JPS6347321A - Dephosphorization of molten pig iron - Google Patents
Dephosphorization of molten pig ironInfo
- Publication number
- JPS6347321A JPS6347321A JP19012986A JP19012986A JPS6347321A JP S6347321 A JPS6347321 A JP S6347321A JP 19012986 A JP19012986 A JP 19012986A JP 19012986 A JP19012986 A JP 19012986A JP S6347321 A JPS6347321 A JP S6347321A
- Authority
- JP
- Japan
- Prior art keywords
- slag
- hot metal
- dephosphorization
- pig iron
- molten pig
- 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
- 229910000805 Pig iron Inorganic materials 0.000 title abstract 7
- 239000002893 slag Substances 0.000 claims abstract description 68
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 27
- 238000007664 blowing Methods 0.000 claims abstract description 23
- 239000002184 metal Substances 0.000 claims description 57
- 229910052751 metal Inorganic materials 0.000 claims description 57
- 238000000034 method Methods 0.000 claims description 35
- 238000007654 immersion Methods 0.000 claims description 11
- 239000012159 carrier gas Substances 0.000 claims description 8
- 238000006243 chemical reaction Methods 0.000 abstract description 12
- 238000010079 rubber tapping Methods 0.000 abstract description 5
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 230000004907 flux Effects 0.000 description 28
- 238000011282 treatment Methods 0.000 description 22
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 18
- 239000000843 powder Substances 0.000 description 14
- 235000012255 calcium oxide Nutrition 0.000 description 9
- 239000000292 calcium oxide Substances 0.000 description 9
- 238000002347 injection Methods 0.000 description 7
- 239000007924 injection Substances 0.000 description 7
- 230000007423 decrease Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 4
- 230000003628 erosive effect Effects 0.000 description 4
- 229910052698 phosphorus Inorganic materials 0.000 description 3
- 239000011574 phosphorus Substances 0.000 description 3
- 238000011144 upstream manufacturing Methods 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000009628 steelmaking Methods 0.000 description 2
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 229910001634 calcium fluoride Inorganic materials 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 238000005188 flotation Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
この発明は高炉出銑樋で脱りんする方法に係り、より詳
しくは脱りん剤をキャリアガスと共にランスで吹込む方
法で効率よく脱りんして低りん溶銑を得ることができる
溶銑の脱りん方法に関する。[Detailed Description of the Invention] Industrial Application Field This invention relates to a method for dephosphorizing in a blast furnace tap trough, and more specifically, a method for efficiently dephosphorizing and reducing the amount of phosphor by injecting a dephosphorizing agent together with a carrier gas using a lance. This invention relates to a method for dephosphorizing hot metal that can obtain phosphorous hot metal.
技術的背景
高炉から出銑された溶銑の成分組成は次の製鋼工程にお
ける精錬能率や鋼の品質に大きく影響するので、製鋼工
程を合理化し、操業を容易にするため溶銑の成分組成や
生産鋼種に応じて種々の溶銑予備処理法が適宜に採用さ
れている。溶銑の予備処理としては脱珪、脱りん、脱硫
等があり、その方法としては高炉出銑樋、溶銑取鍋、ト
ーピードカー等で行なわれている。Technical background The composition of hot metal tapped from a blast furnace greatly affects the refining efficiency and quality of steel in the next steelmaking process, so in order to streamline the steelmaking process and make operations easier, the composition of hot metal and the type of steel produced are determined. Various hot metal pretreatment methods are appropriately adopted depending on the situation. Preliminary treatments for hot metal include desiliconization, dephosphorization, and desulfurization, which are carried out in blast furnace tap runners, hot metal ladles, torpedo cars, and the like.
従来技術とその問題点
高炉出銑樋で溶銑の脱りん処理を行なう方法としては、
スキンマーによって高炉滓を除去した後、以下に示す三
つの方法で処理する方法が知られている。Conventional technology and its problems As a method for dephosphorizing hot metal in a blast furnace tap pipe,
There are three known methods in which blast furnace slag is removed by a skinmer and then treated using the following three methods.
■ 出銑樋内の溶銑に対し粉体フラックスを添加して脱
珪、脱りん処理を行なう方法。すなわち、この方法は出
銑樋内を流れる溶銑に粉体フラックスを上置きし、−緒
に流れていく間の自然な混合を利用して脱珪、脱りん処
理を行なう方法である（特開昭５８−６７８１０等）。■ A method in which powder flux is added to the hot metal in the tap hole to perform desiliconization and dephosphorization treatment. In other words, this method is a method in which powder flux is placed on top of the hot metal flowing in the tap hole, and the natural mixing as it flows together is used to perform desiliconization and dephosphorization treatment (Unexamined Japanese Patent Publication No. (Sho 58-67810, etc.)
