JPH05255725A - Method for pre-treating molten iron - Google Patents
Method for pre-treating molten ironInfo
- Publication number
- JPH05255725A JPH05255725A JP7837192A JP7837192A JPH05255725A JP H05255725 A JPH05255725 A JP H05255725A JP 7837192 A JP7837192 A JP 7837192A JP 7837192 A JP7837192 A JP 7837192A JP H05255725 A JPH05255725 A JP H05255725A
- Authority
- JP
- Japan
- Prior art keywords
- hot metal
- slag
- flux
- desulfurization
- blown
- 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
Landscapes
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は溶銑の予備処理方法に係
り、特に脱珪、脱りん後にMg系フラックスを使用して
脱硫する脱硫効率の優れた溶銑の予備処理方法に関し、
製鉄、製鋼の分野で広く利用される。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot metal pretreatment method, and more particularly to a hot metal pretreatment method of desulfurization using Mg flux after desiliconization and dephosphorization, which has excellent desulfurization efficiency.
Widely used in the fields of steelmaking and steelmaking.
【0002】[0002]
【従来の技術】高炉から混銑車等の容器に収容された溶
銑中にランスを浸漬して、該ランスを介して不活性ガス
等でフラックスを溶銑中に吹込む脱珪、脱りん、脱硫等
の予備処理は広く実施されている。一般に、Mg系フラ
ックスは脱硫にすぐれた効果があることが認められてい
る。しかしながら、従来行われている脱硫と脱りんを同
時に進行させる方法では、脱りん反応を促進するために
はスラグ中の酸素ポテンシャルを高めておく必要がある
が、一方、Mgは酸素と激しい反応を生じるのでこの場
合はMgが使用できず、極低硫銑の製造は極めて困難で
あった。2. Description of the Related Art Degassing, dephosphorization, desulfurization, etc., in which a lance is immersed in hot metal contained in a container such as a hot metal car from a blast furnace, and a flux is blown into the hot metal through the lance with an inert gas or the like. The pretreatment of is widely practiced. It is generally accepted that Mg-based flux has an excellent effect on desulfurization. However, in the conventional method of simultaneously advancing desulfurization and dephosphorization, it is necessary to increase the oxygen potential in the slag in order to promote the dephosphorization reaction, while Mg reacts violently with oxygen. In this case, Mg cannot be used because it occurs, and it was extremely difficult to produce ultra-low sulfur content.
【0003】また、Mg系フラックスによる溶銑の脱硫
においては、生成したMgSが少量の溶鋼中の酸素ある
いはスラグ中のFeOと反応してMgSのMgが容易に酸
化してMgOを生成し復硫現象が発生する。更に溶銑中
の酸素あるいはスラグ中のFeOとフラックス中のMgが
反応して吹込んだ高価なMgが脱硫に有効に利用されな
いという問題があった。すなわち、Mg系フラックスは
脱硫にすぐれた効果が認められているものの、従来の脱
りんと脱硫を同時に進行させる方法では、原単位の上昇
による費用の高騰と、溶銑への復硫という2つの大きな
問題があった。Further, in the desulfurization of hot metal with Mg-based flux, the produced MgS reacts with a small amount of oxygen in the molten steel or FeO in the slag to easily oxidize Mg in MgS to produce MgO, and a re-sulfurization phenomenon. Occurs. Further, there is a problem in that oxygen in Fe or FeO in slag reacts with Mg in the flux and expensive Mg blown in is not effectively used for desulfurization. That is, although the Mg-based flux has been confirmed to have an excellent effect on desulfurization, the conventional method of simultaneously promoting dephosphorization and desulfurization has two major problems: a rise in cost due to an increase in the basic unit and a re-sulfurization to hot metal. was there.
【0004】[0004]
【発明が解決しようとする課題】本発明の目的は、上記
従来技術の課題を解決し、復硫を防止し、有効にMg系
フラックスを作用させる溶銑の予備処理方法を提供する
にある。SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a pretreatment method for hot metal which prevents vulcanization and effectively causes Mg-based flux to act.
