JP2005336586A - Dephosphorizing treatment method for molten iron - Google Patents

Dephosphorizing treatment method for molten iron Download PDF

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JP2005336586A
JP2005336586A JP2004160409A JP2004160409A JP2005336586A JP 2005336586 A JP2005336586 A JP 2005336586A JP 2004160409 A JP2004160409 A JP 2004160409A JP 2004160409 A JP2004160409 A JP 2004160409A JP 2005336586 A JP2005336586 A JP 2005336586A
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hot metal
dephosphorization
medium solvent
oxygen source
dephosphorizing
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JP5031977B2 (en
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Yoshiteru Kikuchi
良輝 菊地
Eiju Matsuno
英寿 松野
Ikuhiro Sumi
郁宏 鷲見
Akitoshi Matsui
章敏 松井
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JFE Steel Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To effectively dephosphorize molten iron in spite of the use of a little quantity of flux for dephosphorizing by quickly slagging added flux for dephosphorizing, in the dephosphorizing treatment for molten iron. <P>SOLUTION: In the dephosphorizing treatment method for molten iron, in the case of applying the dephosphorizing treatment to the molten iron by supplying oxygen source, the molten iron 14 having ≤0.2 mass% silicon content is used and the heated or heated/melted powdery flux 16 for dephosphorizing mainly containing CaO is adding by blowing together with the oxygen source through a top-blown lance 3 toward bath surface of the molten iron to perform the dephosphorizing treatment. In this case, fuel is blown from the top part of the top-blown lance and this fuel is burnt, and the flux for dephosphorizing can be heated with generated flame. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、溶銑中の燐を除去する脱燐処理方法に関するものである。   The present invention relates to a dephosphorization method for removing phosphorus in hot metal.

高炉で製造された溶銑から鋼材を製造するには、製鋼精錬過程において、溶銑に含まれる不純物元素を所定値まで低減したうえで、その鋼材に要求される組成範囲に調整することが必要である。この不純物元素としては、４質量％以上含まれる炭素の他に、燐、硫黄などがあり、一方、鋼材の必要とする元素としては、強度及び靭性を高めるマンガン、珪素などがある。   In order to produce steel from hot metal produced in a blast furnace, it is necessary to reduce the impurity elements contained in the hot metal to a predetermined value in the steelmaking refining process, and then adjust the composition range required for the steel. . Examples of the impurity element include phosphorus and sulfur in addition to carbon contained in an amount of 4% by mass or more. On the other hand, examples of the element required for the steel material include manganese and silicon that increase strength and toughness.

転炉を用い、溶銑中の炭素と燐とを同時に酸化除去していた従来の製鋼精錬方法に対し、近年、溶銑段階で予め脱燐処理（「予備脱燐処理」ともいう）を実施し、溶銑中の燐を或る程度除去した後、この溶銑を転炉に装入して転炉で脱炭精錬を実施する製鋼方法が発展してきた。この場合、溶銑の脱燐処理は、トーピードカー、溶銑鍋、転炉などの設備を用い、ＣａＯ系の脱燐用媒溶剤と酸素ガス及び固体の酸化鉄などの酸素源とを溶銑に添加して、溶銑中の燐を酸素源によって酸化し、生成した燐酸化物をＣａＯ系の脱燐用媒溶剤などからなるスラグ中に取り込み、溶銑中の燐を除去するという方法で行われている。   In contrast to the conventional steelmaking refining method in which carbon and phosphorus in the hot metal are simultaneously oxidized and removed using a converter, in recent years, a dephosphorization process (also referred to as “preliminary dephosphorization process”) is performed in advance in the hot metal stage. A steelmaking method has been developed in which after removing a certain amount of phosphorus in the hot metal, the hot metal is charged into a converter and decarburized and refined in the converter. In this case, the hot metal dephosphorization treatment uses equipment such as a torpedo car, hot metal pan, and converter, and adds a CaO-based dephosphorization medium solvent and an oxygen source such as oxygen gas and solid iron oxide to the hot metal. In this method, phosphorus in the hot metal is oxidized by an oxygen source, and the generated phosphorus oxide is taken into a slag made of a CaO-based dephosphorization medium solvent and the phosphorus in the hot metal is removed.

この脱燐処理の際、少ない脱燐用媒溶剤で溶銑中の燐を溶銑側からスラグ側に効率的に移行させるためには、適正な組成のスラグを迅速に形成させることが極めて重要であり、従来、スラグを迅速に形成させるための種々の方法が提案されている。   In this dephosphorization treatment, in order to efficiently transfer the phosphorus in the hot metal from the hot metal side to the slag side with a small amount of dephosphorization medium solvent, it is extremely important to quickly form a slag having an appropriate composition. Conventionally, various methods for rapidly forming slag have been proposed.

例えば、特許文献１には、脱燐用媒溶剤として添加するＣａＯの質量と添加する酸素源中の酸素の質量との質量比（ＣａＯ／Ｏ）を１．０〜２．５の範囲に規定するのみならず、脱燐用媒溶剤中のＣａＦ2 及びＡｌ2 Ｏ3 の総質量とＣａＯの質量との質量比（（ＣａＦ2 +Ａｌ2 Ｏ3 ）／ＣａＯ）を０．１〜１．０の範囲とし、更に、脱燐用媒溶剤中のＡｌ2 Ｏ3 の質量とＣａＦ2 の質量との質量比（Ａｌ2 Ｏ3 ／ＣａＦ2 ）を０．０５〜２０．０の範囲に規定した脱燐用媒溶剤を用いて脱燐処理する方法が提案されている。特許文献２には、生石灰の滓化を促進させるために、転炉型反応容器に収容された溶銑に対して上吹きランスから生石灰粉を酸素ガスと共に吹き付けると同時に、炉底或いは側壁から溶銑中に攪拌用ガスを吹き込んで脱燐処理する方法が提案されている。また、特許文献３には、脱燐用媒溶剤の滓化を促進させるために、ＣａＯを主体とし、酸化鉄及びＳｉＯ2 を含有するプリメルトフラックスを生石灰に加えて脱燐用媒溶剤として使用した脱燐処理方法が提案されている。
特開昭６３−５７７１２号公報 特開平８−３１１５２３号公報 特開２０００−８７１２５号公報 For example, in Patent Document 1, the mass ratio (CaO / O) of the mass of CaO added as a dephosphorization medium solvent to the mass of oxygen in the oxygen source to be added is specified in the range of 1.0 to 2.5. In addition, the mass ratio ((CaF 2 + Al 2 O 3 ) / CaO) of the total mass of CaF 2 and Al 2 O 3 and the mass of CaO in the dephosphorization medium solvent is 0.1 to 1. Further, the mass ratio (Al 2 O 3 / CaF 2 ) between the mass of Al 2 O 3 and the mass of CaF 2 in the dephosphorization medium solvent is specified in the range of 0.05 to 20.0. A method of dephosphorizing using a dephosphorizing medium solvent has been proposed. In Patent Document 2, in order to promote hatching of quicklime, quicklime powder is sprayed together with oxygen gas from an upper blowing lance against hot metal accommodated in a converter type reaction vessel, and at the same time, hot metal is being heated from the furnace bottom or side wall. There has been proposed a method of dephosphorizing by blowing a stirring gas. Further, in Patent Document 3, in order to promote hatching of a dephosphorization medium solvent, a premelt flux containing CaO as a main component and containing iron oxide and SiO 2 is added to quicklime and used as a dephosphorization medium solvent. A dephosphorization method has been proposed.
JP 63-57712 A Japanese Patent Laid-Open No. 8-311523 JP 2000-87125 A

このように、従来、脱燐用媒溶剤の滓化を促進させるための種々の方法が提案されてきたが、何れの方法もその効果は十分ではなく、やむなく、大量の脱燐用媒溶剤を使用したり、処理時間を延長したりして対処しており、製造コストの上昇をもたらしていた。   As described above, various methods for accelerating the hatching of the dephosphorization medium solvent have been proposed in the past. However, none of these methods is sufficiently effective. It has been dealt with by using it or extending the processing time, resulting in an increase in manufacturing cost.

本発明は上記事情に鑑みてなされたもので、その目的とするところは、溶銑の脱燐処理において、添加した脱燐用媒溶剤を迅速に滓化することにより、少ない脱燐用媒溶剤の使用量でも効率的に脱燐することのできる脱燐処理方法を提供することである。   The present invention has been made in view of the above circumstances, and the object of the present invention is to reduce the amount of dephosphorization medium solvent by rapidly hatching the added dephosphorization medium solvent in the dephosphorization treatment of hot metal. It is an object of the present invention to provide a dephosphorization method that can efficiently dephosphorize even the amount used.

本発明者等は、上記課題を解決すべく、鋭意検討・研究を行なった。以下に、検討・研究結果を説明する。   The present inventors have intensively studied and studied to solve the above problems. The results of the examination and research are explained below.

