JPS6362562B2 - - Google Patents
Info
- Publication number
- JPS6362562B2 JPS6362562B2 JP55034693A JP3469380A JPS6362562B2 JP S6362562 B2 JPS6362562 B2 JP S6362562B2 JP 55034693 A JP55034693 A JP 55034693A JP 3469380 A JP3469380 A JP 3469380A JP S6362562 B2 JPS6362562 B2 JP S6362562B2
- Authority
- JP
- Japan
- Prior art keywords
- hot metal
- mainly
- desulfurization
- treatment
- iron oxide
- 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.)
- Expired
Links
- 238000000034 method Methods 0.000 claims description 23
- 239000002184 metal Substances 0.000 claims description 22
- 229910052751 metal Inorganic materials 0.000 claims description 22
- 229910000831 Steel Inorganic materials 0.000 claims description 18
- 238000006477 desulfuration reaction Methods 0.000 claims description 18
- 230000023556 desulfurization Effects 0.000 claims description 18
- 239000010959 steel Substances 0.000 claims description 18
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 16
- 239000002893 slag Substances 0.000 claims description 8
- 238000006243 chemical reaction Methods 0.000 claims description 7
- 239000011261 inert gas Substances 0.000 claims description 7
- 229910052698 phosphorus Inorganic materials 0.000 claims description 7
- 238000007670 refining Methods 0.000 claims description 7
- 229910052710 silicon Inorganic materials 0.000 claims description 7
- 238000007664 blowing Methods 0.000 claims description 6
- 239000012159 carrier gas Substances 0.000 claims description 6
- 239000011574 phosphorus Substances 0.000 claims description 6
- 239000010703 silicon Substances 0.000 claims description 6
- 238000009628 steelmaking Methods 0.000 claims description 6
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 4
- 238000010079 rubber tapping Methods 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims 2
- 238000005261 decarburization Methods 0.000 claims 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 18
- 239000000292 calcium oxide Substances 0.000 description 9
- 235000012255 calcium oxide Nutrition 0.000 description 9
- 229910052717 sulfur Inorganic materials 0.000 description 7
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 5
- 230000004907 flux Effects 0.000 description 5
- 230000001590 oxidative effect Effects 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000011593 sulfur Substances 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 239000012535 impurity Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910000805 Pig iron Inorganic materials 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 230000008094 contradictory effect Effects 0.000 description 2
- 238000005262 decarbonization Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- -1 mill scale Chemical compound 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910004261 CaF 2 Inorganic materials 0.000 description 1
- SKZKKFZAGNVIMN-UHFFFAOYSA-N Salicilamide Chemical compound NC(=O)C1=CC=CC=C1O SKZKKFZAGNVIMN-UHFFFAOYSA-N 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 229910000514 dolomite Inorganic materials 0.000 description 1
