JPS6152210B2 - - Google Patents
Info
- Publication number
- JPS6152210B2 JPS6152210B2 JP8933181A JP8933181A JPS6152210B2 JP S6152210 B2 JPS6152210 B2 JP S6152210B2 JP 8933181 A JP8933181 A JP 8933181A JP 8933181 A JP8933181 A JP 8933181A JP S6152210 B2 JPS6152210 B2 JP S6152210B2
- Authority
- JP
- Japan
- Prior art keywords
- oxygen
- liquid
- amount
- lance
- blowing
- 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.)
- Expired
Links
- 238000007664 blowing Methods 0.000 claims description 42
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 39
- 229910052760 oxygen Inorganic materials 0.000 claims description 39
- 239000001301 oxygen Substances 0.000 claims description 39
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 36
- 239000007788 liquid Substances 0.000 claims description 33
- 238000007670 refining Methods 0.000 claims description 23
- 239000002184 metal Substances 0.000 claims description 22
- 229910052751 metal Inorganic materials 0.000 claims description 22
- 238000000034 method Methods 0.000 claims description 22
- 238000009628 steelmaking Methods 0.000 claims description 11
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 8
- 229910052799 carbon Inorganic materials 0.000 claims description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 6
- 230000035515 penetration Effects 0.000 claims description 5
- 239000007921 spray Substances 0.000 claims description 2
- 238000003756 stirring Methods 0.000 description 19
- 238000005261 decarburization Methods 0.000 description 16
- 230000007423 decrease Effects 0.000 description 14
- 230000000694 effects Effects 0.000 description 14
- 229910000831 Steel Inorganic materials 0.000 description 13
- 239000010959 steel Substances 0.000 description 13
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 12
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 12
- 238000007654 immersion Methods 0.000 description 11
- 238000009834 vaporization Methods 0.000 description 8
- 230000008016 vaporization Effects 0.000 description 8
- 238000002347 injection Methods 0.000 description 7
- 239000007924 injection Substances 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 6
- 229910002092 carbon dioxide Inorganic materials 0.000 description 6
- 239000001569 carbon dioxide Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000036284 oxygen consumption Effects 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 239000011261 inert gas Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000001294 propane Substances 0.000 description 3
