JPS6184311A - Method for heating molten iron by secondary combustion method - Google Patents

Abstract

PURPOSE:To increase additionally the rate of utilizing gaseous oxygen for secondary combustion reaction as a heating source by supplying said gaseous oxygen in the direction where the gaseous flow blows off so as not to contact with a molten iron bath. CONSTITUTION:The gaseous carbon monoxide generated as a result of the oxidation of the carbon in the molten iron or separately added carbon source in a refining vessel 1 is oxidized further to gaseous carbon dioxide by the gaseous oxygen from tuyeres 5 for secondary combustion in the vessel 1 and the reaction heat thereof is transmitted to the molten iron 3 in a secondary combustion method. Two pieces a set of the tuyeres 5 are installed to the opposite furnace walls to prevent the contact of the blow off direction of the gaseous oxygen with the molten iron 3. The tuyeres are installed in such direction where the central axes of the gaseous oxygen flow collide against each other in the space of the vessel 1. Each tuyere consists of double pipes, of which the inside pipe 7 ejects the oxygen. A cooling gas for protecting the tuyeres is ejected from the spacing between the inside pipe 7 and the outside pipe 8.

Description

【発明の詳細な説明】 （産業上の利用分野） 溶銑の脱炭の如き溶鉄精錬の改善に関してこの明細書で
述べる技術内容は、該精錬に随伴して発生し又は発生さ
せたＣＯガスを、精錬容器内でＣＯ３にまで酸化させ、
それにより発生する酸化反応熱゛を効率的に溶鉄に伝え
ることについての開発研究の成果、とり分は溶銑の脱炭
精錬時における熱補償の向上に関するものであり、より
具体的にいうと転炉内での脱炭精錬時に発生するＯＯガ
スをＣＯ３−□まで酸化燃焼させてその反応熱を溶鉄に
効率よく伝えようとするものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The technical content described in this specification regarding improvements in molten iron refining such as decarburization of hot metal is intended to reduce CO gas generated or produced accompanying the smelting. It is oxidized to CO3 in the refining vessel,
The results of research and development on how to efficiently transfer the resulting oxidation reaction heat to molten iron are mainly related to improving heat compensation during decarburization and refining of hot metal. The purpose is to oxidize and burn the OO gas generated during decarburization and refining to CO3-□, and efficiently transfer the reaction heat to the molten iron.

最近の製鋼技術の発展は、従来転炉内で除去していた燐
を転炉装入ｍＷ入前に除去する溶銑脱燐技術の工程化に
おいて顕著である。Recent developments in steelmaking technology are remarkable in the processization of hot metal dephosphorization technology in which phosphorus, which was conventionally removed in the converter, is removed before charging mW into the converter.

しかしこの溶銑脱燐に伴う大幅な温度降下のために、通
常の転炉操業では目標とする吹錬終了温度が得られない
場合があり、やむなくＦａ　−８ｉ合金や炭素源を転炉
内に添加して、Ｓｌ又はＣの酸化発熱により目標温度を
得る操作が必要となる。However, due to the large temperature drop associated with this hot metal dephosphorization, the target blowing completion temperature may not be achieved during normal converter operation, so Fa-8i alloy and carbon sources have to be added to the converter. Therefore, it is necessary to perform an operation to obtain the target temperature by generating heat of oxidation of Sl or C.

一方においてＭｎ鉱石やＯｒ鉱鉱石どを転炉内に添加し
、該鉱石の還元によって合金成分のＩｎやＱｒを回収す
る方法の利用も進められつつあるがこの場合には、鉱石
の顕熱と還元吸熱とを補うため、転炉に多量の炭素源た
とえばコークスを添力１し、その酸化反応熱により不足
熱を補う必要があ゛る。On the other hand, the use of a method in which Mn ore, Or ore, etc. is added to the converter and the alloying components In and Qr are recovered by reducing the ore is also progressing, but in this case, the sensible heat of the ore and In order to compensate for the reduction endotherm, it is necessary to add a large amount of carbon source, such as coke, to the converter, and to compensate for the insufficient heat with the heat of the oxidation reaction.