しかし、この方法では溶銑に添加された粉体フラックス
は溶銑上に浮遊したまま流れ易いため、前記のような自
然混合では出銑樋内で十分に混合されず、溶銑と粉体フ
ラックスとの反応効率が低いという欠点がある。However, in this method, the powder flux added to the hot metal tends to flow while floating on the hot metal, so the natural mixing described above does not mix sufficiently in the tap hole, and the reaction between the hot metal and the powder flux occurs. It has the disadvantage of low efficiency.
■ 出銑樋内の溶銑中に浸漬したランスまたは底吹ノス
ズルから粉体フラックスをキャリアガスと共に吹込むイ
ンジェクション法（特公昭５０−３３０１０、特公昭５
３−３３９３５．特公昭６０−３５４０８等）。■ Injection method in which powder flux is blown along with carrier gas from a lance immersed in hot metal in the tap runner or from a bottom blowing nozzle (Special Publication No. 50-33010, Special Publication No. 5
3-33935. Special Publication No. 60-35408, etc.).
この方法は前記■の欠点を解消するため、粉体フラック
スの添加方法を改善したもので、特に浸漬ランスによる
方法は粉体フラックスと溶銑の接触性が良好で反応効率
が高い。しかしながら、この方法では浸漬ランスの溶損
が著しく、予備処理費が高くつく欠点がある。また、底
吹ノズルによる方法は、ノズルの溶損が著しいだけでな
く、出銑樋の大幅改善を必要とし設備費が高くつくこと
、浴深さが一般に１．０ｍ以下と浅いため、粉体フラッ
クスが溶銑と十分に接触する前に浮上してしまい、反応
効率の大幅向上が望めない等の欠点があった。This method is an improved method of adding powder flux in order to eliminate the above-mentioned drawback (2). In particular, the method using an immersion lance has good contact between the powder flux and hot metal and has high reaction efficiency. However, this method has the disadvantage that the immersion lance is significantly damaged by erosion and the pretreatment cost is high. In addition, the method using a bottom blowing nozzle not only suffers from significant nozzle erosion, but also requires significant improvement of the tap culvert, resulting in high equipment costs. There were drawbacks such as the fact that the flux floated to the surface before it came into sufficient contact with the hot metal, making it impossible to expect a significant improvement in reaction efficiency.
■ 非浸漬上吹きランスにより粉体フラックスをキャリ
アガスと共に吹込む方法（特開昭５８−１３０２０Ｂ、
特開昭６０−１８４６１１等）。この方法は前記■の浸
漬ランス、底吹ノズルの溶損を軽減する方法として提案
されたもので、溶銑との直接接触がないためランスの溶
損は浸漬方式に比べ大幅に軽減され、反応効率も上昇す
るが、脱りん処理前［Ｐ］＝ ０．１０％の場合、処理
後［Ｐ］＝ ０．０４〜０．０５％にとどまっており、
これ以下の低りん溶銑を出銑樋上で得ることができなか
った。■ Method of blowing powder flux together with carrier gas using a non-immersed top blowing lance (Japanese Patent Application Laid-Open No. 58-13020B,
JP-A-60-184611, etc.). This method was proposed as a method to reduce the erosion of the immersion lance and bottom-blowing nozzle mentioned in ① above.Since there is no direct contact with the hot metal, the erosion of the lance is significantly reduced compared to the immersion method, and the reaction efficiency is However, when [P] = 0.10% before dephosphorization treatment, [P] = 0.04-0.05% after treatment,
It was not possible to obtain hot metal with a lower phosphorus content on the tap tap.
発明の目的
この発明は従来の前記問題点を解決するためになされた
もので、非浸漬上吹ランスによるインジェクション法で
高い反応効率が得られる溶銑脱りん方法を提案せんとす
るものである。Purpose of the Invention The present invention was made to solve the above-mentioned conventional problems, and it is an object of the present invention to propose a method for dephosphorizing hot metal in which high reaction efficiency can be obtained by an injection method using a non-immersed top blowing lance.
