CN116377158A - Method for controlling nitrogen content of molten steel of all-three-stripping smelting low-nitrogen variety - Google Patents

Method for controlling nitrogen content of molten steel of all-three-stripping smelting low-nitrogen variety Download PDF

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Publication number
CN116377158A
CN116377158A CN202310254595.2A CN202310254595A CN116377158A CN 116377158 A CN116377158 A CN 116377158A CN 202310254595 A CN202310254595 A CN 202310254595A CN 116377158 A CN116377158 A CN 116377158A
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China
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molten steel
smelting
tapping
nitrogen
control
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CN202310254595.2A
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Inventor
孟德伟
赵立国
郭小龙
边吉明
陈先才
李光辉
王德庆
时岱
张惠鑫
张凯
范立新
刁华
丁立丰
白艳江
李勇
丁国慧
刘明杰
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Shougang Jingtang United Iron and Steel Co Ltd
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Shougang Jingtang United Iron and Steel Co Ltd
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Priority to CN202310254595.2A priority Critical patent/CN116377158A/en
Publication of CN116377158A publication Critical patent/CN116377158A/en
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/30—Regulating or controlling the blowing
    • C21C5/35—Blowing from above and through the bath
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0006—Adding metallic additives
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0068—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 by introducing material into a current of streaming metal
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Multimedia (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)

Abstract

The application relates to the field of steel smelting, in particular to a method for controlling the nitrogen content of molten steel of a low-nitrogen variety in total three-stripping smelting; the method comprises the following steps: obtaining molten steel after smelting; carrying out total three-stripping smelting on the molten steel to obtain molten steel with low nitrogen content; wherein, in the whole three-strip smelting process, process charging, process gun position, converter bottom blowing and tapping charging are respectively controlled; the method has the advantages that the method aims at the characteristic of small total three-strip smelting slag quantity, the molten steel covering effect in the process of melting slag can be enhanced by controlling the process feeding, the full nitrogen absorption of molten steel is guaranteed by controlling the process gun position and the bottom blowing of the converter, the situation that the molten steel covering effect is poor due to small slag quantity so that nitrogen absorption is insufficient is made up, the steel tapping feeding is controlled, the alloying use process of the steel tapping feeding is standardized, the consumption of alloy with high nitrogen increasing content is controlled, and the stable control of the nitrogen component of the molten steel of the total three-strip smelting converter is comprehensively guaranteed.

Description

Method for controlling nitrogen content of molten steel of all-three-stripping smelting low-nitrogen variety
Technical Field
The application relates to the field of steel smelting, in particular to a method for controlling the nitrogen content of molten steel of a low-nitrogen variety in total three-stripping smelting.
Background
The total three-stripping smelting has the advantages of small addition amount of slag materials such as lime and the like, quick production rhythm and great advantage for high-efficiency low-cost smelting of steel production, but has poor covering effect on molten steel due to small slag amount in the smelting process, so that nitrogen absorption of molten steel in the blowing process is serious.
Therefore, how to ensure the stable control of the nitrogen content of the molten steel of the full three-stripping smelting converter is a technical problem which needs to be solved at present.
Disclosure of Invention
The application provides a method for controlling the nitrogen content of molten steel of a full three-strip smelting low-nitrogen variety, which aims to solve the technical problem that the nitrogen content of molten steel of a full three-strip smelting converter is difficult to control stably in the prior art.
In a first aspect, the present application provides a method for controlling nitrogen content of a molten steel of a total triple-strip smelting low-nitrogen variety, the method comprising:
obtaining molten steel after smelting;
carrying out total three-stripping smelting on the molten steel to obtain molten steel with low nitrogen content;
wherein, in the whole three-strip smelting process, the process charging, the process gun position, the converter bottom blowing and the tapping charging are respectively controlled.
Optionally, the control of the process charging comprises control of the total addition amount of decarburized smelted lime, control of the lime addition amount of the dynamic process, control of the ore addition amount of the dynamic process and control of charging in the converting return period.
Optionally, the total addition amount of the decarburized smelting lime is 5-6 t;
lime addition amount in the dynamic process is more than or equal to 0.5t;
the ore addition amount in the dynamic process is 0.5 t-1.0 t.
Optionally, the feeding to the converting return dry period comprises: the Rong slag agent or fluorite is added in a mode of feeding in batches, wherein the adding amount of the feeding in batches is 280 kg-320 kg each time.
Optionally, the control of the gun position in the process comprises the control of the adjustment height of the converting gun in the converting period and the control of the adjustment height of the gun position in the returning period.