さらには、鉄源価格の変動に従い、溶銑よりスクラップ
（ｆＩｉ屑）が安価な場合には、転炉へのスクラップ投
入量を増加するいわゆる低溶読比操業゛による経済的吹
錬が所期されるがこの場合にもスクラップの溶解熱を補
償するため、同じく多量の炭素源による熱補償対策が必
要とされる。Furthermore, in accordance with fluctuations in iron source prices, if scrap (fIi scrap) is cheaper than hot metal, economical blowing by so-called low melting ratio operation, which increases the amount of scrap input to the converter, is expected. However, in this case as well, heat compensation measures using a large amount of carbon source are required to compensate for the heat of melting the scrap.

以上のように炭素源などを転炉内に添加する場合も含め
、上記の如き各種の精錬における熱補償゛′。Heat compensation in various types of refining as described above, including when carbon sources are added into the converter.

をより有利に成就するところに、この発明の有用性は、
以下逐次にのべるとおり明らかである。The usefulness of this invention is that it more advantageously achieves the following:
This is clear as described below.

（従来の技術） 特公昭！５９−２１８６号公報では、とくに含りｐム鋼
の脱炭精錬に際し、溶鉄浴面にて発生する゛−□ＣＯガ
スの燃焼を図るため酸素ガスを該浴面上に吹つけること
が開示されている。しかるにこの場合燃焼反応生成物で
あるＣＯ，ガスが、鋼中Ｃと反応して再び００ガスにな
り、この反応は吸熱を伴うので、溶鉄加熱の熱源として
利用度が減殺され′□”る不利があった。(Conventional technology) Tokukosho! Publication No. 59-2186 discloses that during decarburization refining of PM-containing steel, oxygen gas is blown onto the molten iron bath surface in order to burn the ゛-□CO gas generated on the bath surface. ing. However, in this case, CO gas, which is a combustion reaction product, reacts with C in the steel and becomes 00 gas again, and this reaction is accompanied by heat absorption, so its utility as a heat source for heating molten iron is reduced, which is a disadvantage. was there.

（発明が解決しようとする問題点） 溶鉄の脱炭精錬に際し溶鉄浴面で生成するＣＯガスの該
溶鉄に対する加熱源としての利用度をさらに高める方途
を招くことがこの発明の目的であ゛る。(Problems to be Solved by the Invention) It is an object of the present invention to provide a method for further increasing the utilization of CO gas generated on the surface of a molten iron bath during decarburization and refining of molten iron as a heating source for the molten iron. .

（問題を解決するための手段） この発明の目的は次の事項で有利に充足される。(Means to solve the problem) The objects of the invention are advantageously fulfilled by the following.

溶鉄中の炭素ないしは別に添加した炭素源が精錬容器の
内部で酸化して発生する一酸化炭素ガス１パを、精錬容
器内で更に二酸化炭素ガスになるまで酸化し、その反応
熱を溶鉄に伝えるいわゆる２次燃焼法による溶鉄の加熱
に際し、 ２次燃焼反応用の酸素ガスを、その気流の吹出し方向が
溶鉄浴と接触しない向きとしてスラグ中１′に供給する
ことを特徴とする、２次燃焼による溶鉄の加熱方法。The carbon monoxide gas generated by the oxidation of carbon in the molten iron or a separately added carbon source inside the smelting vessel is further oxidized into carbon dioxide gas within the smelting vessel, and the heat of reaction is transferred to the molten iron. When heating molten iron by the so-called secondary combustion method, the secondary combustion method is characterized in that oxygen gas for the secondary combustion reaction is supplied into the slag 1' with the blowing direction of the airflow not coming into contact with the molten iron bath. method of heating molten iron.

