JPS63169320A - Production of low-sulfur steel - Google Patents
Production of low-sulfur steelInfo
- Publication number
- JPS63169320A JPS63169320A JP31564686A JP31564686A JPS63169320A JP S63169320 A JPS63169320 A JP S63169320A JP 31564686 A JP31564686 A JP 31564686A JP 31564686 A JP31564686 A JP 31564686A JP S63169320 A JPS63169320 A JP S63169320A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- slag
- converter
- ladle
- desulfurization
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 46
- 239000010959 steel Substances 0.000 title claims abstract description 46
- 238000004519 manufacturing process Methods 0.000 title claims description 3
- 229910052717 sulfur Inorganic materials 0.000 title claims description 3
- 239000011593 sulfur Substances 0.000 title claims description 3
- 239000002893 slag Substances 0.000 claims abstract description 42
- 238000006477 desulfuration reaction Methods 0.000 claims abstract description 28
- 230000023556 desulfurization Effects 0.000 claims abstract description 28
- 238000000034 method Methods 0.000 claims abstract description 18
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims abstract description 10
- 235000011941 Tilia x europaea Nutrition 0.000 claims abstract description 10
- 239000004571 lime Substances 0.000 claims abstract description 10
- 239000000463 material Substances 0.000 claims abstract description 9
- 238000010079 rubber tapping Methods 0.000 claims abstract description 9
- 239000000203 mixture Substances 0.000 claims description 13
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 2
- 230000003009 desulfurizing effect Effects 0.000 abstract description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract description 3
- 239000003795 chemical substances by application Substances 0.000 abstract description 3
- 229910052593 corundum Inorganic materials 0.000 abstract description 3
- 229910001845 yogo sapphire Inorganic materials 0.000 abstract description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract 4
- 238000007664 blowing Methods 0.000 abstract 3
- 229910052681 coesite Inorganic materials 0.000 abstract 2
- 229910052906 cristobalite Inorganic materials 0.000 abstract 2
- 239000000377 silicon dioxide Substances 0.000 abstract 2
- 235000012239 silicon dioxide Nutrition 0.000 abstract 2
- 229910052682 stishovite Inorganic materials 0.000 abstract 2
- 229910052905 tridymite Inorganic materials 0.000 abstract 2
- 238000003723 Smelting Methods 0.000 abstract 1
- 241001062472 Stokellia anisodon Species 0.000 abstract 1
- 238000002407 reforming Methods 0.000 abstract 1
- 238000007670 refining Methods 0.000 description 10
- 239000000843 powder Substances 0.000 description 4
- 239000010436 fluorite Substances 0.000 description 3
- 238000010587 phase diagram Methods 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 2
- 238000007872 degassing Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 229910018663 Mn O Inorganic materials 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は転炉出鋼後の取鍋溶鋼脱硫工程、特に減圧上粉
体吹込みにおける溶鋼の脱硫方法に関し、鋼中［５］濃
度を５ｐｐｍ以下に短時間で容易に得ることが出来る溶
鋼の脱硫方法に関するものである。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a ladle molten steel desulfurization process after steel tapping in a converter, particularly a method for desulfurizing molten steel in powder injection under reduced pressure. The present invention relates to a method for desulfurizing molten steel that can easily obtain a concentration of 5 ppm or less in a short time.
［従来の技術］
最近、耐サワーラインパイプ材等の分野において、溶鋼
の清浄化や硫化物形態制御等を含めた品質要求の厳格化
は著しい。このような要求を満足させるためには、転炉
のみの脱［Ｓ］では不可能であり、転炉出鋼後に取鍋脱
硫処理を実施する必要がある。従来、取鍋溶鋼脱硫工程
においては、転炉から出鋼時スラグが取鍋内に流出し、
この流出スラグ中のＦｅｄ、 ＭｎＯが脱硫を阻害する
ため、特願昭６１−１０３１２１ 、特開昭６１−６４
８１１．特開昭６１−１４３５１０号公報で各々提案さ
れているように、下記の手段等によって実施されている
。[Prior Art] Recently, in the field of sour-resistant line pipe materials, quality requirements including cleaning of molten steel, control of sulfide morphology, etc. have become significantly stricter. In order to satisfy such requirements, it is impossible to remove [S] only in the converter, and it is necessary to carry out ladle desulfurization treatment after tapping the steel in the converter. Conventionally, in the ladle molten steel desulfurization process, slag flows into the ladle when steel is tapped from the converter.