- 239000002893 slag Substances 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- 239000002253 acid Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000000112 cooling gas Substances 0.000 description 1
- 238000005262 decarbonization Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000000855 fermentation Methods 0.000 description 1
- 230000004151 fermentation Effects 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
- C21C5/285—Plants therefor
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/04—Removing impurities other than carbon, phosphorus or sulfur
Description
本発明は、製鋼精錬法に関するものである。
本発明は製鋼精錬法において設備コストの低減
溶鋼歩留を著しく向上せしめ、酸素原単位を向上
せしめる等の顕著な効果を示す方法を提供するも
のであり、その目的とするところはマルチランス
からの酸素上吹きによる超ソフトブローでスロツ
ピング、スピツテイングの減少をはかり、さらに
浸漬ランスあるいは底吹きノズルからの液体酸素
あるいは液体炭酸の吹込みによる強撹拌を行い、
その相乗効果により鉄酸化ロスを減少し、溶鋼歩
留を向上させる製鋼精錬法を提供することにあ
る。
現在のLD転炉酸素製鋼法における、上吹酸素
ランスは１本でマルチノズル（多孔ノズル）が一
般的である。
最近底吹転炉（Ｑ−BOP）あるいは上底吹複
合転炉（LD−OB，LD−KG，LBE等）が続々開
発されている。
予備処理として脱Si、脱Ｓを行い、転炉で脱
Ｃ、脱Ｐを行う方法も既知である。LD，Ｑ−
BOP，LD−OB等を使用する場合、通常Ｌ／Ｌp
＝0.5〜1.0（Ｌ：酸素ジエツトの溶湯浸入深さ、
Ｌp；溶湯深さ）、Ｌp／Ｄp＜0.5（Ｌp；溶湯深
さ、Ｄp；容器平均径）である。
しかし上記従来技術では膨大な設備費を必要と
し吹錬中に噴出物が炉口に堆積したり、炉外に飛
散し歩留の低下をきたしていた。
底吹用ノズルの構造は通常２重管となつてお
り、内管より気体酸素、外管より冷却用ガス（プ
ロパンガス、CO2ガス等）を吹込むようになつて
いるのが一般的である。
LD−KG，LBEの場合は単管ノズルあるいは炉
底ポーラスプラグからの不活性ガス吹込みを行つ
ている。
上吹LD転炉において、多孔ノズルで吹錬する
場合には鋼浴面における狭い火点（Fire Spot）
で酸素の授受が行なわれる。高圧で大量の酸量を
噴射するため炉底の損傷及び吹錬中のスロツピイ
ング、スピツテイング現象が増加し、歩留低下あ
るいはランス寿命が短いという欠点を有してい
た。またランス高さを上げたり、或いは流量調整
により酸素をソフトに噴射させる方法等がある
が、本来の多孔ノズルの使い方ではなく、いたず
らに鉄酸化ロスを増すだけであつた。
これらの問題を解決するため、底吹転炉、上底
吹複合転炉が開発されている。しかし底吹用ノズ
ルが２重管で外管から冷却用としてプロパンガス
を流す場合溶鋼中へのプロパンガスの分解による
〔Ｈ〕のピツクアツプが問題となつている。一方
底吹用として不活性ガスを使用する場合は上記問
題はなくなるが、上吹LD転炉と同様の大容量酸
素を上吹きランスから噴射させるため、スロツピ
ング、スピツテイング現象は防ぎ得ず歩留低下を
きたしていた。
本発明者らは、上記の如き諸欠点は、撹拌力と
精錬を同時に酸素ジエツトに求めていたことに起
因することに着目し、撹拌力と精錬の２つの機能
に分離することによる効果が著大なことを知見し
た。
すなわち本発明は上記の如き問題をすべて有利
に解決する方法で、その特徴とするところは精錬
容器においてマルチランス（ランス２本以上）か
らの気体酸素の上吹きにおいてＬ／Ｌp0.3
（Ｌ；酸素ジエツトの溶湯浸入深さ、Ｌp；溶湯深
さ）とし、浸漬ランスあるいは底吹ノズルから液
体酸素を1.3／min以上又は液体炭酸を2.1／
min以上吹込むことを特徴とする製鋼精錬法であ
る。
又本発明においては撹拌力を浸漬ランスからの
液体酸素、又は液体炭酸の吹込みで得られること
により、溶湯深さは従来とは逆に深くなければな
らない（溶湯深さ／容器平均径0.5）前式より
浅いと、従来の酸素ジエツトと同じようにスピツ
チング、スロツピングが生ずる。
さらに、脱炭精錬用の気体酸素の吹込みは少量
かつ低圧が可能となるものである。
すなわち本発明の第２の発明はこれらの知見に
基づき完成したものであり、精錬鍋にＬp／Ｄp
0.5（Ｌp；溶湯深さ、Ｄp：容器平均径）を満た
すように溶銑を保持し、マルチランス（ランス２
本以上）からの、気体酸素をＬ／Ｌp0.2（Ｌ：
酸素ジエツトの溶湯浸入深さ、Ｌp；溶湯深さ）
を満足するように吹付け、かつ浸漬ランスあるい
は底吹ノズルから液体酸素を1.3／min以上、