さて精錬容器中に炭素源を加える場合も含めて、該容器
中における酸化反応熱の利用は、次式（１）によってあ
られされる。　　　　　　　　　　　　　パ０　−＋４
　０．＝　　００　＋８２　７４０　（ｃａｔ／ｍｏｌ
　　　）　　・　（１）ここでＣは溶鉄中の炭素および
添加した炭素源。Utilization of the heat of oxidation reaction in the refining vessel, including the case where a carbon source is added to the vessel, is expressed by the following equation (1). Pa0 −+4
0. = 00 +82 740 (cat/mol
) ・ (1) Here, C is the carbon in the molten iron and the added carbon source.

溶鉄中炭素濃度（以下Ｃ％Ｃ〕）が高い場合には、（１
）式の反応が大部分であるが、低Ｃ％Ｏ）の−場合や、
上吹き酸素ガスの流量やランス高さを調整することによ
り次式の反応の発熱も得ることができる。When the carbon concentration in molten iron (hereinafter referred to as C%C) is high, (1
) reaction is the majority, but in the case of - with low C%O),
By adjusting the flow rate of top-blown oxygen gas and the lance height, it is possible to obtain the heat generated by the following reaction.

００　＋−；Ｏ，＝　Ｃｏ、　＋　６１７５０（ｃａｊ
／ｍｏ、ｇ　　）　・（２）前述の熱補償の目的のため
には高Ｃ％Ｏ〕の場合でも（２）式の反応を進めて大量
の発熱を得ることが望ましいが、通常の転炉操業では、
発生するＣＯガスのうち高々２０％を燃焼させるにとど
まっていた。00 +-;O,=Co, +61750(caj
/mo, g) ・(2) For the purpose of heat compensation mentioned above, it is desirable to proceed with the reaction of equation (2) to generate a large amount of heat even in the case of high C%O], but it is desirable to proceed with the reaction of equation (2) to obtain a large amount of heat. In operation,
Only 20% of the generated CO gas was combusted.

この発明では、従来技術の欠点であったＣＯガスのｃｏ
、への燃焼効率の低さを大幅に改善するため、とくにス
ラグ中への酸素供給用羽目の浸漬配置により、酸素気流
が溶鉄に接しない゛ようにその噴出方向を溶鉄浴面と事
実上平行にする。In this invention, CO gas, which was a drawback of the prior art, is
In order to significantly improve the low combustion efficiency of the molten iron, in particular, by immersing the oxygen supply blades into the slag, the jetting direction is virtually parallel to the molten iron bath surface so that the oxygen stream does not come into contact with the molten iron. Make it.

第１図に従い具体的に説明を加えると図中１は２．。To give a more specific explanation according to Figure 1, 1 in the figure is 2. .

転炉炉体、２は底吹き羽口、８は溶鉄、４はスラ゛グ、
そして５は２次燃焼酸素供給用羽口であり、６は脱炭用
の酸素を供給するランスである。Converter furnace body, 2 is bottom blowing tuyere, 8 is molten iron, 4 is slag,
Further, 5 is a tuyere for supplying secondary combustion oxygen, and 6 is a lance for supplying oxygen for decarburization.

ここにスラグ４中へ浸漬されている２次燃焼酸素供給用
羽口５は、溶銑装入時や溶鋼出刃時に炉゛体を傾動して
も鉄浴面下に浸漬しない位置にて、２本１組で対向する
炉壁に設置し、酸素気流の中心軸が転炉炉体１の空間で
衝突するように方向を決定する。Two tuyeres 5 for supplying secondary combustion oxygen are immersed in the slag 4 at a position where they will not be immersed below the surface of the iron bath even if the furnace body is tilted during charging of hot metal or tapping of molten steel. They are installed as a pair on opposing furnace walls, and the directions are determined so that the central axes of the oxygen gas flow collide in the space of the converter body 1.

この設置要領を採用しないと、スラグ４の形成１′。If this installation procedure is not adopted, the slag 4 will be formed 1'.

が未だ不十分で２次燃焼酸素供給用羽口５がスラグ中に
浸漬されないとき、酸素気流が対向する炉壁に直接衝突
して、炉壁耐大物を著しく溶損する。When the secondary combustion oxygen supplying tuyere 5 is not immersed in the slag because of insufficient combustion, the oxygen stream directly collides with the opposing furnace wall, causing significant erosion of the furnace wall sturdiness.

