JP2001271111A - Method for desiliconizing and desulfurizing molten iron - Google Patents
Method for desiliconizing and desulfurizing molten ironInfo
- Publication number
- JP2001271111A JP2001271111A JP2000083525A JP2000083525A JP2001271111A JP 2001271111 A JP2001271111 A JP 2001271111A JP 2000083525 A JP2000083525 A JP 2000083525A JP 2000083525 A JP2000083525 A JP 2000083525A JP 2001271111 A JP2001271111 A JP 2001271111A
- Authority
- JP
- Japan
- Prior art keywords
- hot metal
- slag
- cao
- desulfurization
- desulfurizing
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はハロゲン化物を一切
使用せず、また効率的な溶銑の脱珪・脱硫方法に関する
ものであって、銑鉄を原料とする鋼の精錬プロセスに広
く利用される。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently desiliconizing and desulfurizing hot metal which does not use any halide and is widely used in a refining process of steel using pig iron as a raw material.
【０００２】[0002]
【従来の技術】鋼材使用環境の厳格化に伴い、りん、硫
黄に代表される鋼中の不純物元素の低減に対する要求は
厳しい。一方、鉄鋼材料は大量に利用される基礎素材で
あり、品質もさることながら、安価であることも重要で
あり品質、コストを両立させるためより効率的な製造プ
ロセスを求めて技術開発がなされている。こうした中、
珪素、硫黄、りんを事前に取り除いた銑鉄を転炉吹錬に
て鋼を得る、いわゆる溶銑予備処理技術が発展して来て
いるが、精錬剤である生石灰の滓化促進剤として従来、
蛍石（主成分はCaF2）が利用されてきた。2. Description of the Related Art Along with the stricter use environment of steel materials, demands for reduction of impurity elements in steel represented by phosphorus and sulfur are severe. On the other hand, steel materials are basic materials that are used in large quantities, and it is important that they are inexpensive as well as quality.Technological developments have been made in pursuit of more efficient manufacturing processes to balance quality and cost. I have. Under these circumstances,
The so-called hot metal pretreatment technology, which obtains steel by converter blowing of pig iron from which silicon, sulfur, and phosphorus have been removed in advance, has been developed.However, as a slag accelerating agent for quicklime, which is a refining agent,
Fluorite (main component is CaF 2 ) has been used.
【０００３】近年、環境問題に対する社会的関心が高ま
る中、鉄鋼精錬工程において発生する様々な副産物の処
理方法についても問題が提起されている。特に、スラグ
中に含まれるフッ素は環境への溶出が問題となってお
り、製鋼プロセスでは蛍石等、ハロゲン化物を添加する
ことは望ましくなく、本来、使用しないのが望ましいが
完全に使用しない方法は未だ確立されていない。[0003] In recent years, with increasing public interest in environmental issues, problems have been raised with respect to methods for treating various by-products generated in the steel refining process. In particular, fluorine contained in slag has a problem of elution into the environment, and it is not desirable to add a halide such as fluorite in the steel making process. Has not yet been established.
【０００４】一方、溶銑予備処理工程については、反応
面からは脱珪、脱りん、脱硫といった各々の反応を各々
分割して専用の精錬装置を用いて行うのが良いが、その
ためには各々の反応容器が必要となって設備費用が高価
になること、溶銑の移し替えが必要となり、移し替えに
伴う熱ロスが増大すること、およびその度に排滓が必要
となり、排滓に伴う熱ロス増、スラグ中に何らかの形で
トラップされている鉄分をロスする、という問題が生じ
る。また、完全にスラグを除去できる技術は未だに確立
されておらず、不可避的にスラグが溶銑とともに次工程
に持ち越される、いわゆるキャリーオーバースラグが発
生する。これによりスラグから不純物が戻る現象が次工
程で問題となり、また排滓の程度がばらつくので、精錬
のばらつき要因となり制御性が悪化する。そのため全て
を分割するのではなく、一部の精錬機能を集約し、２分
割程度にして脱珪と脱硫、脱珪と脱りん、あるいは脱り
んと脱硫を同一炉内で行う工程集約の方法も種々検討さ
れているが、この様に、不純物除去、環境、機能集約の
三つの側面からプロセスを最適化する必要がある。[0004] On the other hand, in the hot metal pretreatment step, from the reaction side, each reaction such as desiliconization, dephosphorization, and desulfurization is preferably performed by dividing each reaction and using a dedicated refining apparatus. The need for a reaction vessel increases equipment costs, the transfer of hot metal becomes necessary, the heat loss associated with the transfer increases, and waste is required each time, and the heat loss associated with the waste is required. In addition, there is a problem in that iron trapped in the slag in some form is lost. Further, a technique for completely removing slag has not yet been established, and so-called carryover slag occurs, inevitably slag is carried over to the next step together with hot metal. As a result, the phenomenon that impurities return from the slag becomes a problem in the next step, and the degree of waste varies, which causes a variation in refining and deteriorates controllability. Therefore, instead of splitting the whole, some refining functions are integrated, and there are various methods of integrating the processes of desiliconization and desulfurization, desiliconization and dephosphorization, or dephosphorization and desulfurization in the same furnace with about two divisions. As discussed above, it is necessary to optimize the process from the three aspects of impurity removal, environment, and function integration.