- 239000010459 dolomite Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 235000017550 sodium carbonate Nutrition 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 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
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/072—Treatment with gases
-
- 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
- C21C1/00—Refining of pig-iron; Cast iron
-
- 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
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
-
- 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
- C21C5/285—Plants therefor
-
- 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
- C21C5/56—Manufacture of steel by other methods
-
- 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
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
-
- 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
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/04—Removing impurities other than carbon, phosphorus or sulfur
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Botany (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Description
本発明は溶湯中の不純物を脱処理する各種反応
を工程別に分割して精錬する製鋼方法に関するも
のである。
近年、極低硫鋼、極低燐鋼の開発に伴ない各成
分の管理が益々厳しくなつている。通常の製鋼方
法では不純物の大半は転炉吹錬の工程で除去され
ているが、この場合転炉の操業負担が大きくな
る。そこで転炉の操業負担を軽減するためと、各
成分管理の容易化を目的として溶銑の段階で各種
の不純物をあらかじめ脱処理することが知られて
いる。すなわち、特開昭52−127421号公報には酸
化鉄または酸素により脱珪処理し、次いで
Na2CO3で脱燐、脱硫の同時処理を行なう方法が
開示されている。
このように溶銑の段階で珪素、燐、硫黄などこ
れらのすべてを脱処理することは望ましいのであ
るが、本来脱硫処理は還元性雰囲気のもとで行な
われ、一方脱燐処理は酸化性雰囲気のもとで行な
われるのが望ましく、両者の処理条件は全く相反
するものである。したがつて脱硫と脱燐の同時処
理は効率のよいものではなく実用的には問題が残
されている。
現在、同時脱硫脱燐処理において主に使用され
るフラツクスとしては次の２種類が挙げられる。
すなわち、Na2CO3系と酸素源（ミルスケール、
鉄鉱石、気体酸素etc.）＋CaO系である。Na2CO3
は特開昭52−127421号公報で例示されているよう
に、低珪素溶銑でのNa2CO3は有効なる同時脱硫
脱燐フラツクスである。すなわち、Na2CO3その
ものに酸化源であるＯと塩基Na2Oを有してお
り、脱燐反応ではＯとNa2OがＰと反応し、50
（Na2CO3より）＋2P＋3Na2O→3Na2OP2O5とな
り、脱硫反応ではNa2OがＳと反応し、Na2O＋
Ｓ＝Na2S＋Ｏとなる。
しかしながら前記公知例で示されるように、
Na2CO3の処理原単位は10〜60Kg／ｔと高い。
Na2CO3の使用はコストの上からも、又激しい反
応性に帰因する耐火物の溶損および噴煙、ヒユー
ムの発生等の環境の上からも問題がありNa2CO3
系を実機フラツクスとして用いることは適切では
ない。
一方、酸化源＋CaO系の場合を考えると、本来
脱硫処理は還元性雰囲気のもとで（スラグ中（％
FeO）を低く）、脱燐処理は酸化性雰囲気のもと
で（スラグ中（％FeO）をある程度高く）行なわ
れるのが望ましく、両者の処理条件は相反するも
のである。酸化源とCaO系フラツクスの場合、酸
化源のある酸化雰囲気下で脱硫処理を実施するた
めには過剰にCaOが必要であり、同時脱硫脱燐処
理は効率の悪いものである。従つて脱硫処理と脱
燐処理は分離すべきものである。
ところで、溶銑段階でSi，Ｐ，Ｓについて脱処
理することは望ましいことであり、種々の提案は
あるが溶銑段階で脱珪、脱燐、脱硫処理と三段階
のプロセスを持つことは工程的に複雑となり、し
かも温度降下が大きく工業的には実施不可能であ
る。
他方近年、清浄鋼の要請が益々厳しくなつてき
ており、特に介在物の除去ならびに形態のコント
ロール等の必要があり、転炉吹錬、出鋼後の２次
精錬の開発が進められている。かかる観点からこ
の溶鋼段階で介在物除去だけではなく、同時に精
錬効果をもたせることは有効な製鋼手段と考えら
れる。すなわち介在物除去を目的とした取鍋内の
溶鋼への不活性ガス吹込みに加え、たとえばCaO
を合わせて吹き込み、脱硫処理を溶銑段階で行な
う代りに溶鋼段階へほぼ全面的に移行すると、前
述の溶銑処理におけるプロセスの複雑化、温度降
下の問題等を解決できる。さらに溶鋼脱硫の利点
は、熱力学的に有利な高温の反応であること、又
炉内復硫防止のため転炉に装入するスクラツプは
低硫品位のものを厳選しなければならないという
制約条件も同時に解決できることである。
なお、これまでに述べた脱硫、脱珪、脱燐のそ
れぞれ単独の処理技術或はそれらのうち複数の同
時処理、連続処理等については、数多くの提案が
なされているが、溶銑中の全不純物のすべてを対
象として工程的に完結した処理技術としては未だ
有効な手段の提案はなされていない。
本発明は各脱処理技術を一連の完結した処理工
程として、最適順序、条件下に組み合わせたこと