Optionally, the height of the blowing gun in the blowing period from the liquid level of molten steel is adjusted to be 1.6-1.7 m;
the height between the gun position and the liquid level of molten steel is adjusted to be 2.6 m-3.0 m in the dry returning period.
Optionally, the converter bottom blowing comprises converter bottom blowing with argon or a mixed gas, wherein the mixed gas comprises a mixed gas of carbon dioxide and argon.
Optionally, the flow rate of the converter bottom blowing is less than or equal to 800Nm 3 /h。
Optionally, the control of the tapping charging comprises control of the bottom blowing time before tapping, control of the tapping alloying moment and control of the manganese element adjusting process.
Optionally, the bottom blowing time before tapping is 20-30 s; the tapping and alloying time is from tapping to 150 t; the manganese element adjusting process comprises the following steps: and adjusting manganese element by using low-carbon ferromanganese and medium-carbon ferromanganese as adjusting agents.
Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:
according to the method for controlling the nitrogen content of the molten steel of the all-three-strip smelting low-nitrogen variety, through the characteristics of small amount of all-three-strip smelting slag, the molten steel covering effect in the process of slagging can be enhanced through controlling the process feeding, excessive nitrogen is prevented from being inhaled into the molten steel, the gun position of the process and the bottom blowing of the converter are controlled, the gas position and the gas flow of the entering molten steel can be controlled, so that the nitrogen absorption of the molten steel is ensured to be full, the situation that the nitrogen absorption is insufficient due to poor molten steel covering effect caused by small amount of slag is overcome, the steel tapping feeding is controlled, the alloying use process of the steel tapping feeding is standardized, the use amount of alloy with high nitrogen increasing is controlled, and the stable control of the nitrogen content of the molten steel of the all-three-strip smelting converter is comprehensively ensured.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.
In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, and it will be obvious to a person skilled in the art that other drawings can be obtained from these drawings without inventive effort.
Fig. 1 is a schematic flow chart of a method provided in an embodiment of the present application.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.
In one embodiment of the present application, as shown in fig. 1, a method for controlling nitrogen content of molten steel of all three-stripping smelting low-nitrogen variety is provided, which includes:
s1, obtaining molten steel after smelting;
s2, carrying out full three-way smelting on the molten steel to obtain molten steel with low nitrogen content;
wherein, in the whole three-strip smelting process, the process charging, the process gun position, the converter bottom blowing and the tapping charging are respectively controlled.
In some alternative embodiments, the control of the process feed includes control of the total addition of decarbonized smelted lime, control of the lime feed to the dynamic process, control of the ore feed to the dynamic process, and control of the feed to the converting return dry stage.
In this embodiment, through the control to the different reinforced stages of full three process of taking off, control lime total addition earlier, thereby guarantee lime slagging effect's abundant, guarantee the slag content, thereby can strengthen molten steel coverage effect, and then reduce the nitrogen absorption volume, the rethread is controlled the lime addition in the dynamic process, can guarantee the proper foaming of in-process slag of dynamic, and then make molten steel coverage effect good, reduce blowing later stage and inhale nitrogen, control the reinforced of blowing return dry period again, thereby can guarantee the even going on of slag process, and then further reduce the nitrogen absorption volume of molten steel.
In some alternative embodiments, the total addition amount of the decarburized smelted lime is 5t to 6t;
lime addition amount in the dynamic process is more than or equal to 0.5t;
the ore addition amount in the dynamic process is 0.5 t-1.0 t.
In the embodiment of the application, the positive effect that the total addition amount of the decarburized smelting lime is 5-6 t is that in the addition amount range, the sufficient slag amount of lime slagging can be ensured, so that molten steel can be completely covered, and the possibility of nitrogen absorption of the molten steel is reduced; when the total addition is smaller than the minimum end point value of the range, the adverse effect is that too low lime cannot generate enough slag quantity, and thus molten steel cannot be completely covered.
The lime adding amount in the dynamic process is more than or equal to 0.5t, and the positive effect of the lime adding amount is that in the range of the adding amount, enough slag amount can be generated in the lime slag in the dynamic process, so that the molten steel is completely covered in the dynamic process; when the addition amount of lime is too low, the slag amount is insufficient, and the molten steel cannot be completely covered in a dynamic process, so that the control of nitrogen absorption of the molten steel is affected.
The ore adding amount in the dynamic process is 0.5 t-1.0 t, and the beneficial effects are that in the range of the adding amount, the proper foaming of slag in the dynamic process can be ensured by adding the ore oxidizing slag melting agent, the complete coverage of slag on molten steel is further promoted, the molten steel covering effect is improved, and the nitrogen absorption amount in the later stage of blowing is reduced; when the addition amount is larger or smaller than the end value of the range, the foaming effect is influenced, so that the covering effect of molten steel is influenced.
