CN114941048A - Method for mixing carbon dioxide and nitrogen as converter bottom blowing medium - Google Patents
Method for mixing carbon dioxide and nitrogen as converter bottom blowing medium Download PDFInfo
- Publication number
- CN114941048A CN114941048A CN202210399819.4A CN202210399819A CN114941048A CN 114941048 A CN114941048 A CN 114941048A CN 202210399819 A CN202210399819 A CN 202210399819A CN 114941048 A CN114941048 A CN 114941048A
- Authority
- CN
- China
- Prior art keywords
- carbon dioxide
- bottom blowing
- nitrogen
- blowing
- converter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 title claims abstract description 74
- 238000007664 blowing Methods 0.000 title claims abstract description 55
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 title claims abstract description 53
- 229910002092 carbon dioxide Inorganic materials 0.000 title claims abstract description 37
- 239000001569 carbon dioxide Substances 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 31
- 229910052757 nitrogen Inorganic materials 0.000 title claims abstract description 24
- 239000007789 gas Substances 0.000 claims abstract description 25
- 238000003723 Smelting Methods 0.000 claims abstract description 13
- 239000000203 mixture Substances 0.000 claims abstract description 7
- 229910001873 dinitrogen Inorganic materials 0.000 claims abstract description 5
- 230000008569 process Effects 0.000 claims description 12
- 239000000428 dust Substances 0.000 claims description 7
- 239000012535 impurity Substances 0.000 claims description 7
- 230000007797 corrosion Effects 0.000 claims description 5
- 238000005260 corrosion Methods 0.000 claims description 5
- 238000012423 maintenance Methods 0.000 claims description 3
- 238000009991 scouring Methods 0.000 claims description 2
- 230000003628 erosive effect Effects 0.000 claims 1
- 229910000831 Steel Inorganic materials 0.000 abstract description 16
- 239000010959 steel Substances 0.000 abstract description 16
- 238000004064 recycling Methods 0.000 abstract description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 229910052786 argon Inorganic materials 0.000 description 4
- 238000009628 steelmaking Methods 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 239000002131 composite material Substances 0.000 description 3
- 238000005261 decarburization Methods 0.000 description 3
- 229910052748 manganese Inorganic materials 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- AAEGEOXHMYAZAY-UHFFFAOYSA-N [Ar].O=C=O Chemical compound [Ar].O=C=O AAEGEOXHMYAZAY-UHFFFAOYSA-N 0.000 description 1
- KPAMAAOTLJSEAR-UHFFFAOYSA-N [N].O=C=O Chemical compound [N].O=C=O KPAMAAOTLJSEAR-UHFFFAOYSA-N 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000009851 ferrous metallurgy Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- 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
-
- 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
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/122—Reduction of greenhouse gas [GHG] emissions by capturing or storing CO2
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
The invention discloses a method for using carbon dioxide and nitrogen gas mixture as a converter bottom blowing medium, converter smelting is generally divided into four stages, namely a blowing early stage, a blowing middle stage), a blowing later stage and a blowing final stage, and the method is characterized in that a bottom blowing carbon dioxide and nitrogen gas mixture gas supply scheme is formulated according to the characteristics of the four stages of smelting by using different bottom blowing gas supply intensities. The invention aims to solve the problems of reducing the nitrogen content of the molten steel at the end point of the converter and recycling carbon dioxide resources.
Description
Technical Field
The invention relates to the technical field of ferrous metallurgy, in particular to a method for using mixture of carbon dioxide and nitrogen as a converter bottom blowing medium.
Background
The top-bottom composite blowing technology of the oxygen converter is a steelmaking technology developed in the middle and later period of the 70 s. The composite converting method utilizes the bottom blowing airflow to overcome the defect that the stirring capacity of the top blowing oxygen flow to the molten pool is insufficient, the reaction in the furnace is close to balance, the iron loss is reduced, and simultaneously the advantage that the slagging process is easy to control by the top blowing method is kept, so the composite converting method has better technical and economic indexes than the top blowing and the bottom blowing.
In China, most combined blown converter bottom blowing systems use nitrogen and argon as gas media and use nitrogen and argon to switch gas supply modes. Nitrogen can be used as an easily available gas source in a large amount, but the content of nitrogen in steel exceeds a certain range, so that the steel quality is deteriorated, the plasticity, the welding performance and the aging performance of the steel are poor, and the production cost exceeds the standard by only using argon. Meanwhile, on the premise of reducing carbon emission and developing green and environment-friendly steel production, how to effectively carry out carbon dioxide recycling and reducing carbon emission also become important targets of energy-saving production of various steel plants. Therefore, how to solve the nitrogen content of the molten steel at the end point of the converter and effectively recycle the carbon dioxide resource becomes the key point of the technical attack in the steel-making industry in China.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide a method for using carbon dioxide and nitrogen mixed as a bottom blowing medium of a converter, and solves the problems of reducing the nitrogen content of molten steel at the end point of the converter and recycling carbon dioxide resources.