一方、２次燃焼酸素供給用羽口５の設置高さは、転炉が
直立状態でかつ脱炭吹錬の進行中、脱炭用“゛の酸素ラ
ンス６の下端より下方でしがも鉄浴表面より上方になけ
ればならないが、転炉本体１の形状や耐火物レンガの内
容積、ランス高さ下限などによっても変化するので、一
般的には決められず、各転炉毎に決定するを要する。　
　　　　　　　パ□２次燃焼酸素供給用羽口５は、いわ
ゆる２重管１羽口とし、その内管７より酸素又は酸素含
有ガスを、内管７と外管８との間のすき間から、羽口保
護用の冷却ガスを、それぞれ噴出するようにすることが
のぞましい。On the other hand, the installation height of the tuyeres 5 for supplying secondary combustion oxygen is such that when the converter is in an upright state and decarburization blowing is in progress, It must be located above the bath surface, but this varies depending on the shape of the converter body 1, the internal volume of the refractory bricks, the lower limit of the lance height, etc., so it cannot be determined in general and must be determined for each converter. It takes.
The tuyere 5 for supplying secondary combustion oxygen is a so-called double-pipe tuyere, and oxygen or oxygen-containing gas is supplied from the inner pipe 7 to the tuyere through the gap between the inner pipe 7 and the outer pipe 8. It is desirable that a protective cooling gas be ejected from each of them.

第２図に脱炭精錬挙動を模式的に示すように、ＣＯガス
によってフォーミング（泡立ち）したスラグに対して、
鋼浴と接触しないように２次燃焼用酸素供給用羽口５か
らスラグ４中に酸素を吹込むと、溶鉄８の浴面で発生し
たＣＯはＯＯｌまで酸１゛化され、その反応熱はスラグ
に蓄えられる。As shown in Fig. 2, which schematically shows the decarburization refining behavior, for slag formed by CO gas,
When oxygen is blown into the slag 4 through the secondary combustion oxygen supply tuyere 5 so as not to come into contact with the steel bath, the CO generated on the bath surface of the molten iron 8 is converted into acid 1 to OOl, and the reaction heat is stored in slag.

この蓄熱分は、底吹き羽口２を通して供給した精錬用ガ
スによるスラグ／メタルの強攪拌の下に溶鉄８側へ伝え
られる。This accumulated heat is transferred to the molten iron 8 side while the slag/metal is strongly stirred by the refining gas supplied through the bottom blowing tuyeres 2.

すなわち、大量の熱がスラグ４を媒介として溶゛゛鉄８
へ移行するので、発生したＣＯ８が次式（８）％式％（
８） に従って再びＯＯになるような吸熱反応を生ぜず、効率
よく溶鉄加熱に活用できる。In other words, a large amount of heat is transferred to molten iron 8 through slag 4.
The generated CO8 is expressed by the following formula (8) % formula % (
8) According to the above, an endothermic reaction such as becoming OO again does not occur, and it can be efficiently used for heating molten iron.

この発明の効果を十分に得るため、底吹き羽口２′。In order to fully obtain the effects of this invention, the bottom blowing tuyere 2'.

２を通して、溶鉄浴中に吹き込む精錬用ガスによ゛る強
攪拌を加えることがのぞましくここに底吹きガス流量は
、スラグ４中の（１ＦｅＯ）を低減する効果の著しいと
されている０、１　Ｎｍ８７ｍ１ｎ−を以上がとくに好
ましい。It is desirable to add strong stirring by the refining gas blown into the molten iron bath through 2. It is said that the bottom blown gas flow rate has a remarkable effect of reducing (1FeO) in the slag 4. 0.1 Nm87m1n- or more is particularly preferred.