又は液体酸素を2.1／min以上吹込み脱炭する
ことを特徴とする製鋼精錬法である。
つぎに図面に示す実施態様例によつて本発明を
詳細に述べる。
第１図ａ，ｂ，ｃは夫々従来のLD，Ｏ−
BOP，LD−OBのランスあるいはノズルの説明図
で底吹ノズルは２重管となつている。
第２図、第３図は本発明の実施態様を示すもの
で、精錬容器において精錬を行うに当り、マルチ
ランスによる気体酸素の噴射及び浸漬ランスある
いは底吹ノズルからの液体酸素あるいは液体炭酸
の吹込みを行う実施態様を示したものである。
まず精錬容器１内に溶銑５を装入し、浸漬ラン
ス（耐火物被覆）２あるいは底吹ノズル４から液
体酸素あるいは液体炭酸を吹込むと同時にマルチ
ランス３本から気体酸素を噴出する。
第２図はマルチランスとして２本及び浸漬ラン
ス１本、第３図はマルチランスとして３本及び底
吹ノズル４本で示されているが、これらは選択自
在である。
ランス本数とスピツテイング量及び均一混合時
間との関係を第４図に示す。酸素トータル流量−
定の条件でランス本数が増えるとスピツテイング
量は減少するが一方撹拌力が弱まり均一混合時間
が長くなる。そこでランス本数としては３本程度
が最適といえる。マルチランスの位置は精錬容器
の中心と壁の中間の円周上が好ましい。
本発明において、Ｌ／Ｌp0.3としたのは、
0.3を越えるとスピツテイング量が多くなり、溶
鋼歩留の低下をきたすためである。従来上吹転炉
におけるＬ／Ｌpは略0.8程度でありこの位の値で
なければ良好な脱炭反応を起せ得なかつた。これ
に対して本発明は浸漬ランス又は底吹ノズルから
の液体酸素又は液体炭酸を吹込むことによつて撹
拌を充分行い得るので脱炭反応を促進できる。つ
ぎに浸漬ランスあるいは底吹ノズルから液体酸素
あるいは液体炭酸を吹込む理由であるが、気化熱
が液体酸素で50kcal／Kgあり、液体炭酸で
137kcal／Kgあり、この気化熱により浸漬ランス
あるいは底吹ノズルの溶損防止が可能となる。さ
らに液体酸素の場合、気化による体積膨張が約
800倍、液体炭酸で約470倍となり、少量でも大き
な撹拌効果が得られるからである。
第５図に液体酸素吹込量（／min）とスピツ
テイング量及び脱炭酸素効率の関係を示した。こ
の図から液体酸素吹込量の増大に伴ない、スピツ
テイング量が少なくなり、かつ脱炭酸素効率も向
上する。
第６図に液体炭酸吹込量（／min）とスピツ
テイング量及び脱炭酸素効率の関係を示した。そ
の効果については液体酸素使用の場合と同様液体
炭酸吹込量の増大に伴ないスピツテイング量が少
なく、又脱炭酸素効率も向上する。ここで液体酸
素使用の場合は気化による体積膨張が約800倍、
液体炭酸使用の場合は約470倍となる。従つて液
体酸素及び液体炭酸は、不活性ガスに比較して少
ない吹込量でも大きな撹拌効果が得られ、スピツ
テイング量が少なく、かつ脱炭酸素効率は良くな
る。
さらに液体酸素と液体炭酸を比較すれば液体酸
素の方がより少ない量で大きな効果を有するもの
である。吹込み量については、液体酸素の場合
1.3／min以上、液体炭酸の場合は2.1／min
以上必要で、これ未満では撹拌不足により、脱炭
酸素効率が減少し、かつスピツテイングが大とな
り、溶鋼歩留不良となるためである。
また上限については特に限定されるものではな
いが液体酸素で4.0／min、液体炭酸で6.0／
min程度で充分でありそれ以上吹込んでもコスト
に見合つた効果の上昇は望めない。
表−１は本発明法(a)と従来法(b)で実施した場合
の結果を示したものである。本発明法は10チヤー
ジの平均値、従来法は25チヤージの平均値であ
る。
実施例で示すとおり、上吹きマルチランスと浸
漬ランスからの液体酸素による溶湯撹拌効果によ
り、従来法に比し、溶鋼歩留が向上（95％→97
％）し、酸素原単位が低減（49Nm3／ｔ→46N
m3／ｔ）、さらに製鋼時間が短縮（20分→18分）
でき、工業上大きな効果を有するものである。
表−２は上吹きランス条件と溶湯撹拌条件を種
種変えて試験を行い、上吹きランス本数、撹拌用
液化ガス種類及び吹込み量（撹拌用動力＝
watt／ton）、酸素原単位、溶鋼歩留等の結果を示
したものである。本発明法と比較例より撹拌用液
体として、液体酸素の場合1.3／min以上、液
体炭酸で2.1／min以上吹込むことにより、溶
鋼歩留が向上し、かつ酸素原単位が低減し、製鋼
精錬法上大きな効果を有するものである。
The present invention relates to a steel manufacturing and refining method. The present invention provides a method that exhibits remarkable effects such as reducing equipment costs, significantly improving molten steel yield, and improving oxygen consumption in steelmaking and refining methods. We aim to reduce slotting and spitting by ultra-soft blowing using oxygen top blowing, and we also perform strong stirring by blowing liquid oxygen or liquid carbon dioxide from a submerged lance or bottom blowing nozzle.