ＣａＯを主体とする脱燐用媒溶剤を用いた溶銑の脱燐処理における脱燐反応は、ＣａＯを主体とする脱燐用媒溶剤が、溶銑の顕熱によって昇温されると同時に、この脱燐用媒溶剤を低融点化して溶解させる酸化物と混合され、溶融スラグが形成されることによって進行する。形成される溶融スラグの量及び溶融スラグの形成されるまでの時間は、主に、溶銑の温度、及び、添加された脱燐用媒溶剤の近傍で生成される珪酸及び酸化鉄などの低融点化を促進させる酸化物の生成量に依存する。しかし、特許文献２のように、粉状の生石灰を酸素ガスと共に吹き付けて添加し、酸素ガスによって酸化して生成される珪酸及び酸化鉄の生成箇所に集中させて生石灰粉を添加しても溶融スラグの形成は十分ではないことから、珪酸及び酸化鉄の溶融物と粉状の生石灰とを攪拌場で接触させただけでは、生石灰はそれほど短時間には溶解しないことが分かる。   The dephosphorization reaction in the dephosphorization treatment of the hot metal using the dephosphorization medium solvent mainly composed of CaO is performed at the same time as the temperature of the dephosphorization medium solvent mainly composed of CaO is raised by the sensible heat of the hot metal. It proceeds by forming a molten slag by mixing the phosphorus solvent with an oxide that lowers the melting point and dissolves it. The amount of molten slag to be formed and the time until the molten slag is formed mainly consist of the melting point of the hot metal and low melting points such as silicic acid and iron oxide produced in the vicinity of the added dephosphorization medium solvent. Depends on the amount of oxides that promote crystallization. However, as in Patent Document 2, powdered quick lime is sprayed and added together with oxygen gas, and melted even if quick lime powder is added by concentrating on the production site of silicic acid and iron oxide generated by oxidation with oxygen gas. Since the formation of slag is not sufficient, it can be understood that quick lime does not dissolve in such a short time by simply bringing a melt of silicic acid and iron oxide into contact with powdered quick lime in a stirring field.

そこで、溶融スラグの迅速な形成を得るべく種々検討した結果、適正なスラグ組成へと迅速に調製するためには、脱燐用媒溶剤自体の分散を更に高めるか、または、脱燐用媒溶剤を低融点化させる物質（「滓化促進剤」と呼ぶ）或いは反応を促進させる物質を脱燐用媒溶剤に事前に混合するか、若しくは、予め加熱した脱燐用媒溶剤または予め溶融した脱燐用媒溶剤を使用することが効果的であるとの知見が得られた。脱燐用媒溶剤の全部或いは一部をこれらのような状態にすることにより、溶銑との接触と同時に脱燐反応が進行したり、接触した時点から脱燐反応開始までの時間を短縮させることが期待できる。   Therefore, as a result of various studies to obtain a rapid formation of molten slag, in order to quickly prepare an appropriate slag composition, the dispersion of the dephosphorization medium solvent itself is further increased, or the dephosphorization medium solvent A substance that lowers the melting point (referred to as “a hatching accelerator”) or a substance that promotes the reaction is mixed in advance with a dephosphorization medium solvent, or a preheated dephosphorization medium solvent or a premelted degassing medium. The knowledge that it is effective to use a phosphorus medium solvent was obtained. By making all or part of the dephosphorization medium solvent into such a state, the dephosphorization reaction proceeds simultaneously with the contact with the hot metal, or the time from the contact point to the start of the dephosphorization reaction is shortened. Can be expected.

そのなかで、溶銑の脱燐反応を特に効率的に促進させるには、予め加熱したり予め溶融させた脱燐用媒溶剤を添加することが最も効果的であるとの結論に至った。この結論に基づき、予め加熱する或いは予め溶融させるための種々の方法について検討した。その結果、粉状のＣａＯを主体とする脱燐用媒溶剤を、バーナーによる燃焼火炎中を通過させて加熱或いは加熱・溶融すると共に、この脱燐用媒溶剤を酸素ガスと共に溶銑浴面に吹き付けて添加することで、スラグ化した脱燐用媒溶剤と溶銑との混合・接触の観点から見た場合、最適な条件になることが分かった。即ち、反応の促進に適正なスラグ組成へと迅速に調製することを、脱燐用媒溶剤の添加と同時に達成し、その結果、脱燐反応を促進させることができるとの知見が得られた。尚、ＣａＯを主体とする脱燐用媒溶剤とは、ＣａＯを含有し、本件の意図する脱燐処理ができるものであれば特にＣａＯの含有量に制約はないが、通常は、ＣａＯ単味またはＣａＯを５０質量％以上含有し、必要に応じてその他の成分としてＡｌ2 Ｏ3 、ＣａＦ2 などの滓化促進剤を含有するものである。 Among them, it was concluded that the addition of a pre-heated or pre-melted dephosphorization medium solvent is the most effective in promoting the dephosphorization reaction of the hot metal particularly efficiently. Based on this conclusion, various methods for preheating or premelting were examined. As a result, the dephosphorization medium solvent mainly composed of powdered CaO is heated or heated / melted by passing it through the combustion flame by the burner, and this dephosphorization medium solvent is sprayed onto the hot metal bath surface together with oxygen gas. From the viewpoint of mixing and contacting the sludge dephosphorization medium solvent and hot metal, it was found that the optimum conditions were obtained. That is, it was found that the rapid preparation of a slag composition suitable for promoting the reaction was achieved simultaneously with the addition of the dephosphorization medium solvent, and as a result, the dephosphorization reaction could be promoted. . The dephosphorization medium solvent mainly composed of CaO is not particularly limited as long as it contains CaO and can be subjected to the intended dephosphorization treatment. or containing CaO 50 wt%, those containing a slag formation accelerator such as Al 2 O 3, CaF 2 as other components, if necessary.

加熱・溶融化の手段として、ＣａＯを主体とする脱燐用媒溶剤に予め滓化促進剤などを混合し、この脱燐用媒溶剤をスラグ溶解炉などで昇温し溶融することも可能ではあるが、この場合には、設備が大掛かりになり、また、昇温・溶融した脱燐用媒溶剤を単に溶銑上に添加しても、溶銑との混合は充分ではなく、添加と同時に反応が促進されることを達成するのは困難である。しかし、この問題は、脱燐用媒溶剤の添加をバーナー方式のランスで行い、このランスからの噴出過程で、バーナーによって形成される燃焼火炎中を通過させ、昇温し溶融することで解決される。   As a means of heating / melting, it is not possible to mix a hatching accelerator in advance with a dephosphorization medium solvent mainly composed of CaO, and heat the dephosphorization medium solvent in a slag melting furnace to melt it. However, in this case, the facilities become large, and even if the dephosphorization medium solvent that has been heated and melted is simply added onto the hot metal, mixing with the hot metal is not sufficient, and the reaction occurs simultaneously with the addition. It is difficult to achieve what is promoted. However, this problem is solved by adding a dephosphorizing medium solvent with a burner-type lance, passing through the combustion flame formed by the burner in the process of jetting from this lance, raising the temperature and melting. The

更に、バーナー方式のランスで燃焼させた燃焼ガスを有効に活用することも可能であることが分かった。バーナー方式のランスにおいては、粉体の脱燐用媒溶剤をバーナーの火炎中を通過させ、火炎で生成した熱を粉体の昇温或いは溶融に利用するものであり、火炎形成時の発生熱量の一部が脱燐用媒溶剤の加熱に利用される。しかし、その熱の利用効率は数１０％以下であり、未利用の熱は燃焼ガスの顕熱になる。この燃焼ガスの顕熱を有効利用することを検討した結果、燃焼ガスを酸素ガスのジェットと共に溶銑に吹き付けることが有効であることが分かった。   Furthermore, it has been found that the combustion gas burned by the burner type lance can be used effectively. In the burner type lance, the dephosphorizing medium solvent of the powder is passed through the flame of the burner, and the heat generated by the flame is used for the temperature rise or melting of the powder. Part of this is used for heating the dephosphorization medium solvent. However, the utilization efficiency of the heat is several tens of percent or less, and the unused heat becomes sensible heat of the combustion gas. As a result of examining effective utilization of the sensible heat of the combustion gas, it was found that it is effective to blow the combustion gas together with the oxygen gas jet onto the hot metal.

燃焼ガスは、二酸化炭素及び水蒸気を主体としている。この燃焼ガスが溶銑浴面に吹き付けられると、二酸化炭素中の酸素及び水蒸気中の酸素により溶銑の酸化反応が起こる。この場合、高温の燃焼ガスから溶銑への伝熱が起こるものの、二酸化炭素中の酸素及び水蒸気中の酸素による酸化反応はトータルでは吸熱反応であるため、燃焼ガスを溶銑浴面に吹き付けることで、反応界面を脱燐反応に有利な高酸素ポテンシャルに維持しつつ、同時に、反応界面を脱燐反応に有利な低温に維持する効果が発揮される。脱燐反応は、溶銑温度が低いほど促進されることから、燃焼ガスを酸素ガスのジェットと共に溶銑に吹き付けることで、酸素ガスと燃焼ガスとが溶銑浴面に衝突し、反応界面における酸素ポテンシャルを高く維持すると同時に、燃焼ガスが反応界面の温度を低くするように作用し、脱燐反応を効率的に行うことができる。即ち、燃焼ガスを冷却剤として酸素ガスと共に積極的に溶銑浴面に吹き付けることが好ましいとの知見が得られた。   The combustion gas is mainly composed of carbon dioxide and water vapor. When this combustion gas is sprayed onto the hot metal bath surface, the hot metal oxidation reaction occurs due to oxygen in carbon dioxide and oxygen in water vapor. In this case, although heat transfer from hot combustion gas to hot metal occurs, the oxidation reaction by oxygen in carbon dioxide and oxygen in water vapor is an endothermic reaction in total, so by blowing the combustion gas on the hot metal bath surface, While maintaining the reaction interface at a high oxygen potential advantageous for the dephosphorylation reaction, the effect of maintaining the reaction interface at a low temperature advantageous for the dephosphorization reaction is exhibited. Since the dephosphorization reaction is promoted as the hot metal temperature is lower, the oxygen gas and the combustion gas collide with the hot metal bath surface by blowing the combustion gas to the hot metal together with the oxygen gas jet, and the oxygen potential at the reaction interface is reduced. While maintaining high, the combustion gas acts to lower the temperature of the reaction interface, and the dephosphorization reaction can be performed efficiently. That is, it has been found that it is preferable to positively spray combustion gas on the hot metal bath surface together with oxygen gas as a coolant.

