CN110551869A - method for modifying slag in slag splashing stage of converter - Google Patents
method for modifying slag in slag splashing stage of converter Download PDFInfo
- Publication number
- CN110551869A CN110551869A CN201910905070.4A CN201910905070A CN110551869A CN 110551869 A CN110551869 A CN 110551869A CN 201910905070 A CN201910905070 A CN 201910905070A CN 110551869 A CN110551869 A CN 110551869A
- Authority
- CN
- China
- Prior art keywords
- slag
- furnace
- converter
- modifier
- steel
- 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
Links
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
- C21C5/36—Processes yielding slags of special composition
-
- 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
- C21C5/42—Constructional features of converters
- C21C5/44—Refractory linings
- C21C5/441—Equipment used for making or repairing linings
- C21C5/443—Hot fettling; Flame gunning
-
- 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
Abstract
The invention discloses a method for modifying slag in a slag splashing stage of a converter, which comprises the following steps: 1) the tapping temperature of the converter is controlled to be 1620-1690 ℃, and the final-point steel carbon discharge is controlled to be 0.03-0.20%. 2) And after tapping of the converter is finished, the furnace is rocked to the zero position, and the slag modifier is added. 3) And (4) shaking the furnace body towards the back of the furnace, returning to the zero position, and then shaking the furnace towards the front of the furnace, and returning to the zero position. 4) Lowering the lance to the oxygen lance scale and opening nitrogen to splash slag. 5) And after slag splashing, closing the gas stripping gun to a position above the furnace mouth, shaking the furnace 20-65 ℃ to the front of the furnace, directly adding scrap steel and iron without pouring slag, and smelting in the next furnace. The invention effectively reduces the FeO content of the slag, increases the MgO content of the slag, further increases the melting point of the slag, shortens the slag-forming inoculation time, and improves the adhesion capability and the corrosion resistance capability of the slag after splashing, thereby obviously improving the effect of splashing slag and protecting the converter of the converter.
Description
Technical Field
the invention belongs to the field of steelmaking, and particularly relates to a method for modifying slag in a converter splashing slag protection stage.
Background
At present, because the low-carbon steel of the ledeburite and the low-phosphorus steel (C is less than or equal to 0.07 percent and P is less than or equal to 0.020 percent) are more and more, the deep blowing at the smelting end point of the converter is serious due to the low-carbon and low-phosphorus steel, and the total iron content of the final slag of individual furnace times even reaches more than 20 percent. On the one hand, the consumption of steel materials is increased due to too high TFe; on the other hand, the slag TFe is too high, so that the melting point and viscosity of the slag are reduced, the slag splashing furnace protection effect of the converter is seriously influenced, and great pressure is brought to the maintenance work of the converter body of the converter; meanwhile, slag splashing time is too long, and the time for repairing the furnace is too long, so that the production rhythm is seriously influenced; too high TFe can cause difficulty in stopping slag due to over-dilution of slag, increase consumption of alloy deoxidizer due to slagging heat, and even serious pollution to molten steel.
Therefore, in order to improve the slag splashing furnace protection effect of low-carbon and low-phosphorus steel, the development of a technology for reducing the slag TFe is urgent.
Disclosure of Invention
Aiming at the problems that low-carbon steel slag is strong in oxidability, slag-forming time is long in the slag splashing protection process, the slag is difficult to adhere to a furnace lining, and the slag is not corrosion-resistant after splashing, a method for modifying the slag in the slag splashing stage of the converter is provided. According to the method, the mixed compression ball containing the C, Al and MgO composite materials is added into the converter before the converter splashes the slag, so that the content of the slag (FeO) is reduced, the content of MgO in the slag is increased, the melting point of the slag is further increased, the slag starting inoculation time is shortened, the adhesion capability and the corrosion resistance capability of the slag after splashing are improved, and the converter splashing protection effect of the converter is obviously improved.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
1) The tapping temperature of the converter is controlled to be 1620-1690 ℃, and the final-point steel carbon discharge is controlled to be 0.03-0.20%. The steel tapping amount is 130-145 tons.
2) And after tapping of the converter is finished, the furnace is rocked to a zero position, and the slag modifier is added from a high-position bin.
