Method for increasing residual manganese content in molten steel at end point of converter

A converter end point and content technology, which is applied in the field of steelmaking technology, can solve the problems that the tapping temperature cannot meet the requirements of tapping, the unfavorable cleanliness of molten steel, and the reduction of molten steel in the furnace, etc., so as to prevent rephosphorization and tapping Effects of lowering slag, reducing converter blowing loss, and reducing steelmaking cost

CN108396093AInactive Publication Date: 2018-08-14ANGANG STEEL CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2018-08-14
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a method for increasing the residual manganese content in molten steel at the end point of a converter. According to the method, the waste steel loading amount of the converteris controlled according to the waste steel ratio of not more than 15%; at the early stage of the smelting, the iron-carbon ball slag is added while the white ash slag is added into the converter, theadding amount of the first batch of the slagging material is 50-70% of the total adding amount, the blowing starting position of the oxygen gun is 0.8-1.2 m, and the gun position is increased to 2.2-2.6 m after blowing is performed for 1-2 min; 25-40% of the remaining slag is added after blowing is performed for 3-6 min; at the middle stage of the smelting, the oxygen gun is lifted to 2.5-3.0 m, blowing is performed for 10-30 s, and then the oxygen gun is lowered to the basic gun position; and at the late stage of the smelting, the gun position is controlled at 1.0-1.2 m, and the remaining slag is added to the converter at 2-5 min before the tapping. According to the present invention, with the method, the residual manganese content in the end point molten steel can be increased, the alloyaddition amount during alloying can be reduced, the steelmaking cost can be reduced, the FeO content in the final slag can be reduced, the converter blow loss can be reduced, and the rephosphorization and the tapping slag discharge can be effectively prevented.
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Description

technical field

[0001] The invention belongs to the field of steelmaking technology, in particular to a method for increasing the residual manganese content of molten steel at the end point of a converter. Background technique

[0002] Manganese can improve the tensile strength, machinability, toughness, hardness and wear resistance of steel, and can also reduce the adverse effects of sulfur in steel, so manganese is regarded as one of the main elements in steel. After the converter completes the task of smelting molten iron, most of the manganese in the original molten iron is oxidized. According to different steel types, it is necessary to add manganese-ferroalloy to the molten steel to meet the composition requirements of the steel type. In the actual production process, the residual manganese content in molten steel has an important impact on the amount of ferromanganese added, the higher the residual manganese content, the less the amount of alloyed ferromanganese added...

Examples

Embodiment 1

[0043] Table 1 shows the conditions of molten iron and steel scrap mixed into the converter for blowing low-carbon steel with a steel carbon requirement of 0.05-0.10%.

[0044] Table 1 The situation of molten iron and steel scrap blended into the converter

[0045] C％

Si%

Mn%

P％

S％

T 铁 ℃

Amount of molten iron t

Amount of scrap steel t

4.02

0.46

0.12

0.075

0.005

1290

101

6

[0046] The total amount of lime added is converted according to the effective CaO content of 80%, the adjustment coefficient λ value of 1.1, and the final slag basicity of 3.0. The amount of added iron per ton is:

[0047] Then, the total amount of lime that needs to be added is: 40.59×101=4099.59kg≈4.1t.

[0048] When blowing oxygen in the lowering lance, first add 2.5t of lime and 0.5t of iron carbon balls to the first batch of slag, add the second batch of lime slag after blowing for 4.5min, the addition amount is 0.48t, and 3min befor...

Embodiment 2

[0058] Table 3 shows the conditions of molten iron and steel scrap that are blended into the converter for blowing high-carbon steel with a steel carbon requirement of 0.35-0.60%.

[0059] Table 3 The situation of molten iron and steel scrap blended into the converter

[0060] C％

Si%

Mn%

P％

S％

T 铁 ℃

Amount of molten iron t

Amount of scrap steel t

4.14

0.52

0.13

0.070

0.005

1330

102

5

[0061] The total amount of lime added is converted according to the effective CaO content of 80%, the adjustment coefficient λ value of 1.0, and the final slag basicity of 3.0.

[0062] It can be seen that the amount of iron added per ton is:

[0063] Then, the total amount of lime that needs to be added is: 45.9×102=4681.8kg≈4.7t.

[0064] When blowing oxygen in the lowering lance, first add 2.8t of lime to the first batch of slag, and add 0.6t of iron carbon balls. After blowing for 5 minutes, add the second batch of lime a...