In order to solve the technical problems, the invention adopts the following technical scheme:
the invention discloses a method for using carbon dioxide and nitrogen to mix as a converter bottom blowing medium, converter smelting is generally divided into four stages, namely a blowing early stage, a blowing middle stage), a blowing later stage and a blowing final stage, and the method is characterized in that aiming at the characteristics of the four stages of smelting, the bottom blowing gas supply strength is different, and a bottom blowing carbon dioxide and nitrogen mixed gas supply scheme is formulated as shown in the following table:
bottom blowing technical scheme for each smelting stage
Furthermore, in the daily maintenance and inspection process, the carbon dioxide switching valve welded junction, the conveying pipeline and the flow valve of the bottom blowing valve station are periodically maintained and inspected, and the corrosion phenomenon is found and should be immediately replaced to prevent the occurrence of carbon dioxide leakage accidents.
Furthermore, carbon dioxide is purified in the using process, accompanying dust impurities in the gas are filtered, and therefore the phenomenon that the dust impurities erode the inside of the conveying pipeline in the conveying process of high-pressure carbon dioxide is avoided, and the pipeline leakage accidents are reduced.
Compared with the prior art, the invention has the beneficial technical effects that:
by adopting the method, the use cost of the bottom blowing medium is effectively reduced, and the nitrogen element content in the molten steel at the end point of the converter is effectively reduced.
Detailed Description
Carbon dioxide belongs to weak oxidizing gas, and the standard Gibbs free energy of the reaction with elements such as C, Mn and Fe in a molten pool is as follows:
the standard free energy changes of the reactions (1) to (3) at the steelmaking temperature are negative, which shows that C, Mn and the oxidation reaction of Fe element can be carried out, and the reactions are completely carried out in an equilibrium state.
According to the change of the standard free energy of the reaction, at the steelmaking temperature, C and CO are contained 2 An oxidation reaction may be performed. When the mixed gas is used for bottom blowing stirring, when the initial smelting temperature is low, silicon and manganese are preferentially oxidized; in the middle smelting period with the highest decarburization speed, bottom blown CO 2 Mainly reacts with carbon to perform molten steel decarburization reaction by adopting bottom blowing CO 2 The decarburization rate of the molten pool is higher than that of other gases blown from the bottom; at the end of smelting, bottom blowing CO2 is mainly mixed with [ Fe ]]And (4) acting. CO is introduced into 2 The gas is used for bottom blowing stirring, the quality of the molten steel cannot be influenced, the nitrogen supply amount is reduced, the dissolving amount of nitrogen in the molten steel is reduced, and the aim of effectively reducing the content of the nitrogen in the molten steel at the end point of the converter can be achieved.
Bottom blowing CO due to the presence of chemical reactions 2 Bottom blowing N 2 Or Ar gasThe bubble peak height is about 1/3, and the dynamic effect of bottom blowing is enhanced.
Based on the aspects of reducing the production cost of enterprises and improving the quality of the molten steel at the end point of the converter, the invention provides a method for mixing carbon dioxide and nitrogen to be used as a bottom blowing medium of the converter, wherein the preparation price of the carbon dioxide is lower than N 2 And meanwhile, additional equipment is not required.
So that the manner in which the above recited aspects, features and advantages of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
Converter smelting is generally divided into four stages. The early stage of blowing (within 3 minutes of starting oxygen supply), the middle stage of blowing (3-9 minutes of starting oxygen supply), the late stage of blowing (9-12 minutes of starting oxygen supply), and the final stage of blowing (12 minutes of starting oxygen supply-finishing). By using the invention, aiming at the characteristics of the four stages of smelting, the mixed gas supply scheme of bottom blowing carbon dioxide and nitrogen is formulated as shown in Table 2 by using different bottom blowing gas supply strengths.
TABLE 2 technical scheme of bottom blowing gas supply in each smelting stage
It should be noted that although the medium conveying pipeline does not need to be replaced, carbon dioxide belongs to weak oxidizing gas, and two points of attention are paid to long-term use.
1. The use conditions of a welded junction, a conveying pipeline and a flow valve of a bottom blowing valve station at the carbon dioxide switching valve need to be continuously paid attention to and checked. Different from nitrogen gas in property, carbon dioxide belongs to weak oxidizing gas, and can generate oxidation reaction on a welded junction at a carbon dioxide switching valve, a conveying pipeline and a flow valve of a bottom blowing valve station in the long-term use process and cause corrosion of a quick connection valve, so that the phenomenon of gas leakage is caused. Therefore, in the daily maintenance process, the positions need to be maintained regularly, and the corrosion phenomenon is found and should be replaced immediately to prevent the carbon dioxide leakage accident.