【0005】[0005]
【課題を解決するための手段】本発明による請求項1の
要旨とするところは次の如くである。すなわち、混銑車
等の容器に収容された溶銑にフラックスを吹込んで脱
珪、脱りん、脱硫等を行う溶銑の予備処理方法におい
て、フラックスを吹込んで脱珪、脱りんを行いその後除
滓する段階と、前記除滓後金属Al粉もしくは金属Al粉
を含むフラックスを溶銑中に吹込んで溶銑を脱酸する段
階と、前記脱酸後Mgを含むフラックスを溶銑中に吹込
み溶銑中の酸素が6ppm以下の状態で脱硫処理する段階
と、を有して成ることを特徴とする溶銑の予備処理方
法、である。The subject matter of claim 1 according to the present invention is as follows. That is, in the hot metal pretreatment method of performing desiliconization, dephosphorization, desulfurization, etc. by injecting flux into the hot metal contained in a container such as a hot metal car, the step of degassing and dephosphorizing by injecting flux And a step of degassing the hot metal by blowing the metal Al powder after the slag removal or a flux containing the metal Al powder into the hot metal, and a flux containing Mg after the deoxidation is blown into the hot metal to obtain 6 ppm of oxygen in the hot metal. And a step of performing a desulfurization treatment in the following state.
【0006】請求項2の要旨とするところは、第1発明
と同様にフラックスを吹込んで脱珪、脱りんを行いその
後除滓する段階と、前記除滓後、金属Al粉もしくは金
属Al粉を含むフラックスおよびMgを含むフラックスを
同時に溶銑に吹込み溶銑の酸素が6ppm以下の状態で脱
硫処理する段階と、を有して成ることを特徴とする溶銑
の予備処理方法である。また、請求項3の要旨とすると
ころは次の如くである。すなわち、請求項1、2の発明
と同様にフラックスを吹込んで脱珪、脱りんを行いその
後除滓する段階と、前記除滓後Al滓と炭酸カルシウム
をスラグに添加して該スラグのT.Fe(全鉄)を3%以
下に改質する段階と、前記スラグの改質後Mgを含むフ
ラックスを溶銑に吹込み脱硫処理する段階と、を有して
成ることを特徴とする溶銑の予備処理方法である。According to the second aspect of the present invention, as in the first aspect of the present invention, a step of blowing flux to desiliconize and dephosphorize and then remove slag, and after the slag removal, metal Al powder or metal Al powder is removed. And a flux containing Mg and a flux containing Mg are simultaneously blown into the hot metal to carry out a desulfurization treatment in a state where the oxygen in the hot metal is 6 ppm or less, which is a pretreatment method for hot metal. The subject matter of claim 3 is as follows. That is, in the same manner as in the first and second aspects of the present invention, a step of blowing flux to desiliconize and dephosphorize and then remove the slag, and adding Al slag and calcium carbonate to the slag after the slag to remove the T. Preliminary hot metal preparation comprising the steps of reforming Fe (total iron) to 3% or less, and blowing the flux containing Mg after reforming the slag into the hot metal for desulfurization treatment. It is a processing method.
【0007】請求項1および2の発明は、脱珪、脱りん
と脱硫を分離し、脱珪、脱りん後にスラグを除滓し、そ
の後更にAl粉により溶銑の酸素ポテンシャルを限界ま
で低減後あるいは低減中にMg系フラックスを吹込み、
Mgを有効に脱硫作用に働かせるものである。次に本発
明において、脱硫のためMg系フラックスを吹込む時の
溶銑の酸素ポテンシャルを6ppm以下に限定した理由を
説明する。溶銑の脱珪、脱りんを行って除滓後に、溶銑
中の酸素およびMgの濃度を種々に変更した基礎実験を
行って、溶銑中の成分の平衡関係を調査した。1300
℃における溶銑中の酸素と平衡するMgを図1に、溶銑
中のMgと平衡するSを図2に示した。図1から酸素を
下げるとMgの溶解度が上昇することが分かる。図2か
らMgの上昇によりSの溶解度が低下することが分か
る。According to the first and second aspects of the present invention, desiliconization, dephosphorization and desulfurization are separated, slag is removed after desiliconization and dephosphorization, and then the oxygen potential of the hot metal is further reduced or reduced to the limit by Al powder. Inject Mg flux into the
It effectively uses Mg for the desulfurization action. Next, in the present invention, the reason why the oxygen potential of the hot metal when the Mg-based flux is blown for desulfurization is limited to 6 ppm or less will be described. After desiliconizing and dephosphorizing the hot metal and removing the slag, a basic experiment was conducted in which the concentrations of oxygen and Mg in the hot metal were variously changed, and the equilibrium relationship of the components in the hot metal was investigated. 1300
The Mg equilibrium with oxygen in the hot metal at ℃ is shown in FIG. 1, and the S equilibrium with Mg in the hot metal is shown in FIG. It can be seen from FIG. 1 that the solubility of Mg increases when oxygen is lowered. It can be seen from FIG. 2 that the solubility of S decreases with the increase of Mg.