【０００５】特開平9-261634号公報には、攪拌下、珪素
濃度0.1%以上の溶銑に鉄酸化物とCaO 、CaF2を添加しス
ラグ中酸化鉄濃度をFe換算値で5%以下とする脱珪工程
と、その後、攪拌下、CaO とCaF2を含む脱硫剤を添加し
て脱硫を行う方法が記載されている。また、特開昭58-1
6007号公報には、CaO 系フラックスを用い、スラグの塩
基度(CaO)/(SiO2)が2.0 以上、酸化鉄濃度が15％以下と
なるよう溶銑の脱りん処理を行い、引き続きスラグを排
滓することなく、溶銑中へキャリアガスとともに脱硫剤
を吹込んで脱硫処理を行う方法が開示されている。Japanese Patent Application Laid-Open No. 9-261634 discloses that iron oxide, CaO, and CaF 2 are added to hot metal having a silicon concentration of 0.1% or more under stirring to reduce the iron oxide concentration in slag to 5% or less in terms of Fe. It describes a desiliconization step, and then a method of desulfurization by adding a desulfurizing agent containing CaO and CaF 2 with stirring. In addition, JP-A-58-1
Japanese Patent No. 6007 discloses dephosphorization of hot metal using a CaO-based flux so that the basicity (CaO) / (SiO 2 ) of the slag becomes 2.0 or more and the iron oxide concentration becomes 15% or less, and then the slag is discharged. There is disclosed a method of performing a desulfurization treatment by blowing a desulfurizing agent together with a carrier gas into hot metal without slagging.
【０００６】[0006]
【発明が解決しようとする課題】しかし、特開平9-2616
34号公報に記載された方法では、機能集約という点では
良いが、トップスラグと溶銑間の反応で酸化反応である
脱珪反応と還元反応である脱硫反応の両者を行わせる必
要があり、効率的とは言えない。更には、CaF2使用量を
最少限に抑えると述べているが、CaF2を全く使用しない
場合には特に脱硫工程で、スラグの流動性が全くなくな
り、脱硫反応が極めて遅くなるので、5%程度の添加は必
須となる。また、特開昭58-16007号公報に記載された方
法では、脱りん後のスラグを排滓しないで残すことにな
り、脱硫処理中にはそのスラグ中の酸化鉄の還元が進行
するので、りんをスラグ中に保持することが困難とな
り、脱硫処理中にりんがスラグから溶銑に戻る、いわゆ
る復りんを招く。それを避けるために脱りん後のスラグ
中の酸化鉄濃度を高めておけば、脱硫効率が低下する、
という結果をまねく。また、より強力な精錬剤としてソ
ーダ系フラックスを使用する方法もあるが、この場合に
はフラックスが高価であることと、ソーダの熱分解によ
る熱ロスを助長するという問題もある。更には、復りん
がおきるかどうかの極めて不安定な状況となり精錬後の
りん濃度がばらつき、次工程での転炉操業が不安定にな
る、という問題がある。SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No. 9-2616
The method described in Japanese Patent No. 34 is good in terms of function consolidation, but it is necessary to carry out both the desiliconization reaction which is an oxidation reaction and the desulfurization reaction which is a reduction reaction in the reaction between the top slag and the hot metal, and the Not a target. Furthermore, it states that the amount of CaF 2 used is kept to a minimum, but especially when no CaF 2 is used, especially in the desulfurization step, the fluidity of the slag is completely lost, and the desulfurization reaction becomes extremely slow, so 5% Addition of a certain degree is essential. In the method described in JP-A-58-16007, the slag after dephosphorization is left without being discharged, and during the desulfurization treatment, the reduction of iron oxide in the slag proceeds. It becomes difficult to retain phosphorus in the slag, which causes phosphorus to return from the slag to the hot metal during desulfurization, so-called rephosphorization. If the concentration of iron oxide in the slag after dephosphorization is increased to avoid it, the desulfurization efficiency will decrease,
That leads to the result. There is also a method of using soda-based flux as a stronger refining agent, but in this case, there are problems that the flux is expensive and promotes heat loss due to thermal decomposition of soda. Furthermore, there is a problem that the situation is extremely unstable whether rephosphorization occurs or not, and the phosphorus concentration after refining fluctuates, and the operation of the converter in the next step becomes unstable.