溶銑の脱燐反応は、基本的に、溶銑中の燐を酸化し、生成する酸性酸化物（燐酸）を塩基性の脱燐用媒溶剤で固定することによって行われる。即ち、酸素ガスなどの気体酸素源及び鉄鉱石などの固体酸素源による高い酸素ポテンシャルの維持と、生成した燐酸を安定化させうる塩基度（ＣａＯ／ＳｉＯ2 ）の高いスラグが必須である。具体的には、脱燐処理温度における多成分系スラグにおいて、ＣａＯの活量を高位に維持することが必須であり、スラグの状態図でＣａＯ飽和に相当する融点などから選定することができる。 The hot metal dephosphorization reaction is basically carried out by oxidizing the phosphorus in the hot metal and fixing the resulting acidic oxide (phosphoric acid) with a basic dephosphorizing medium solvent. That is, it is essential to maintain a high oxygen potential by a gaseous oxygen source such as oxygen gas and a solid oxygen source such as iron ore and to have a high basicity (CaO / SiO 2 ) that can stabilize the generated phosphoric acid. Specifically, in the multi-component slag at the dephosphorization temperature, it is essential to maintain the activity of CaO at a high level, and it can be selected from the melting point corresponding to CaO saturation in the slag phase diagram.

このスラグの塩基度は、ＣａＯ源として通常用いられる生石灰の使用量で調整するが、事前に溶銑中の珪素を少なくすること、及び、反応容器内のＳｉＯ2 量を少なくすることで、少ない生石灰の使用量で高い塩基度を確保することができる。溶銑中の珪素含有量を減じると、脱燐処理中に生成するＳｉＯ2 が減少し、塩基度を確保するための生石灰の使用量を減らすことができるからである。効率的に脱燐処理し、生石灰使用量及びスラグ量を少なくする観点から、溶銑の珪素含有量を脱燐処理前に予め０．２質量％以下、望ましくは０．１質量％以下に低減しておく必要のあることが分かった。 The basicity of this slag is adjusted by the amount of quicklime that is usually used as a CaO source, but by reducing the amount of silicon in the hot metal in advance and reducing the amount of SiO 2 in the reaction vessel, the amount of quicklime is reduced. A high basicity can be ensured by the amount used. This is because if the silicon content in the hot metal is reduced, the amount of SiO 2 produced during the dephosphorization treatment is reduced, and the amount of quicklime used to ensure basicity can be reduced. From the viewpoint of efficiently dephosphorizing and reducing the amount of quicklime used and the amount of slag, the silicon content of the hot metal is reduced to 0.2% by mass or less, preferably 0.1% by mass or less in advance before dephosphorization. I knew I needed to keep it.

通常、脱燐反応は、酸素ガス、酸素含有ガスなどの気体酸素源、または鉄鉱石、ミルスケールなどの酸化鉄からなる固体酸素源を供給して行うが、固体酸素源を使用する場合には、固体酸素源自体の昇熱に要する熱量と、脱燐反応により固体酸素源が還元されて鉄を生成（吸熱反応）することによる熱量とが必要になるため、溶銑を脱燐処理する際に鉄スクラップを投入しようとする場合、或いは溶銑温度を高く維持しようとする場合には、固体酸素源の使用は不利となる。即ち、脱燐処理終了時に溶銑の保有する熱を十分高く保持するためには、酸化反応による発熱によって溶銑温度を上昇させることができる気体酸素源を使用することが好ましい。具体的には、供給する全ての酸素源のうちの少なくとも５０質量％以上、望ましくは全量を気体酸素源とすることが好ましい。   Usually, the dephosphorization reaction is performed by supplying a gaseous oxygen source such as oxygen gas or oxygen-containing gas, or a solid oxygen source made of iron oxide such as iron ore or mill scale, but when a solid oxygen source is used. The amount of heat required for heating the solid oxygen source itself and the amount of heat generated by reducing the solid oxygen source by the dephosphorization reaction to produce iron (endothermic reaction) are required. The use of a solid oxygen source is disadvantageous when iron scrap is to be charged or when the hot metal temperature is to be kept high. That is, it is preferable to use a gaseous oxygen source capable of raising the hot metal temperature by heat generated by the oxidation reaction in order to keep the heat of the hot metal sufficiently high at the end of the dephosphorization treatment. Specifically, it is preferable that at least 50% by mass or more, preferably the total amount of all the oxygen sources to be supplied is a gaseous oxygen source.

本発明は、上記検討結果に基づいてなされたものであり、第１の発明に係る溶銑の脱燐処理方法は、酸素源を供給して溶銑を脱燐処理する際に、珪素含有量が０．２質量％以下の溶銑を用い、当該溶銑の浴面に向かって、加熱または加熱・溶融したＣａＯを主体とする粉状の脱燐用媒溶剤を、気体酸素源と共に上吹きランスを介して吹き付けて添加し、脱燐処理することを特徴とするものである。   The present invention has been made on the basis of the above examination results, and the hot metal dephosphorization method according to the first invention has a silicon content of 0 when the hot metal is dephosphorized by supplying an oxygen source. .2% by mass or less of hot metal toward the bath surface of the hot metal, a heated or heated and melted CaO-based powder dephosphorization medium solvent together with a gaseous oxygen source through an upper blowing lance It is added by spraying and dephosphorizing.

第２の発明に係る溶銑の脱燐処理方法は、第１の発明において、前記酸素源のうちの５０質量％以上を気体酸素源とすることを特徴とするものである。   The hot metal dephosphorization method according to the second invention is characterized in that, in the first invention, 50% by mass or more of the oxygen source is a gaseous oxygen source.

第３の発明に係る溶銑の脱燐処理方法は、第１または第２の発明において、前記ＣａＯを主体とする粉状の脱燐用媒溶剤として、実質的にフッ素を含まない脱燐用媒溶剤を使用し、当該脱燐用媒溶剤の５０質量％以上を、気体酸素源と共に上吹きランスから溶銑の浴面に向けて吹き付けて添加することを特徴とするものである。   The hot metal dephosphorization method according to the third invention is the dephosphorization medium substantially free of fluorine as the powder dephosphorization medium solvent mainly composed of CaO in the first or second invention. A solvent is used, and 50 mass% or more of the dephosphorization medium solvent is sprayed and added to the bath surface of the hot metal from the top blowing lance together with the gaseous oxygen source.

第４の発明に係る溶銑の脱燐処理方法は、第１ないし第３の発明の何れかにおいて、前記脱燐用媒溶剤は、脱燐処理後の溶銑の脱炭精錬時に生成したスラグを主体とすることを特徴とするものである。   The hot metal dephosphorization method according to a fourth aspect of the present invention is the hot metal dephosphorization method according to any one of the first to third aspects, wherein the dephosphorization solvent is mainly slag generated during decarburization refining of the hot metal after the dephosphorization process. It is characterized by that.

第５の発明に係る溶銑の脱燐処理方法は、第１ないし第４の発明の何れかにおいて、前記上吹きランスの先端に設けたノズルから、炭化水素系のガス燃料、炭化水素系の液体燃料のうちの何れか１種以上を供給し、前記気体酸素源によって炭化水素系ガス燃料または炭化水素系液体燃料を燃焼させて火炎を形成し、当該火炎によって前記脱燐用媒溶剤を加熱または加熱・溶融することを特徴とするものである。   A hot metal dephosphorization method according to a fifth aspect of the present invention is the method of any one of the first to fourth aspects, wherein a hydrocarbon-based gas fuel or a hydrocarbon-based liquid is supplied from a nozzle provided at a tip of the top blowing lance. Any one or more of fuels are supplied, a hydrocarbon gas fuel or a hydrocarbon liquid fuel is burned by the gaseous oxygen source to form a flame, and the dephosphorization medium solvent is heated by the flame or It is characterized by heating and melting.

第６の発明に係る溶銑の脱燐処理方法は、第５の発明において、前記上吹きランスの中心孔から搬送用ガスとしての気体酸素源と共に脱燐用媒溶剤を供給し、中心孔の周囲の周囲孔から炭化水素系ガス燃料、炭化水素系液体燃料のうちの何れか１種以上を供給することを特徴とするものである。   The hot metal dephosphorization processing method according to the sixth invention is the method according to the fifth invention, wherein a dephosphorization medium solvent is supplied together with a gaseous oxygen source as a carrier gas from the center hole of the upper blowing lance, Any one or more of a hydrocarbon-based gas fuel and a hydrocarbon-based liquid fuel are supplied from the peripheral holes of the above.

第７の発明に係る溶銑の脱燐処理方法は、第５または第６の発明において、上吹きランスから供給する気体酸素源中の酸素ガス量と、炭化水素系ガス燃料及び炭化水素系液体燃料の理論燃焼分の酸素ガス量との比である酸素比が１．０以上となるように、気体酸素源の供給量、または、炭化水素系ガス燃料及び炭化水素系液体燃料の供給量を調整することを特徴とするものである。   The hot metal dephosphorization processing method according to the seventh invention is the method of the fifth or sixth invention, wherein the amount of oxygen gas in the gaseous oxygen source supplied from the top blowing lance, the hydrocarbon gas fuel, and the hydrocarbon liquid fuel Adjust the supply amount of gaseous oxygen source or the supply amount of hydrocarbon-based gas fuel and hydrocarbon-based liquid fuel so that the oxygen ratio, which is the ratio of the theoretical combustion amount of oxygen gas to 1.0 or more, becomes 1.0 or more It is characterized by doing.

