CN114990279B - Method for reducing iron-steel ratio under limit heat balance - Google Patents
Method for reducing iron-steel ratio under limit heat balance Download PDFInfo
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- CN114990279B CN114990279B CN202210735005.3A CN202210735005A CN114990279B CN 114990279 B CN114990279 B CN 114990279B CN 202210735005 A CN202210735005 A CN 202210735005A CN 114990279 B CN114990279 B CN 114990279B
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- steel ratio
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 82
- 239000010959 steel Substances 0.000 title claims abstract description 82
- 238000000034 method Methods 0.000 title claims abstract description 29
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 40
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 39
- 239000001301 oxygen Substances 0.000 claims abstract description 39
- 238000009628 steelmaking Methods 0.000 claims abstract description 15
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 37
- 229910052742 iron Inorganic materials 0.000 claims description 18
- 238000007664 blowing Methods 0.000 claims description 7
- 230000009286 beneficial effect Effects 0.000 abstract description 6
- 238000006243 chemical reaction Methods 0.000 description 12
- 230000008569 process Effects 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 238000005261 decarburization Methods 0.000 description 6
- 239000007789 gas Substances 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- 238000003723 Smelting Methods 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 239000002893 slag Substances 0.000 description 3
- 239000003034 coal gas Substances 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000017525 heat dissipation Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000036284 oxygen consumption Effects 0.000 description 2
- 229910000805 Pig iron Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002699 waste material Substances 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
-
- 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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- 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 relates to the technical field of steelmaking, in particular to a method for reducing iron-steel ratio under extreme heat balance, which comprises the steps of performing early-stage converting, medium-stage converting and later-stage converting during converter steelmaking; wherein the middle converting comprises controlling gun position to 1.4-1.6mControlling the oxygen flow to 22000-24000Nm 3 And/h, controlling the outlet pressure to be 0.60-0.70MPa. The method for reducing the iron-steel ratio under the limit heat balance can effectively reduce the iron-steel ratio, improves the limit of the scrap steel ratio, and is beneficial to improving the adding amount of the scrap steel.
Description
Technical Field
The invention relates to the technical field of steelmaking, in particular to a method for reducing iron-steel ratio under extreme heat balance.
Background
The iron-steel ratio is the ratio of the amount of iron and steel charged in the steelmaking process to the steel yield. The reduction of the iron-steel ratio is helpful for maximally improving the steel yield under the condition of limited molten iron resources, thereby realizing the maximization of benefits. In order to pursue the maximization of benefit, various means are adopted in the related art to reduce the iron-steel ratio and increase the addition amount of scrap steel.
However, the related art has a bottleneck in lowering the iron to steel ratio, i.e., the lowering of the iron to steel ratio is limited; the addition amount of the scrap steel is difficult to increase.
Disclosure of Invention
The invention aims to provide a method for reducing the iron-steel ratio under the limit heat balance, which can effectively reduce the iron-steel ratio and improve the scrap steel ratio limit, thereby being beneficial to improving the adding amount of scrap steel.
The invention is realized in the following way:
the invention provides a method for reducing iron-steel ratio under limit heat balance, which comprises the following steps:
when the converter steelmaking is performed, performing early converting, medium converting and later converting; wherein,,
the middle converting comprises controlling gun position at 1.4-1.6m, and controlling oxygen flow at 22000-24000Nm 3 And/h, controlling the outlet pressure to be 0.60-0.70MPa.
In an alternative embodiment, the mid-stage converting includes controlling the oxygen flow to 23000Nm 3 And/h, the middle converting comprises controlling the outlet pressure to be 0.64MPa.
In an alternative embodiment, the mid-term converting time is 11-13 minutes.
In an alternative embodiment, the pre-converting includes controlling the oxygen flow to 29000-31000Nm 3 /h，And controlling the outlet pressure to be 0.80-0.90MPa.
In an alternative embodiment, the pre-converting comprises controlling the oxygen flow to 30000Nm 3 And controlling the outlet pressure to be 0.83MPa.
In an alternative embodiment, the time for the pre-converting is 210-240s.
In an alternative embodiment, the gun position is controlled to be 1.8-2.0m during the first 110-120s of the front converting, and then the gun position can be gradually reduced to be 1.6m.