に重要な意味があり、実用的に有効な製鋼法を提
供するものである。
以下に本発明の構成要件について述べる。
まず第１の工程ではミルスケールなどの酸化鉄
主体の酸化源を溶銑に添加することによつて主と
して珪素の含有量を低減させる。酸化鉄の添加の
タイミングとしては、例えば高炉から出銑した溶
銑に対して高炉鋳床の樋内に投入し、樋内での溶
銑流動により或はこれに強制的な撹拌を加える方
法が選ばれる。また別の手段としては、高炉樋か
ら流出する溶銑を混銑車に受け、混銑車内の溶銑
に不活性ガスなどのキヤリヤ―ガスで吹き込むこ
とにより果される。この工程では一般に珪素量
0.50％程度のレベルから0.15％程度のレベルまで
に低減される。なおこの段階で発生するスラグは
次工程に持ち込まれないように分離、排出される
ことが望ましい。
次に第２の工程では、混銑車或は取鍋に移しか
えられたスラグ除去後の溶銑に対して脱燐処理が
施される。ここでは例えばミルスケール等の酸化
鉄主体の酸素源とCaO，CaF2を例えば４：２：
１の配合比で配合された１mm以下の粒度に整粒さ
れた粉末状の混合フラツクス30〜50Kg／ton溶銑
を、キヤリヤ―ガスとして不活性ガスを用いて溶
銑内に吹込む。その際一般に処理後の燐含有量は
0.015〜0.040％程度のレベルまでに低減される。
次いで第３の工程では、得られた前記の低珪
素、低燐銑を、転炉にスクラツプとともに装入
し、脱炭吹錬する。なおこの場合転炉炉材保護の
ために副原料として例えば溶銑ton当り生石灰10
Kg、軽焼ドロマイト６Kg等が投入される。また前
記第２工程の脱燐処理において燐の含有量が所望
のレベルまで十分に低減されていない場合、また
は十分に低減された場合には若干の調整のために
生石灰、ドロマイド等を更に適量増減して投入す
ることが可能である。
吹錬後出鋼時には転炉スラグの取鍋内流入を極
力避けて溶鋼を取鍋内に受鋼し、例えばAlを溶
鋼ton当り2.4Kg投入添加して脱酸する。
第４工程では前述のごとく脱珪素、脱燐、脱炭
素の各ステツプを終えた溶鋼に対して最後に脱硫
処理が施される。その手段としては、例えば前記
の取鍋内溶鋼にCaO粉末を不活性ガスなどのキヤ
リヤ―ガスによつて溶鋼ton当り約２Kg吹込み、
硫黄含有量を0.030％程度のレベルから0.010％程
度のレベルまでに低減させる。かくして所定の硫
黄成分まで調整し最終目標の成分の鋼を得るもの
である。
以上に示した実施態様において、それぞれの工
程の中で行なわれる脱処理手段については例示し
た条件のみに特限定されるものではなく、本発明
の意図するところは溶銑から溶鋼に至る全精錬工
程に関し４つに分割した工程を持ち、それぞれ独
立して主たる脱処理成分を限定するとともに、そ
の独立した脱処理工程が(1)脱珪素、(2)脱燐、(3)脱
炭素、(4)脱硫黄の順序に限定配列したことに特徴
を有するものである。
このように本発明は転炉吹錬を境にして溶銑の
段階と溶鋼の段階に、しかも４つの主要脱処理成
分にそれぞれ分割して合理的かつ適切な順序に配
置することによつて製鋼品質上ならびに経済上総
合的にもつとも均衡のとれた精錬方法が確立され
うる。
次に本発明の方法により分割精錬された各工程
における処理後の溶鋼成分の実例を第１表に示
す。
The present invention relates to a steelmaking method in which various reactions for removing impurities in molten metal are divided into steps for refining. In recent years, with the development of ultra-low sulfur steel and ultra-low phosphorus steel, control of each component has become increasingly strict. In normal steelmaking methods, most of the impurities are removed during the converter blowing process, but in this case, the operational burden on the converter increases. Therefore, it is known to remove various impurities in advance at the hot metal stage in order to reduce the operating burden of the converter and to facilitate the management of each component. That is, Japanese Patent Application Laid-Open No. 127421/1987 discloses that desiliconization treatment is performed using iron oxide or oxygen, and then
A method of simultaneously performing dephosphorization and desulfurization using Na 2 CO 3 is disclosed. It is desirable to remove all of silicon, phosphorus, and sulfur at the hot metal stage, but desulfurization treatment is originally performed in a reducing atmosphere, while dephosphorization treatment is performed in an oxidizing atmosphere. It is preferable that the treatment be carried out at the same time, and the treatment conditions for the two are completely contradictory. Therefore, simultaneous desulfurization and dephosphorization treatment is not efficient and problems remain in practice. Currently, the following two types of fluxes are mainly used in simultaneous desulfurization and dephosphorization treatment.