【0008】これらの結果から溶銑中のSを10ppm以
下にするためには、Mgを40ppm以上とする必要があ
り、更にMgを40ppm以上とするためには酸素を6ppm
以下としなければならない。従って本発明においては、
S:10ppm以下を目標に脱硫するため、Mg吹込み時の
溶銑の酸素を6ppm以下に限定した。しかし、スラグ組
成、温度その他の操業のばらつきを考慮すれば3ppm以
下が安定した結果を得るため好ましい。次に、脱硫後の
溶銑中のSを10ppm以下を目標とした場合の溶銑中の
酸素とMg原単位の関係を図3に示した。図2から酸素
濃度の減少にともなってMg原単位は減少する。酸素濃
度を1ppm低下させるとMg原単位は約5%低減できる。From these results, in order to reduce S in the hot metal to 10 ppm or less, it is necessary to set Mg to 40 ppm or more, and in order to set Mg to 40 ppm or more, oxygen is 6 ppm.
Must be: Therefore, in the present invention,
S: To desulfurize with a target of 10 ppm or less, the oxygen content of the hot metal during Mg injection was limited to 6 ppm or less. However, considering variations in slag composition, temperature and other operations, 3 ppm or less is preferable because a stable result can be obtained. Next, FIG. 3 shows the relationship between oxygen in the hot metal and the Mg basic unit when S in the hot metal after desulfurization is set to 10 ppm or less. From FIG. 2, the Mg unit consumption decreases as the oxygen concentration decreases. If the oxygen concentration is lowered by 1 ppm, the Mg basic unit can be reduced by about 5%.
【0009】請求項2の発明においては、Al粉とMgと
を同時に吹込み、Mgの一部がAl2O3の還元反応に消費
されるのでMgの原単位が多少上昇する。高価なMgの使
用量をできるだけ少なくするには、Al系フラックスに
よる脱酸を十分に行い、かつ生成されたAl2O3を浮上
分離した後、Mg系フラックスを吹込むことが肝要であ
る。請求項3の発明はMg系フラックスの吹込み前に除
滓し、Al滓と炭酸カルシウムを添加し十分撹拌するこ
とにより、スラグ中のFeOとAl系フラックスが結合し
て、スラグ中のFeOを低下させスラグを改質し、しか
る後Mgを含むフラックスを溶銑に吹込んで脱硫処理す
る方法であって、Mgの酸化損失の低減を意図したもの
である。In the second aspect of the present invention, Al powder and Mg are blown in at the same time, and a part of Mg is consumed in the reduction reaction of Al 2 O 3 , so that the basic unit of Mg slightly increases. In order to reduce the amount of expensive Mg used as much as possible, it is important to sufficiently perform deoxidation with an Al-based flux, and to float the separated Al 2 O 3 produced, and then blow in the Mg-based flux. The invention of claim 3 removes the Mg-based flux before blowing it, adds Al slag and calcium carbonate, and sufficiently stirs the FeO in the slag and the Al-based flux to combine to form FeO in the slag. It is a method of lowering the slag to modify the slag, and then blowing a flux containing Mg into the hot metal for desulfurization treatment, which is intended to reduce the oxidation loss of Mg.