The object of the present invention is to provide a steelmaking and refining method that reduces iron oxidation loss and improves molten steel yield through the synergistic effect. In the current LD converter oxygen steelmaking process, a single top-blowing oxygen lance and a multi-nozzle (porous nozzle) are common. Recently, bottom-blown converters (Q-BOP) and top-bottom-blown combined converters (LD-OB, LD-KG, LBE, etc.) have been developed one after another. There is also a known method in which removal of Si and S is performed as a preliminary treatment, and removal of C and P is performed in a converter. LD, Q-
When using BOP, LD-OB, etc., usually L/L p
= 0.5 to 1.0 (L: depth of oxygen jet penetration into the molten metal,
L p : molten metal depth), L p /D p <0.5 (L p : molten metal depth, D p : average diameter of the container). However, the above-mentioned conventional technology requires a huge amount of equipment cost, and during blowing, ejected material accumulates at the furnace mouth or scatters outside the furnace, resulting in a decrease in yield. The structure of the bottom blowing nozzle is usually a double tube, with gaseous oxygen being blown into the inner tube and cooling gas (propane gas, CO 2 gas, etc.) being blown into the outer tube. In the case of LD-KG and LBE, inert gas is injected through a single tube nozzle or a porous plug at the bottom of the furnace. When blowing with a multi-hole nozzle in a top-blown LD converter, there is a narrow fire spot on the steel bath surface.
Oxygen is exchanged. Since a large amount of acid is injected at high pressure, damage to the bottom of the furnace and sloppy and spitting phenomena during blowing increase, resulting in lower yields and shorter lance life. There are also methods to softly inject oxygen by raising the lance height or adjusting the flow rate, but these methods are not the original use of a multi-hole nozzle and only increase the iron oxidation loss. In order to solve these problems, bottom blowing converters and top and bottom blowing combined converters have been developed. However, when the bottom blowing nozzle is a double pipe and propane gas is flowed from the outer pipe for cooling purposes, there is a problem of pick-up of [H] due to decomposition of the propane gas into the molten steel. On the other hand, when inert gas is used for bottom blowing, the above problem is eliminated, but since a large capacity of oxygen is injected from the top blowing lance, similar to the top blowing LD converter, slopping and spitting phenomena cannot be prevented and the yield decreases. It was causing a problem. The present inventors focused on the fact that the above-mentioned drawbacks were due to the fact that stirring power and refining were required in the oxygen jet at the same time, and found that the effect of separating the two functions of stirring power and refining was significant. I learned something big. That is, the present invention is a method that advantageously solves all of the above-mentioned problems, and its feature is that in the top blowing of gaseous oxygen from multiple lances (two or more lances) in a refining vessel, L/L p 0.3
(L: molten metal penetration depth of oxygen jet, L p : molten metal depth), and liquid oxygen is applied at 1.3/min or more from an immersion lance or bottom blowing nozzle, or liquid carbonic acid is applied at 2.1/min or more.
This is a steelmaking and refining method characterized by injecting more than min. Furthermore, in the present invention, the stirring force is obtained by blowing liquid oxygen or liquid carbon dioxide from an immersion lance, so the molten metal depth must be deeper than in the past (molten metal depth/vessel average diameter 0.5). If it is shallower than the previous formula, spitting and slopping will occur as with conventional oxygen jets. Furthermore, gaseous oxygen for decarburization refining can be blown in a small amount and at a low pressure. That is, the second invention of the present invention was completed based on these findings, and the refining pot contains L p /D p
Hold the hot metal so that it fills 0.5 (L p : molten metal depth, D p : average diameter of the container), and use a multi lance (lance 2
gaseous oxygen from L/L p 0.2 (L:
Molten metal penetration depth of oxygen jet, L p ;molten metal depth)
Spray liquid oxygen at a rate of 1.3 min or more from a submerged lance or bottom blowing nozzle to satisfy
Alternatively, it is a steelmaking and refining method characterized by decarburizing by injecting liquid oxygen at a rate of 2.1/min or more. Next, the present invention will be described in detail with reference to embodiments shown in the drawings. Figure 1 a, b, and c are conventional LD and O-
In the illustration of the lance or nozzle of BOP and LD-OB, the bottom blowing nozzle is a double pipe. Figures 2 and 3 show embodiments of the present invention, in which gaseous oxygen is injected by a multi-lance and liquid oxygen or liquid carbonate is blown from a submerged lance or a bottom blowing nozzle during refining in a refining vessel. This figure shows an embodiment in which the loading is performed. First, hot metal 5 is charged into the refining vessel 1, and liquid oxygen or liquid carbonate is blown from the immersion lance (refractory coated) 2 or the bottom blowing nozzle 4, and at the same time gaseous oxygen is blown out from the three multi-lances. Although FIG. 2 shows two multi-lances and one immersion lance, and FIG. 3 shows three multi-lances and four bottom-blown nozzles, these can be selected freely. FIG. 4 shows the relationship between the number of lances, the amount of spitting, and the uniform mixing time. Oxygen total flow rate -
If the number of lances increases under certain conditions, the amount of spitting will decrease, but on the other hand, the stirring force will weaken and the uniform mixing time will increase. Therefore, it can be said that the optimum number of lances is about three. The multi-lance is preferably located on the circumference between the center and the wall of the refining vessel. In the present invention, L/L p is set to 0.3 because
This is because if it exceeds 0.3, the amount of spitting will increase and the yield of molten steel will decrease. Conventionally, L/L p in a top-blown converter was approximately 0.8, and a good decarburization reaction could not occur unless the value was around this value. In contrast, in the present invention, sufficient stirring can be achieved by blowing liquid oxygen or liquid carbon dioxide from a submerged lance or a bottom blowing nozzle, so that the decarburization reaction can be promoted. Next, the reason why liquid oxygen or liquid carbonic acid is injected from the immersion lance or bottom blowing nozzle is that the heat of vaporization is 50kcal/Kg for liquid oxygen, and the heat of vaporization for liquid oxygen is 50kcal/Kg.