問題点を解決するための手段
この発明は高炉出銑樋で脱りんする方法において、非浸
漬上吹ランスにより脱りん剤をキャリアガスと共に溶銑
中に吹込む際、溶銑中のＳｉ含有量が０．２０％以下で
、低塩基性スラグを１０ｋＣＪ／Ｐ−Ｔ以下まで除滓し
た俊、樋長手方向に少なくとも浴深さの２．５倍以上の
間隔を隔てて多段配置した非浸漬上吹ランスにて脱りん
剤を吹込むことによって、高い脱りん効率を得る方法で
ある。Means for Solving the Problems This invention provides a method for dephosphorizing using a blast furnace tap runner, in which the Si content in the hot metal is reduced to 0 when a dephosphorizing agent is blown into the hot metal together with a carrier gas using a non-immersed top blowing lance. .20% or less and low basicity slag removed to 10kCJ/PT or less. Non-immersed top blowing lance arranged in multiple stages at intervals of at least 2.5 times the bath depth in the longitudinal direction of the gutter. This method achieves high dephosphorization efficiency by injecting a dephosphorizing agent into the tank.
ここで、脱りん剤吹込み用非浸漬上吹ランスを多段配置
とした理由について、以下に説明する。Here, the reason why the non-immersed top blowing lance for blowing the dephosphorizing agent is arranged in multiple stages will be explained below.
まず、この発明者らが事前に行なった調査結果について
説明する。この発明者らは、出銑樋上で従来のランス吹
込み方式にて脱珪、脱りん処理を行なった場合の脱りん
串の低下原因を調査するため、小型炉（５０ｋｇ溶解炉
）にて溶銑（［Ｃ］ ４．２〜４．４％、 ［Ｓｊ］
＜ ０．０３％、 ［Ｐ］０．０９〜０．１１％、
［１″）ｎ］ ０．１８〜０．２５％）にＣａＯ５Ｌ
Ｏ２−Ｆｅ２０３−１０％ＣａＦ２系フラックスを溶銑
１均当り６０ｇ添加した。その際、０．５Ｑ／ｍｉｎの
Ａｒガスによって溶銑を撹拌した。その際、フラックス
添加後１２分に溶銑とスラグを採取し、Ｐ分配比とＣａ
ｂ／５ＬＯ２の関係を調べた結果を第４図に示す。第４
図より、■ＣａＯ／ ５Ｌ０２の増加によりＰ分配比は
増加すること、■高炉樋脱Ｐの場合は前記小型炉で得ら
れたＰ分配比より劣っていることがわかる。つまり、フ
ラックスは脱りんの余力を有しており、反応の改善が可
能であることがわかる。First, the results of a study conducted by the inventors in advance will be explained. The inventors investigated the cause of the drop in dephosphorization when performing desiliconization and dephosphorization using the conventional lance blowing method on the tap runner. ([C] 4.2-4.4%, [Sj]
<0.03%, [P]0.09-0.11%,
[1″)n] 0.18~0.25%) with CaO5L
60g of O2-Fe203-10% CaF2-based flux was added per 1 uniformity of hot metal. At that time, the hot metal was stirred with Ar gas at 0.5 Q/min. At that time, hot metal and slag were sampled 12 minutes after flux addition, and the P distribution ratio and Ca
Figure 4 shows the results of examining the relationship between b/5LO2. Fourth
From the figure, it can be seen that (1) the P distribution ratio increases with an increase in CaO/5L02, and (2) the P distribution ratio in the case of blast furnace gutter deP is inferior to the P distribution ratio obtained in the small furnace. In other words, it can be seen that the flux has a surplus capacity for dephosphorization, and it is possible to improve the reaction.
次に、高炉出銑樋で脱珪、脱りんを行なった時の［Ｐ］
の推移を第５図に示す。第５図より、粉体の脱りん用フ
ラックスを吹込むと、［Ｐ］は急激に低下し［Ｐ］＝
０．０４〜０．０５％が得られているが、その後［Ｐ］
は一定値を示しており脱りんは進行していないことがわ
かる。これは、浸漬ランスまたは非浸漬ランスを用いる
インジェクション法により粉体フラックスを吹込むと、
フラックスと溶銑の接触は良好であるが、いったんフラ
ツクスガ湯面に浮上するとフラックスと溶銑の接触が不
足し前記上置き法と同様に脱りん反応が進行しなくなる
ためである。Next, [P] when desiliconization and dephosphorization were performed in the blast furnace tap channel
Figure 5 shows the changes in . From Figure 5, when powder dephosphorization flux is injected, [P] decreases rapidly and [P] =
0.04-0.05% was obtained, but after that [P]
shows a constant value, indicating that dephosphorization is not progressing. This is achieved by injecting powder flux using an injection method using a immersed or non-immersed lance.