第８図には底吹きガス流量とスラグ／メタル間の温度差
との関係を示し、底吹きガス流量が０．１Ｎｍ”７ｍ１
ｎ−を以上の場合にスラグ／メタル間の温度差は著しく
小さく、スラグ／メタル間の混合が十分になされて、伝
熱が効率よく行われていること１パを示す。Figure 8 shows the relationship between the bottom blowing gas flow rate and the temperature difference between slag and metal.
When n- or more, the temperature difference between the slag and metal is extremely small, indicating that the slag and metal are sufficiently mixed and heat transfer is performed efficiently.

これに対し第４図（ａ）　（ｂ）に示した上掛特公昭５
９−２１８６７号公報に開示のような従来の技術では、
脱炭精錬の反応生成物である００ガスの二次燃焼酸素と
して獣吹きランス９又は、炉口近くの炉１゛壁に設けた
吹込み口１０から酸素又は酸素含有ガスを溶鉄浴８に向
って下向きに吹付けているので、さきに式（３）にて示
した吸熱反応を生じて、事実上、式（１）による反応熱
、しか利用され得なかったのである。　　　　　　　　
　　　　　　　　　　　　、１゜上記のようにして、こ
の発明の実施が、底吹き゛転炉又は、上底吹き転炉にお
いて有利に適合するのは明らかである。On the other hand, as shown in Figure 4 (a) and (b),
In the conventional technology as disclosed in Publication No. 9-21867,
Oxygen or oxygen-containing gas is directed to the molten iron bath 8 from the blow lance 9 or from the inlet 10 provided in the wall of the furnace 1 near the furnace mouth as secondary combustion oxygen of 00 gas, which is a reaction product of decarburization refining. Since the gas is blown downward, the endothermic reaction shown in equation (3) occurs, and in fact, only the reaction heat shown in equation (1) can be utilized.
, 1° As described above, it is clear that the implementation of the invention is advantageously suited in bottom-blown converters or top-bottom-blown converters.

（実施例） 実施例１ 第１図に示した４容５トンの上底吹き転炉を用い、２次
燃焼酸素供給用羽口５はとくにトラニオン軸近傍にて転
炉炉体１の直径上で向い合う２本１組のみを設置した。(Example) Example 1 Using the 4 volume 5 ton top blowing converter shown in FIG. Only one set of two facing each other was installed.

酸素ガスは炉底羽口２から５　Ｎｍ　／ｍｉｎ　ｓ上吹
き“゛ランス６から１０　Ｍｍ　／ｍｉｎとし、そして
２次燃焼酸素供給用羽口５からは２本の合計で５　Ｎｍ
”／ｍｉｎをそれぞれ供給した。Oxygen gas was supplied at 5 Nm/min from the bottom tuyere 2, 10 Mm/min from the top blow lance 6, and a total of 5 Nm from the two tuyeres 5 for supplying secondary combustion oxygen.
”/min, respectively.

約５トンの溶銑を表１に示す条件にて転炉内に装入した
後に上述の酸素ガスで吹錬を続けて、炭゛゛素濃度〔％
Ｃ〕が約０．１０　％になった時点での溶ｆｌｉ温度を
測定しこの間また、〔ｑｂＣ〕が約１係の時点で出鋼孔
から炉内のガス採取を行い、ガスクロマトグラフィーに
よりガス組成の分析も行って、表１に示す精錬成績を得
た。　　　　　　　　　”°□。Approximately 5 tons of hot metal was charged into a converter under the conditions shown in Table 1, and then blowing was continued with the oxygen gas described above to reduce the carbon concentration [%].
The melt fli temperature was measured when [qbC] reached approximately 0.10%, and during this time, when [qbC] was approximately 1%, the gas in the furnace was sampled from the tapping hole, and the gas was analyzed using gas chromatography. The composition was also analyzed and the refining results shown in Table 1 were obtained. ”°□.