【０００７】[0007]
【課題を解決するための手段】本発明は上記課題を解決
するためになされたものであり、次のとおりである。 （１）蛍石などのハロゲン化物を使用せず、生石灰源と
酸素源を添加して溶銑の脱珪処理を行う第一工程と、酸
素供給を止め、引き続き脱硫剤を溶銑中に吹込んで脱硫
処理を行う第二工程からなる溶銑の脱珪・脱硫方法、 （２）第一工程で生成するスラグの塩基度を1.0 以上と
し、第二工程において脱硫剤の吹込み深さが溶銑表面下
1.5m以上であることを特徴とする（１）記載の溶銑の脱
珪・脱硫方法。ただし、塩基度は（Ａ）式で定義する、 塩基度＝(T-(CaO)-f-(CaO))/(SiO2) （Ａ） ここに、T-(CaO):全CaO 濃度、f-(CaO):フリーライム濃
度、(SiO2)：SiO2濃度 （３）第一工程において（Ｂ）式で定義される溶銑の攪
拌力を1.1 以上kw/t以上とすることを特徴とする（１）
乃至（２）記載の溶銑の脱珪・脱硫方法、 ε＝0.0062 Qg T ｛ln(1+H0/1.54)+(1-Tg /T) ｝/Wm （Ｂ） ここに、Q g ：ガス吹込み量(Nl/min)、T ：溶銑温度
(K) 、H0：吹込み深さ(m) 、T g ：吹込み前のガス温度
(K) 、W m ：溶銑量(t)である。Means for Solving the Problems The present invention has been made to solve the above problems, and is as follows. (1) The first step of desiliconizing hot metal by adding quick lime source and oxygen source without using halide such as fluorite, and stopping oxygen supply, and then desulfurizing by blowing a desulfurizing agent into hot metal (2) The basicity of the slag produced in the first step is set to 1.0 or more, and the depth of injection of the desulfurizing agent in the second step is set below the hot metal surface.
The method for desiliconizing and desulfurizing hot metal according to (1), wherein the length is 1.5 m or more. Here, the basicity is defined by the formula (A). Basicity = (T- (CaO) -f- (CaO)) / (SiO 2 ) (A) where, T- (CaO): total CaO concentration, f- (CaO): free lime concentration, (SiO 2 ): SiO 2 concentration (3) In the first step, the stirring power of the hot metal defined by the formula (B) is set to 1.1 or more kw / t or more. Do (1)
And (2) the method for desiliconization and desulfurization of hot metal described in (2), ε = 0.0062 Q g T ｛ln (1 + H 0 /1.54)+(1-T g / T)｝ / W m (B) g : Gas injection rate (Nl / min), T: Hot metal temperature
(K), H 0 : Blowing depth (m), T g : Gas temperature before blowing
(K), W m: is a hot metal amount (t).