It has 137kcal/Kg, and this heat of vaporization can prevent erosion of immersion lances or bottom blow nozzles. Furthermore, in the case of liquid oxygen, the volumetric expansion due to vaporization is approximately
This is because even a small amount can produce a large stirring effect, as it is 800 times more powerful and about 470 times more powerful with liquid carbonic acid. Figure 5 shows the relationship between the amount of liquid oxygen blown (/min), the amount of spitting, and the decarburization oxygen efficiency. This figure shows that as the amount of liquid oxygen blown increases, the amount of spitting decreases and the decarburization oxygen efficiency also improves. Figure 6 shows the relationship between the amount of liquid carbon blown (/min), the amount of spitting, and the decarburization oxygen efficiency. As for the effect, as in the case of using liquid oxygen, the amount of spitting decreases as the amount of liquid carbon blown increases, and the decarburization oxygen efficiency also improves. When using liquid oxygen, the volume expansion due to vaporization is approximately 800 times,
If liquid carbonic acid is used, it will be about 470 times more. Therefore, compared to inert gas, liquid oxygen and liquid carbonic acid can provide a large stirring effect even with a small amount of injection, reduce the amount of spitting, and improve the decarburizing oxygen efficiency. Furthermore, when comparing liquid oxygen and liquid carbonic acid, liquid oxygen has a greater effect with a smaller amount. Regarding the amount of injection, in the case of liquid oxygen
1.3/min or more, 2.1/min for liquid carbonate
This is because if it is less than this, the decarburization oxygen efficiency will decrease due to insufficient stirring, and spitting will become large, resulting in poor molten steel yield. The upper limit is not particularly limited, but it is 4.0/min for liquid oxygen and 6.0/min for liquid carbonate.
About min is sufficient, and even if you inject more than that, you cannot expect an increase in the effect commensurate with the cost. Table 1 shows the results of the method (a) of the present invention and the conventional method (b). The method of the present invention is an average value of 10 charges, and the conventional method is an average value of 25 charges. As shown in the example, the molten steel yield improved (95%→97
%) and reduced oxygen consumption (49Nm 3 /t → 46N
m 3 /t), further shortening steelmaking time (20 minutes → 18 minutes)
This has great industrial effects. Table 2 shows the number of top blowing lances, type of liquefied gas for stirring, and amount of blowing (power for stirring =
watt/ton), oxygen consumption rate, molten steel yield, etc. From the method of the present invention and comparative examples, by blowing liquid oxygen at 1.3/min or more and liquid carbonic acid at 2.1/min or more as the stirring liquid, the molten steel yield improves, the oxygen consumption rate decreases, and the steelmaking and refining process improves. This has a significant legal effect.