In some alternative embodiments, the feeding of the converting return dry stage comprises: the Rong slag agent or fluorite is added in a mode of feeding in batches, wherein the adding amount of the feeding in batches is 280 kg-320 kg each time.
In the embodiment of the application, the adding amount of batch charging is 280 kg-320 kg each time, and the positive effects are that in the adding amount range, slag agent or fluorite can be fully melted, so that slag covered on molten steel is decomposed and floated, and the purity of the molten steel is further ensured; when the added amount is larger or smaller than the end value of the range, the slag removal effect of the molten steel is incomplete, and the quality of the molten steel is further affected.
In some alternative embodiments, the control of the process gun position includes control of the converting gun adjustment height during converting and control of the return dry stage gun position adjustment height.
In the embodiment of the application, the position and the height of the gun are suitable in the converting process through controlling the gun position in the process comprising controlling the height of the converting gun in the converting period and controlling the height of the gun position in the returning period, so that the slag is fully melted, and even molten steel with low nitrogen content is obtained.
In some alternative embodiments, the blowing gun in the blowing period is adjusted to be 1.3 m-1.7 m from the liquid level of molten steel;
the height between the gun position and the liquid level of molten steel is adjusted to be 2.6 m-3.0 m in the dry returning period.
In the embodiment of the application, the positive effect that the height of the converting gun in the converting period is adjusted to be 1.3-1.7 m from the liquid level of molten steel is that the height of the converting gun in the converting period is proper in the height range, so that the slag is taken out and evenly distributed; when the height is greater than or less than the end value of the range, the height of the converting gun is not suitable for promoting the generation of slag, and thus the sufficient melting of slag cannot be ensured.
The positive effect of adjusting the height of the gun position from the liquid level of molten steel to be 2.6 m-3.0 m in the dry return period is that the slag in the dry return period can be fully melted in the height range; when the height is greater than or less than the end value of the range, the height of the converting gun is not suitable for melting the slag, so that the slag cannot be melted sufficiently.
In some alternative embodiments, the converter bottom blowing comprises converter bottom blowing with argon or a mixture comprising carbon dioxide and argon.
In the embodiment of the application, the gas used for bottom blowing is limited, so that the bottom blowing of molten steel can be controlled in combination with actual conditions, nitrogen absorption of molten steel is avoided, molten steel can be fully stirred, and the quality of molten steel is improved.
In some alternative embodiments, the flow rate of the converter bottom blowing is less than or equal to 800Nm 3 /h。
In the embodiment of the application, the flow rate of the bottom blowing of the converter is less than or equal to 800Nm 3 The positive effect of/h is that in the flow range, the sufficient bottom blowing of molten steel can be ensured, thereby avoiding nitrogen absorption of molten steel, fully stirring the molten steel and improving the quality of the molten steel.
In some alternative embodiments, the control of the tapping charge includes control of the pre-tapping bottom-blowing time, control of the tapping addition timing, and control of the manganese element adjustment process.
According to the embodiment of the application, the control of the bottom blowing time before tapping, the control of the tapping alloy adding moment and the control of the manganese element adjusting process form the tapping charging control, so that the nitrogen absorption of molten steel is further prevented through the tapping bottom blowing, and the high nitrogen adding alloy consumption is controlled through the control of the tapping alloy adding moment and the manganese element adjusting process, so that conditions are created for controlling the stability of the nitrogen content of the molten steel.
In some alternative embodiments, the tapping time of the bottom blowing before tapping is 20 s-30 s; the tapping and alloying time is from tapping to 150 t; the manganese element adjusting process comprises the following steps: and adjusting manganese element by using low-carbon ferromanganese and medium-carbon ferromanganese as adjusting agents.
In the embodiment of the application, the positive effect that the bottom blowing time before tapping is 20-30 s is that in the time range, the stirring of molten steel after bottom blowing can be ensured to be more uniform, and meanwhile, nitrogen absorption of the molten steel is prevented; when the time value is larger or smaller than the end value of the range, uneven stirring distribution of molten steel in the bottom blowing process is caused.
By limiting the tapping time of the alloy to 150t, the alloy can be ensured not to influence the tapping quality in the process of adding the alloy in the tapping stage, and meanwhile, the alloying of molten steel can be ensured to be smoothly carried out.
The manganese element adjusting process is carried out by limiting the use of low-carbon ferromanganese and medium-carbon ferromanganese as the adjusting agents, so that excessive or insufficient carbon is prevented from being added, and the quality of molten steel is prevented from being influenced.