In an alternative embodiment, the post converting comprises controlling the gun position to be 1.1-1.3m and controlling the oxygen flow to be 37000-39000Nm 3 And/h, controlling the outlet pressure to be 0.90-0.95MPa and converting time to be 60-90s.
In an alternative embodiment, the post converting comprises controlling the gun position to be 1.2m and controlling the oxygen flow to be 38000Nm 3 And/h, controlling the outlet pressure to be 0.92MPa.
The invention has the following beneficial effects:
the method for reducing the iron-steel ratio under the limit heat balance provided by the invention controls the gun position to be 1.4-1.6m and controls the oxygen flow to be 22000-24000Nm during mid-term converting 3 Controlling the outlet pressure to be 0.60-0.70MPa so as to increase the impact area and reduce the impact depth during soft blowing, so that the generated CO gas and O blown out by the oxygen lance 2 The reaction is equivalent to that the heat generated by CO (coal gas) combustion is supplied to molten steel for heating, so that the temperature of a molten pool is increased, normal converting can be realized even under the condition of adding more scrap steel, the terminal point is ensured to be not oxidized, and the terminal point temperature is qualified; further, the burning loss of iron is reduced, the aim of reducing the iron-steel ratio is fulfilled, the limit of the scrap steel ratio can be improved, the scrap steel ratio reaches 26.7%, and the adding amount of the scrap steel is improved.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
In the converter steelmaking process, adding scrap steel into a converter through a scrap steel hopper in the related art (CN 108085577B), wherein the adding amount of the scrap steel is 350-370kg/t, and the tapping temperature is controlled at 1570-1590 ℃; in the step, a low gun position operation mode is adopted, the gun position control is reduced by 100-200cm compared with the traditional process, the gun position control is controlled to be 600-800cm, the oxygen gun pressure is controlled to be 1.0MPa, and the whole-process oxygen bottom blowing flow is controlled to be 400m 3 Over/h; the proportion of the scrap steel in the scheme is more than 30%, but the scrap steel is added in a multi-point mode, rather than the one-time adding mode of the invention, the related technology requires that a sufficient volume is needed for storing the scrap steel barrels to stack the scrap steel, and the scrap steel is high in the converter pile ratio in the smelting process, so that the scrap steel is easy to burn; and the oxygen consumption is high in the smelting process, so that the smelting cost is increased more.
In converter steelmaking, the main sources of heat required generally include two aspects: firstly, the physical heat of the temperature of the molten iron is derived, and the temperature of the molten iron is a sign of the physical heat; and secondly, chemical heat emitted by elements in molten iron in the oxidation process.
The heat consumption of a converter is also generally divided into two parts: part of the heat is heat directly used for steelmaking, namely, heat used for heating molten steel and slag; the other part is heat which is not directly used for steelmaking and comprises heat taken away by waste and smoke dust, heat taken away by cooling water, heat dissipation loss of furnace mouth and furnace shell, heat absorption of coolant and the like.
When the scrap ratio increases to a certain amount, there will be zero surplus heat, i.e., surplus heat=income heat-expenditure heat, which is the critical point of the scrap ratio. The method for reducing the iron-steel ratio under the limit heat balance can effectively reduce the iron-steel ratio, improves the scrap steel occupying ratio limit and is beneficial to improving the adding amount of scrap steel.
The method for reducing the iron-steel ratio under the limit heat balance comprises the steps of performing early converting, medium converting and later converting during converter steelmaking.
The earlier stage converting comprises controlling oxygen flow to 29000-31000Nm 3 And controlling the outlet pressure to be 0.80-0.90MPa.
In a preferred embodiment, the pre-converting comprises controlling the oxygen flow to 30000Nm 3 And controlling the outlet pressure to be 0.83MPa.
The time of the preliminary converting is 210-240s; the slag in the current period floats up faster and the converting process is stable, and the next operation can be performed after converting for about 210 seconds.
The gun position control of the earlier converting can be controlled to be 1.8-2.0m according to the front 110-120s, and then the gun position can be gradually reduced to 1.6m; in a preferred embodiment, the gun position is gradually reduced to 1.6m after the preliminary converting for about 120 s.
The middle converting comprises controlling gun position at 1.4-1.6m, and controlling oxygen flow at 22000-24000Nm 3 And/h, controlling the outlet pressure to be 0.60-0.70MPa.