【0010】次に本発明において、除滓後Al滓と炭酸
カルシウムを添加した際、スラグののT.Fe(全鉄)を
3%以下に限定した理由を説明する。すなわち、除滓後
Al滓と炭酸カルシウムをスラグに添加させて、スラグ
中のT.Fe量およびスラグの塩基度を種々に変更し、そ
れぞれの場合について、その後、Mg系フラックスを添
加して脱硫処理を行う基礎実験を行った。スラグ中の
T.Feとマグネシウム原単位の関係を図4に、スラグ塩
基度と復りん量との関係を図5に示した。図4から明ら
かな如く、スラグ中のT.Feが4%近傍からMg原単位
が上昇するので、本発明においては、スラグ中のT.Fe
を3%以下に限定した。Next, in the present invention, the reason why the T.Fe (total iron) of the slag is limited to 3% or less when Al slag and calcium carbonate are added after the slag is explained. That is, after slag removal, Al slag and calcium carbonate were added to the slag to change the amount of T.Fe in the slag and the basicity of the slag variously, and in each case, a Mg-based flux was then added for desulfurization. A basic experiment to perform the treatment was performed. The relationship between T.Fe in the slag and the basic unit of magnesium is shown in FIG. 4, and the relationship between the slag basicity and the amount of reconstituted phosphorus is shown in FIG. As is clear from FIG. 4, the T.Fe in the slag increases from around 4% in the Mg basic unit. Therefore, in the present invention, the T.Fe in the slag is increased.
Was limited to 3% or less.
【0011】次に図5において、縦軸の復りん量は、ス
ラグ改質後の溶銑中のP量からスラグ改質前の溶銑中の
P量を差引いた数字である。図5から明らかな如く、ス
ラグ中の塩基度が3.0未満では、復りん量が増加する
ので、この結果から復りんを防止するためには、スラグ
の塩基度は3.0以上を必要とすることが判明できた。
次に請求項3の発明において除滓後スラグにAl滓と炭
酸カルシウムを添加し、しかも炭酸カルシウム量をAl
滓量の20〜50%の範囲に限定した理由について説明
する。この処理は、Mg添加による脱硫効果をできるだ
け効果的に行うためにスラグ中のT.Feを低減して改質
するためであり、その脱酸剤として価格的に有利なAl
滓を利用するもので、その主要組成は表1に示すとおり
である。Next, in FIG. 5, the reconstitution amount on the vertical axis is a number obtained by subtracting the P amount in the hot metal before slag reforming from the P amount in the hot metal after slag reforming. As is clear from FIG. 5, when the basicity in the slag is less than 3.0, the amount of recondensation increases, so from this result, the basicity of the slag must be 3.0 or more in order to prevent reconstitution. I was able to find out.
Next, in the invention of claim 3, after the slag is removed, Al slag and calcium carbonate are added, and the calcium carbonate content is Al
The reason for limiting the amount of slag to the range of 20 to 50% will be described. This treatment is for reducing T.Fe in the slag and modifying it in order to perform the desulfurization effect by adding Mg as effectively as possible.
The slag is used and its main composition is as shown in Table 1.
【表1】 しかしてAl滓による還元作用を促進し、かつ生成され
るAl2O3を浮上分離するために、溶銑の撹拌と同時に
ガス発生物質であるCaCO3を添加することにより、発
生CO2による溶銑の撹拌と生成Al2O3の浮上分離を図
ったものである。[Table 1] Thus promoting reduction action by Al slag and the Al 2 O 3 which is generated to flotation, by adding CaCO 3 is a gas generating material simultaneously with stirring molten iron, by generating CO 2 in the hot metal It is intended to separate the Al 2 O 3 by stirring and floating.