Since Fed and MnO in this outflow slag inhibit desulfurization,
811. As proposed in Japanese Unexamined Patent Publication No. 61-143510, these methods are implemented by the following means.
（１）転炉出鋼時のスラグ流にＣａＣ，等を投入し、Ｆ
ｅＯ。(1) Add CaC, etc. to the slag flow during steel tapping in the converter, and F
eO.
ＭｎＯを還元する方法
（２）取鍋内に流出した転炉スラグを除去した後、脱硫
フラックスを溶鋼上に添加し、アーク加熱等により脱硫
スラグを滓加させ、脱硫を行う方法。Method for reducing MnO (2) After removing the converter slag that has flowed into the ladle, desulfurization flux is added onto the molten steel, and the desulfurization slag is added to the molten steel by arc heating or the like to perform desulfurization.
（３）浴面上のスラグを攪拌又は流動させることなく溶
鋼中に石灰を主成分とする脱硫材を添加する方法
［発明が解決しようとする問題点コ
しかしく１）の方法では脱硫を阻害するＦｅｄ、 Ｍｎ
Ｏは還元されるが、ＣａＣ，等は高価でありコスト負担
が大きいこと、（２）の方法では鋼中［Ｓ］濃度を５ｐ
ｐｍ以下に短時間に効率的には得られないこと、（３）
の方法では吹込んだ脱硫材が十分滓化しない等の問題点
がある。(3) A method of adding a desulfurization agent mainly composed of lime to molten steel without stirring or fluidizing the slag on the bath surface [Problems to be solved by the invention However, method 1) inhibits desulfurization. Fed, Mn
O is reduced, but CaC, etc. are expensive and the cost burden is large, and method (2) reduces the [S] concentration in the steel to 5p.
pm or less cannot be obtained efficiently in a short time; (3)
This method has problems such as the injected desulfurization material not turning into slag sufficiently.
本発明は鋼中［Ｓコ濃度を５ｐｐｍ以下に短時間で効率
的かつ安定して溶製できることを目的とする溶鋼の精錬
法を提案するものである。The present invention proposes a method for refining molten steel, which aims to efficiently and stably produce molten steel in a short period of time to reduce the S concentration in the steel to 5 ppm or less.
［問題点を解決するための手段］
本発明に係る溶鋼の脱硫法は、以上述べた従来技術が有
する多くの問題点を解決したもので、転炉出鋼時にスラ
グ改質用脱硫材投入量を転炉吹止鋼中［Ｏ］濃度から決
定するか、あるいは転炉流出スラグ量が多い場合は転炉
吹止鋼中［Ｏ］濃度と転炉流出スラグ量から決定し、取
鍋脱硫工程前のスラグ中ＣａＯが６０乃至７５％、１２
０．が１５乃至２５％。[Means for Solving the Problems] The molten steel desulfurization method according to the present invention solves many of the problems of the conventional techniques described above. is determined from the [O] concentration in the converter blow-off steel, or if the amount of slag flowing out from the converter is large, it is determined from the [O] concentration in the converter blow-stop steel and the amount of slag flowing out from the converter, and then the ladle desulfurization process is performed. CaO in the previous slag is 60 to 75%, 12
0. is 15 to 25%.
ＳｉＯ□が５乃至１５％にコントロールし、しかる後石
灰を主成分とする脱硫材を溶鋼中に吹込みつつ脱硫処理
を行い、その間スラグ組成がＣａＯが６０乃至７０％、
ＡＱ２０３が２５乃至３５％、 ＳｉＯ□が１０％以下
に維持することを特徴とする低硫鋼の製造法である。After controlling the SiO□ content to 5 to 15%, desulfurization treatment is carried out while injecting a desulfurization material mainly composed of lime into the molten steel, during which time the slag composition is 60 to 70% CaO
This is a method for producing low sulfur steel characterized by maintaining AQ203 at 25 to 35% and SiO□ at 10% or less.
［作用］
粉体吹込みを行う取鍋精錬法において、脱硫−に最適な
スラグ組成は第１図のとと＜ １６００℃におけるＣａ
Ｏ−ＡＱ ２０．−３ｉ０．３元系スラグ状態図ではＣ
ａＯが約６５％、Ａｌ２Ｏ３が約３０％、 ＳｉＯ２が
約５％近傍（第２図Ａ′部）のスラグ組成が脱硫能が高
い。[Function] In the ladle refining method that involves powder injection, the optimum slag composition for desulfurization is as shown in Figure 1 and Ca at < 1600°C.