本発明によれば、珪素含有量が０．２質量％以下の溶銑を用い、溶銑の浴面に向かって、加熱または加熱・溶融したＣａＯを主体とする粉状の脱燐用媒溶剤を、上吹きランスを介して気体酸素源と共に吹き付けて添加して脱燐処理するので、添加した脱燐用媒溶剤を脱燐反応の促進に適正な組成のスラグへと迅速に調製することが可能となり、従来に比較して迅速に脱燐反応を推進させることができ、燐含有量の低い溶銑を容易に製造することが可能となる。その結果、脱燐処理工程における脱燐用媒溶剤の削減及びエネルギーロスの低減化が可能になるのみならず、次工程の転炉脱炭精錬では、脱燐のための脱燐用媒溶剤が不要になるなど、省資源、省エネルギーが達成されると共に、転炉脱炭操業の安定化が達成され、工業上有益な効果がもたらされる。   According to the present invention, using a hot metal having a silicon content of 0.2% by mass or less, a powdered dephosphorization medium solvent mainly composed of CaO heated or heated and melted toward the bath surface of the hot metal, Since the dephosphorization treatment is performed by spraying with a gaseous oxygen source through the top blowing lance, it becomes possible to quickly prepare the added dephosphorization medium solvent into a slag having an appropriate composition for promoting the dephosphorization reaction. Thus, the dephosphorization reaction can be promoted more rapidly than in the prior art, and hot metal having a low phosphorus content can be easily produced. As a result, it is possible not only to reduce the dephosphorization medium solvent and the energy loss in the dephosphorization process, but also to remove the dephosphorization medium solvent for dephosphorization in the converter decarburization refining in the next process. Resource saving and energy saving, such as no longer necessary, are achieved, and converter decarburization operation is stabilized, resulting in industrially beneficial effects.

以下、本発明を具体的に説明する。本発明に係る脱燐処理で用いる溶銑は、高炉などの溶銑製造設備で製造された溶銑であり、脱燐処理の前に予め溶銑の珪素含有量を０．２質量％以下、望ましくは０．１質量％以下まで低減させておく。溶銑の珪素含有量をこの範囲まで下げる手段としては、溶銑製造用原料に予備処理などを施し、高炉などの溶銑製造設備への珪酸分の全装入量を低減したり、高炉々内における珪酸の還元反応を抑制するために低温操業或いはコークスの偏在装入などの対策を講じることができる。また、製造された溶銑に酸素ガスまたは酸化鉄などの酸素源を供給し、これらの酸素源によって珪素を酸化させ、珪素を酸化物として強制的に除去すること（「溶銑の脱珪処理」と呼ぶ）もできる。   The present invention will be specifically described below. The hot metal used in the dephosphorization process according to the present invention is a hot metal produced in a hot metal production facility such as a blast furnace, and prior to the dephosphorization process, the silicon content of the hot metal is 0.2 mass% or less, preferably 0. Reduce to 1% by mass or less. As a means to lower the silicon content of the hot metal to this range, the raw material for hot metal production is pre-treated to reduce the total amount of silicic acid charged to the hot metal production equipment such as a blast furnace, In order to suppress the reduction reaction, it is possible to take measures such as low temperature operation or uneven charging of coke. Also, an oxygen source such as oxygen gas or iron oxide is supplied to the produced hot metal, and silicon is oxidized by these oxygen sources, and the silicon is forcibly removed as an oxide (“hot metal desiliconization process”). Can also be called).

溶銑の脱珪処理の具体的な方法は、例えば、高炉から出銑された溶銑を高炉鋳床の溶銑樋を経由して溶銑鍋、トーピードカーなどの溶銑搬送容器で受銑する際に、溶銑に酸素ガスまたは鉄鉱石などの酸化鉄を供給して行う方法、或いは、溶銑搬送容器内で溶銑に酸素ガスまたは鉄鉱石などの酸化鉄を供給して行う方法を用いることができる。その際に、溶銑に撹拌用ガスを吹き込んで脱珪反応を促進させたり、生石灰などのＣａＯ源を添加して生成するスラグの塩基度を調整してもよい。溶銑搬送容器内に限らず、専用の反応容器に移し替えて行うこともできる。   A specific method for desiliconization of hot metal is, for example, when hot metal discharged from a blast furnace is received in a hot metal transfer container such as a hot metal ladle or torpedo car via the hot metal of a blast furnace casting floor. A method of supplying iron oxide such as oxygen gas or iron ore or a method of supplying iron oxide such as oxygen gas or iron ore to hot metal in a hot metal transfer container can be used. At that time, stirring gas may be blown into the hot metal to promote the desiliconization reaction, or the basicity of the slag generated by adding a CaO source such as quicklime may be adjusted. Not only in the hot metal transfer container but also in a dedicated reaction container.

このようにして得た溶銑に対して本発明による脱燐処理を施す。本発明による脱燐処理では、反応効率を高めるためにスラグの塩基度を２．５以上、できれば４．０以上とすることが好ましく、従って、生石灰などのＣａＯ源の添加量が基本的に多くなる。スラグの高い塩基度を確保した上で且つ生石灰などのＣａＯ源の必要量を極力少なくするために、即ちスラグ量を極力少なくするために、前工程の脱珪処理などで生成したスラグを排滓し、脱燐処理工程への珪酸分の混入を極力少なくすることが好ましい。   The hot metal thus obtained is subjected to the dephosphorization treatment according to the present invention. In the dephosphorization treatment according to the present invention, the basicity of the slag is preferably 2.5 or more, preferably 4.0 or more in order to increase the reaction efficiency. Therefore, the amount of CaO source such as quicklime is basically increased. Become. In order to ensure the high basicity of slag and to reduce the required amount of CaO source such as quick lime as much as possible, that is, to reduce the amount of slag as much as possible, the slag generated by the desiliconization process in the previous process is rejected. In addition, it is preferable to minimize the mixing of silicic acid into the dephosphorization process.

本発明による脱燐処理は、溶銑鍋またはトーピードカーなどの溶銑搬送容器内で行うこともできるが、これらの溶銑搬送容器に比べてフリーボードが大きく、溶銑を強攪拌することが可能であり且つ大量の排ガスの処理設備を備えている転炉型の精錬設備で行うことが好ましい。図１は、本発明に最適な転炉型精錬設備の１例を示す概略図である。   The dephosphorization treatment according to the present invention can be carried out in a hot metal transfer container such as a hot metal ladle or a torpedo car. However, the free board is larger than these hot metal transfer containers, and the hot metal can be vigorously stirred. It is preferable to carry out in a converter type refining facility equipped with the exhaust gas treatment facility. FIG. 1 is a schematic diagram showing an example of a converter-type refining facility optimum for the present invention.

この転炉型精錬設備１は、図１に示すように、溶銑１４を収容する炉本体２と、この炉本体２の内部に挿入され、上下方向に移動可能な上吹きランス３と、炉本体２の内部に原材料を投入するための原料投入装置４とを備え、炉本体２の炉底には、ガス導入管６と接続した、撹拌用ガスを吹き込むための底吹き羽口５が設けられている。上吹きランス３には、酸素ガス配管７及び燃料配管８が接続されており、気体酸素源としての酸素ガスが酸素ガス配管７を介し、また、プロパンガス、天然ガスなどの炭化水素系ガス燃料、或いは、重油、灯油などの炭化水素系液体燃料のうちの１種以上が燃料配管８を介し、それぞれ任意の流量で上吹きランス３から炉本体２の内部に供給されるようになっている。上吹きランス３には、冷却水配管（図示せず）が接続されている。   As shown in FIG. 1, the converter-type refining equipment 1 includes a furnace main body 2 that accommodates hot metal 14, an upper blowing lance 3 that is inserted into the furnace main body 2 and is movable in the vertical direction, and a furnace main body. 2 is provided with a raw material charging device 4 for charging raw materials, and a bottom blowing tuyere 5 for blowing a stirring gas connected to a gas introduction pipe 6 is provided at the bottom of the furnace body 2. ing. An oxygen gas pipe 7 and a fuel pipe 8 are connected to the top blowing lance 3, and oxygen gas as a gaseous oxygen source passes through the oxygen gas pipe 7 and is also a hydrocarbon gas fuel such as propane gas or natural gas. Alternatively, one or more hydrocarbon liquid fuels such as heavy oil and kerosene are supplied from the top blowing lance 3 to the inside of the furnace body 2 through the fuel pipe 8 at an arbitrary flow rate. . A cooling water pipe (not shown) is connected to the upper blowing lance 3.

酸素ガス配管７は酸素ガス配管７Ａに分岐しており、酸素ガス配管７から分岐した酸素ガス配管７Ａは、ＣａＯを主体とする脱燐用媒溶剤１６を収容したディスペンサー９に連結し、ディスペンサー９は、媒溶剤移送配管１３を介して酸素ガス配管７に連結している。即ち、ディスペンサー９の内部に供給された酸素ガスは、ディスペンサー９に収容された脱燐用媒溶剤１６の搬送用ガスとして機能し、媒溶剤移送配管１３を経由して上吹きランス３の先端から脱燐用媒溶剤１６を炉本体２の内部に吹き付けて供給することができるようになっている。酸素ガス配管７には流量調整弁１０が設けられ、酸素ガス配管７Ａには流量調整弁１１が設けられており、酸素ガスを上吹きランス３から直接吹き込むことも、また、ディスペンサー９を経由して吹き込むことも任意に調整することができるようになっている。燃料配管８には、炭化水素系ガス燃料或いは炭化水素系液体燃料の流量を調整するための流量調整弁１２が設けられている。   The oxygen gas pipe 7 is branched into an oxygen gas pipe 7A, and the oxygen gas pipe 7A branched from the oxygen gas pipe 7 is connected to a dispenser 9 containing a dephosphorization medium solvent 16 mainly composed of CaO. Is connected to the oxygen gas pipe 7 through the solvent transfer pipe 13. That is, the oxygen gas supplied to the inside of the dispenser 9 functions as a transfer gas for the dephosphorization medium solvent 16 accommodated in the dispenser 9, and passes through the medium solvent transfer pipe 13 from the tip of the upper blowing lance 3. The dephosphorizing medium solvent 16 can be supplied by spraying the inside of the furnace body 2. The oxygen gas pipe 7 is provided with a flow rate adjusting valve 10, and the oxygen gas pipe 7 A is provided with a flow rate adjusting valve 11, and the oxygen gas can be directly blown from the upper blow lance 3 or via the dispenser 9. Can be adjusted arbitrarily. The fuel pipe 8 is provided with a flow rate adjusting valve 12 for adjusting the flow rate of the hydrocarbon gas fuel or the hydrocarbon liquid fuel.