Example 1
As shown in FIG. 1, the method for controlling the nitrogen content of the molten steel of the full triple-strip smelting low-nitrogen variety comprises the following steps:
s1, obtaining molten steel after smelting;
s2, carrying out full three-way smelting on the molten steel to obtain molten steel with low nitrogen content;
wherein, the process charging, the process gun position, the converter bottom blowing and the tapping charging are respectively controlled in the whole three-stripping smelting process.
The control of process charging comprises the control of the total addition amount of decarburized smelting lime, the control of the addition amount of lime in a dynamic process, the control of the addition amount of ore in the dynamic process and the control of charging in a converting return drying period, and meanwhile, coke is not adopted for temperature raising in the process charging stage.
The total addition amount of the decarburized smelting lime is 5.5t;
lime addition amount in the dynamic process is 1.5t;
the ore addition amount in the dynamic process is 0.7t.
The feeding of the converting return dry period comprises the following steps: the rong slag agent or fluorite is added in a fed-batch manner, with the addition amount of 300kg each time.
The control of the process gun position comprises the control of the height adjustment of the converting gun in the converting period and the control of the height adjustment of the gun position in the returning period.
The height between the blowing gun and the molten steel liquid level in the blowing period is adjusted to be 1.6m;
the height of the gun position from the molten steel liquid level is adjusted to be 2.8m in the dry returning period.
The converter bottom blowing comprises the converter bottom blowing with argon or a mixed gas, wherein the mixed gas comprises a mixed gas of carbon dioxide and argon.
The flow rate of the bottom blowing of the converter was 600Nm 3 /h。
The control of tapping charging comprises the control of the bottom blowing time before tapping, the control of the tapping alloy moment and the control of the manganese element adjusting process.
The bottom blowing time before tapping is 25s; the tapping and alloying time is from tapping to 150 t; the manganese element adjusting process comprises the following steps: and adjusting manganese element by using low-carbon ferromanganese and medium-carbon ferromanganese as adjusting agents.
Example 2
Example 2 and example 1 were compared, and the difference between example 2 and example 1 is that:
the total addition amount of decarburized smelting lime is 5t;
lime addition amount in the dynamic process is 0.5t;
the ore addition amount in the dynamic process is 0.5t.
The amount of the batch feed was 280kg each.
The height between the blowing gun and the molten steel liquid level in the blowing period is adjusted to be 1.3m;
the height of the gun position from the molten steel liquid level is adjusted to be 2.6m in the dry returning period.
The bottom blowing time before tapping is 20s.
Example 3
Example 3 was compared with example 1, and the difference between example 3 and example 1 was:
the total addition amount of decarburized smelting lime is 6t;
the ore addition amount in the dynamic process is 1.0t.
The amount of the batch feed was 320kg each time.
The height between the blowing gun and the molten steel liquid level in the blowing period is adjusted to be 1.7m;
the height of the gun position from the molten steel liquid level is adjusted to be 3.0m in the dry returning period.
The bottom blowing time before tapping is 30s.
Comparative example 1
Comparative example 1 was compared with example 1, and the difference between comparative example 1 and example 1 was that:
the process charging, the process gun position, the converter bottom blowing and the tapping charging are not controlled respectively.
Comparative example 2
Comparative example 2 and example 1 were compared, and the comparative example 2 and example 1 differ in that:
the total addition amount of decarburized smelting lime is 4t;
lime addition amount in the dynamic process is 0.2t;
the ore addition amount in the dynamic process is 0.4t.
The amount added was 250kg each time.
The height between the blowing gun and the molten steel liquid level in the blowing period is adjusted to be 1.6m;
the height of the gun position from the molten steel liquid level is adjusted to be 2.5m in the dry returning period.
The bottom blowing time before tapping is 10s.
Comparative example 3
Comparative example 3 was compared with example 1, and the difference between comparative example 3 and example 1 was that:
the total addition amount of decarburized smelting lime is 8t;
the ore addition amount in the dynamic process is 1.5t.
The amount added was 350kg per batch.
The height between the blowing gun and the molten steel liquid level in the blowing period is adjusted to be 1.7m;
the height of the gun position from the molten steel liquid level is adjusted to be 3.5m in the dry returning period.
The bottom blowing time before tapping is 40s.
Related experiments:
the nitrogen content in the molten steels obtained in examples 1 to 3 and comparative examples 1 to 3 was counted, respectively, and the results are shown in Table 1.
Test method of related experiment:
nitrogen content: the measurement was performed by using an EMGA-620W type oxygen nitrogen analyzer from HORIBA (HORIBA).