3) and (4) shaking the furnace body towards the back of the furnace, then returning to the zero position, then shaking the furnace towards the front of the furnace, and then returning to the zero position.
4) Lowering the gun and opening nitrogen to splash slag.
5) And after slag splashing is finished, closing the gas stripping gun to a position above a furnace mouth, shaking the furnace at 20-65 ℃ until the furnace is in front, adding scrap steel and adding iron, and smelting in the next furnace.
Further, in the step 2), the added slag modifier is a mixed pressed sphere containing C, Al and MgO components.
The slag modifier is well known in the art, preferably comprises, by weight, 5-10% of lime powder, 40-60% of anthracite powder, 15-30% of dolomite powder, 5-20% of AD powder and other components as binders, and is prepared and pressed into spherical particles. The sum of the weight of the raw materials is 100 percent.
preferably, the lime powder is active lime powder, the CaO content of the lime powder is more than or equal to 80 percent, the SiO 2 content of the lime powder is less than or equal to 5 percent, and the particle size fraction of the lime powder less than 3mm is more than or equal to 90 percent.
Preferably, the carbon content of the anthracite powder is more than or equal to 90 percent, the Sd is less than or equal to 0.5 percent, and the particle size fraction of less than 2mm is more than or equal to 90 percent.
preferably, the dolomite powder contains more than or equal to 18 percent of MgO, less than or equal to 3.5 percent of SiO 2, and more than or equal to 90 percent of granularity less than 3 mm.
Preferably, the AD powder contains 15-30% of Al.
Preferably, the shape of the slag modifier is granular, and the diameter of the slag modifier is 10-30 mm.
Preferably, the binder comprises one or more of carboxymethylcellulose, bentonite, smectite-like silicates, fine crystalline alumina and diatomaceous earth.
Preferably, in the step 2), the slag modifier is added to the surface of the molten steel in the converter before the steel is discharged from the converter or is added into the converter before slag splashing, and the adding amount is as follows according to the terminal oxygen content of the molten steel in the converter:
when the end point oxygen content is 400-500 ppm, adding 0.5-1 kg of modifier into each ton of steel;
when the end point oxygen content is 500-600 ppm, adding 1-1.5 kg of modifier into one ton of steel;
When the end point oxygen content is 600-700 ppm, adding 1.5-2.0 kg of modifier into each ton of steel;
When the end point oxygen content is 700-800 ppm, adding 2.0-2.5 kg of modifier into each ton of steel;
When the end point oxygen content is 800-900 ppm, adding 2.5-3.0 kg of modifier into each ton of steel;
when the end point oxygen content is 900-1000 ppm, adding 3.0-3.5 kg of modifier into each ton of steel;
when the end point oxygen content is more than or equal to 1000ppm, adding 3.5-5.5 kg of modifier into each ton of steel;
Preferably, in the step 3), the modifier is added, the furnace is shaken at 45-60 degrees after the furnace is started, the zero position is returned, and then the furnace is shaken at 45-60 degrees before the furnace is started, and the zero position is returned.
Preferably, in the step 4), the pressure of nitrogen gas blown at the position of 3-4 meters of the oxygen lance scale is 1.0-1.2 Mpa, the pressure of the oxygen lance is reduced by 0.3-0.5 meter every 15-30 seconds, and the pressure of the nitrogen gas is increased by 0.1-0.4 Mpa every 15-30 seconds. And turning off the air stripping gun when the slag slices cannot be seen.
Compared with the prior art, the invention has the advantages that:
The method can quickly reduce the content of FeO in the slag, improve the content of MgO in the slag, improve the melting point and viscosity of the slag, effectively shorten the slag splashing time, improve the slag splashing furnace protection effect, further reduce the furnace repairing times and effectively improve the converter productivity; in the invention, after the modifier is added, the furnace is shaken at 45-60 degrees before and after the furnace, so that the modifier can be fully contacted with the furnace slag, and the furnace slag can be better attached to the slag surface and the steel surface; the slag splashed in the invention adopts a gradual grading gun descending mode to ensure that the slag is more uniformly attached to the furnace lining after being splashed; after the modified furnace slag is used for modification, all the modified furnace slag is reserved for next furnace for cyclic utilization, so that the consumption of lime, dolomite, iron and steel materials, nitrogen and the like of the converter can be effectively reduced, the times of repairing the furnace can be greatly reduced, the operations of tiling, gunning and the like can be greatly reduced, and the labor intensity of workers can be effectively reduced; indirectly reduce the energy consumption of various comprehensive societies.