【0012】しかして、この場合のCaCO3の添加量を
添加Al滓量の20〜50%に限定した理由は次の如く
である。すなわち、本発明者らはRH処理による高清浄
度鋼製造時の転炉スラグ改質と同様に、生成Al2O3の
吸収能の高いスラグ組成とするため、CaO/Al2O3の
比が1.6〜1.8の範囲になることを目標とし、かつC
aCO3の分解によって発生するCO2ガスによる溶銑の
撹拌効果を考慮し、添加Al滓量の20%より少くなる
と十分な撹拌効果が得られず、また50%を超えるとガ
ス発生が過剰となり、かえってAl2O3の浮上分離を阻
害するので20〜50%の範囲に限定した。The reason why the amount of CaCO 3 added in this case is limited to 20 to 50% of the amount of added Al slag is as follows. That is, the present inventors, like the converter slag reforming at the time of producing high cleanliness steel by RH treatment, have a CaO / Al 2 O 3 ratio of CaO / Al 2 O 3 in order to obtain a slag composition having a high absorption capacity for the produced Al 2 O 3. Is in the range of 1.6 to 1.8, and C
Considering the stirring effect of the hot metal by the CO 2 gas generated by the decomposition of aCO 3, if the amount of added Al is less than 20%, a sufficient stirring effect cannot be obtained, and if it exceeds 50%, the gas generation becomes excessive, On the contrary, since it hinders the floating separation of Al 2 O 3 , it was limited to the range of 20 to 50%.
【0013】[0013]
【実施例1】混銑車に200tの溶銑を受入れ、請求項
1の方法により28Kg/tの酸化鉄を溶銑に吹込み、20
分間脱珪、脱りんを行い、スラグを除去した。次に0.
1Kg/tの金属Al粉を吹込んで3分間精錬をして酸素の
含有量を2ppm以下に脱酸し、続いて0.5Kg/tのMgを
含むフラックスを吹込んで5分間脱硫を行った。脱硫中
は溶銑の酸素含有量は2ppm以下であり、その結果溶銑
中のSを10ppm以下に脱硫することができた。本実施
例は溶銑を2ppm以下の酸素まで脱酸してMg系フラック
スを吹込んだので、少量のMgを有効に使用して低いMg
原単位でSを10ppm以下まで脱硫することができた。Example 1 200 tons of hot metal was received in a hot metal wheel, and 28 kg / t of iron oxide was blown into the hot metal according to the method of claim 1 to obtain 20
Slag was removed by performing desiliconization and phosphorus removal for a minute. Then 0.
1 kg / t metal Al powder was blown and refined for 3 minutes to deoxidize the oxygen content to 2 ppm or less, and then a flux containing 0.5 kg / t Mg was blown for desulfurization for 5 minutes. During desulfurization, the oxygen content of the hot metal was 2 ppm or less, and as a result, S in the hot metal could be desulfurized to 10 ppm or less. In this embodiment, since the hot metal was deoxidized to oxygen of 2 ppm or less and the Mg-based flux was blown, a small amount of Mg was effectively used to obtain a low Mg.
It was possible to desulfurize S to 10 ppm or less per unit.
【0014】[0014]
【実施例2】混銑車に200tの溶銑を受入れ、請求項
3の方法により28Kg/tの酸化鉄を吹込み20分間脱
珪、脱硫を行いスラグを除去した。次に0.5Kg/tのAl
滓と0.2Kg/tの炭酸カルシウムをスラグに添加してス
ラグ中のT.Feを2%に改質してスラグ塩基度を3.5
にした後、0.5Kg/tのMg系フラックスを溶銑に吹込ん
で5分間脱硫処理を行った。その結果処理前の溶銑のS
含有量200ppmを20ppmまで脱硫することができた。
なお、脱硫処理前後の溶銑中の復りんは認められなかっ
た。本実施例は除滓後、スラグ中のT.Feを3%以下の
2%に改質し、同時にスラグ塩基度を3.0以上の3.5
にした後、Mg系フラックスを吹込んだので、少量のMg
を有効に使用して復りんすることなく低いMg原単位で
脱硫することができた。Example 2 200 tons of hot metal was received in a hot metal wheel, and 28 kg / t of iron oxide was blown by the method of claim 3 for 20 minutes for desiliconization and desulfurization to remove slag. Then 0.5 Kg / t Al
Slag and 0.2Kg / t calcium carbonate are added to the slag to modify the T.Fe in the slag to 2% and the slag basicity to 3.5.
After that, 0.5 kg / t of Mg-based flux was blown into the hot metal to perform desulfurization treatment for 5 minutes. As a result, S of hot metal before processing
It was possible to desulfurize the content of 200 ppm to 20 ppm.
No recondensing phosphorus was found in the hot metal before and after the desulfurization treatment. In this example, after the slag was removed, T.Fe in the slag was modified to 3% or less and 2%, and at the same time, the slag basicity was 3.0 or more and 3.5.
