continues, the slag overflows from the slag discharge pot, and the slag discharge rate stops at 15%. However, post-expansion after slagging did not occur. In Example 14, due to V water / V slag Compared with the present invention, the range is too small, so the foaming suppression effect is small, although the slag discharge is temporarily interrupted, the foaming in the slag discharge pot continues and the slag overflows. Therefore, the slagging rate is limited to 30%. In addition, post-expansion occurred after slagging. Example 15 V water / V slag The range was too large compared to the present invention, so sufficient foaming suppression effect could not be obtained, and although slag overflow did not occur, the slag discharge rate was limited to 43%. But no post-expansion occurred after de...

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PUM

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Abstract

In the slag foaming method, when discharging slag from a furnace mouth of a converter into a slag pot disposed below the converter, a water jet is jetted to a slag falling position in the slag pot ata rate satisfying the range of expression (1) after the start of slag discharge. Vwater: water jet jetting rate from start to end of deslagging (kg / min.); Vslag: slag discharge rate for two minutes after start of deslagging (kg / min).

Description

technical field [0001] The present invention relates to a method for suppressing foaming (air bubbles) of slag and a converter refining method. Background technique [0002] In the iron and steel manufacturing process, the molten iron produced by the blast furnace has a C concentration as high as 4 to 5% by mass and a P concentration as high as about 0.1% by mass. When it is directly solidified in this way to form pig iron, it is difficult to use it as steel because of its low workability and toughness. products for use. Therefore, in the refining process, dephosphorization and decarburization are performed, and various components are adjusted, thereby manufacturing steel satisfying the required quality. Although it is possible to oxidize and remove C and P in molten iron with oxygen and slag containing FeO in this dephosphorization and decarburization treatment, Si contained in molten iron is more easily oxidized than P, so desiliconization and dephosphorization are substa...

Claims

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Application Information

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IPC IPC(8): C21C5/28C21C1/02C21C1/04
CPCC21C1/02C21C1/04C21C5/28Y02P10/20C21C5/36C21C2005/366
Inventor 松泽玲洋沼田政宪尾林智
Owner NIPPON STEEL CORP