Detailed Description
The present invention will be further described with reference to the following specific examples.
Example 1
The preparation of the slag modifier comprises the following steps:
Preparing raw materials, namely preparing active lime powder with 85 percent of CaO content of the lime powder, 20 percent of AD powder with Al content, anthracite powder with 90 percent of C and dolomite powder with 25 percent of MgO as raw material ingredients, wherein the binder comprises: 50% of bentonite, 25% of methyl cellulose, 15% of montmorillonite silicate and 10% of fine crystalline alumina, wherein the raw materials are mixed according to the proportion of 7% of lime powder, 15% of AD powder, 50% of anthracite powder, 24% of dolomite powder and 4% of binder, and the prepared raw materials are fully stirred and mixed by a stirrer and then are made into spherical particles with the diameter of 15mm by a ball pressing device. The pressure during the press forming was 35 Mpa. Drying in a drying device, wherein the water content is 0.5 percent after drying
A method for modifying slag in a slag splashing stage of a converter comprises the following steps:
1) The SPHC is smelted in a converter, the tapping temperature of the converter is 1675 ℃, the end point oxygen is 500ppm, the tapping amount is 130 tons,
2) After tapping of the converter, the converter is shaken to the zero position, and 195kg of slag modifier is added.
3) and (4) shaking the furnace body to the rear of the furnace by 60 degrees, returning to the zero position, and then shaking the furnace to the front of the furnace by 60 degrees, and returning to the zero position.
4) Lowering the lance to 4m on the oxygen lance scale, lowering the oxygen lance by 0.3 m every 30 seconds, and increasing the nitrogen pressure by 0.2MPa every 25 seconds. And turning off the air stripping gun when the slag slices cannot be seen.
5) And after slag splashing, closing the gas stripping gun to a position above the furnace mouth, shaking the furnace to 45 ℃ to the front of the furnace, directly adding scrap steel and iron without pouring slag, and smelting in the next furnace.
Through comparison of slag samples before and after slag splashing, TFe in the slag is reduced by 3.89% and MgO in the slag is improved by 2.55% after the process operation, and the slag splashing effect of the furnace lining is observed visually.
Example 2
the preparation of the slag modifier comprises the following steps:
Preparing raw materials, namely preparing active lime powder with 90% of CaO content of the lime powder, 25% of AD powder with Al content, anthracite powder with 92% of C content and dolomite powder with 28% of MgO content as raw material ingredients, wherein the binder comprises: 40% of bentonite, 25% of methyl cellulose, 25% of montmorillonite silicate and 10% of fine crystalline alumina, mixing the raw materials according to the proportion of 10% of lime powder, 12% of AD powder, 55% of anthracite powder, 20% of dolomite powder and 3% of bonding, fully stirring and mixing the prepared raw materials by a stirrer, and preparing spherical particles with the diameter of 15mm by a ball pressing device. The pressure during the press forming was 38 Mpa. Drying in a drying device, wherein the moisture content is 0.6 percent after drying.
A method for modifying slag in a slag splashing stage of a converter comprises the following steps:
1) smelting 235B in a converter, wherein the tapping temperature of the converter is 1655 ℃, the end point oxygen is 600ppm, the tapping amount is 130 tons,
2) after tapping of the converter, the converter is shaken to the zero position, and 260kg of slag modifier is added.
3) and (4) shaking the furnace body to the rear of the furnace by 60 degrees, returning to the zero position, and then shaking the furnace to the front of the furnace by 60 degrees, and returning to the zero position.
4) And lowering the lance to the position 3.5 meters away from the oxygen lance scale, opening nitrogen to splash slag, lowering the oxygen lance by 0.2 meter every 30 seconds, and increasing the nitrogen pressure by 0.2MPa every 20 seconds. And turning off the air stripping gun when the slag slices cannot be seen.
