JPH0525526A - Desulfurizing method of molten iron - Google Patents
Desulfurizing method of molten ironInfo
- Publication number
- JPH0525526A JPH0525526A JP17560991A JP17560991A JPH0525526A JP H0525526 A JPH0525526 A JP H0525526A JP 17560991 A JP17560991 A JP 17560991A JP 17560991 A JP17560991 A JP 17560991A JP H0525526 A JPH0525526 A JP H0525526A
- Authority
- JP
- Japan
- Prior art keywords
- desulfurization
- desulfurizing agent
- molten iron
- pressure
- hot metal
- 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、粉体の利用効率に優れ
た加圧下での粉体吹込みによる溶銑の脱硫方法に関する
ものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of desulfurizing hot metal by injecting powder under pressure, which is excellent in powder utilization efficiency.
【0002】[0002]
【従来の技術】溶銑予備処理(脱燐、脱硫)は清浄鋼を
経済的に製造するために必須のプロセスとして鉄鋼一貫
製鉄所に広く普及している。最近、高純度鋼の溶製要求
が強く、溶銑中のP≦ 0.020%、S≦ 0.003%を必要と
する場合が多く、時にはS≦ 0.001%が要求されること
もある。引き続く転炉精錬では脱硫が困難であり、2次
精錬で脱硫を行うのは経済的でないため、特に溶銑のS
レベルは低くする必要がある。2. Description of the Related Art Hot metal pretreatment (dephosphorization, desulfurization) is widely used in integrated steelworks as an essential process for economically producing clean steel. Recently, there are strong demands for high-purity steel to be melted, and in many cases P ≦ 0.020% and S ≦ 0.003% in the hot metal are required, and sometimes S ≦ 0.001%. Desulfurization is difficult in subsequent converter refining, and it is not economical to perform desulfurization in secondary refining.
The level needs to be low.
【0003】溶銑の脱硫を効果的に行い、脱硫剤の利用
効率を高める方法として、例えば特開平2-10095号公報
の方法を提案した。この方法は、溶銑中に吹込まれた炭
酸ソーダ(ソーダ灰)と溶銑との接触機会を高めるのに
有効であるが、大気圧下で処理を行っているため、次の
(1)式の反応によって生じるNaの損失を抑えることが
難しい。このため、ダスト生成による炭酸ソーダ損失が
多い(吹込み量の20〜30%)のが欠点である。As a method for effectively desulfurizing hot metal and increasing the utilization efficiency of a desulfurizing agent, for example, the method disclosed in Japanese Patent Laid-Open No. 2-10095 has been proposed. This method is effective in increasing the chance of contact between the sodium carbonate (soda ash) blown into the hot metal and the hot metal, but since the treatment is performed under atmospheric pressure, the reaction of the following equation (1) It is difficult to suppress the loss of Na caused by. For this reason, there is a large loss of sodium carbonate due to dust generation (20 to 30% of the blowing amount), which is a disadvantage.
【0004】 Na2CO3(l)+2C=2Na(g)+3CO(g) …(1) 例えば鉄と鋼、64(1978)9、P.1323〜1332に示され
ているように金属マグネシウムも溶銑中のSとの化学的
親和力が強く、金属マグネシウム単独かあるいは CaOや
CaC2との混合品の形で用いられている。しかしながら、
金属マグネシウムも蒸気圧が高いため大気圧下ではその
脱硫反応への利用効率が低いという欠点がある。Na 2 CO 3 (l) +2 C = 2 Na (g) +3 CO (g) (1) Iron and steel, 64 (1978) 9, P. As shown in 1323 to 1332, metallic magnesium also has a strong chemical affinity with S in the hot metal, and metallic magnesium alone or CaO or
It is used in the form of a mixture with CaC 2 . However,
Since metal magnesium also has a high vapor pressure, it has a drawback that its utilization efficiency for desulfurization reaction is low under atmospheric pressure.
【0005】[0005]
【発明が解決しようとする課題】本発明は前記従来技術
の問題点を解消すべく、炭酸ソーダもしくは金属マグネ
シウムと脱硫助剤から成る脱硫剤の優れた脱硫能を効果
的とするため、その欠点である蒸発による損失を抑えつ
つ溶銑中に搬送ガスとともに吹込むことができる溶銑の
脱硫方法を提供することを目的とするものである。DISCLOSURE OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention makes effective the desulfurization ability of a desulfurization agent composed of sodium carbonate or metallic magnesium and a desulfurization aid. It is an object of the present invention to provide a method for desulfurizing hot metal that can be blown into the hot metal together with a carrier gas while suppressing the loss due to evaporation.