i.e. Na 2 CO 3 system and oxygen source (mill scale,
Iron ore, gaseous oxygen, etc.) + CaO system. Na2CO3 _
As exemplified in JP-A-52-127421, Na 2 CO 3 in low-silicon hot metal is an effective simultaneous desulfurization and dephosphorization flux. That is, Na 2 CO 3 itself has O as an oxidation source and Na 2 O as a base, and in the dephosphorization reaction, O and Na 2 O react with P, resulting in 50
(From Na 2 CO 3 ) + 2P + 3Na 2 O → 3Na 2 OP 2 O 5 , and in the desulfurization reaction, Na 2 O reacts with S and Na 2 O +
S=Na 2 S+O. However, as shown in the above-mentioned known example,
The processing unit consumption of Na 2 CO 3 is high at 10 to 60 kg/t.
The use of Na 2 CO 3 is problematic not only from a cost perspective but also from an environmental standpoint, such as the erosion of refractories and the generation of smoke and fumes due to its severe reactivity .
It is not appropriate to use the system as an actual flux. On the other hand, considering the case of oxidation source + CaO system, desulfurization treatment is originally performed in a reducing atmosphere (in slag (%
It is desirable that the dephosphorization treatment be carried out in an oxidizing atmosphere (with a somewhat high (%FeO) in the slag), and the two treatment conditions are contradictory. In the case of an oxidizing source and a CaO-based flux, an excessive amount of CaO is required to perform desulfurization treatment in an oxidizing atmosphere with an oxidizing source, and simultaneous desulfurization and dephosphorization treatment is inefficient. Therefore, desulfurization treatment and dephosphorization treatment should be separated. By the way, it is desirable to de-treat Si, P, and S at the hot metal stage, and there are various proposals, but it is not practical from a process standpoint to have a three-step process of desiliconization, dephosphorization, and desulfurization treatment at the hot metal stage. This method is complicated and causes a large temperature drop, making it industrially impracticable. On the other hand, in recent years, the demand for clean steel has become more and more severe, and in particular there is a need to remove inclusions and control the morphology, and development of converter blowing and secondary refining after tapping is progressing. From this point of view, it is considered an effective steelmaking method to not only remove inclusions but also to provide a refining effect at the same time at this molten steel stage. In other words, in addition to injecting inert gas into the molten steel in the ladle for the purpose of removing inclusions, for example, CaO
If the desulfurization treatment is transferred almost entirely to the molten steel stage instead of being blown into the hot metal stage, the problems of complicating the process and temperature drop in the hot metal treatment described above can be solved. Furthermore, the advantage of molten steel desulfurization is that it is a thermodynamically advantageous high-temperature reaction, and the constraint is that the scrap charged to the converter must be carefully selected with a low sulfur content to prevent resulfurization in the furnace. can be solved at the same time. Although many proposals have been made for the treatment techniques of desulfurization, desiliconization, and dephosphorization mentioned above, or for simultaneous treatment or continuous treatment of multiple of them, No effective method has yet been proposed as a process-complete processing technology for all of the above. The present invention has an important meaning in that each detreatment technique is combined as a series of complete treatment steps in an optimal order and under conditions, and provides a practically effective steel manufacturing method. The constituent elements of the present invention will be described below. First, in the first step, the silicon content is mainly reduced by adding an oxidation source mainly composed of iron oxide, such as mill scale, to the hot metal. As for the timing of adding iron oxide, for example, a method is selected in which the hot metal tapped from the blast furnace is introduced into the gutter of the blast furnace casting bed, and the hot metal flows in the gutter or is forcibly stirred. . Another method is to receive the hot metal flowing out of the blast furnace gutter into a mixer car, and to blow a carrier gas such as an inert gas into the hot metal in the mixer car. In this process, the amount of silicon is generally
It is reduced from a level of about 0.50% to a level of about 0.15%. Note that it is desirable that the slag generated at this stage be separated and discharged so as not to be carried into the next process. Next, in the second step, the hot metal from which the slag has been removed and which has been transferred to the pig iron mixing car or ladle is subjected to a dephosphorization treatment. Here, for example, an oxygen source mainly composed of iron oxide such as mill scale and CaO, CaF 2 are mixed in a ratio of 4:2:
A powdery mixed flux of 30 to 50 kg/ton of hot metal mixed with a blending ratio of 1 mm and sized to a particle size of 1 mm or less is blown into the hot metal using an inert gas as a carrier gas. In general, the phosphorus content after treatment is
It is reduced to a level of about 0.015 to 0.040%. Next, in the third step, the obtained low-silicon, low-phosphorus pig iron is charged into a converter together with scrap and decarburized and blown. In this case, for example, 10 quicklime per ton of hot metal is used as an auxiliary raw material to protect the converter furnace materials.