5) And after slag splashing, closing the gas stripping gun to a position above the furnace mouth, shaking the furnace to 45 ℃ to the front of the furnace, directly adding scrap steel and iron without pouring slag, and smelting in the next furnace. By comparing slag samples before and after slag splashing, TFe in the slag is reduced by 3.76% and MgO in the slag is improved by 3.13% after the process operation, and the slag splashing effect of the furnace lining is good.
the above embodiments are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modifications made on the basis of the technical scheme according to the technical idea of the present invention fall within the protection scope of the present invention.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited. Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (5)
1. A method for modifying slag in a slag splashing stage of a converter comprises the following steps:
1) the tapping temperature of the converter is controlled to be 1620-1690 ℃, the steel carbon discharged at the end point is controlled to be 0.03-0.20%, and the tapping amount is 130-145 tons;
2) After tapping of the converter is finished, the furnace is rocked to a zero position, and a slag modifier is added;
3) Shaking the furnace body towards the back of the furnace, then returning to the zero position, then shaking the furnace towards the front of the furnace, and then returning to the zero position;
4) Lowering the gun and opening nitrogen to splash slag;
5) And after slag splashing, lifting the lance, shaking the furnace at 20-65 ℃ until the furnace is in front of the furnace, adding scrap steel and iron, and smelting in the next furnace.
2. The method for modifying the slag in the slag splashing stage of the converter according to claim 1, wherein in the step 2), the slag modifier comprises, by weight, 5-10% of lime powder, 40-60% of anthracite powder, 15-30% of dolomite powder, 5-20% of AD powder, and 2-6% of a binder.
3. The method for modifying slag in the slag splashing stage of the converter according to claim 1 or 2, wherein in the step 2), the slag modifier is added to the surface of the molten steel in the converter before the steel is discharged from the converter or is added to the converter before the slag is splashed, and the adding amount is determined according to the terminal oxygen content of the molten steel in the converter:
when the end point oxygen content is 400-500 ppm, adding 0.5-1 kg of modifier into each ton of steel;
When the end point oxygen content is 500-600 ppm, adding 1-1.5 kg of modifier into one ton of steel;
when the end point oxygen content is 600-700 ppm, adding 1.5-2.0 kg of modifier into each ton of steel;
When the end point oxygen content is 700-800 ppm, adding 2.0-2.5 kg of modifier into each ton of steel;
when the end point oxygen content is 800-900 ppm, adding 2.5-3.0 kg of modifier into each ton of steel;
When the end point oxygen content is 900-1000 ppm, adding 3.0-3.5 kg of modifier into each ton of steel;
When the end point oxygen content is more than or equal to 1000ppm, 3.5-5.5 kg of modifier is added into one ton of steel.
4. The method for modifying the slag in the slag splashing stage of the converter according to claim 1, wherein in the step 3), the modifier is added, the furnace is shaken at 45-60 degrees after the modifier is added, the zero position is returned, and then the furnace is shaken at 45-60 degrees before the converter, and the zero position is returned.
5. The method for modifying slag in a slag splashing stage of the converter as claimed in claim 1, wherein in the step 4), the pressure of nitrogen gas is blown at a position 3-4 m away from a scale of the oxygen lance by 1.0-1.2 MPa, the pressure of the nitrogen gas is reduced by 0.3-0.5 m every 15-30 s, and the pressure of the nitrogen gas is increased by 0.1-0.4 MPa every 15-30 s.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910905070.4A CN110551869A (en) | 2019-09-24 | 2019-09-24 | method for modifying slag in slag splashing stage of converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910905070.4A CN110551869A (en) | 2019-09-24 | 2019-09-24 | method for modifying slag in slag splashing stage of converter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110551869A true CN110551869A (en) | 2019-12-10 |
Family
ID=68741287