【0006】[0006]
【課題を解決するための手段】前記目的を達成するため
の本発明は、容器内の溶銑を圧力 1.2気圧以上、 9.9気
圧以下の加圧雰囲気下で、該溶銑内に炭酸ソーダもしく
は純分10〜70重量%の金属マグネシウムからなる脱硫主
剤に、 CaOまたはCaC2を主成分とする脱硫助剤を30〜90
重量%の範囲で配合した脱硫剤を搬送ガスと共に吹込む
ことを特徴とする溶銑の脱硫方法である。Means for Solving the Problems The present invention for achieving the above-mentioned object is to provide a molten metal in a container under a pressure atmosphere of 1.2 atm or more and 9.9 atm or less under pressure of sodium carbonate or a pure content of 10%. the desulfurization main agent consisting of 70 wt% of the metal magnesium, the desulfurizing aids mainly comprising CaO or CaC 2 30 to 90
It is a desulfurization method for hot metal, characterized in that a desulfurizing agent mixed in a range of wt% is blown together with a carrier gas.
【0007】[0007]
【作 用】容器内圧力を1.2atm以上にすることによって
ソーダ灰ダストの発生が抑制されソーダ灰の脱硫反応効
率向上効果が見られた。この現象は金属マグネシウムを
含む脱硫剤を用いた場合も同様であった。圧力が高けれ
ば高いほどその効果は向上するが、 10atm以上にしても
図1に示すソーダ灰ダストの発生量が示すように、顕著
な改善が認められない。したがって、1.2atm以上9.9atm
以下の加圧雰囲気が良く、設備の安価さ、保守性等を勘
案すると実用上は1.2atm以上5atm 以下で十分である。[Operation] By increasing the pressure in the container to 1.2 atm or more, the generation of soda ash dust was suppressed and the effect of improving the desulfurization reaction efficiency of soda ash was observed. This phenomenon was the same when a desulfurizing agent containing metallic magnesium was used. The higher the pressure is, the more the effect is improved. However, as shown in the amount of soda ash dust generation shown in FIG. Therefore, 1.2 atm or more and 9.9 atm
The following pressurized atmosphere is good, and 1.2 atm or more and 5 atm or less is practically sufficient considering the cost of equipment and maintainability.
【0008】脱硫剤を炭酸ソーダもしくは金属マグネシ
ウムを含むものに限定するのは、これらの脱硫剤を用い
た時に加圧すれば顕著な改善効果が得られるからであ
る。次に金属マグネシウムを用いる脱硫剤においてマグ
ネシウムの組成割合を限定するのは、 金属マグネシウムが10%未満では加圧による改善効
果が得られるものの十分でない。 金属マグネシウムが70%を超えても加圧効果はもち
ろん認められるが、金属マグネシウム純分当たりの反応
効率向上効果はむしろやや低下するので70%以下で経済
的に十分である。70%を超えて反応効率向上が低下する
のは、生成した MgSが湯面のスラグに吸収されることな
く、スラグ中の FeOや MnOと反応し、再び溶銑中にSと
して戻ることによる。 脱硫助剤として CaOもしくはCaC2を用いるのは、大
気中やスラグ中の酸素と反応して、次の(2)式 MgS+(O)→ MgO+S …(2) により復硫が生じるのを防ぐため、より安定な CaSとし
てスラグ中に吸収させる。脱硫助剤の量30〜90%は金属
マグネシウムの脱硫効果を実験的に調べて決定した。 金属マグネシウムで脱硫する際には、マグネシウム
と溶銑の接触面積を増し、生成した MgSを凝集させるた
めに粒子の衝突の機会を増し、前述のCaSとして生成し
た硫化物を安定して固定化するのに CaOもしくはCaC2の
添加が不可欠である。The desulfurizing agent is limited to those containing sodium carbonate or metallic magnesium, because a remarkable improvement effect can be obtained by applying pressure when using these desulfurizing agents. Next, in the desulfurizing agent using metallic magnesium, it is not sufficient to limit the composition ratio of magnesium if the amount of metallic magnesium is less than 10%, although an improvement effect by pressurization can be obtained. Of course, even if the content of metallic magnesium exceeds 70%, the pressurizing effect is recognized, but the effect of improving the reaction efficiency per pure metal magnesium is rather lowered, so 70% or less is economically sufficient. The reason why the improvement of the reaction efficiency declines by more than 70% is that the generated MgS reacts with FeO and MnO in the slag without being absorbed by the slag on the surface of the molten metal, and returns to S in the hot metal again. The use of CaO or CaC 2 as a desulfurization aid prevents the reaction of oxygen in the atmosphere or slag to cause re-sulfurization by the following formula (2) MgS + (O) → MgO + S … (2) Therefore, it is absorbed in the slag as more stable CaS. The amount of desulfurization aid was 30-90%, which was determined by experimentally examining the desulfurization effect of metallic magnesium. When desulfurizing with magnesium metal, the contact area between magnesium and hot metal is increased, the chance of particle collision is increased to agglomerate the generated MgS, and the sulfide generated as CaS described above is stably immobilized. The addition of CaO or CaC 2 is essential.
【0009】[0009]
【実施例】図1は容器内に収容した 300kgの溶銑に、容
器内の圧力を調整しつつ1320±30℃でソーダ灰を 200g
/min で5min 間搬送ガスとして空気50Nl/min で吹込
んだ場合のダスト発生量(g/kg溶銑)を通常の大気圧
下での場合を1として指数化したものである。EXAMPLE FIG. 1 shows 300 g of hot metal contained in a container and 200 g of soda ash at 1320 ± 30 ° C. while adjusting the pressure in the container.