Then, since a Mg-based flux was blown in, a small amount of Mg
Was used effectively and it was possible to desulfurize with low Mg unit consumption without re-phosphorization.
【0015】[0015]
【発明の効果】本発明は上記実施例からも明らかな如
く、脱珪、脱りん後にスラグを除去し、Alで脱酸後に
Mg系フラックスを吹込むか、もしくはAlとMgを含む
フラックスを同時に吹込んで、溶銑中の酸素が6ppm以
下の状態で脱硫するか、または脱珪、脱りん後にスラグ
を除去後、Al滓と炭酸カルシウムを添加してスラグの
T.Feを3%以下に改質し、併せてスラグの塩基度を
3.0以上とした後Mg系フラックスを吹込んで脱硫する
ことによって、Mgの酸化ロスを減少させ、Mg系フラッ
クスの原単位を低減して復りんを防止しながら有効に脱
硫することができた。As is apparent from the above-mentioned embodiment, the present invention removes slag after desiliconization and dephosphorization and blows a Mg-based flux after deoxidizing with Al, or a flux containing Al and Mg at the same time. Blow-in to desulfurize the oxygen in the hot metal to 6ppm or less, or remove slag after desiliconization and dephosphorization, and then add Al slag and calcium carbonate to improve T.Fe of slag to 3% or less. At the same time, the basicity of the slag is adjusted to 3.0 or more, and then Mg-based flux is blown to desulfurize to reduce the oxidation loss of Mg and reduce the basic unit of Mg-based flux to prevent re-phosphorus. However, it was able to effectively desulfurize.
【図1】本発明を得る基礎実験の脱硫段階における溶銑
中の酸素と平衡するMgを示す平衡図である。FIG. 1 is an equilibrium diagram showing Mg equilibrated with oxygen in hot metal in a desulfurization step of a basic experiment for obtaining the present invention.
【図2】本発明を得る基礎実験の脱硫段階における溶銑
中のMgと平衡するSを示す平衡図である。FIG. 2 is an equilibrium diagram showing S in equilibrium with Mg in hot metal in the desulfurization step of the basic experiment for obtaining the present invention.
【図3】脱硫の目標を溶銑中のS含有量10ppm以下と
した時の脱硫段階における溶銑中の酸素とMg原単位の
関係を示す相関図である。FIG. 3 is a correlation diagram showing the relationship between oxygen in the hot metal and Mg basic unit in the desulfurization stage when the desulfurization target is an S content of 10 ppm or less in the hot metal.
【図4】本発明を得る基礎実験の脱硫段階におけるスラ
グ中のT.FeとMg原単位との関係を示す相関図であ
る。FIG. 4 is a correlation diagram showing the relationship between T.Fe in the slag and the Mg basic unit in the desulfurization step of the basic experiment for obtaining the present invention.
【図5】本発明を得る基礎実験の脱硫段階におけるスラ
グ塩基度と復りん量との関係を示す相関図である。FIG. 5 is a correlation diagram showing the relationship between the slag basicity and the amount of reconstituted phosphorus in the desulfurization stage of the basic experiment for obtaining the present invention.
─────────────────────────────────────────────────────
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【手続補正書】[Procedure amendment]
【提出日】平成5年3月31日[Submission date] March 31, 1993
【手続補正1】[Procedure Amendment 1]
【補正対象書類名】図面[Document name to be corrected] Drawing
【補正対象項目名】全図[Correction target item name] All drawings
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【図1】 [Figure 1]
【図2】 [Fig. 2]
【図3】 [Figure 3]
【図4】 [Figure 4]
【図5】 [Figure 5]
フロントページの続き (72)発明者 黒瀬 芳和 岡山県倉敷市水島川崎通一丁目(番地な し) 川崎製鉄株式会社水島製鉄所内クロ セヨシカス゛Front page continued (72) Inventor Yoshikazu Kurose 1-chome, Kawashima-dori, Mizushima Kurashiki-shi, Okayama (No house number) Kawasaki Steel Co., Ltd.