2. During the carbon dioxide collection process, gas may enter the transfer pipe along with the dust impurities. Therefore, the carbon dioxide is required to be purified in the using process, and the dust impurities possibly accompanying in the gas are filtered, so that the mechanical scouring corrosion phenomenon generated by the dust impurities to the inside of the conveying pipeline in the high-pressure carbon dioxide conveying process is avoided, and the pipeline leakage accident is reduced.
Production experiments were carried out using the present invention in a 240t top-bottom combined blown converter. The experiment adopts a blank group and experiment group comparison experiment method, wherein the blank group adopts a bottom blowing nitrogen and argon switching mode, and the experiment group adopts a bottom blowing carbon dioxide nitrogen mixed gas and argon carbon dioxide mixed gas switching mode. The method has the beneficial effects that after the method is adopted, the use cost of the bottom blowing medium is effectively reduced, and the nitrogen element content in the molten steel at the end point of the converter is effectively reduced. The results of the nitrogen content test of the molten steel at the end point of the converter are shown in Table 1.
TABLE 1 comparison of blank and Experimental data
The above-described embodiments are only intended to illustrate the preferred embodiments of the present invention, and not to limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims (3)
1. A method for using carbon dioxide and nitrogen gas mixture as a converter bottom blowing medium is characterized in that aiming at the characteristics of the four smelting stages, the bottom blowing gas supply strength is different, and the bottom blowing carbon dioxide and nitrogen gas mixture gas supply scheme is formulated as shown in the following table:
bottom blowing technical scheme for each smelting stage
2. The method for utilizing the mixture of carbon dioxide and nitrogen as the bottom blowing medium of the converter according to claim 1, wherein the weld seam, the conveying pipeline and the flow valve of the bottom blowing valve station at the carbon dioxide switching valve are periodically maintained and inspected in the daily maintenance process, and the corrosion phenomenon is found to be immediately replaced to prevent the occurrence of carbon dioxide leakage accidents.
3. The method for using the mixture of carbon dioxide and nitrogen as the bottom blowing medium of the converter according to claim 1, wherein the carbon dioxide is purified during the use process to filter the accompanying dust impurities in the gas, thereby avoiding the mechanical scouring erosion phenomenon of the dust impurities on the inner part of the conveying pipeline during the conveying process of the high-pressure carbon dioxide and reducing the occurrence of pipeline leakage accidents.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210399819.4A CN114941048A (en) | 2022-04-15 | 2022-04-15 | Method for mixing carbon dioxide and nitrogen as converter bottom blowing medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210399819.4A CN114941048A (en) | 2022-04-15 | 2022-04-15 | Method for mixing carbon dioxide and nitrogen as converter bottom blowing medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114941048A true CN114941048A (en) | 2022-08-26 |
Family
ID=82907190
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210399819.4A Pending CN114941048A (en) | 2022-04-15 | 2022-04-15 | Method for mixing carbon dioxide and nitrogen as converter bottom blowing medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114941048A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101818227A (en) * | 2010-05-05 | 2010-09-01 | 北京科技大学 | Method for recycling CO2 separated from converter steel-making gas for top blowing and bottom blowing |
| CN108251593A (en) * | 2018-02-08 | 2018-07-06 | 北京科技大学 | A kind of pneumatic steelmaking dynamic regulation bottom blowing CO2The method that flow improves denitrogenation |
| CN109234490A (en) * | 2018-11-07 | 2019-01-18 | 北京科技大学 | A kind of vanadium extraction-decarburization duplex converter high-efficiency long-life blowing method and system |
| CN112094980A (en) * | 2020-08-18 | 2020-12-18 | 北京科技大学 | System and method for efficient smelting of converter through top-bottom composite powder injection |
-
2022
- 2022-04-15 CN CN202210399819.4A patent/CN114941048A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101818227A (en) * | 2010-05-05 | 2010-09-01 | 北京科技大学 | Method for recycling CO2 separated from converter steel-making gas for top blowing and bottom blowing |
| CN108251593A (en) * | 2018-02-08 | 2018-07-06 | 北京科技大学 | A kind of pneumatic steelmaking dynamic regulation bottom blowing CO2The method that flow improves denitrogenation |
| CN109234490A (en) * | 2018-11-07 | 2019-01-18 | 北京科技大学 | A kind of vanadium extraction-decarburization duplex converter high-efficiency long-life blowing method and system |
| CN112094980A (en) * | 2020-08-18 | 2020-12-18 | 北京科技大学 | System and method for efficient smelting of converter through top-bottom composite powder injection |
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| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
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Application publication date: 20220826 |