上吹きランス３は、図２に示すように、円筒状のランス本体１７と、このランス本体１７の下端に溶接などにより接続された銅製のランスノズル１８とで構成されており、ランス本体１７は、外管１９、中管２０、内管２１、最内管２２の同心円状の４種の鋼管、即ち四重管で構成されている。酸素ガス配管７は最内管２２に連通し、燃料配管８は内管２１に連通しており、従って、脱燐用媒溶剤１６が酸素ガスと共に最内管２２の内部を通って供給され、また、炭化水素系ガス燃料或いは炭化水素系液体燃料が最内管２２と内管２１との間隙を通って供給されるようになっている。内管２１と中管２０との間隙及び中管２０と外管１９との間隙は、冷却水の給排水流路となっている。   As shown in FIG. 2, the upper blowing lance 3 is composed of a cylindrical lance body 17 and a copper lance nozzle 18 connected to the lower end of the lance body 17 by welding or the like. The outer tube 19, the middle tube 20, the inner tube 21, and the innermost tube 22 are composed of four concentric steel pipes, that is, a quadruple pipe. The oxygen gas pipe 7 communicates with the innermost pipe 22, and the fuel pipe 8 communicates with the inner pipe 21, so that the dephosphorization medium solvent 16 is supplied together with oxygen gas through the inside of the innermost pipe 22, Further, hydrocarbon gas fuel or hydrocarbon liquid fuel is supplied through the gap between the innermost tube 22 and the inner tube 21. The gap between the inner pipe 21 and the middle pipe 20 and the gap between the middle pipe 20 and the outer pipe 19 serve as a cooling water supply / drain passage.

最内管２２はランスノズル１８のほぼ中心位置に配置された中心孔２３と連通し、内管２１は、中心孔２３の周囲に複数個設置された周囲孔２４に連通している。中心孔２３は酸素ガス或いは酸素ガスと共に脱燐用媒溶剤１６を吹き込むためのノズルであり、周囲孔２４は炭化水素系ガス燃料或いは炭化水素系液体燃料を吹き込むためのノズルである。尚、酸素ガス配管７を内管２１に連通し、燃料配管８を最内管２２に連通することで、中心孔２３からは炭化水素系ガス燃料或いは炭化水素系液体燃料を吹き込み、周囲孔２４からは酸素ガス或いは酸素ガスと共に脱燐用媒溶剤１６を吹き込むこともできるが、本発明を実施する上では、脱燐用媒溶剤１６の加熱・溶融を促進させる観点から、中心孔２３から酸素ガスと共に脱燐用媒溶剤１６を吹き込み、この周囲に火炎を形成することが好ましい。また、図２に示すように、中心孔２３及び周囲孔２４は、その断面が縮小する部分と拡大する部分の２つの円錐体で構成された、所謂ラバールノズルの形状を採っているが、ストレート形状であってもよい。   The innermost tube 22 communicates with a central hole 23 disposed substantially at the center position of the lance nozzle 18, and the inner tube 21 communicates with a plurality of peripheral holes 24 provided around the central hole 23. The central hole 23 is a nozzle for blowing the dephosphorization medium solvent 16 together with oxygen gas or oxygen gas, and the peripheral hole 24 is a nozzle for blowing hydrocarbon-based gas fuel or hydrocarbon-based liquid fuel. The oxygen gas pipe 7 is connected to the inner pipe 21, and the fuel pipe 8 is connected to the innermost pipe 22, so that hydrocarbon gas fuel or hydrocarbon liquid fuel is blown from the center hole 23, and the peripheral hole 24. From the viewpoint of promoting heating and melting of the dephosphorization medium solvent 16, oxygen gas from the center hole 23 can be used for carrying out the present invention. It is preferable to blow the dephosphorization medium solvent 16 together with the gas to form a flame around this. In addition, as shown in FIG. 2, the center hole 23 and the peripheral hole 24 have a so-called Laval nozzle shape composed of two cones, a portion whose cross section is reduced and a portion where the cross section is enlarged. It may be.

尚、本発明による脱燐方法を実施する場合、上吹きランス３は燃料の供給流路を兼ねる必要はなく、上吹きランス３とは別に燃料の供給用ランスを設置してもよい。但し、炉本体２の上方部における設備配置が煩雑になるので、これを防止するためには上吹きランス３が燃料の供給流路を兼ねることが好ましい。   When carrying out the dephosphorization method according to the present invention, the upper blowing lance 3 does not need to serve as a fuel supply flow path, and a fuel supply lance may be provided separately from the upper blowing lance 3. However, since the arrangement of equipment in the upper part of the furnace body 2 becomes complicated, it is preferable that the top blowing lance 3 also serves as a fuel supply flow path in order to prevent this.

このような構成の転炉型精錬設備１を用い、予め珪素含有量を０．２質量％以下とした溶銑１４に対して、以下のようにして本発明による脱燐処理を実施する。   Using the converter type refining equipment 1 having such a configuration, the dephosphorization treatment according to the present invention is performed as follows on the hot metal 14 in which the silicon content is 0.2 mass% or less in advance.

先ず、炉本体２に溶銑１４を装入し、次いで、底吹き羽口５から窒素ガスなどの非酸化性ガスまたはＡｒガスなどの希ガスを撹拌用ガスとして溶銑１４中に吹き込みながら、酸素ガスと共にＣａＯを主体とする脱燐用媒溶剤１６を上吹きランス３の中心孔２３から溶銑１４の浴面に向けて吹き付け、溶銑１４の脱燐処理を実施する。そして、中心孔２３からの脱燐用媒溶剤１６の供給開始に前後して、周囲孔２４から炭化水素系ガス燃料或いは炭化水素系液体燃料を吹き込む。炉内が高温であるため、吹き込まれた燃料は同時に吹き込まれる酸素ガスによって自然に燃焼を開始する。確実に燃焼させるために、上吹きランス３に着火装置を設置してもよい。燃料は、少なくとも脱燐用媒溶剤１６が吹き込まれている期間中は供給を継続する。脱燐処理前の溶銑温度は、通常の１２５０〜１３５０℃の範囲であれば、問題なく脱燐処理することができ、更に低温であっても脱燐処理することができる。   First, hot metal 14 is charged into the furnace body 2, and then oxygen gas is introduced into the hot metal 14 from the bottom blowing tuyere 5 as a stirring gas with a non-oxidizing gas such as nitrogen gas or an Ar gas. At the same time, a dephosphorization medium solvent 16 mainly composed of CaO is sprayed from the center hole 23 of the upper blowing lance 3 toward the bath surface of the hot metal 14 to perform dephosphorization of the hot metal 14. Then, before or after the supply of the dephosphorization medium solvent 16 from the center hole 23 is started, hydrocarbon gas fuel or hydrocarbon liquid fuel is blown from the peripheral hole 24. Since the inside of the furnace is at a high temperature, the injected fuel starts to combust naturally by the oxygen gas injected at the same time. In order to ensure combustion, an ignition device may be installed on the upper blowing lance 3. The supply of fuel is continued at least during the period when the dephosphorization medium 16 is being blown. If the hot metal temperature before the dephosphorization treatment is within a range of 1250 to 1350 ° C., the dephosphorization treatment can be performed without any problem, and even at a lower temperature, the dephosphorization treatment can be performed.

本発明では、燃料を酸素ガスで燃焼させたときに発生する燃焼熱を利用して脱燐用媒溶剤１６の昇温・溶融を図る。燃料は、上吹きランス３の先端位置から燃焼を開始して高温の火炎を形成する。但し、溶銑１４の浴面に到達するまでには燃焼させる。火炎の形状は、燃料及び酸素ガスの供給量または供給流速によって調整することができる。脱燐用媒溶剤１６は、火炎中で燃焼熱により加熱され、受熱量及び脱燐用媒溶剤１６の組成によっては、部分的或いは全体が溶融して溶銑１４の浴面に到達する。   In the present invention, the temperature of the dephosphorization medium solvent 16 is raised and melted by utilizing the combustion heat generated when the fuel is burned with oxygen gas. The fuel starts combustion from the tip position of the top blowing lance 3 to form a high-temperature flame. However, it is burned until it reaches the bath surface of the hot metal 14. The shape of the flame can be adjusted by the supply amount or supply flow rate of fuel and oxygen gas. The dephosphorization medium solvent 16 is heated by combustion heat in a flame, and partially or entirely melts and reaches the bath surface of the hot metal 14 depending on the amount of heat received and the composition of the dephosphorization medium solvent 16.