The amount of dust generated (g / kg hot metal) when air is blown at 50 Nl / min as a carrier gas for 5 min / min is indexed as 1 under normal atmospheric pressure.
【0010】また図2は Mg 20%−CaO 75%−COKe 5%
の−1mmの脱硫剤を 100g/min で5min 間、1320〜13
60℃の50kgの溶銑に搬送ガスN2 60Nl/min を用いて吹
込みその後吹込みを停止したままの状態でさらに5min
間保持した場合の脱硫曲線を大気圧下と2.5atm以下の状
態との比較で示す。図1からソーダ灰ダスト発生量は容
器内圧力が1.2atm以上になると急激に低下することがわ
かる。また図2からは2.5atmにおける溶銑中のS濃度は
大気圧下におけるそれに対して大幅に低減することがわ
かる。FIG. 2 shows Mg 20% -CaO 75% -COKe 5%.
-1mm of desulfurizing agent at 100g / min for 5min for 1320 ~ 13
Blow with 50 kg of hot metal at 60 ° C using carrier gas N 2 60Nl / min and then for another 5 minutes with the blowing stopped.
The desulfurization curve when held for a while is shown by comparison between atmospheric pressure and a state of 2.5 atm or less. It can be seen from Fig. 1 that the amount of soda ash dust generated sharply decreases when the pressure inside the container exceeds 1.2 atm. Further, it can be seen from FIG. 2 that the S concentration in the hot metal at 2.5 atm is significantly reduced compared to that at atmospheric pressure.
【0011】[0011]
【発明の効果】以上説明したように本発明によれば脱硫
剤の主剤である炭酸ソーダもしくは金属マグネシウムの
蒸発による損失を容器内の溶銑を加圧雰囲気にすること
により抑制して吹込むことができるので脱硫剤の反応効
率向上が容易に達成できる。As described above, according to the present invention, the loss due to the evaporation of sodium carbonate or magnesium metal, which is the main component of the desulfurization agent, can be suppressed and blown by making the hot metal in the container a pressurized atmosphere. Therefore, the reaction efficiency of the desulfurizing agent can be easily improved.
【図1】容器内圧力とソーダ灰ダスト発生量の関係を示
す線図である。FIG. 1 is a diagram showing a relationship between a container internal pressure and a soda ash dust generation amount.
【図2】容器内雰囲気圧力と溶銑脱硫による溶銑Sの推
移を示す線図である。FIG. 2 is a diagram showing changes in the atmospheric pressure in a container and the hot metal S due to hot metal desulfurization.
Claims (1)
気圧以下の加圧雰囲気下で、該溶銑内に炭酸ソーダもし
くは純分10〜70重量%の金属マグネシウムからなる脱硫
主剤に、 CaOまたはCaC2を主成分とする脱硫助剤を30〜
90重量%の範囲で配合した脱硫剤を搬送ガスと共に吹込
むことを特徴とする溶銑の脱硫方法。[Claims] [Claim 1] The molten pig iron in the container has a pressure of 1.2 atm or more, 9.9
Under a pressure atmosphere of atmospheric pressure or less, a desulfurization main agent composed of sodium carbonate or a magnesium content of 10 to 70% by weight of metallic magnesium in the hot metal, a desulfurization auxiliary agent containing CaO or CaC 2 as a main component is 30 to
A method for desulfurizing hot metal, characterized in that a desulfurizing agent mixed in a range of 90% by weight is blown together with a carrier gas.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17560991A JPH0525526A (en) | 1991-07-16 | 1991-07-16 | Desulfurizing method of molten iron |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17560991A JPH0525526A (en) | 1991-07-16 | 1991-07-16 | Desulfurizing method of molten iron |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0525526A true JPH0525526A (en) | 1993-02-02 |
Family
ID=15999088
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP17560991A Pending JPH0525526A (en) | 1991-07-16 | 1991-07-16 | Desulfurizing method of molten iron |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0525526A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0345111A2 (en) * | 1988-05-27 | 1989-12-06 | RHONE-POULENC GERONAZZO S.p.A. | Surfactant based on an oxyethylene and oxypropylene phenyl-1-ethyl phenol, method for its preparation, its use in obtaining concentrated solutions of active compounds |
CN1325663C (en) * | 2003-12-10 | 2007-07-11 | 蒋祖滨 | Purifying agent |
-
1991
- 1991-07-16 JP JP17560991A patent/JPH0525526A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0345111A2 (en) * | 1988-05-27 | 1989-12-06 | RHONE-POULENC GERONAZZO S.p.A. | Surfactant based on an oxyethylene and oxypropylene phenyl-1-ethyl phenol, method for its preparation, its use in obtaining concentrated solutions of active compounds |
EP0345111B1 (en) * | 1988-05-27 | 1993-07-21 | RHONE-POULENC GERONAZZO S.p.A. | Surfactant based on an oxyethylene and oxypropylene phenyl-1-ethyl phenol, method for its preparation, its use in obtaining concentrated solutions of active compounds |
CN1325663C (en) * | 2003-12-10 | 2007-07-11 | 蒋祖滨 | Purifying agent |
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