In the converter steelmaking process, gaseous oxygen reacts with carbon in steel [ C ] +1/2{ O2} = { CO }, ΔH= -152.47KJ, and the reaction is exothermic; the temperature of the molten pool can be increased by 120 ℃ every 1% of carbon in the molten pool, and the heat released by the reaction is an important source for converter steelmaking. Carbon also reacts with oxygen dissolved in the metal [ C ] + [ O ] = { CO }, Δh= -35.6KJ. This reaction is a weak exothermic reaction and the evolved heat can also be used for converter steelmaking.
And the iron oxide in the slag reacts with the steel carbon in an endothermic manner, (FeO) + [ C ] = [ Fe ] + { CO }, and ΔH= 85.31KJ.
It follows that by the mutual cancellation of the exothermic and endothermic reactions described above, the total amount of heat evolved is less.
The gun position, the oxygen flow and the outlet pressure are controlled in the middle converting stage, so that the impact area can be increased and the impact depth can be reduced in the soft converting stage, namely, the gun position is controlled relatively low, the stirring intensity of a molten pool can be ensured, and the impact area can be increased by controlling the lower oxygen flow, so that the generated CO gas and O blown out by the oxygen gun can be increased 2 The reaction is equivalent to heating the heat generated by burning CO (gas) by supplying molten steelThe temperature of the molten pool is high, so that normal converting can be guaranteed to be realized even under the condition of adding more scrap steel, the terminal point is guaranteed to be not oxidized, and the terminal point temperature is qualified; further, the loss of iron is reduced, the aim of reducing the iron-steel ratio is fulfilled, the limit of the scrap steel ratio can be improved, the scrap steel ratio reaches 26.7%, and the addition of the scrap steel is facilitated to be improved. In addition, the method of the invention does not need to add a heating agent and pig iron, can further control the iron-steel ratio, and can effectively reduce the cost.
In a preferred embodiment, the mid-term converting comprises controlling the oxygen flow to 23000Nm 3 And/h, the middle converting comprises controlling the outlet pressure to be 0.64MPa. Thus, in a preferred embodiment, the ratio of the oxygen flow rate of the early-stage blowing to the oxygen flow rate of the middle-stage blowing is controlled to be 30:23 (approximately 75:57 in terms of conversion), and CO and O can be effectively increased 2 The reaction of the steel is improved, the heat quantity of molten steel is improved, the loss quantity of iron is reduced, the aim of reducing the iron-steel ratio is fulfilled, the limit of the scrap steel ratio can be improved, and the adding quantity of the scrap steel is improved.
In the related art, when oxygen is introduced for converting, the oxygen flow is larger for converting by introducing oxygen once; compared with the converting method provided by the related art, the early converting oxygen flow and the middle converting oxygen flow are both reduced compared with the related art, and the cost is reduced.
The middle converting time of the invention can be 11-13min.
In a preferred embodiment, the middle converting time is about 12 minutes.
In the invention, the post converting comprises controlling the gun position to be 1.1-1.3m and controlling the oxygen flow to be 37000-39000Nm 3 And/h, controlling the outlet pressure to be 0.90-0.95MPa and converting time to be 60-90s.
In a preferred embodiment, the post converting comprises controlling the gun position to be 1.2m and controlling the oxygen flow to be 38000Nm 3 And/h, controlling the outlet pressure to be 0.92MPa. Therefore, on one hand, the decarburization can be fast carried out, the time for reaching the reaction end point is shortened, and the heat dissipation is reduced; on the other hand, the impact of the molten pool is enhanced, the impact depth is increased, and the decarburization reaction is fast.
The converter steelmaking decarburization is generally divided into three processes: firstly, in the oxidation period of silicon and manganese, the decarburization speed Vc is continuously accelerated along with the blowing; secondly, in the carbon oxidation period, the decarburization speed is stable and depends on the oxygen supply intensity; thirdly, in the later smelting stage, the oxidation speed Vc of carbon is linearly reduced; however, the method for reducing the iron-steel ratio under the limit heat balance can ensure rapid decarburization in the later stage through the control of the position of the oxygen lance and the control of the oxygen flow and the control of the outlet pressure during the later stage blowing.
In a preferred embodiment, the time ratio of the front-stage converting, the middle-stage converting and the rear-stage converting is controlled to be approximately 23:70:7, and the time of the middle-stage converting can be prolonged to ensure the CO and the O 2 The oxygen consumption is increased, the gas recovery is reduced, so as to effectively increase the heat of molten steel, effectively reduce the iron-steel ratio, improve the limit of the scrap steel ratio and be beneficial to improving the adding amount of the scrap steel.