ＣａＯを主体とする脱燐用媒溶剤１６としては、生石灰粉を使用することができる。生石灰粉にアルミナ粉などを滓化促進剤として加えてもよいが、本発明においては加熱した脱燐用媒溶剤１６を溶銑浴面に吹き付けて添加するため、生石灰粉単体であっても十分に滓化するので、アルミナ粉などの滓化促進剤は用いなくても十分に脱燐することができる。特に、スラグ１５からのフッ素の溶出量を抑えて環境を保護する観点から、蛍石などのフッ素含有物質は滓化促進剤として使用しないことが好ましい。但し、フッ素が不純物成分として不可避的に混入した物質については使用しても構わない。また、脱燐処理後の溶銑１４を次工程の転炉で脱炭精錬した際に発生するスラグ（「脱炭滓」ともいう）を、ＣａＯを主体とする脱燐用媒溶剤１６として使用することもできる。このスラグは、ＣａＯを主成分としており、且つ、燐含有量が少ないことから、脱燐用媒溶剤１６として利用することができる。   As the dephosphorization medium solvent 16 mainly composed of CaO, quick lime powder can be used. Alumina powder or the like may be added to the quicklime powder as a hatching accelerator. However, in the present invention, the heated dephosphorization medium solvent 16 is sprayed onto the hot metal bath surface, so that even the quicklime powder alone is sufficient. Since it hatches, it can fully dephosphorize even if it does not use hatching promoters, such as an alumina powder. In particular, from the viewpoint of protecting the environment by suppressing the amount of fluorine eluted from the slag 15, it is preferable not to use a fluorine-containing substance such as fluorite as a hatching accelerator. However, a substance in which fluorine is inevitably mixed as an impurity component may be used. Further, slag (also referred to as “decarburized soot”) generated when the hot metal 14 after dephosphorization is decarburized and refined in the converter of the next process is used as a dephosphorization medium solvent 16 mainly composed of CaO. You can also This slag can be used as a dephosphorization medium solvent 16 because it contains CaO as a main component and has a low phosphorus content.

底吹き羽口５から吹き込まれた攪拌用ガスによって溶銑１４は攪拌され、浴面に吹き付けられた脱燐用媒溶剤１６は予め加熱或いは溶融しているので、速やかにスラグ１５を形成する。脱燐反応のためには、生成されるスラグ１５の塩基度は高いことが好ましく、少なくとも塩基度が２．０以上となるように、脱燐用媒溶剤１６の添加量を調整する。具体的には、脱燐用媒溶剤１６からのＣａＯ量と、溶銑１４中の珪素が酸化して生成するＳｉＯ2 量に基づき、脱燐用媒溶剤１６の添加量を設定する。ＣａＯを主体とする脱燐用媒溶剤１６は全て上吹きランス３から添加する必要はなく、原料投入装置４を用いて溶銑１４の浴面上に塊状の脱燐用媒溶剤を上置き添加してもよいが、脱燐用媒溶剤の滓化を促進させて脱燐反応を円滑に行うために、少なくとも添加する脱燐用媒溶剤のうちの５０質量％以上は、上吹きランス３を介して添加することが好ましい。 The hot metal 14 is stirred by the stirring gas blown from the bottom blowing tuyere 5, and the dephosphorizing medium solvent 16 sprayed on the bath surface is heated or melted in advance, so that the slag 15 is quickly formed. For the dephosphorization reaction, the basicity of the slag 15 to be produced is preferably high, and the addition amount of the dephosphorization medium solvent 16 is adjusted so that at least the basicity is 2.0 or more. Specifically, the addition amount of the dephosphorization medium solvent 16 is set based on the amount of CaO from the dephosphorization medium solvent 16 and the amount of SiO 2 generated by oxidation of silicon in the molten iron 14. It is not necessary to add all of the dephosphorization medium solvent 16 mainly composed of CaO from the top blowing lance 3, and a bulk dephosphorization medium solvent is added on the bath surface of the hot metal 14 using the raw material charging device 4. However, in order to promote the hatching of the dephosphorization medium solvent and perform the dephosphorization reaction smoothly, at least 50 mass% of the dephosphorization medium solvent to be added passes through the top blowing lance 3. Is preferably added.

脱燐反応のための酸素源としては、上記の酸素ガスなどの気体酸素源の他に、鉄鉱石、ミルスケールなどの酸化鉄を固体酸素源として使用することができる。通常、粉状の固体酸素源は、上吹きランス３から添加する脱燐用媒溶剤１６に混合させたり、インジェクション法により添加し、一方、塊状の固体酸素源は、溶銑１４に上置きして添加する。但し、固体酸素源を添加すると、溶銑１４の昇熱には不利であるので、酸素源のうちの５０質量％以上は、気体酸素源を使用することが好ましい。気体酸素源としては、上記の酸素ガスの他に、空気及び酸素富化空気などを使用することができるが、本発明は燃焼熱によって脱燐用媒溶剤１６を加熱することを目的としており、排ガスの量を少なくさせ、加熱温度を高める観点から、酸素ガスを用いることが好ましい。そして、上吹きランス３から供給する酸素ガス量と、炭化水素系ガス燃料及び炭化水素系液体燃料の理論燃焼分の酸素ガス量との比である酸素比が１．０以上となるように、気体酸素源の供給量、または、炭化水素系ガス燃料及び炭化水素系液体燃料の供給量を調整することが好ましい。   As an oxygen source for the dephosphorization reaction, iron oxide such as iron ore and mill scale can be used as a solid oxygen source in addition to the gaseous oxygen source such as the oxygen gas described above. Usually, the powdered solid oxygen source is mixed with the dephosphorization medium solvent 16 added from the top blowing lance 3 or added by the injection method, while the bulk solid oxygen source is placed on the hot metal 14. Added. However, since the addition of a solid oxygen source is disadvantageous for heating the hot metal 14, it is preferable to use a gaseous oxygen source for 50% by mass or more of the oxygen source. As the gaseous oxygen source, air and oxygen-enriched air can be used in addition to the above oxygen gas, but the present invention aims to heat the dephosphorization medium solvent 16 by combustion heat, From the viewpoint of reducing the amount of exhaust gas and increasing the heating temperature, it is preferable to use oxygen gas. The oxygen ratio, which is the ratio of the amount of oxygen gas supplied from the top blowing lance 3 and the amount of oxygen gas for the theoretical combustion of the hydrocarbon gas fuel and hydrocarbon liquid fuel, is 1.0 or more. It is preferable to adjust the supply amount of the gaseous oxygen source or the supply amounts of the hydrocarbon-based gas fuel and the hydrocarbon-based liquid fuel.

脱燐反応は、溶銑温度が低いほど促進される。前記酸素比を１．０以上として燃料を完全に燃焼させることで、燃焼ガスは、二酸化炭素と水蒸気とを主体とするガスとなり、この燃焼ガスが溶銑１４の浴面に吹き付けられるため、溶銑１４の珪素或いは炭素との還元反応、即ち吸熱反応を起こし、脱燐反応界面の温度上昇が抑制される。   The dephosphorization reaction is promoted as the hot metal temperature is lower. By completely burning the fuel at an oxygen ratio of 1.0 or more, the combustion gas becomes a gas mainly composed of carbon dioxide and water vapor, and this combustion gas is blown onto the bath surface of the hot metal 14, so the hot metal 14 This causes a reduction reaction with silicon or carbon, that is, an endothermic reaction, and the temperature rise at the dephosphorization reaction interface is suppressed.

脱燐用媒溶剤１６を添加し、且つ、酸素ガスを供給して脱燐し、溶銑１４の燐濃度が所定の値になるまで脱燐処理を継続する。この場合、処理時間の制約などを考慮しながら、脱燐用媒溶剤１６と溶銑１４とを迅速に反応させるために、攪拌強度及び脱燐用媒溶剤１６の添加速度などを適正化する。脱燐処理終了時の溶銑温度は、余り高温では脱燐反応が阻害され、一方、余り低温では次工程における熱余裕が少なくなることから、これらを考慮して脱燐処理終了時の溶銑温度を決定する。   The dephosphorization medium solvent 16 is added, oxygen gas is supplied to perform dephosphorization, and the dephosphorization process is continued until the phosphorus concentration in the hot metal 14 reaches a predetermined value. In this case, the stirring strength and the addition rate of the dephosphorization medium solvent 16 are optimized in order to cause the dephosphorization medium solvent 16 and the molten iron 14 to react quickly, taking into account the processing time limitation. As for the hot metal temperature at the end of the dephosphorization treatment, if the temperature is too high, the dephosphorization reaction is inhibited.On the other hand, if the temperature is too low, the thermal margin in the next process is reduced. decide.

以上説明したように、本発明に係る溶銑の脱燐方法では、酸素源を供給して溶銑１４を脱燐処理する際に、珪素含有量が０．２質量％以下の溶銑１４を用い、溶銑１４の浴面に向かって、加熱または加熱・溶融したＣａＯを主体とする粉状の脱燐用媒溶剤１６を、上吹きランス３を介して気体酸素源と共に吹き付けて添加して脱燐処理するので、添加した脱燐用媒溶剤１６を脱燐反応の促進に適正な組成のスラグ１５へと迅速に調製することが可能となり、従来に比較して迅速に脱燐反応を推進させることができ、燐含有量の低い溶銑を容易に製造することが可能となる。   As described above, in the hot metal dephosphorization method according to the present invention, when the hot metal 14 is dephosphorized by supplying an oxygen source, the hot metal 14 having a silicon content of 0.2% by mass or less is used. A powdered dephosphorization medium solvent 16 mainly composed of heated or heated and melted CaO is sprayed along with a gaseous oxygen source through an upper blowing lance 3 toward the bath surface 14 and added to perform dephosphorization treatment. Therefore, it is possible to quickly prepare the added dephosphorization medium solvent 16 into the slag 15 having an appropriate composition for promoting the dephosphorization reaction, and to promote the dephosphorization reaction more quickly than in the past. It is possible to easily produce hot metal having a low phosphorus content.