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910905070.4A Pending CN110551869A (en) | 2019-09-24 | 2019-09-24 | method for modifying slag in slag splashing stage of converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110551869A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115572787A (en) * | 2022-09-29 | 2023-01-06 | 日照钢铁控股集团有限公司 | Process method for reducing thermal-state furnace slag through slag splashing furnace protection |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100490737B1 (en) * | 2000-11-30 | 2005-05-24 | 주식회사 포스코 | Slag coating mixed powder and slag coating method by splasing on the wall firebrick in converter |
| CN104673960A (en) * | 2015-02-25 | 2015-06-03 | 宣化钢铁集团有限责任公司 | Method for splashing slag of converter for protecting furnace |
| CN105821175A (en) * | 2016-05-27 | 2016-08-03 | 山东钢铁股份有限公司 | Slag-splashing converter protection method for controlling converter profiles |
| CN109266807A (en) * | 2018-10-29 | 2019-01-25 | 甘肃酒钢集团宏兴钢铁股份有限公司 | A kind of big flow bottom blowing splashes slag and splashes furnace retaining technique in conjunction with slag phase with top blast |
-
2019
- 2019-09-24 CN CN201910905070.4A patent/CN110551869A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100490737B1 (en) * | 2000-11-30 | 2005-05-24 | 주식회사 포스코 | Slag coating mixed powder and slag coating method by splasing on the wall firebrick in converter |
| CN104673960A (en) * | 2015-02-25 | 2015-06-03 | 宣化钢铁集团有限责任公司 | Method for splashing slag of converter for protecting furnace |
| CN105821175A (en) * | 2016-05-27 | 2016-08-03 | 山东钢铁股份有限公司 | Slag-splashing converter protection method for controlling converter profiles |
| CN109266807A (en) * | 2018-10-29 | 2019-01-25 | 甘肃酒钢集团宏兴钢铁股份有限公司 | A kind of big flow bottom blowing splashes slag and splashes furnace retaining technique in conjunction with slag phase with top blast |
Non-Patent Citations (2)
| Title |
|---|
| 李荣等: "《转炉炼钢操作与控制》", 30 June 2012, 冶金工业出版社 * |
| 王雪松等: "转炉溅渣护炉调质剂的开发研究", 《炼钢》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115572787A (en) * | 2022-09-29 | 2023-01-06 | 日照钢铁控股集团有限公司 | Process method for reducing thermal-state furnace slag through slag splashing furnace protection |
| CN115572787B (en) * | 2022-09-29 | 2024-03-29 | 日照钢铁控股集团有限公司 | Process method for reducing thermal state slag through slag splashing protection |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101613779B (en) | Slagging agent, preparation method and use method thereof | |
| KR20070085069A (en) | A smelting process of ferronickel with nickel oxide ore free of crystal water in a blast furnace | |
| CN106544464A (en) | Environment-friendly type splashing slag in converter material and preparation method thereof | |
| CN111057817A (en) | Economic and environment-friendly efficient desulfurization refining slag system and production method thereof | |
| CN101177722A (en) | Al-Ca matter converter slag deacidizing modifier | |
| CN111593162A (en) | Converter slag pressing agent and use method thereof | |
| CN105063268A (en) | Slag melting agent and preparation method thereof and semi-steel steelmaking method adopting slag melting agent | |
| CN107201421A (en) | A kind of production method of super-low sulfur molten steel | |
| CN111455169B (en) | Manganese ore directly-alloyed ball and preparation method thereof | |
| CN103643094B (en) | The smelting process of high carbon ferromanganese | |
| CN110551869A (en) | method for modifying slag in slag splashing stage of converter | |
| CN113122680A (en) | Steel slag modifier and preparation and use methods thereof | |
| CN1818094A (en) | Steel liquid cleaner for steel smelting | |
| CN101613786A (en) | Boron-containing modifier for ladle covering slag and using method thereof | |
| CN101550465A (en) | Manganese-based fluxing agent for converter steelmaking and preparation method thereof | |
| CN101967530A (en) | Method for reducing iron by smelting reduction in electrometallurgy | |
| CN1064714C (en) | Method for reforming slags system of smelting steel with low-Si molten iron or semisteel by using slag inclusion of converter as slag modifier | |
| CN1124780A (en) | Dephosphorising agent for iron and steel foam | |
| CN104328361A (en) | Anti-seismic steel bar and preparation method thereof | |
| CN112695155A (en) | Steelmaking process of molten iron containing vanadium and titanium | |
| CN113278765A (en) | Desulfurizing agent for converter and desulfurizing method | |
| CN101736115B (en) | Converter-strengthened slagging agent and preparation method and using method thereof | |
| CN110564917A (en) | Slag modifier and preparation method thereof | |
| CN113136480B (en) | Ladle slag modifier and preparation and use method thereof | |
| CN110093472A (en) | A kind of gray cast iron production method for high-intensitive valve body |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 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 | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20191210 |