Claims (5)
ックスを吹込んで脱珪、脱りん、脱硫等を行う溶銑の予
備処理方法において、フラックスを吹込んで脱珪、脱り
んを行いその後除滓する段階と、前記除滓後金属Al粉
もしくは金属Al粉を含むフラックスを溶銑中に吹込ん
で溶銑を脱酸する段階と、前記脱酸後Mgを含むフラッ
クスを溶銑中に吹込み溶銑中の酸素が6ppm以下の状態
で脱硫処理する段階と、を有して成ることを特徴とする
溶銑の予備処理方法。1. A method for pretreatment of hot metal in which flux is blown into hot metal contained in a container such as a hot metal car to perform desiliconization, dephosphorization, desulfurization, etc. A slag, a step in which the metal Al powder after the slag removal or a flux containing the metal Al powder is blown into the hot metal to deoxidize the hot metal, and a flux containing Mg after the deoxidation is blown into the hot metal in the hot metal And a step of performing a desulfurization treatment in a state where oxygen is 6 ppm or less, a method for pretreatment of hot metal.
ックスを吹込んで脱珪、脱りん、脱硫等を行う溶銑の予
備処理方法において、フラックスを吹込んで脱珪、脱り
んを行いその後除滓する段階と、前記除滓後金属Al粉
もしくは金属Al粉を含むフラックスおよびMgを含むフ
ラックスを同時に溶銑に吹込み溶銑中の酸素が6ppm以
下の状態で脱硫処理する段階と、を有して成ることを特
徴とする溶銑の予備処理方法。2. In a hot metal pretreatment method in which flux is blown into hot metal contained in a container such as a hot metal car to perform desiliconization, dephosphorization, desulfurization, etc., the flux is blown to desiliconize and dephosphorize and then remove. And a step of performing a desulfurization treatment in which the metal Al powder or the flux containing the metal Al powder and the flux containing Mg are blown into the hot metal at the same time and the oxygen in the hot metal is 6 ppm or less. A pretreatment method for hot metal, characterized in that
ックスを吹込んで脱珪、脱りん、脱硫等を行う溶銑の予
備処理方法において、フラックスを吹込んで脱珪、脱り
んを行いその後除滓する段階と、前記除滓後Al滓と炭
酸カルシウムをスラグに添加して該スラグ中のT.Fe
(全鉄)を3%以下に改質する段階と、前記スラグの改
質後Mgを含むフラックスを溶銑に吹込み脱硫処理する
段階と、を有して成ることを特徴とする溶銑の予備処理
方法。3. In a hot metal pretreatment method in which flux is blown into hot metal contained in a container such as a hot metal car to perform desiliconization, dephosphorization, desulfurization, etc., a flux is blown to desiliconize and dephosphorize and then remove. The step of slagging, and adding Al slag and calcium carbonate to the slag after removing the slag to remove the T.Fe in the slag.
A pretreatment of hot metal, which comprises a step of reforming (total iron) to 3% or less, and a step of blowing a flux containing Mg after reforming the slag into the hot metal for desulfurization treatment. Method.
加量の20〜50重量%の範囲である請求項3記載の溶
銑の予備処理方法。4. The method for pretreatment of hot metal according to claim 3, wherein the amount of calcium carbonate added is in the range of 20 to 50% by weight of the amount of Al slag added.
後のスラグ塩基度は3.0以上である請求項3もしくは
4記載の溶銑の予備処理方法。5. The hot metal pretreatment method according to claim 3, wherein the slag basicity after the reforming in which the flux containing Mg is blown is 3.0 or more.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP35088891 | 1991-12-11 | ||
JP3-350888 | 1991-12-11 |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH05255725A true JPH05255725A (en) | 1993-10-05 |
Family
ID=18413580
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP7837192A Pending JPH05255725A (en) | 1991-12-11 | 1992-02-28 | Method for pre-treating molten iron |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH05255725A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015028191A (en) * | 2013-07-30 | 2015-02-12 | Jfeスチール株式会社 | Desulfurization method for molten iron |
-
1992
- 1992-02-28 JP JP7837192A patent/JPH05255725A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015028191A (en) * | 2013-07-30 | 2015-02-12 | Jfeスチール株式会社 | Desulfurization method for molten iron |
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