これに対して酸素供給は上述の条件に揃えて　２０　Ｎ
ｍ　／ｍｉｎとし、全量を底吹き羽口２のみから供給す
る従来の底吹き吹錬（従来例１．Ｂ）と５　Ｎｍ’／ｍ
ｉｎを底吹きランス２よりまた、１５　）Ｊｍ８／ｍｉ
ｎを上吹きランス６から供給する従来の上底吹−□き吹
錬（従来例８，４）とについても同様な測定を行い、成
績を比較した。On the other hand, the oxygen supply was adjusted to the above conditions at 20 N.
m/min, and the total amount is supplied only from the bottom blowing tuyere 2 (conventional example 1.B) and 5 Nm'/min.
In from bottom blowing lance 2, 15) Jm8/mi
Similar measurements were made for conventional top and bottom blowing (conventional examples 8 and 4) in which n was supplied from the top blowing lance 6, and the results were compared.

装入溶銑の条件すなわち温度、Ｏ、Ｓｉ濃度ともほぼ同
一の範囲内にあり、かつ吹止め時のＣ濃度も同一範囲で
あっても吹止時温度は従来例１．＋□３と比べて５０〜
７０℃、同じく８．４と比べて８０〜５０℃高くなって
いる。Even though the charging hot metal conditions, that is, the temperature, O, and Si concentrations are in almost the same range, and the C concentration at the time of blow-off is also in the same range, the temperature at blow-off is the same as that of conventional example 1. 50~ compared to +□3
70℃, which is 80-50℃ higher than 8.4.

またガス中のＣＯ３濃度も明らかに高く、２次燃焼の効
果が明確に現われている。Furthermore, the CO3 concentration in the gas is clearly high, and the effect of secondary combustion is clearly evident.

ば従来例１．８では８．４〜５．４優、同８．４でも１
１．１〜１２．２％であるのに対し、この発明の場合に
は２６．５〜８４．５％まで上昇している。For example, the conventional example 1.8 is 8.4 to 5.4 excellent, and the same 8.4 is 1
While it is 1.1 to 12.2%, in the case of this invention it increases to 26.5 to 84.5%.

この実施例では２次燃焼用酸素を５　Ｎｍ’／ｍｉｎ　
一定としたため、高々８４．５　％の２次燃焼率であっ
′°□たが、別に行った実験で１０　Ｎｍ８７ｍ１ｎま
で２次燃１焼用酸素を増加した時にはく脱炭用酸素は１
５Ｎｍ’／ｍｉｎ　）　２次燃焼率は６２％まで上昇し
、溶鋼温度は１７４０°Ｃ以上を記録した。In this example, the oxygen for secondary combustion was 5 Nm'/min.
Since the secondary combustion rate was kept constant, the secondary combustion rate was at most 84.5%, but in a separate experiment, when the secondary combustion oxygen was increased to 10 Nm87mln, the decarburization oxygen was 1
5Nm'/min) The secondary combustion rate increased to 62%, and the molten steel temperature was recorded at 1740°C or higher.

実施例８ 実施例１と同じ５トン転炉を用いて、同一の２次燃焼用
羽口を使用し、酸素を供給しつつ、溶鋼温度が１５５０
〜１６００℃になるようにり四ム鉱石とコークス塊を炉
口から投入した。コークス塊は２５　ｋｙ　／ｍｉｎ　
、クロム鉱石は温度の高低によＩｌｌり投入量を調整し
た。この事例はクロム鉱石中のクロム酸化物を炭素還元
して、溶鉄中に回収する目的に従い、り四ム鉱石を大量
に短時間に投入して生産性の向上を期するものである。Example 8 Using the same 5-ton converter as in Example 1 and using the same secondary combustion tuyeres, the molten steel temperature was raised to 1550°C while supplying oxygen.
Shimu ore and coke lumps were charged from the furnace mouth so that the temperature reached ~1600°C. Coke mass is 25 ky/min
The input amount of chromium ore was adjusted depending on the temperature. In this case, chromium oxide in chromium ore is reduced with carbon and recovered in molten iron, and a large amount of chromium ore is introduced in a short period of time to improve productivity.