【０００８】即ち、本発明は蛍石等、従来生石灰の滓化
剤として用いられていたハロゲン化物を一切使用するこ
となく、同一炉内で溶銑の脱珪・脱硫を安定に行うこと
を意図しているものであり、鉄鋼の精錬プロセスに広く
採用し得る。その原理は、一般に溶銑の脱珪処理を行う
と低塩基度、高FeO 濃度のスラグが生成し、そのまま脱
硫剤を添加して脱硫処理を行おうとしても、スラグの塩
基度が低いので脱硫能力が無く、また酸素ポテンシャル
も高いため還元反応である脱硫反応は効率が低下すると
考えられている。しかし、この様な状況でも蛍石等のハ
ロゲン化物を使用せず、脱硫剤を溶銑表面下、1.0m以上
の深さから吹込むと、脱硫反応も充分生じるという、新
しい知見による。即ち、溶銑上に低塩基度、高FeO 濃度
のスラグが存在しても、蛍石等のハロゲン化物を使用し
なければ、スラグの固相率は高く、流動性に乏しくそれ
程悪影響は無く、また、吹込まれた脱硫剤は溶銑中を浮
上する間に充分な脱硫反応を生じるのでそれ程効率が低
下しない、という事実を見出したことによる。もちろ
ん、溶銑上の低塩基度、高FeO 濃度のスラグの悪影響が
全く無い訳ではないので、その固相率を更に確保して流
動性、反応性に乏しいスラグとするのが望ましいが、そ
のためには脱珪処理後スラグの塩基度1.0 以上を確保す
ること、更には脱珪処理時の攪拌力を1.1kw/t 以上とし
てFeO 濃度を下げることが望ましい。That is, the present invention is intended to stably desiliconize and desulfurize hot metal in the same furnace without using any halide, such as fluorite, which has been used as a caking agent for quicklime. It can be widely used in steel refining processes. The principle is that, when the hot metal is desiliconized, slag with a low basicity and high FeO concentration is generated, and even if a desulfurizing agent is added as it is to perform the desulfurization treatment, the desulfurization capacity is low because the slag has a low basicity. It is considered that the efficiency of the desulfurization reaction, which is a reduction reaction, is reduced due to the absence of oxygen and the high oxygen potential. However, it is based on the new finding that, even in such a situation, if a desulfurizing agent is blown from a depth of 1.0 m or more below the surface of the hot metal without using a halide such as fluorite, a sufficient desulfurization reaction occurs. That is, even if slag with a low basicity and a high FeO concentration exists on the hot metal, unless a halide such as fluorite is used, the solid phase ratio of the slag is high, the fluidity is poor and the slag is not so badly affected, and However, the fact that the injected desulfurizing agent causes a sufficient desulfurization reaction while floating in the hot metal does not reduce the efficiency so much. Of course, the slag of low basicity and high FeO concentration on the hot metal is not completely free from adverse effects, so it is desirable to further secure the solid fraction and make the slag poor in fluidity and reactivity. It is desirable to ensure that the basicity of the slag after desiliconization treatment is 1.0 or more, and to further lower the FeO concentration by setting the stirring force during desiliconization treatment to 1.1 kw / t or more.
【０００９】[0009]
【発明の実施の形態】本願発明者らは、本願発明に至る
詳細な研究の結果、以下の様な実験事実を明らかとし
た。即ち、図１に示す転炉タイプの溶銑予備処理炉１を
用い、スクラップ10を装入後、更に溶銑２を装入し、炉
底よりN2ガスをキャリアーとして石灰石粉を、吹込み羽
口６より吹込んで溶銑２を攪拌しながら、酸素源と生石
灰源を炉上ホッパー９より添加し、酸素上吹きランス３
より酸素ガスを吹き付けて脱珪処理を行う。引き続き、
酸素を止め、吹込み羽口６より生石灰粉を主成分とする
脱硫剤を吹込み、脱硫処理を行う。この時、脱硫剤の吹
込み深さを1.0m以上として、脱珪処理後のスラグの塩基
度を1.0 以上を確保し、底吹き攪拌力を1.1kw/t 以上確
保し、蛍石等のハロゲン化物等のスラグの固相率を低め
るような滓化促進剤を一切使用しなければ脱珪後スラグ
の固相率を高く保つことができる。そのため、溶銑を浮
上する間に硫黄を高濃度で吸収した生石灰粒子は、トッ
プスラグと均一に混合することなく、硫黄を高濃度で含
んだままの形態でトップスラグに物理的にトラップさ
れ、硫黄を溶銑に戻す、いわゆる復硫反応を最少限に抑
えることができることがわかった。その結果、効率的な
脱硫処理が可能となり、脱珪脱硫を排滓や溶銑の反応容
器の移し替えを行う必要がなく、工程省略が可能とな
る。この時、低攪拌エネルギーで処理を行なうとトップ
スラグのFeO が高くなり、その結果、液相率が高くなる
とともに、スラグの酸素ポテンシャルが高くなる。ま
た、CaF2等のハロゲン化物を使用すると、やはり液相率
が高くなる。このような場合、硫黄を高濃度で含んだ脱
硫剤がトップスラグと混合され、硫黄はスラグ中に溶解
することになるが、本来、このスラグは塩基度が低く、
硫黄を保持する能力が無いため、そのままでは硫黄が再
び溶銑中に戻る、いわゆる復硫反応を生じ、脱硫効率は