Although the contact between the flux and the hot metal is good, once the flux floats to the surface of the hot metal, the contact between the flux and the hot metal is insufficient and the dephosphorization reaction does not proceed as in the above-mentioned overlay method.
以上の調査結果を踏まえて、この発明者らは脱りん反応
を平衡に近づけ、脱りんを改善すべく、フラックス吹込
み用ランスを多段配置として脱りんする方法をとったの
である。Based on the above investigation results, the inventors adopted a method of dephosphorizing by arranging flux injection lances in multiple stages in order to bring the dephosphorization reaction closer to equilibrium and improve dephosphorization.
第６図は１段吹込みと２段吹込みの場合のスラグ伍と到
達［Ｐ］の関係を示す図である。すなわち、スラグ−メ
タル間のＰ分配比（（Ｐ）／［Ｐ］）が５０の場合（１
段吹込み）、スラグ量が少ない領域ではわずかなスラグ
量の増加で溶銑中［Ｐ］が効果的に低下する。一方、ス
ラグ量が多い領域ではスラグ量を増加させてもスラグ−
メタル間のＰ分配比が同一でもＰの物質収支の制約から
、溶銑中の［Ｐ］の低下は少ない。このため、−船釣に
はスラグ量の少ない領域の効果的な脱りんを利用するた
め、脱りん処理を行なった後にスラグを排滓して次の脱
りん処理を行なうダブルスラグ法が用いられる。FIG. 6 is a diagram showing the relationship between the slag level and the arrival [P] in the case of one-stage blowing and two-stage blowing. In other words, when the P distribution ratio ((P)/[P]) between slag and metal is 50 (1
In the region where the amount of slag is small, [P] in the hot metal can be effectively reduced by a slight increase in the amount of slag. On the other hand, in areas with a large amount of slag, even if the amount of slag is increased, the slag
Even if the P distribution ratio between metals is the same, the decrease in [P] in hot metal is small due to restrictions on the P mass balance. For this reason, in boat fishing, in order to utilize effective dephosphorization in areas with a small amount of slag, the double slug method is used, in which the slag is removed after dephosphorization treatment and the next dephosphorization treatment is performed. .
一方、第４図に示したごとく、高炉出銑樋での脱りんば
、平衡まで達せず反応が未完了であるが、多段吹込みを
行なうと前記ダブルスラグの効果をスラグ排滓なしで達
成でき、脱りん反応を平衡に近づけられることが判明し
た。例えば、第４図中テＣａＯ／ ５ｉ０２＝ ８．０
（７）場合、平衡（Ｐ）／［Ｐ］ ＝１００であるが、
高炉出銑訓脱りんの１段吹込みでは（Ｐ）／［Ｐ］ ＝
５’Ｏにとどまっていた。しかるに、１段目のランスよ
り吹込まれたフラックスが浮上する地点の下流に２段目
のランスを配置しフラックスを吹込むと、第４図破線で
示すごとく溶銑中［Ｐ］が減少した。すなわち、１段目
でスラグ量が３０ｈ／ｒ、２段目でもスラグ量が３０ｋ
ｇ／丁になるように吹込むと、［Ｐ］＜ ０．０２％ま
で減少するとともに、ＣａＯ／ ５ｊ０２＝ ６．０の
平衡値（Ｐ）／［Ｐ］−１００のＰ分配比で脱りんした
場合に近づくことが判明した。On the other hand, as shown in Figure 4, the dephosphorization in the blast furnace tap culvert does not reach equilibrium and the reaction is incomplete, but if multi-stage injection is performed, the double slag effect can be achieved without slag waste. It was found that the dephosphorization reaction could be brought closer to equilibrium. For example, in Fig. 4 Te CaO/5i02=8.0
In case (7), equilibrium (P)/[P] = 100, but
In the first stage of blast furnace tapping training dephosphorization, (P)/[P] =
It stayed at 5'O. However, when the second stage lance was placed downstream of the point where the flux injected from the first stage lance rose to the surface and the flux was injected, [P] in the hot metal decreased as shown by the broken line in Figure 4. In other words, the slag amount is 30h/r in the first stage, and the slag amount is 30k in the second stage.
g/ton, it decreases to [P] < 0.02% and dephosphorizes at the equilibrium value (P)/[P]-100 of CaO/5j02=6.0. It turns out that if you do it, you will get closer.