kg, 6 kg of light calcined dolomite, etc. are input. In addition, if the phosphorus content is not sufficiently reduced to the desired level in the dephosphorization treatment in the second step, or if it has been sufficiently reduced, the amount of quicklime, dolomide, etc. may be further increased or decreased to make slight adjustments. It is possible to put it in. When tapping after blowing, the molten steel is received in the ladle while avoiding the flow of converter slag into the ladle as much as possible, and deoxidized by adding, for example, 2.4 kg of Al per ton of molten steel. In the fourth step, as described above, the molten steel that has undergone the steps of desiliconization, dephosphorization, and decarbonization is finally subjected to a desulfurization treatment. As a means for this, for example, about 2 kg of CaO powder is injected into the molten steel in the ladle using a carrier gas such as an inert gas, per ton of molten steel.
Reduce the sulfur content from a level of about 0.030% to a level of about 0.010%. In this way, the sulfur content is adjusted to a predetermined value to obtain steel with the final target content. In the embodiments shown above, the de-treatment means carried out in each process are not limited to the exemplified conditions only, and the present invention is intended to apply to the entire refining process from hot metal to molten steel. The process is divided into four parts, each of which independently limits the main decomposition components, and the independent deprocessing processes are (1) desilicification, (2) dephosphorization, (3) decarbonization, and (4) It is characterized by a limited arrangement in the order of desulfurization. In this way, the present invention improves steelmaking quality by dividing the converter blowing into the hot metal stage and molten steel stage, and furthermore, into the four main deprocessing components and arranging them in a rational and appropriate order. A refining method that is comprehensively and economically balanced can be established. Next, Table 1 shows examples of molten steel components after treatment in each step of split refining according to the method of the present invention.
【表】
以上の如く本発明によれば効率的な処理工程の
結合により、製鋼の実操業上、極めて合理的で有
効な効果が達成されうるものである。[Table] As described above, according to the present invention, extremely rational and effective effects can be achieved in actual steelmaking operations by efficiently combining processing steps.
Claims (1)
または容器内に溶銑を収容して不活性ガス等のキ
ヤリヤ―ガスで酸化鉄を吹き込むことにより、主
として脱珪反応を促進せしめ珪素含有量を0.1〜
0.2％程度まで低下せしめ、生成したスラグを分
離する第１の工程と、次いで容器内の溶銑に酸化
鉄およびCaOを主体とした脱燐剤を不活性ガス等
のキヤリヤ―ガスで吹き込むことにより、主とし
て脱燐反応を促進せしめ燐含有量を0.015〜0.040
％程度まで低下せしめ、生成したスラグを排滓す
る第２の工程と、次いで転炉吹錬により、主とし
て脱炭反応を促進せしめて昇温する第３の工程
と、出鋼後容器内の溶鋼にCaOを主体とする脱硫
剤を不活性ガス等のキヤリヤ―ガスで吹き込むこ
とにより、主として脱硫処理を行なう第４の工程
とからなることを特徴とする分割精錬による製鋼
方法。1 By adding iron oxide to the hot metal flowing out of the blast furnace, or storing the hot metal in a container and blowing iron oxide with a carrier gas such as an inert gas, the desiliconization reaction is mainly promoted and the silicon content is reduced to 0.1. ~
The first step is to reduce the slag to about 0.2% and separate the generated slag, and then blow a dephosphorizing agent mainly composed of iron oxide and CaO into the hot metal in the container using a carrier gas such as an inert gas. Mainly promotes dephosphorization reaction and reduces phosphorus content from 0.015 to 0.040
%, and the generated slag is discharged, and then the third step is to mainly accelerate the decarburization reaction and raise the temperature by converter blowing, and the molten steel in the container after tapping. A steelmaking method by split refining characterized by comprising a fourth step in which desulfurization is mainly carried out by injecting a desulfurization agent mainly containing CaO into a carrier gas such as an inert gas.