低下する。BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have clarified the following experimental facts as a result of detailed studies leading to the present invention. That is, using a hot metal pretreatment furnace 1 of the converter type shown in FIG. 1, after charging the scrap 10, further charged with molten pig iron 2, the limestone powder N 2 gas as a carrier from the furnace bottom, blowing tuyere 6 while stirring the hot metal 2 while adding the oxygen source and the quicklime source from the on-furnace hopper 9,
Desiliconization treatment is performed by blowing more oxygen gas. Continued
The oxygen is stopped, and a desulfurizing agent mainly containing quicklime powder is blown from the blowing tuyere 6 to perform a desulfurization treatment. At this time, the desulfurizing agent injection depth was set to 1.0 m or more, the basicity of the slag after the desiliconization treatment was secured to 1.0 or more, the bottom blow stirring power was secured to 1.1 kw / t or more, and halogen such as fluorite was If no slag-promoting agent is used to lower the solid phase ratio of slag such as chloride, the solid phase ratio of slag can be kept high after desiliconization. As a result, quicklime particles that have absorbed sulfur at a high concentration while floating hot metal do not mix uniformly with the top slag, but are physically trapped in the top slag in a form that still contains a high concentration of sulfur. It has been found that the so-called resulfurization reaction can be minimized, which is to return the molten iron to hot metal. As a result, efficient desulfurization treatment becomes possible, and there is no need to perform the desiliconization desulfurization by transferring the waste or the reaction vessel of the hot metal, and the process can be omitted. At this time, when the treatment is performed with low stirring energy, the FeO of the top slag increases, and as a result, the liquid phase ratio increases and the oxygen potential of the slag increases. Also, when a halide such as CaF 2 is used, the liquid phase ratio also increases. In such a case, a desulfurizing agent containing a high concentration of sulfur is mixed with the top slag, and the sulfur is dissolved in the slag, but originally, this slag has a low basicity,
Since there is no ability to retain sulfur, as it is, sulfur returns to the hot metal again, that is, a so-called resulfurization reaction occurs, and the desulfurization efficiency decreases.
【００１０】[0010]
【実施例】次に本願発明による実施例、および比較例を
示す。実験は図１に示す、炉底にガス、及び粉体を吹込
む羽口を設けた転炉タイプの精錬炉を用いた。 （実施例１）溶銑278tをスクラップとともに装入し、上
方より生石灰を添加した。上吹きランスより酸素ガスを
上吹きしつつ底吹き羽口より溶銑に窒素ガスにて石灰石
粉を吹込みつつ脱珪処理を行った。４分間の精錬後、酸
素ガスを止め、CaO+Al灰脱硫剤を溶銑1tあたり4.2kg/t
底から吹込み脱硫処理を実施した。この結果、珪素濃度
は0.54％から0.011%まで低下し、硫黄濃度は0.023%から
0.005%まで低下した。（Ｃ）式で定義される脱硫剤のＫ
値は0.36が得られた。 K ＝ln([%S] initial ／[%S]final ) / W flux （Ｃ） [%S]initial ：処理前溶銑中硫黄濃度（重量％）、[%S]
final ：処理後溶銑中硫黄濃度（重量％）、 Wflux：脱
硫剤原単位(kg/t)Next, examples according to the present invention and comparative examples will be described. The experiment used a converter type refining furnace shown in FIG. 1 and provided with a tuyere for blowing gas and powder into the furnace bottom. (Example 1) 278 t of hot metal was charged together with scrap, and quicklime was added from above. The desiliconization treatment was performed while blowing limestone powder with nitrogen gas from the bottom blowing tuyere with nitrogen gas while blowing oxygen gas upward from the top blowing lance. After refining for 4 minutes, stop oxygen gas and apply CaO + Al ash desulfurizer at 4.2kg / t per ton of hot metal
Blowing desulfurization treatment was performed from the bottom. As a result, the silicon concentration decreases from 0.54% to 0.011%, and the sulfur concentration decreases from 0.023%.