TABLE 1
Group of Nitrogen content (ppm)
Example 1 13
Example 2 15
Example 3 14
Comparative example 1 20
Comparative example 2 19
Comparative example 3 16
Table 1 detailed analysis:
the nitrogen content refers to the nitrogen content in the obtained molten steel, and the more the nitrogen content meets the standard, the more accurate the nitrogen content control of the molten steel product is indicated.
From the data of examples 1-3, the method of the application can ensure the stable control of the nitrogen content of the molten steel of the full three-strip smelting converter by controlling the process charging, the process gun position, the converter bottom blowing and the tapping charging respectively in the full three-strip smelting process.
From the data of comparative examples 1-3, it can be seen that:
if the method is not adopted, or all the process parameters are not controlled in the corresponding ranges, the nitrogen content of the final steel grade after the total three-strip smelting is affected.
One or more technical solutions in the embodiments of the present application at least further have the following technical effects or advantages:
(1) According to the method provided by the embodiment of the application, the process charging, the process gun position, the converter bottom blowing and the tapping charging are controlled respectively, the molten steel covering effect in the process of slagging can be enhanced by controlling the process charging, excessive nitrogen is prevented from being inhaled into molten steel, the process gun position and the converter bottom blowing are controlled through controlling the gas position and the gas flow of entering molten steel, so that the nitrogen absorption of the molten steel is ensured to be full, the situation that the nitrogen absorption is insufficient due to poor molten steel covering effect caused by small slag quantity is overcome, the tapping charging is controlled again, the alloying use process of the tapping charging is standardized, and the use amount of alloy with high nitrogen increment is controlled, so that the stable control of the nitrogen component of the molten steel of the full three-stripping smelting converter can be ensured.
(2) The method provided by the embodiment of the application provides a set of effective operation guidance for the full three-stripping smelting process, and creates favorable conditions for production stability and quality stability.
(3) The method provided by the embodiment of the application can also effectively control the content of manganese element, avoid carburetion of molten steel in the alloying process, and provide guarantee for the quality of molten steel.
It should be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The foregoing is only a specific embodiment of the invention to enable those skilled in the art to understand or practice the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A method for controlling the nitrogen content of molten steel of a low nitrogen variety in total three-stripping smelting, which is characterized by comprising the following steps:
obtaining molten steel after smelting;
carrying out total three-stripping smelting on the molten steel to obtain molten steel with low nitrogen content;
wherein, in the whole three-strip smelting process, the process charging, the process gun position, the converter bottom blowing and the tapping charging are respectively controlled.
2. The method of claim 1, wherein the controlling of the process charge comprises controlling the total addition of decarburized smelted lime, controlling the lime addition to the dynamic process, controlling the ore addition to the dynamic process, and controlling the charge to the converting return dry stage.
3. The method according to claim 2, wherein the total addition amount of the decarburized smelted lime is 5t to 6t;
lime addition amount in the dynamic process is 5 t-6 t;
the ore addition amount in the dynamic process is 0.5 t-1.0 t.
4. The method of claim 2, wherein the feeding of the converting rebate comprises: the Rong slag agent or fluorite is added in a mode of feeding in batches, wherein the adding amount of the feeding in batches is 280 kg-320 kg each time.
5. The method of claim 1, wherein the control of the process lance position comprises control of an adjustment height of the converting lance during converting and control of an adjustment height of the lance position during return drying.
6. The method according to claim 5, wherein the height of the blowing gun from the molten steel liquid level in the blowing period is adjusted to be 1.6-1.7 m;
the height between the gun position and the liquid level of molten steel is adjusted to be 2.6 m-3.0 m in the dry returning period.
7. The method of claim 1, wherein the converter bottom blowing comprises converter bottom blowing with argon or a mixture comprising carbon dioxide and argon.
8. The method according to claim 7, wherein the flow rate of the converter bottom blowing is less than or equal to 800Nm 3 /h。
9. The method according to claim 1, wherein the control of the tapping charge comprises control of the time of bottom blowing before tapping, control of the moment of tapping the alloy and control of the manganese element adjustment process.
10. The method according to claim 9, wherein the pre-tapping bottom blowing time is 20 s-30 s; the tapping and alloying time is from tapping to 150 t; the manganese element adjusting process comprises the following steps: and adjusting manganese element by using low-carbon ferromanganese and medium-carbon ferromanganese as adjusting agents.
CN202310254595.2A 2023-03-16 2023-03-16 Method for controlling nitrogen content of molten steel of all-three-stripping smelting low-nitrogen variety Pending CN116377158A (en)

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