O-AQ 20. -3i0. In the ternary slag phase diagram, C
A slag composition of approximately 65% aO, approximately 30% Al2O3, and approximately 5% SiO2 (section A' in Figure 2) has a high desulfurization ability.
しかし出鋼時転炉から取鍋へ流出する転炉スラグを除去
しない本発明法では、取鍋精錬法でスラグ中Ｆｅｄ、
ＭｎＯが還元されてスラグ中のＡｌ２２０．が増加する
ため、取鍋精錬中にスラグ組成を第２図に示すＡ′の領
域に維持することは困難である。However, in the method of the present invention, in which the converter slag flowing out from the converter to the ladle during tapping is not removed, the Fed in the slag is removed by the ladle refining method.
MnO is reduced and Al220. As a result, it is difficult to maintain the slag composition in the region A' shown in FIG. 2 during ladle refining.
そこで上記に示すように、取鍋精錬処理前のスラグ組成
を第１段階として第２図に示すＡの領域にコントロール
し、取鍋精錬開始直後から取鍋精錬終了まで第２図に示
すＡ′の領域にスラグ組成を常にコントロールするよう
に、取鍋精錬で石灰ホタル石粉を鋼中に吹込み、脱硫能
の高いスラグと溶鋼の反応により溶鋼を脱硫するもので
ある。Therefore, as shown above, the slag composition before the ladle refining treatment is controlled in the region A shown in Fig. 2 as the first step, and from immediately after the start of ladle refining to the end of ladle refining, the slag composition is controlled in the region A' shown in Fig. 2. Lime fluorite powder is injected into the steel during ladle refining so that the slag composition is constantly controlled within the range of 100 to 100%, and the molten steel is desulfurized by the reaction between the slag, which has a high desulfurization ability, and the molten steel.
［実施例コ
３００トン転炉において脱炭、脱リン等の処理を行った
後、吹止鋼中酸素濃度を測定し、その後スラグボール等
を用いること等により転炉から出鋼中に取鍋中へ流出す
るスラグ量をコントロールし、第３図に示す基準に基づ
いて石灰を１５００ｋｇ投入するとともに、石灰を滓化
する目的でホタル石を３００ｋｇ投入した。出鋼後のス
ラグをサンプリングし、分析を行った所、ＣａＯが６８
％、ＡＱ、０．が１８％。[Example 1] After decarburization, dephosphorization, etc. were carried out in a 300-ton converter, the oxygen concentration in the blow-stop steel was measured, and then a ladle was removed during tapping from the converter by using a slag ball, etc. The amount of slag flowing into the tank was controlled, and 1,500 kg of lime was added based on the standards shown in Figure 3, and 300 kg of fluorspar was added for the purpose of turning the lime into slag. When the slag after tapping was sampled and analyzed, the CaO content was 68.
%, AQ, 0. is 18%.
Ｓｉｎ、が１４％であるスラグが得られた。A slag with a Sin of 14% was obtained.
その後減圧下で粉体吹込みが可能な取鍋精錬設備で脱ガ
スと同時に脱硫を行う目的で石灰を１０００ｋｇ 。After that, 1000 kg of lime was added for the purpose of degassing and desulfurization at the same time as degassing in a ladle refining facility that can inject powder under reduced pressure.
ホタル石を２５０ｋｇ投入し脱硫処理を行い、第１表に
示すような組成の鋼が得られた。このときのスラグ組成
はＣａＯが６５％、ＡＱ２０．が３θ％、 Ｓｉｎ、が
５％であった。250 kg of fluorspar was added and desulfurized, and steel having the composition shown in Table 1 was obtained. The slag composition at this time was 65% CaO and 20% AQ. was 3θ% and Sin was 5%.
第 １ 表
第４図は脱硫処理後の溶鋼中［Ｓ］濃度を従来法と共に
示し、第５図は本発明による鋼中［Ｓ］の時間的推移を
示す。Table 1, FIG. 4 shows the [S] concentration in molten steel after desulfurization treatment as well as the conventional method, and FIG. 5 shows the time course of [S] in steel according to the present invention.