It decreased to 0.005%. K of the desulfurizing agent defined by the formula (C)
A value of 0.36 was obtained. K = ln ([% S] initial / [% S] final ) / W flux (C) [% S] initial : Sulfur concentration in hot metal before treatment (% by weight), [% S]
final : Sulfur concentration in hot metal after treatment (% by weight), W flux : Desulfurizer basic unit (kg / t)
【００１１】（実施例２）溶銑263tを装入し、上方より
生石灰を添加した。上吹きランスから酸素ガスを上吹き
しつつ底吹き羽口より石灰石粉2.7kg/t を窒素ガスにて
吹込み溶銑に1.8kw/t の攪拌力を付与しつつ脱珪処理を
行った。脱珪後のスラグ塩基度を2.5 とした。脱珪処理
後、上吹き酸素ガスを止め、底吹き羽口よりCaO+Al灰脱
硫剤を吹込んで脱硫処理を行った。この結果、珪素濃度
は0.51％から0.06％、硫黄濃度は0.017%から0.001%まで
低下した。（Ｃ）式で定義されるＫ値は0.39であった。(Example 2) 263t of hot metal was charged, and quicklime was added from above. 2.7 kg / t of limestone powder was blown in with nitrogen gas from the bottom-blowing tuyere while oxygen gas was blown up from the top-blowing lance, and the molten iron was desiliconized while applying a stirring force of 1.8 kw / t. The slag basicity after desiliconization was set to 2.5. After the desiliconization treatment, the top-blown oxygen gas was stopped, and the desulfurization treatment was performed by blowing a CaO + Al ash desulfurization agent from the bottom-blown tuyere. As a result, the silicon concentration decreased from 0.51% to 0.06%, and the sulfur concentration decreased from 0.017% to 0.001%. The K value defined by the equation (C) was 0.39.
【００１２】（実施例３）溶銑272tをスクラップ18t と
ともに装入し、上方より生石灰を添加した。上吹きラン
スより酸素ガスを上吹きしつつ溶銑の脱珪処理を５分間
行った。この時、炉底に設けた羽口より連続して石灰石
粉を窒素ガスにて吹込み、溶銑の攪拌を行った。攪拌力
は1.5kw/t とした。3.2min間の精錬後、上吹き酸素ガス
を止め、底吹き羽口より窒素ガスにてCaO+Al灰脱硫剤を
溶銑1tあたり6.7kg/t 吹込み、脱硫処理を実施した。こ
の結果、珪素濃度は0.35％から0.12％に低下し、硫黄濃
度は0.022%から0.002%に低下した。（Ｃ）式で定義され
る脱硫剤のＫ値は極めて高く、0.46が得られた。(Example 3) 272t of hot metal was charged together with 18t of scrap, and quicklime was added from above. The hot metal was desiliconized for 5 minutes while blowing oxygen gas upward from the upper blowing lance. At this time, limestone powder was continuously blown in with nitrogen gas from a tuyere provided at the furnace bottom to stir the hot metal. The stirring power was 1.5 kw / t. After refining for 3.2 min, the top-blown oxygen gas was stopped, and 6.7 kg / t of CaO + Al ash desulfurizing agent was blown in from the bottom-blown tuyere with nitrogen gas per 1 t of hot metal to perform desulfurization treatment. As a result, the silicon concentration decreased from 0.35% to 0.12%, and the sulfur concentration decreased from 0.022% to 0.002%. The K value of the desulfurizing agent defined by the formula (C) was extremely high, and 0.46 was obtained.
【００１３】（比較例１）溶銑286tを装入し、上方より
生石灰、鉄鉱石を添加後、上吹きランスより酸素ガスを
上吹きしつつ、溶銑の脱珪処理を行った。この時、炉底
に設けた羽口より連続して石灰石粉を窒素ガスにて吹込
み、溶銑の攪拌を行った。3.3min間の精錬後、上吹き酸
素ガスを止め、上方よりCaO+Al灰ブリケット脱硫剤を溶
銑1tあたり5.9kg/t 添加し、脱硫処理を行った。この場
合、硫黄濃度は0.018%から0.016%に低下するに留まり、
Ｋ値は0.02と低値に留まった。この場合、脱硫剤の吹込
み法では脱硫剤の溶銑中の浮上中に脱硫反応が生じるの
に対し、脱珪処理で生じたFeO 濃度の高いトップスラグ
との反応となるため、脱硫効率が著しく低かったものと
思われる。(Comparative Example 1) 286t of hot metal was charged, and after adding quicklime and iron ore from above, desiliconization of the hot metal was performed while blowing oxygen gas upward from an upper blowing lance. At this time, limestone powder was continuously blown in with nitrogen gas from a tuyere provided at the furnace bottom to stir the hot metal. After refining for 3.3 min, the top-blown oxygen gas was stopped, and CaO + Al ash briquette desulfurizing agent was added from above to add 5.9 kg / t per 1 t of hot metal to perform desulfurization treatment. In this case, the sulfur concentration only drops from 0.018% to 0.016%,
The K value stayed as low as 0.02. In this case, in the desulfurizing agent injection method, the desulfurization reaction occurs during the floating of the desulfurizing agent in the hot metal, whereas the reaction with the top slag with a high FeO concentration generated by the desiliconization treatment leads to a marked increase in the desulfurization efficiency. It seems to have been low.