Priority Applications (12)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3469380A JPS56133413A (en) | 1980-03-21 | 1980-03-21 | Steel making method by divided refining |
| AU68239/81A AU6823981A (en) | 1980-03-21 | 1981-03-10 | Multi-stage steel making |
| US06/243,451 US4388112A (en) | 1980-03-21 | 1981-03-13 | Steelmaking process with separate refining steps |
| BE0/204174A BE888007A (en) | 1980-03-21 | 1981-03-18 | PROCESS FOR THE PREPARATION OF STEEL WITH SEPARATE REFINING STEPS |
| CA000373463A CA1166018A (en) | 1980-03-21 | 1981-03-19 | Steelmaking process with separate refining steps |
| DE3110787A DE3110787C2 (en) | 1980-03-21 | 1981-03-19 | Steel manufacturing process |
| FR8105574A FR2478671B1 (en) | 1980-03-21 | 1981-03-20 | PROCESS FOR THE PREPARATION OF STEEL BY SEPARATE REFINING STEPS |
| BR8101709A BR8101709A (en) | 1980-03-21 | 1981-03-23 | STEEL MANUFACTURING PROCESS WITH SEPARATE REFINING STAGES |
| GB8108981A GB2072221B (en) | 1980-03-21 | 1981-03-23 | Steelmaking process with separate refining steps |
| US06/362,839 US4411696A (en) | 1980-03-21 | 1982-03-29 | Steelmaking process with separate refining steps |
| US06/504,285 US4457778A (en) | 1980-03-21 | 1983-06-14 | Steelmaking process with separate refining steps |
| AU22238/83A AU549698B2 (en) | 1980-03-21 | 1983-12-08 | Steel making process with separate steps in sequence |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3469380A JPS56133413A (en) | 1980-03-21 | 1980-03-21 | Steel making method by divided refining |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56133413A JPS56133413A (en) | 1981-10-19 |
| JPS6362562B2 true JPS6362562B2 (en) | 1988-12-02 |
Family
ID=12421453
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3469380A Granted JPS56133413A (en) | 1980-03-21 | 1980-03-21 | Steel making method by divided refining |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS56133413A (en) |
| BE (1) | BE888007A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5831012A (en) * | 1981-08-19 | 1983-02-23 | Nippon Steel Corp | Preferential desiliconizing method for molten iron by blowing of gaseous oxygen |
| JPS591609A (en) * | 1982-06-28 | 1984-01-07 | Nippon Steel Corp | Refining method of molten iron |
| GB2127436B (en) * | 1982-09-23 | 1986-03-19 | Nat Res Dev | Removing phosphorus from iron or iron alloys |
| JP2542137Y2 (en) * | 1990-05-24 | 1997-07-23 | 新技術工営株式会社 | Concrete formwork |
| JP6223249B2 (en) * | 2014-03-19 | 2017-11-01 | 株式会社神戸製鋼所 | Desiliconization, dephosphorization, and decarburization methods that reuse desiliconized slag |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5237510A (en) * | 1975-09-19 | 1977-03-23 | Nippon Steel Corp | Dephosphorization method of molten cast iron |
| JPS5445611A (en) * | 1977-09-16 | 1979-04-11 | Kobe Steel Ltd | Treating molten metal |
-
1980
- 1980-03-21 JP JP3469380A patent/JPS56133413A/en active Granted
-
1981
- 1981-03-18 BE BE0/204174A patent/BE888007A/en not_active IP Right Cessation
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5237510A (en) * | 1975-09-19 | 1977-03-23 | Nippon Steel Corp | Dephosphorization method of molten cast iron |
| JPS5445611A (en) * | 1977-09-16 | 1979-04-11 | Kobe Steel Ltd | Treating molten metal |
Also Published As
| Publication number | Publication date |
|---|---|
| BE888007A (en) | 1981-07-16 |
| JPS56133413A (en) | 1981-10-19 |
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