［発明の効果］
本発明により取鍋内に流出する転炉スラグを除去するこ
となく、脱硫能の高いスラグを容易に調整することが可
能となり、短時間で効率的に鋼中［Ｓ］を５ｐｐｍ＋以
下に溶製することが出来る。[Effect of the invention] The present invention makes it possible to easily prepare slag with high desulfurization ability without removing converter slag flowing into the ladle, and efficiently removes [S] in steel in a short time. It can be dissolved to 5 ppm+ or less.
第１図は最適スラグ組成を示す状態図、第２図は本発明
による取鍋前後のスラグ組成、第３図は本発明による石
灰投入量、第４図は本発明の効果を示す鋼中［Ｓ］のグ
ラフ図、第５図は取鍋精錬での鋼中［：Ｓ］’の時間的
推移を示す図である。Fig. 1 is a phase diagram showing the optimum slag composition, Fig. 2 is the slag composition before and after the ladle according to the present invention, Fig. 3 is the amount of lime input according to the present invention, and Fig. 4 is a phase diagram showing the effect of the present invention. Figure 5 is a graph showing the time course of [:S]' in steel during ladle refining.
Claims (2)
脱硫材を投入するに際し、その投入量を転炉吹止鋼中［
Ｏ］濃度により決定し、投入後のスラグ組成がＣａＯが
６０乃至７５％、Ａｌ＿２Ｏ＿３が１５乃至２５％、Ｓ
ｉＯ＿２が５乃至１５％とし、しかる後石灰を主成分と
する脱硫材を溶鋼中に吹込みつつ脱硫処理を行い、その
間スラグ組成がＣａＯが６０乃至７０％、Ａｌ＿２Ｏ＿
３が２５乃至３５％、ＳｉＯ＿２が１０％以下に維持す
ることを特徴とする低硫鋼の製造法。(1) When tapping steel from the converter to the ladle, when adding desulfurization material whose main component is lime, the amount of desulfurization material in the converter blow-stopping steel [
O] determined by the concentration, and the slag composition after charging is 60 to 75% CaO, 15 to 25% Al_2O_3, S
iO_2 is set to 5 to 15%, and then desulfurization treatment is performed while injecting a desulfurization material mainly composed of lime into the molten steel, during which the slag composition is 60 to 70% CaO, Al_2O_
A method for producing low sulfur steel, characterized in that 3 is maintained at 25 to 35% and SiO_2 is maintained at 10% or less.
炉流出スラグ量から決定することを特徴とする特許請求
の範囲第１項に記載の方法。(2) The method according to claim 1, characterized in that the amount of desulfurization material input is determined from the [O] concentration in the converter blowstop steel and the amount of slag flowing out of the converter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31564686A JPS63169320A (en) | 1986-12-29 | 1986-12-29 | Production of low-sulfur steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31564686A JPS63169320A (en) | 1986-12-29 | 1986-12-29 | Production of low-sulfur steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63169320A true JPS63169320A (en) | 1988-07-13 |
Family
ID=18067870
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31564686A Pending JPS63169320A (en) | 1986-12-29 | 1986-12-29 | Production of low-sulfur steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63169320A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02194113A (en) * | 1989-01-23 | 1990-07-31 | Kawasaki Steel Corp | Method for reforming molten steel slag |
| JPH0310013A (en) * | 1989-01-23 | 1991-01-17 | Kawasaki Steel Corp | Method for reforming slag on molten steel |
| CN102277472A (en) * | 2011-08-22 | 2011-12-14 | 辽宁天和科技股份有限公司 | Quick deep desulfurization method and deep desulfurizing agent for LF (Ladle Furnace) refining |
| JP2012017479A (en) * | 2010-07-06 | 2012-01-26 | Nippon Steel Corp | Molten steel desulfurization method |
-
1986
- 1986-12-29 JP JP31564686A patent/JPS63169320A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02194113A (en) * | 1989-01-23 | 1990-07-31 | Kawasaki Steel Corp | Method for reforming molten steel slag |
| JPH0310013A (en) * | 1989-01-23 | 1991-01-17 | Kawasaki Steel Corp | Method for reforming slag on molten steel |
| JP2012017479A (en) * | 2010-07-06 | 2012-01-26 | Nippon Steel Corp | Molten steel desulfurization method |
| CN102277472A (en) * | 2011-08-22 | 2011-12-14 | 辽宁天和科技股份有限公司 | Quick deep desulfurization method and deep desulfurizing agent for LF (Ladle Furnace) refining |
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