【００１４】[0014]
【発明の効果】本発明により、ハロゲン化物を一切使用
することなく、溶銑の脱珪処理と脱硫処理が同一反応容
器内で効率良く行うことができるようになる。更に、本
願発明は実施例に示した転炉型の反応炉のみならず、
鍋、トーピードカー等、他の設備を用いても可能であ
る。また、脱珪時の生石灰添加方法としては実施例に示
した上方添加のみならず、必要に応じて微粉インジェク
ションでも良いし、上吹き酸素ガスをキャリアーとした
粉体上吹き法も採用できる。According to the present invention, desiliconization and desulfurization of hot metal can be efficiently performed in the same reaction vessel without using any halide. Furthermore, the present invention is not limited to the converter type reactor shown in the embodiment,
It is also possible to use other equipment such as a pot and a torpedo car. As a method for adding quick lime during desiliconization, not only the upward addition shown in the examples, but also fine powder injection may be used, if necessary, or a powder top blowing method using a top blowing oxygen gas as a carrier may be employed.
【図１】 本発明を実施するに好適な転炉タイプの反応
炉の横断面図である。FIG. 1 is a cross-sectional view of a converter type reactor suitable for carrying out the present invention.
１ 転炉 ２ 溶銑 ３ 酸素ガス上吹きランス ４、５ ブロータンク ６ 吹込み羽口 ７ 窒素ガスホルダー ８ 酸素ガスホルダー ９ 炉上ホッパー 10 スクラップ DESCRIPTION OF SYMBOLS 1 Converter 2 Hot metal 3 Oxygen gas top blowing lance 4, 5 Blow tank 6 Blow tuyere 7 Nitrogen gas holder 8 Oxygen gas holder 9 Furnace hopper 10 Scrap
───────────────────────────────────────────────────── フロントページの続き (72)発明者 田崎 智晶 愛知県東海市東海町５−３ 新日本製鐵株 式会社名古屋製鐵所内 Ｆターム(参考） 4K001 AA10 BA04 EA03 GA06 GA18 GB03 JA01 KA06 4K013 BA05 CA01 CA04 CA13 CB04 CC02 EA12 4K014 AA01 AA02 AB03 AC08 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Chiaki Tazaki 5-3 Tokai-cho, Tokai-shi, Aichi F-term in Nagoya Works, Nippon Steel Corporation (reference) 4K001 AA10 BA04 EA03 GA06 GA18 GB03 JA01 KA06 4K013 BA05 CA01 CA04 CA13 CB04 CC02 EA12 4K014 AA01 AA02 AB03 AC08
Claims (3)
石灰源と酸素源を添加して溶銑の脱珪処理を行う第一工
程と、酸素供給を止め、引き続き脱硫剤を溶銑中に吹込
んで脱硫処理を行う第二工程からなる溶銑の脱珪・脱硫
方法。1. A first step in which hot metal is desiliconized by adding a quick lime source and an oxygen source without using a halide such as fluorite, stopping the supply of oxygen, and subsequently blowing a desulfurizing agent into the hot metal. A method for desulfurizing and desulfurizing hot metal comprising a second step of performing desulfurization treatment in a hot metal.
0 以上とし、第二工程において脱硫剤の吹込み深さが溶
銑表面下1.0m以上であることを特徴とする請求項１記載
の溶銑の脱珪・脱硫方法。ただし、塩基度は（Ａ）式で
定義する。 塩基度＝(T-(CaO)-f-(CaO))/(SiO2) （Ａ） ここに、T-(CaO):全CaO 濃度、f-(CaO):フリーライム濃
度、(SiO2)：SiO2濃度2. The slag produced in the first step has a basicity of 1.