尚、上記説明では、脱燐処理設備として転炉型精錬設備１を用いた場合を示したが、脱燐処理設備は上記の転炉型精錬設備１に限るものではなく、取鍋またはトーピードカーなどの溶銑搬送容器などであっても、上吹きランスを介してＣａＯを主体とする粉状の脱燐用媒溶剤１６を吹き付けて添加することが可能である限り、上記に沿って本発明を実施することができる。   In the above description, the converter type refining equipment 1 is used as the dephosphorization processing equipment. However, the dephosphorization processing equipment is not limited to the above converter type refining equipment 1, and a ladle or a torpedo car is used. As long as it is possible to spray and add powdered dephosphorization medium solvent 16 mainly composed of CaO through an upper blowing lance, the present invention is carried out according to the above. can do.

高炉から出銑された溶銑に対して本発明に係る脱燐処理を実施した。高炉で製造された溶銑に対し、先ず、高炉鋳床において鉄鉱石の焼結粉を上置き投入し、溶銑鍋での受銑までに脱珪反応させて脱珪処理を施した。高炉から出銑時の珪素濃度が０．２５〜０．４０質量％であるのに対し、脱珪処理後の珪素濃度は０．０５〜０．１８質量％であった。脱珪処理後、溶銑鍋内のスラグを排滓した後、図１に示す転炉型精錬設備と同一構成の容量が５トンの小型の転炉型精錬試験設備に溶銑を装入し、脱燐処理を施した。   The dephosphorization process according to the present invention was performed on the hot metal discharged from the blast furnace. First, iron ore sintered powder was put on top of the hot metal produced in the blast furnace, and desiliconized by the desiliconization reaction before receiving in the hot metal pan. The silicon concentration at the time of leaving from the blast furnace was 0.25 to 0.40% by mass, whereas the silicon concentration after desiliconization was 0.05 to 0.18% by mass. After desiliconization, the slag in the hot metal ladle is drained, and the hot metal is charged into a small converter type refining test facility with the same configuration as the converter type refining facility shown in FIG. Phosphorus treatment was applied.

脱燐処理は、炉底部の底吹き羽口からの約０．１Ｎｍ3 ／ｍｉｎ・ｔの窒素ガスによる吹き込み攪拌を行いつつ、上吹きランスによる送酸と生石灰粉の添加を行った。この生石灰粉の添加量は、装入された溶銑の珪素濃度及び燐濃度に応じて塩基度が２．０以上となるように定めた。用いた上吹きランスは中心孔と３個の周囲孔とを有し、中心孔からは生石灰粉と酸素ガス、周囲孔からはプロパンガスを供給できるものを用いた。生石灰粉は予め２ｍｍ径以下に粉砕調製されたものである。酸素ガスの流量は４２０Ｎｍ3 ／ｈｒとし、プロパンガスの流量は、脱燐用媒溶剤の供給量及び加熱程度を変えるため、５〜２２Ｎｍ3 ／ｈｒとした。 In the dephosphorization treatment, acid feeding and quick lime powder were added by an upper blowing lance while stirring by blowing with about 0.1 Nm 3 / min · t of nitrogen gas from the bottom blowing tuyere at the bottom of the furnace. The amount of quicklime powder added was determined so that the basicity was 2.0 or more according to the silicon concentration and phosphorus concentration of the molten iron charged. The top blowing lance used had a central hole and three peripheral holes, and those capable of supplying quick lime powder and oxygen gas from the central hole and propane gas from the peripheral hole were used. The quicklime powder is prepared by pulverizing to a diameter of 2 mm or less in advance. The flow rate of oxygen gas was 420 Nm 3 / hr, and the flow rate of propane gas was 5 to 22 Nm 3 / hr in order to change the amount of dephosphorization medium solvent supplied and the degree of heating.

また、一部の試験では、脱燐用媒溶剤として生石灰に代えて、脱燐処理した溶銑の転炉脱炭精錬で発生したスラグ（脱炭滓）を使用し、脱燐反応に及ぼす影響を調査した。脱炭滓の組成は、ＣａＯ：５０．１質量％、ＳｉＯ2 ：１２．４質量％、ＦｅＯ：１４．９質量％であった。ＣａＯの添加量が、生石灰を使用した場合と同じ水準になるように、脱炭滓の添加量を調整した。 In some tests, slag generated from converter decarburization and refining of dephosphorized hot metal instead of quick lime as a dephosphorization medium solvent is used to affect the dephosphorization reaction. investigated. The composition of the decarburized soot was CaO: 50.1% by mass, SiO 2 : 12.4% by mass, and FeO: 14.9% by mass. The added amount of decarburized soot was adjusted so that the added amount of CaO was the same level as when quick lime was used.

表１に、脱燐処理における処理条件及び処理結果を示す。尚、表１には、本発明の範囲以外の処理条件で行った比較例の処理条件及び処理結果を併せて示している。   Table 1 shows treatment conditions and treatment results in the dephosphorization treatment. Table 1 also shows the processing conditions and processing results of the comparative example performed under processing conditions outside the scope of the present invention.

Figure 2005336586
Figure 2005336586

表１から明らかなように、本発明例では、比較例と比べて少ないＣａＯ純分の添加量で低い燐濃度レベルまで溶銑を脱燐処理することができた。特に、脱燐用媒溶剤を加熱することにより、脱燐用媒溶剤として脱炭滓を使用した場合でも、脱燐反応が促進され、溶銑の燐濃度を０．０１５質量％以下まで低下することができた。更に、少ない酸素供給量で脱燐処理でき、脱燐処理中の溶銑の脱炭を抑制すること、即ち、脱燐処理後の溶銑の熱余裕を高めることができた。   As is apparent from Table 1, in the inventive example, the hot metal could be dephosphorized to a low phosphorus concentration level with a smaller amount of pure CaO added than in the comparative example. In particular, by heating the dephosphorization medium solvent, even when decarburized soot is used as the dephosphorization medium solvent, the dephosphorization reaction is promoted, and the phosphorus concentration of the hot metal is reduced to 0.015 mass% or less. I was able to. Furthermore, the dephosphorization process can be performed with a small oxygen supply amount, and the decarburization of the hot metal during the dephosphorization process can be suppressed, that is, the thermal margin of the hot metal after the dephosphorization process can be increased.

図３に、脱燐処理前の溶銑中珪素濃度と生石灰の使用量との関係を示し、図４に、脱燐用媒溶剤の使用量と脱燐処理後の溶銑中燐濃度との関係を示す。本発明では脱燐反応が効率的に行われるため、これらの図に示すように、少ない生石灰の使用量で、所定の燐濃度まで脱燐処理することができた。   FIG. 3 shows the relationship between the silicon concentration in hot metal before dephosphorization and the amount of quicklime used, and FIG. 4 shows the relationship between the amount of solvent used for dephosphorization and the phosphorus concentration in hot metal after dephosphorization. Show. In the present invention, since the dephosphorization reaction is performed efficiently, as shown in these figures, it was possible to dephosphorize to a predetermined phosphorus concentration with a small amount of quicklime used.

本発明を実施する上で最適な転炉型精錬設備の１例を示す概略図である。It is the schematic which shows one example of the converter type refining equipment optimal in implementing this invention. 図１に示す上吹きランスの拡大概略図である。FIG. 2 is an enlarged schematic view of an upper blowing lance shown in FIG. 1. 実施例１において調査した、脱燐処理前の溶銑中珪素濃度と生石灰の使用量との関係を示す図である。It is a figure which shows the relationship between the silicon concentration in hot metal before dephosphorization processing, and the usage-amount of quick lime investigated in Example 1. FIG. 実施例１において調査した、脱燐用媒溶剤の使用量と脱燐処理後の溶銑中燐濃度との関係を示す図である。It is a figure which shows the relationship between the usage-amount of the dephosphorization medium solvent investigated in Example 1, and the phosphorus density | concentration in hot metal after a dephosphorization process.

符号の説明Explanation of symbols

１ 転炉型精錬設備
２ 炉本体
３ 上吹きランス
４ 原料投入装置
５ 底吹き羽口
６ ガス導入管
７ 酸素ガス配管
８ 燃料配管
９ ディスペンサー
１０ 流量調整弁
１１ 流量調整弁
１２ 流量調整弁
１３ 媒溶剤移送配管
１４ 溶銑
１５ スラグ
１６ 脱燐用媒溶剤
１７ ランス本体
１８ ランスノズル
１９ 外管
２０ 中管
２１ 内管
２２ 最内管
２３ 中心孔
２４ 周囲孔 DESCRIPTION OF SYMBOLS 1 Converter type refining equipment 2 Furnace main body 3 Top blowing lance 4 Raw material injection device 5 Bottom blowing tuyere 6 Gas introduction pipe 7 Oxygen gas piping 8 Fuel piping 9 Dispenser 10 Flow rate adjusting valve 11 Flow rate adjusting valve 12 Flow rate adjusting valve 13 Solvent solvent Transfer pipe 14 Hot metal 15 Slag 16 Dephosphorization medium solvent 17 Lance body 18 Lance nozzle 19 Outer pipe 20 Middle pipe 21 Inner pipe 22 Innermost pipe 23 Central hole 24 Peripheral hole

Claims (7)