【表】【table】
【表】
次に第２の発明の実施例を第７図、第８図によ
り説明する。
まず精錬容器６内に予備処理された溶銑を収納
し、着脱自在のフリーボード１０を介して集塵フ
ード１１と連結する。
耐火物被覆の浸漬ランス７あるいは底吹ノズル
９から液体酸素あるいは液体炭酸を吹込むと同時
にマルチランス８から気体酸素を吹付ける。
第７図はマルチランスとして２本、及び浸漬ラ
ンス１本、第８図はマルチランスとして３本、及
び底吹ノズル３本で示されているが、これらは選
択自在である。
この場合のランス本数とスピツチング量及び均
一混合時間との関係は略第４図と同様である。酸
素トータル流量一定の条件でランス本数が増える
とスピツチング量は減少するが、一方撹拌力が弱
まり、均一混合時間が長くなる。そこでランス本
数としては３本程度が最適といえる。マルチラン
スの位置は精錬鍋の中心と壁の中間の円周上が好
ましい。Ｌ／Ｌp0.3としたのは0.3を越える
と、従来の醸素ジエツトと同じ欠点であるスピツ
チング量が多くなり、溶鋼歩留の低下をきたすた
めである。
さらに撹拌力を別に求めているので単なる脱炭
のための少量、低圧での吹込みが可能となつた。
つぎに浸漬ランスあるいは、底吹ノズルから液
体酸素あるいは、液体炭酸を吹込む理由であるが
気化熱が液体酸素50kcal／Kgおよび液体炭酸
137kcal／Kgあり、溶損防止が出来、さらに液体
酸素の場合、気化による体積膨張が800倍、液体
炭酸の場合は470倍となり、少量でも大きな撹拌
効果が得られるからである。底吹き液体吹込量
（／min）とスピツテイング量及び脱炭酸素効
率の関係は略第５図と同様の結果を示し底吹き液
体吹込み量の増大に伴ないスピツテイング量が少
なくなり、かつ脱炭酸素効率も向上する。
底吹液体炭酸吹込量（／min）とスピツテイ
ング量及び脱炭酸素効率の関係も第６図と略同様
の結果を示した。
その効果については、液体酸素使用の場合と同
様液体炭酸吹込量の増大に伴ない、スピツテイン
グ量が少なく、又脱炭酸素効率も向上する。
ここで、液体酸素使用の場合は、気化による体
積膨張が約800倍、液体炭酸使用の場合は約470倍
となる。従つて液体酸素及び液体炭酸は不活性ガ
スに比較して少ない吹込量でも大きな撹拌効果が
得られ、スピツテイング量が少なくかつ脱炭酸素
効率は良くなる。
さらに液体酸素と液体炭酸を比較すれば液体酸
素の方がより少ない量で大きな効果を有するもの
である。
吹込み量については、液体酸素の場合、第５図
で明らかなように1.3／min以上、液体炭酸の
場合は2.1／min以上必要である。
上記数値未満では表−２、試験No.８，10に示す
ように撹拌力不足により脱炭酸素効率が減少し、
かつスロツピングが大となり、歩留不良となるた
めである。
表−３は本発明法(a)と従来法(b)で実施した場合
の結果を示したもので、本発明法は10チヤージの
平均値、従来法は25チヤージの平均値である。[Table] Next, an embodiment of the second invention will be described with reference to FIGS. 7 and 8. First, pretreated hot metal is stored in the refining vessel 6, which is connected to a dust collection hood 11 via a detachable freeboard 10. Liquid oxygen or liquid carbon dioxide is blown from a refractory-coated immersion lance 7 or a bottom blowing nozzle 9, and at the same time gaseous oxygen is blown from a multi-lance 8. Although FIG. 7 shows two multi-lances and one immersion lance, and FIG. 8 shows three multi-lances and three bottom-blowing nozzles, these can be selected freely. In this case, the relationship between the number of lances, the amount of spitting, and the uniform mixing time is approximately the same as that shown in FIG. As the number of lances increases under the condition that the total oxygen flow rate is constant, the amount of spitting decreases, but on the other hand, the stirring force weakens and the uniform mixing time increases. Therefore, it can be said that the optimum number of lances is about three. The preferred position of the multi-lance is on the circumference between the center of the refining pot and the wall. The reason why L/L p is set to 0.3 is because if it exceeds 0.3, the amount of spitting increases, which is the same drawback as conventional fermentation jets, and the yield of molten steel decreases. Furthermore, since stirring power is required separately, it is now possible to blow in small quantities and at low pressure for simple decarburization. Next, the reason why liquid oxygen or liquid carbonate is blown in from the immersion lance or bottom blowing nozzle is that the heat of vaporization is 50kcal/Kg of liquid oxygen and liquid carbonate.