2. The method for desiliconizing and desulfurizing hot metal according to claim 1, wherein the depth of injection of the desulfurizing agent in the second step is at least 1.0 m below the surface of the hot metal. However, the basicity is defined by the formula (A). Basicity = (T- (CaO) -f- (CaO)) / (SiO 2 ) (A) where T- (CaO): total CaO concentration, f- (CaO): free lime concentration, (SiO 2 ): SiO 2 concentration
溶銑の攪拌力を1.1kw/t 以上とすることを特徴とする請
求項１乃至２記載の溶銑の脱珪・脱硫方法。 ε＝0.0062 Qg T ｛ln(1+H0/1.54)+(1-Tg /T) ｝/Wm （Ｂ） ここに、 Qg ：ガス吹込み量(Nl/min)、T : 溶銑温度
(K) 、H0：吹込み深さ(m)、 Tg : 吹込み前のガス温度
(K) 、W m ：溶銑量(t)3. The method for desiliconizing and desulfurizing hot metal according to claim 1, wherein in the first step, the stirring power of the hot metal defined by the formula (B) is set to 1.1 kw / t or more. ε = 0.0062 Q g T ｛ln (1 + H 0 /1.54)+(1-T g / T)｝ / W m (B) where, Q g : gas blowing amount (Nl / min), T: Hot metal temperature
(K), H 0 : Blow depth (m), T g : Gas temperature before blow
(K), W m : Hot metal content (t)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000083525A JP3793390B2 (en) | 2000-03-24 | 2000-03-24 | Hot metal desiliconization and desulfurization methods |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000083525A JP3793390B2 (en) | 2000-03-24 | 2000-03-24 | Hot metal desiliconization and desulfurization methods |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001271111A true JP2001271111A (en) | 2001-10-02 |
| JP3793390B2 JP3793390B2 (en) | 2006-07-05 |
Family
ID=18600143
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000083525A Expired - Fee Related JP3793390B2 (en) | 2000-03-24 | 2000-03-24 | Hot metal desiliconization and desulfurization methods |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3793390B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114210466A (en) * | 2021-12-15 | 2022-03-22 | 安徽大昌矿业集团有限公司 | Ultra-pure fine iron powder multistage desiliconization device |
-
2000
- 2000-03-24 JP JP2000083525A patent/JP3793390B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114210466A (en) * | 2021-12-15 | 2022-03-22 | 安徽大昌矿业集团有限公司 | Ultra-pure fine iron powder multistage desiliconization device |
| CN114210466B (en) * | 2021-12-15 | 2022-11-25 | 安徽大昌矿业集团有限公司 | Ultra-pure fine iron powder multistage desiliconization device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3793390B2 (en) | 2006-07-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO1995001458A1 (en) | Steel manufacturing method using converter | |
| JP6693536B2 (en) | Converter steelmaking method | |
| JP2004190101A (en) | Method for pre-treating molten iron | |
| JP6665884B2 (en) | Converter steelmaking method | |
| JPH09157732A (en) | Method for desulfurizing and dehydrogenating molten steel with little erosion of refractory | |
| JP2002256320A (en) | Method for desiliconizing and dephosphorizing molten iron | |
| JP2003239009A (en) | Dephosphorization refining method of hot metal | |
| JP3790414B2 (en) | Hot metal refining method | |
| JP2001271111A (en) | Method for desiliconizing and desulfurizing molten iron | |
| JP2900011B2 (en) | Converter refining method | |
| CN115074489A (en) | Pretreatment method of molten iron | |
| JP2002105526A (en) | Method for dephosphorizing molten iron generating little non-slagging lime | |
| JP2016079462A (en) | Method for refining hot pig iron | |
| JP2958842B2 (en) | Converter refining method | |
| JPH05156338A (en) | Method for reusing low phosphorus converter slag | |
| JP2607329B2 (en) | Hot metal dephosphorization method | |
| JPH07179920A (en) | Production of molten steel | |
| JP4772454B2 (en) | Hot metal refining method | |
| JP3742543B2 (en) | Hot metal desulfurization method | |
| JP4759832B2 (en) | Hot phosphorus dephosphorization method | |
| JP2001220621A (en) | Method for refining molten steel | |
| JP2003013126A (en) | Method for dephosphorizing molten iron | |
| JPH09176717A (en) | Method for steelmaking molten iron of blast furnace | |
| JPH05140626A (en) | Method for pretreating molten iron | |
| KR970004986B1 (en) | Making method of sulphur steel and mg system desulfurization materials |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20050120 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20050128 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20050329 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20050415 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20050610 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20050722 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20050915 |
|
| A911 | Transfer of reconsideration by examiner before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20050921 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20051216 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20060220 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20060331 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20060407 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 3793390 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090414 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100414 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110414 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120414 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130414 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130414 Year of fee payment: 7 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130414 Year of fee payment: 7 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130414 Year of fee payment: 7 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130414 Year of fee payment: 7 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140414 Year of fee payment: 8 |
|
| LAPS | Cancellation because of no payment of annual fees |