ここで重要なことは、第５図より明らかなごとく脱りん
は粉体が溶銑に侵入している領域でのみ顕著に進んでい
ることであり、この領域を分離つまりフラックス浮上後
に次段のランスからフラックスを吹込めば、第６図に示
すごとくダブルスラグ法の効果が得られる点でおる。な
お、フラックスが浮上するのは、少なくとも浴深さの２
．５倍下流までかかるため、２段目のランスは１段目の
ランスから下流側に浴深さの２．５倍以上離れた位置に
配置する必要がある。他方、２段目のランスを２．５倍
以内に設置してフラックスを吹込んだ場合、１段目と２
段目のフラックスが混合してしまいダブルスラグの効果
を得ることができない。従って、この発明では１段目の
ランスと２段目のランスの間隔を少なくとも浴深さの２
．５倍以上と限定したのでおる。What is important here is that, as is clear from Figure 5, dephosphorization progresses significantly only in the region where the powder has penetrated into the hot metal, and this region is separated, that is, after flux flotation, the next stage lance If flux is injected from the inside, the effect of the double slug method can be obtained as shown in Figure 6. Note that the flux floats to the surface at least 2 times the depth of the bath.
．． Since it takes up to 5 times downstream, the second stage lance needs to be placed downstream from the first stage lance at a distance of at least 2.5 times the bath depth. On the other hand, if the second stage lance is installed within 2.5 times and flux is injected, the first and second stage lances
The fluxes in the stages are mixed together, making it impossible to obtain the double slug effect. Therefore, in this invention, the distance between the first stage lance and the second stage lance is set at least 2 times the bath depth.
．． This is because it is limited to 5 times or more.
また、この発明において脱りん処理前の溶銑中Ｓｉ含有
量を０．２０％以下としたのは、以下に示す理由による
。Further, in this invention, the reason why the Si content in the hot metal before the dephosphorization treatment is set to 0.20% or less is as follows.
すなわち、第４図に示すごと＜Ｃａ○／ ５ｊ０２が高
い程スラグーメタル間のＰ分配比は高くなり、脱りんに
有利でおる。このため、５ＬＯ２源となる溶銑中の［Ｓ
ｉ］は可及的に低いことが望ましい。特に、出銑樋内を
流れる溶銑に対して粉体フラックスを吹込んで脱りん処
理する場合には、フラックスが浮上するまでに脱りんが
十分に進んでいる必要がおるが、溶銑中［Ｓｉ］が高い
と脱珪、脱りんが共に酸化反応で下記（１）（２）式の
ように脱りん処理前［Ｓｉ］は低いことが必要である。That is, as shown in FIG. 4, the higher <Ca○/5j02, the higher the P distribution ratio among the slag metals, which is advantageous for dephosphorization. Therefore, [S] in hot metal, which is a source of 5LO2,
i] is desirably as low as possible. In particular, when dephosphorizing the hot metal flowing in the tap runner by injecting powder flux, it is necessary that the dephosphorization has progressed sufficiently by the time the flux floats to the surface. When Si is high, both desiliconization and dephosphorization are oxidation reactions, and as shown in equations (1) and (2) below, it is necessary that [Si] be low before the dephosphorization treatment.
（Ｓｉ）＋Ｏ□＝（ＳｉＯ□） ・・・・・・・
・・（１）式２〔Ｐ〕＋７０２＝（Ｐ２Ｏ３）１９００
００００．（２）式第７図に脱りん処理前［Ｓｉ］と脱
りん率の関係を示すように、脱りん処理前［ｓｉ］≧０
．２０％では脱りん率の低下が著しいため脱りん処理前
［Ｓｉ］ ＜ ０．２０％以下であることが必要でおる
。(Si)+O□=(SiO□) ・・・・・・・
...(1) Formula 2 [P] + 702 = (P2O3) 1900
0000. (2) Equation As shown in Figure 7, the relationship between [Si] before dephosphorization treatment and the dephosphorization rate, before dephosphorization treatment [si]≧0
．． At 20%, the dephosphorization rate decreases significantly, so it is necessary that [Si] < 0.20% or less before dephosphorization treatment.