It has 137 kcal/Kg, which prevents melting and damage.Furthermore, in the case of liquid oxygen, the volume expansion due to vaporization is 800 times, and in the case of liquid carbonic acid, it is 470 times, so even a small amount can produce a large stirring effect. The relationship between the bottom-blown liquid injection rate (/min), the spitting amount, and the decarburization oxygen efficiency is approximately the same as that shown in Figure 5.As the bottom-blown liquid injection rate increases, the spitting amount decreases, and the decarburization rate decreases. The efficiency also improves. The relationship between the bottom-blown liquid carbon dioxide injection amount (/min), the spitting amount, and the decarburization oxygen efficiency also showed almost the same results as in FIG. 6. Regarding the effect, as with the case of using liquid oxygen, as the amount of liquid carbon dioxide blown increases, the amount of spitting decreases and the decarburization oxygen efficiency also improves. Here, when liquid oxygen is used, the volumetric expansion due to vaporization is about 800 times, and when liquid carbonic acid is used, it is about 470 times. Therefore, compared to inert gas, liquid oxygen and liquid carbonic acid can provide a large stirring effect even with a small amount of injection, and the amount of spitting is small and the decarburizing oxygen efficiency is improved. Furthermore, when comparing liquid oxygen and liquid carbonic acid, liquid oxygen has a greater effect with a smaller amount. Regarding the blowing rate, in the case of liquid oxygen, it is necessary to blow at least 1.3/min, as shown in Figure 5, and in the case of liquid carbonic acid, it is necessary to blow in at least 2.1/min. If the value is less than the above, as shown in Table 2, Test Nos. 8 and 10, the decarburization oxygen efficiency decreases due to insufficient stirring power.
This is because slopping becomes large, resulting in poor yield. Table 3 shows the results when the method of the present invention (a) and the conventional method (b) were used. The method of the present invention is the average value of 10 charges, and the conventional method is the average value of 25 charges.
【表】
表−３に示すごとく本発明法は溶銑を強撹拌し
ながら脱炭し得ることにより、製鋼能率を著しく
増大させ得ることができ、又マルチランスによる
ソフトブローを行うことにより発生スラグが少な
く、気体酸素の使用効率が高く且つ安定している
ため、終点制御が正確であり、トータル酸素原単
位も2.4Nm3／ｔ程節減され、さらに溶鋼歩留が
向上（95％→97％）した。
即ち従来法では、吹錬中に多く発生するスロツ
ピング、スピツテイングによるロスが少い上にス
ラグへ移行する酸化鉄が少なくなること、また表
−３に示すように精錬時間が（20分→18分）短縮
されるため、鉄の揮発量も少なくなるためであ
る。
更に本発明の利点は液体酸素、あるいは液体炭
酸の強撹拌エネルギーがスラグに吸収されること
なく、溶銑に直接働くために、溶銑の流動が良好
となり、酸素と炭素との反応が盛んとなる結果、
脱Ｃが短時間のうちに行われることである。
上述したごとく、本発明は脱Ｃ工程にとどまら
ずその後の成分調整工程に於ても、溶鋼歩留の向
上、酸素原単位の低減、精錬時間の短縮、設備コ
ストの低減と工業上大なる効果を有する製鋼精錬
法である。[Table] As shown in Table 3, the method of the present invention can significantly increase steelmaking efficiency by decarburizing hot metal while stirring it strongly, and by performing soft blowing with a multi-lance, generated slag can be reduced. Because the usage efficiency of gaseous oxygen is high and stable, the end point control is accurate, the total oxygen consumption rate is reduced by 2.4Nm 3 /t, and the molten steel yield is further improved (95% → 97%). did. In other words, with the conventional method, there is less loss due to slopping and spitting, which often occur during blowing, and less iron oxide transfers to slag. ) is shortened, so the amount of iron volatilization is also reduced. A further advantage of the present invention is that the strong stirring energy of liquid oxygen or liquid carbonate is not absorbed by the slag and acts directly on the hot metal, resulting in good fluidity of the hot metal and an active reaction between oxygen and carbon. ,
The decarbonization takes place within a short period of time. As mentioned above, the present invention is not limited to the carbon removal process, but also in the subsequent component adjustment process, and has great industrial effects such as improving molten steel yield, reducing oxygen consumption rate, shortening refining time, and reducing equipment costs. It is a steelmaking and refining method that has
第１図ａ，ｂ，ｃは従来の上吹転炉LD、底吹
転炉Ｑ−BOP、上底吹複合転炉LD−OBの説明
図、第２図は本発明にかかわる浸漬ランスとマル
チランスの説明図。第３図は本発明にかかわる底
吹きノズルとマルチランスの説明図。第４図はラ
ンス本数とスピツテイング量及び均一混合時間の
関係図である。第５図は第１表(a)における条件で
液体酸素吹込み量を変化させた場合のスピツテイ
ング量及び脱炭酸素効率の関係図である。第６図
は第２表No.２における条件で液体炭酸吹込み量を
変化させた場合のスピツテイング量及び脱炭酸素
効率の関係図、第７図、第８図は本発明の他の実
施態様を示す説明図である。
１，６……精錬容器、２，７……浸漬ランス、
３，８……上吹きランス、４，９……底吹きノズ
ル、５，１２……溶銑、１０……フリーボード、
１１……集塵フード。
Figures 1a, b, and c are explanatory diagrams of a conventional top-blown converter LD, bottom-blown converter Q-BOP, and top-bottom-blown combined converter LD-OB, and Figure 2 is an immersion lance and multi-purpose converter according to the present invention. An explanatory diagram of a lance. FIG. 3 is an explanatory diagram of a bottom-blowing nozzle and a multi-lance according to the present invention. FIG. 4 is a diagram showing the relationship between the number of lances, the amount of spitting, and the uniform mixing time. FIG. 5 is a diagram showing the relationship between the amount of spitting and the decarburization oxygen efficiency when the amount of liquid oxygen blown is varied under the conditions shown in Table 1 (a). Fig. 6 is a relationship diagram of spitting amount and decarburization oxygen efficiency when the liquid carbon injection amount is changed under the conditions shown in Table 2 No. 2, and Fig. 7 and Fig. 8 are other embodiments of the present invention. FIG. 1, 6... Refining container, 2, 7... Immersion lance,
3, 8...Top blowing lance, 4,9...Bottom blowing nozzle, 5,12...Hot metal, 10...Freeboard,
11...Dust collection hood.