The converting method of the invention can make the generated CO gas and O blown out by the oxygen lance 2 The reaction is equivalent to that the heat generated by CO (coal gas) combustion is supplied to molten steel for heating, so that the temperature of a molten pool is increased, normal converting can be realized even under the condition of adding more scrap steel, the terminal point is ensured to be not oxidized, and the terminal point temperature is qualified; and can add the scrap steel once before converting, can also reduce the loss of iron, reduce the iron-steel ratio to can improve the scrap steel and occupy the limit, make the scrap steel occupy the ratio and reach 26.7%, improved the scrap steel and added the volume.
The features and capabilities of the present invention are described in further detail below in connection with the examples.
The examples and comparative examples were conducted according to the process parameters of table 1, and the final scrap ratio, iron-to-steel ratio, and scrap addition amount are shown in table 1.
TABLE 1
Parameters such as the molten iron temperature of examples (repeated 3 times) and comparative examples (repeated 2 times) were controlled according to table 2, and scrap steel results were detected.
In conclusion, the method for reducing the iron-steel ratio under the limit heat balance can effectively reduce the iron-steel ratio, improves the scrap steel ratio limit and is beneficial to improving the scrap steel addition.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (6)
1. A method for reducing iron to steel ratio at extreme heat balance comprising:
when the converter steelmaking is performed, performing early converting, medium converting and later converting; wherein,,
the earlier stage converting comprises controlling oxygen flow to 29000-31000Nm 3 And/h, wherein the time of the earlier converting is 210-240s;
the middle converting comprises controlling gun position at 1.4-1.6m, and controlling oxygen flow at 22000-24000Nm 3 And/h, controlling the outlet pressure to be 0.60-0.70Mpa, wherein the middle converting time is 11-13min;
the post converting comprises controlling gun position to be 1.1-1.3m, controlling oxygen flow to be 37000-39000Nm 3 And/h, controlling the outlet pressure to be 0.90-0.95MPa and converting time to be 60-90s.
2. The method for reducing iron to steel ratio at extreme heat balance according to claim 1, wherein said mid-stage converting comprises controlling oxygen flow to 23000Nm 3 And/h, wherein the medium-term converting comprises controlling the outlet pressure to be 0.64MPa.
3. The method for reducing iron to steel ratio at extreme heat balance according to claim 1, wherein the control outlet pressure is 0.80-0.90MPa during the early converting.
4. A method for reducing iron to steel ratio at extreme heat balance according to claim 3, characterized in that the pre-converting comprises controlling oxygen flow to 30000Nm 3 And controlling the outlet pressure to be 0.83MPa.
5. The method for reducing iron to steel ratio under extreme heat balance according to claim 1, wherein the gun position is controlled to be 1.8-2.0m in the first 110-120s of the preliminary blowing, and then the gun position is gradually reduced to be 1.6m.
6. The method for reducing iron to steel ratio under extreme heat balance according to claim 1, wherein the post converting comprises controlling gun position to be 1.2m and controlling oxygen flow to be 38000Nm 3 And/h, controlling the outlet pressure to be 0.92MPa.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210735005.3A CN114990279B (en) | 2022-06-27 | 2022-06-27 | Method for reducing iron-steel ratio under limit heat balance |
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| CN202210735005.3A CN114990279B (en) | 2022-06-27 | 2022-06-27 | Method for reducing iron-steel ratio under limit heat balance |
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| CN102424885B (en) * | 2011-12-31 | 2013-03-27 | 钢铁研究总院 | Less slag decarbonization refining method used in top-bottom combined blowing converter |
| CN104032063B (en) * | 2014-06-19 | 2016-08-24 | 攀钢集团攀枝花钢铁研究院有限公司 | A kind of method of semisteel converter steelmaking |
| CN108893574A (en) * | 2018-06-20 | 2018-11-27 | 山东钢铁股份有限公司 | One kind being used for molten iron [Si]<0.50% converter steel making method |
| CN112609034A (en) * | 2020-11-26 | 2021-04-06 | 柳州钢铁股份有限公司 | Method for efficiently dephosphorizing low-temperature steel tapping in later period of converter |
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