酸素源を供給して溶銑を脱燐処理する際に、珪素含有量が０．２質量％以下の溶銑を用い、当該溶銑の浴面に向かって、加熱または加熱・溶融したＣａＯを主体とする粉状の脱燐用媒溶剤を、気体酸素源と共に上吹きランスを介して吹き付けて添加し、脱燐処理することを特徴とする、溶銑の脱燐処理方法。   When the hot metal is dephosphorized by supplying an oxygen source, the hot metal having a silicon content of 0.2% by mass or less is used, and the hot metal is mainly heated or heated / melted toward the bath surface of the hot metal. A method for dephosphorizing hot metal, which comprises adding a powdery dephosphorization medium solvent together with a gaseous oxygen source by spraying through a top blowing lance, and dephosphorizing. 前記酸素源のうちの５０質量％以上を気体酸素源とすることを特徴とする、請求項１に記載の溶銑の脱燐処理方法。   The hot metal dephosphorization method according to claim 1, wherein 50 mass% or more of the oxygen source is a gaseous oxygen source. 前記ＣａＯを主体とする粉状の脱燐用媒溶剤として、実質的にフッ素を含まない脱燐用媒溶剤を使用し、当該脱燐用媒溶剤の５０質量％以上を、気体酸素源と共に上吹きランスから溶銑の浴面に向けて吹き付けて添加することを特徴とする、請求項１または請求項２に記載の溶銑の脱燐処理方法。   As the powdered dephosphorization medium solvent mainly composed of CaO, a dephosphorization medium solvent substantially free of fluorine is used, and 50 mass% or more of the dephosphorization medium solvent is added together with a gaseous oxygen source. 3. The hot metal dephosphorization method according to claim 1, wherein the hot metal is sprayed from the spray lance toward the hot metal bath surface. 前記脱燐用媒溶剤は、脱燐処理後の溶銑の脱炭精錬時に生成したスラグを主体とすることを特徴とする、請求項１ないし請求項３の何れか１つに記載の溶銑の脱燐処理方法。   The hot metal desorption according to any one of claims 1 to 3, wherein the dephosphorization medium solvent is mainly slag generated during decarburization and refining of hot metal after dephosphorization. Phosphorus treatment method. 前記上吹きランスの先端に設けたノズルから、炭化水素系のガス燃料、炭化水素系の液体燃料のうちの何れか１種以上を供給し、前記気体酸素源によって炭化水素系ガス燃料または炭化水素系液体燃料を燃焼させて火炎を形成し、当該火炎によって前記脱燐用媒溶剤を加熱または加熱・溶融することを特徴とする、請求項１ないし請求項４の何れか１つに記載の溶銑の脱燐処理方法。   One or more of hydrocarbon gas fuel and hydrocarbon liquid fuel is supplied from a nozzle provided at the tip of the upper blow lance, and hydrocarbon gas fuel or hydrocarbon is supplied by the gaseous oxygen source. The hot metal according to any one of claims 1 to 4, wherein a flame is formed by burning a system liquid fuel, and the dephosphorization medium solvent is heated or heated and melted by the flame. Dephosphorization method. 前記上吹きランスの中心孔から搬送用ガスとしての気体酸素源と共に脱燐用媒溶剤を供給し、中心孔の周囲の周囲孔から炭化水素系ガス燃料、炭化水素系液体燃料のうちの何れか１種以上を供給することを特徴とする、請求項５に記載の溶銑の脱燐処理方法。   A dephosphorization medium solvent is supplied from a central hole of the upper blowing lance together with a gaseous oxygen source as a carrier gas, and either a hydrocarbon gas fuel or a hydrocarbon liquid fuel is supplied from a peripheral hole around the center hole. One or more kinds are supplied, The hot metal dephosphorization processing method of Claim 5 characterized by the above-mentioned. 上吹きランスから供給する気体酸素源中の酸素ガス量と、炭化水素系ガス燃料及び炭化水素系液体燃料の理論燃焼分の酸素ガス量との比である酸素比が１．０以上となるように、気体酸素源の供給量、または、炭化水素系ガス燃料及び炭化水素系液体燃料の供給量を調整することを特徴とする、請求項５または請求項６に記載の溶銑の脱燐処理方法。   The oxygen ratio, which is the ratio between the amount of oxygen gas in the gaseous oxygen source supplied from the top blowing lance and the amount of oxygen gas for the theoretical combustion of the hydrocarbon gas fuel and hydrocarbon liquid fuel, is 1.0 or more. The method for dephosphorizing hot metal according to claim 5 or 6, wherein the supply amount of gaseous oxygen source or the supply amount of hydrocarbon gas fuel and hydrocarbon liquid fuel is adjusted. .
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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007092158A (en) * 2005-09-30 2007-04-12 Jfe Steel Kk Dephosphorize-treatment method for molten iron
WO2007100109A1 (en) * 2006-02-28 2007-09-07 Jfe Steel Corporation Method of dephosphorization of molten iron
JP2007262575A (en) * 2006-02-28 2007-10-11 Jfe Steel Kk Method of dephosphorization of molten iron
JP2009052059A (en) * 2007-08-23 2009-03-12 Sumitomo Metal Ind Ltd Method for dephosphorizing molten pig iron
JP2009114489A (en) * 2007-11-05 2009-05-28 Jfe Steel Corp Method for dephosphorizing molten iron
JP2010209436A (en) * 2009-03-12 2010-09-24 Jfe Steel Corp Method for elevating temperature of molten iron
JP2011157570A (en) * 2010-01-29 2011-08-18 Jfe Steel Corp Method for dephosphorizing molten iron and top-blowing lance for refining
JP2012229486A (en) * 2011-04-13 2012-11-22 Jfe Steel Corp Method for producing molten steel
JP2013047371A (en) * 2011-07-27 2013-03-07 Jfe Steel Corp Method for refining molten iron
JP2013047373A (en) * 2011-04-12 2013-03-07 Jfe Steel Corp Method for refining molten iron
JP2013049917A (en) * 2011-07-29 2013-03-14 Jfe Steel Corp Method for refining molten iron in converter
WO2013057927A1 (en) 2011-10-17 2013-04-25 Ｊｆｅスチール株式会社 Powder injection lance and method of refining molten iron using said powder injection lance
JP2013209678A (en) * 2012-03-30 2013-10-10 Jfe Steel Corp Method of manufacturing molten steel
JP2013221159A (en) * 2012-04-13 2013-10-28 Jfe Steel Corp Method of refining molten iron
WO2014112432A1 (en) * 2013-01-18 2014-07-24 Ｊｆｅスチール株式会社 Converter steelmaking process

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5236703U (en) * 1975-09-05 1977-03-15
JPS62161908A (en) * 1986-01-10 1987-07-17 Kobe Steel Ltd Method for dephosphorizing molten pig iron
JPS62222008A (en) * 1986-03-20 1987-09-30 Nippon Steel Corp Treatment for adding additive to molten metal
JPS63210229A (en) * 1987-02-26 1988-08-31 Nippon Steel Corp Desiliconization and dephosphorization of molten pig iron
JP2003172584A (en) * 2001-09-28 2003-06-20 Nippon Sanso Corp Fine particle blowing device and refining method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5236703U (en) * 1975-09-05 1977-03-15
JPS62161908A (en) * 1986-01-10 1987-07-17 Kobe Steel Ltd Method for dephosphorizing molten pig iron
JPS62222008A (en) * 1986-03-20 1987-09-30 Nippon Steel Corp Treatment for adding additive to molten metal
JPS63210229A (en) * 1987-02-26 1988-08-31 Nippon Steel Corp Desiliconization and dephosphorization of molten pig iron
JP2003172584A (en) * 2001-09-28 2003-06-20 Nippon Sanso Corp Fine particle blowing device and refining method

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007092158A (en) * 2005-09-30 2007-04-12 Jfe Steel Kk Dephosphorize-treatment method for molten iron
WO2007100109A1 (en) * 2006-02-28 2007-09-07 Jfe Steel Corporation Method of dephosphorization of molten iron
JP2007262575A (en) * 2006-02-28 2007-10-11 Jfe Steel Kk Method of dephosphorization of molten iron
JP2009052059A (en) * 2007-08-23 2009-03-12 Sumitomo Metal Ind Ltd Method for dephosphorizing molten pig iron
JP2009114489A (en) * 2007-11-05 2009-05-28 Jfe Steel Corp Method for dephosphorizing molten iron
JP2010209436A (en) * 2009-03-12 2010-09-24 Jfe Steel Corp Method for elevating temperature of molten iron
JP2011157570A (en) * 2010-01-29 2011-08-18 Jfe Steel Corp Method for dephosphorizing molten iron and top-blowing lance for refining
JP2013047373A (en) * 2011-04-12 2013-03-07 Jfe Steel Corp Method for refining molten iron
JP2012229486A (en) * 2011-04-13 2012-11-22 Jfe Steel Corp Method for producing molten steel
JP2013047371A (en) * 2011-07-27 2013-03-07 Jfe Steel Corp Method for refining molten iron
JP2013049917A (en) * 2011-07-29 2013-03-14 Jfe Steel Corp Method for refining molten iron in converter
WO2013057927A1 (en) 2011-10-17 2013-04-25 Ｊｆｅスチール株式会社 Powder injection lance and method of refining molten iron using said powder injection lance
US9580764B2 (en) 2011-10-17 2017-02-28 Jfe Steel Corporation Top-blowing lance and method for refining molten iron using the same
JP2013209678A (en) * 2012-03-30 2013-10-10 Jfe Steel Corp Method of manufacturing molten steel
JP2013221159A (en) * 2012-04-13 2013-10-28 Jfe Steel Corp Method of refining molten iron
WO2014112432A1 (en) * 2013-01-18 2014-07-24 Ｊｆｅスチール株式会社 Converter steelmaking process
JP5954551B2 (en) * 2013-01-18 2016-07-20 Ｊｆｅスチール株式会社 Converter steelmaking

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