Claims (1)
以上）からの気体酸素の上吹きにおいてＬ／Ｌp
0.3（Ｌ；酸素ジエツトの溶湯浸入深さ、Ｌp；
溶湯深さ）とし、浸漬ランスあるいは底吹ノズル
から液体酸素を1.3／min以上又は液体炭素を
2.1／min以上吹込むことを特徴とする製鋼精
錬法。 ２ 精錬容器にＬp／Ｄp0.5（Ｌp；溶湯深さ、
Ｄp：容器平均径）を満たすように溶銑を保持
し、マルチランス（ランス２本以上）からの気体
酸素をＬ／Ｌp0.3（Ｌ；酸素ジエツトの溶湯浸
入深さ、Ｌp；溶湯深さ）を満足するように吹付
け、かつ浸漬ランスあるいは底吹ノズルから液体
酸素を1.3／min以上又は液体炭酸を2.1／
min以上吹込み脱炭することを特徴とする製鋼精
錬法。[Claims] 1. In the top blowing of gaseous oxygen from multiple lances (two or more lances) in a refining vessel, L/L p
0.3 (L; penetration depth of oxygen jet into molten metal, L p ;
(depth of the molten metal), and pour liquid oxygen at least 1.3 min. or liquid carbon from a submerged lance or bottom blowing nozzle.
A steelmaking and refining method characterized by blowing at a rate of 2.1/min or more. 2 L p /D p 0.5 (L p ; molten metal depth,
D p : average diameter of the vessel), and gaseous oxygen from a multi-lance (two or more lances) is L/L p 0.3 (L: molten metal penetration depth of oxygen jet, L p : molten metal depth) spray liquid oxygen at 1.3/min or more or liquid carbonate at 2.1/min or more from a submerged lance or bottom blowing nozzle to satisfy
A steelmaking and refining method characterized by decarburizing by blowing over min.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8933181A JPS57203711A (en) | 1981-06-10 | 1981-06-10 | Refining method in steel making |
| AU81848/82A AU532932B2 (en) | 1981-03-30 | 1982-03-24 | Post-refining of basic oxygen steel |
| DE8282102580T DE3269285D1 (en) | 1981-03-30 | 1982-03-26 | A multi-step steelmaking refining method |
| EP19820102580 EP0061749B1 (en) | 1981-03-30 | 1982-03-26 | A multi-step steelmaking refining method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8933181A JPS57203711A (en) | 1981-06-10 | 1981-06-10 | Refining method in steel making |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57203711A JPS57203711A (en) | 1982-12-14 |
| JPS6152210B2 true JPS6152210B2 (en) | 1986-11-12 |
Family
ID=13967696
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8933181A Granted JPS57203711A (en) | 1981-03-30 | 1981-06-10 | Refining method in steel making |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57203711A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59226111A (en) * | 1983-06-06 | 1984-12-19 | Nippon Kokan Kk <Nkk> | Stirring method of molten iron |
| HU196632B (en) * | 1984-08-01 | 1988-12-28 | Vasipari Kutato Fejleszto | Process for producing high-purity steels |
-
1981
- 1981-06-10 JP JP8933181A patent/JPS57203711A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57203711A (en) | 1982-12-14 |
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