脱炭用酸素はｌ　５　Ｎｍ　／ｗｉｎとし、２次燃焼酸
素“′供給用羽口５を通して１０　Ｎｍ　／ｍｉｎの酸
素を供給したところり四ム鉱石は４５〜５０　Ｉｃ９／
ｍｉｎの投入速度で温度は上記範囲に収った。しかし第
４図に示した溶鉄に直接酸素気流が当たる方式の羽目で
は２５〜８０　ｋｇ　／ｈ＋ｉｎの投入速度に止まり、
またパ２次燃焼酸素供給用羽口５を使用せずに全酸素量
゛は同一条件にした場合には、１５〜ｆｌ　Ｏｋｇ／ｒ
ｎｉｎの投入速度しか達成できなかった。Oxygen for decarburization was 15 Nm/win, and 10 Nm/min of oxygen was supplied through the secondary combustion oxygen supply tuyere 5.
The temperature was within the above range at a charging speed of 1 min. However, with the method shown in Figure 4, in which the molten iron is directly exposed to an oxygen stream, the charging speed is limited to 25 to 80 kg/h+in.
Moreover, when the total oxygen amount is kept under the same conditions without using the tuyeres 5 for supplying oxygen for secondary combustion, the
An input speed of only nin could be achieved.

この例から明らかなように、２次燃焼酸素供給用羽口を
設置する位置とその酸素気流の方向をこ゛の発明のよう
にしなければ高い２次燃焼率が得られず、したがって鉱
石投入速度も小さくなることがわかる。As is clear from this example, a high secondary combustion rate cannot be obtained unless the location of the secondary combustion oxygen supply tuyeres and the direction of the oxygen flow are as in this invention, and therefore the ore feeding rate can be reduced. You can see that it becomes smaller.

（発明の効果） この発明によれば、溶鉄の脱炭精錬によって生゛パ戊す
るＣｏガスの適切な２次燃焼が導かれそれによる有効な
溶鉄の加熱が可能になる。(Effects of the Invention) According to the present invention, the decarburization and refining of molten iron leads to appropriate secondary combustion of the Co gas that is produced, thereby making it possible to effectively heat the molten iron.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図はこの発明に従う２次燃焼方法の実施要領を示す
上底吹き転炉の断面図、 第２図は炉内反応挙動を示す模式図であり、第８図は転
炉の底吹きガス流量がスラグ／メタル間温度差に及ぼす
影響を示すグラフであり、第４図は従来法の説明図であ
る。 １・・・転炉炉体　　　　２・・・底吹き羽目８・・・
溶鉄　　　　　　　４・・・スラグ５・・・２次燃焼用
羽目Fig. 1 is a sectional view of a top-bottom blowing converter showing the procedure for implementing the secondary combustion method according to the present invention, Fig. 2 is a schematic diagram showing reaction behavior in the furnace, and Fig. 8 is a bottom-blowing converter gas FIG. 4 is a graph showing the influence of flow rate on the temperature difference between slag and metal, and FIG. 4 is an explanatory diagram of the conventional method. 1...Converter furnace body 2...Bottom blowout 8...
Molten iron 4...Slag 5...Gate for secondary combustion

Claims (1)

【特許請求の範囲】 １、溶鉄中の炭素ないしは別に添加した炭素源が精錬容
器の内部で酸化して発生する一酸化炭素ガスを、精錬容
器内で更に二酸化炭素ガスになるまで酸化し、その反応
熱を溶鉄に伝える、いわゆる２次燃焼法による溶鉄の加
熱に際し、 ２次燃焼反応用の酸素ガスを、その気流の 吹出し方向が溶鉄浴と接触しない向きとしてスラグ中に
供給することを特徴とする、２次燃焼による溶鉄の加熱
方法。 ２、精錬容器が底吹き転炉または上底吹き転炉である１
記載の方法。[Claims] 1. Carbon monoxide gas generated by oxidation of carbon in molten iron or a separately added carbon source inside the refining vessel is further oxidized to carbon dioxide gas within the refining vessel, and then When heating molten iron by the so-called secondary combustion method that transfers reaction heat to molten iron, oxygen gas for the secondary combustion reaction is supplied into the slag with the direction of the airflow not coming into contact with the molten iron bath. A method of heating molten iron using secondary combustion. 2. The refining vessel is a bottom blowing converter or a top and bottom blowing converter1.
Method described.