また、この発明において脱りん処理前に低塩基性スラグ
を１０に一３／Ｐ−Ｔ以下まで除滓するのは、以下に示
す理由による。Furthermore, in the present invention, the reason why the low basicity slag is removed to 10:1/3/P-T or less before the dephosphorization treatment is as follows.
低塩基性スラグとは高炉滓、脱珪滓である。これに対し
高塩基性スラグとは脱りん滓である。高炉出銑樋ではこ
の高塩基性スラグと低塩基性スラグが発生する。このう
ち、高炉滓は、一般にＣａＯ／ ５ｊ０２＝ ｉ、ｏ〜
１．５であり、出銑樋中では低塩基性スラグとなる。つ
まり、高炉がＣａＯ／ ５ｉＯ２＝１．０〜１．５であ
るため、必然的に低塩基性スラグになる。また、脱珪滓
は一般に脱けい剤に酸化鉄、または酸化鉄に少量の生石
灰を添加したものを用いるため、ＣａＯｉｔが少ない一
方、脱珪処理で溶銑中Ｓｊが酸化されて多量の５ｉ０２
が発生する結果、脱珪滓もＣａＯ／ ５ｉ０２が１．５
以下と低く、低塩基性スラグとなる。Low basicity slag is blast furnace slag and desiliconized slag. On the other hand, highly basic slag is dephosphorization slag. High basicity slag and low basicity slag are generated in the blast furnace tap runner. Among these, blast furnace slag generally has CaO/5j02=i,o~
1.5, and it becomes a low basicity slag in the tap hole. In other words, since the blast furnace has CaO/5iO2=1.0 to 1.5, it inevitably becomes a low basicity slag. In addition, since desiliconization slag generally uses iron oxide or iron oxide with a small amount of quicklime added as a desiliconizing agent, it contains little CaOit, but the Sj in the hot metal is oxidized during the desiliconization process, resulting in a large amount of 5i02.
As a result, CaO/5i02 is 1.5 in the desiliconized slag.
It is a low basicity slag.
他方、脱りん滓が高塩基度であるのは、溶銑中のりんを
酸化する酸化力の外に、スラグ中でりんを保持する塩基
度の両方を満足する必要があるため、脱りんを行なう脱
りん滓は高塩基性スラグにする必要があるためである。On the other hand, the reason why the dephosphorization slag has a high basicity is that it is necessary to satisfy both the oxidizing power to oxidize the phosphorus in the hot metal and the basicity to retain the phosphorus in the slag. This is because the dephosphorization slag needs to be made into highly basic slag.
脱りん滓の塩基度は１．５以上である。The basicity of the dephosphorization slag is 1.5 or more.
一方、脱りん処理前のスラグ塩基度が低下すると、第４
図に示すこと＜ （Ｐ）／［Ｐｌが低下するため、脱り
ん不良となる。このため、低塩基性スラグ（高炉滓、脱
珪滓）の流入が著しくなり脱りん後に脱りんスラグと低
塩基性スラグが混合して復りんすることが判明した。第
８図は低塩基性スラグ流人量と２段吹込み直後（下流へ
１．５ｍ ＞とスキンマー除滓直前（２段吹込み位置よ
り上流へ８．０ｍ）の間での復りん量を示す。第８図よ
り、低塩基度スラグ流入１が１０に９／Ｐ−Ｔ未満では
復Ｐｉｌ＜０、００３％であり、１０に＋３／Ｐ−Ｔ以
上で復Ｐ量が増加することがわかった。このため、脱り
ん処理前には低塩基性スラグを１０ｋｉ／Ｐ−Ｔ以下ま
で除滓する必要がある。On the other hand, when the slag basicity before dephosphorization decreases,
What is shown in the figure <(P)/[Pl decreases, resulting in poor dephosphorization. For this reason, it was found that the inflow of low basicity slag (blast furnace slag, desiliconization slag) was significant, and after dephosphorization, the dephosphorization slag and low basicity slag were mixed and rephosphorized. Figure 8 shows the flow rate of low basic slag and the amount of return slag between immediately after the second stage blowing (1.5 m downstream) and immediately before skimmer removal (8.0 m upstream from the second stage blowing position). From Figure 8, when the low basicity slag inflow 1 is less than 10 to 9/P-T, the return Pil is <0,003%, and when it is more than 10 to +3/PT, the return P amount increases. Understood. Therefore, it is necessary to remove the low basicity slag to 10 ki/PT or less before dephosphorization treatment.
第１図はこの発明の一実ｔＭ態様を示す概略図、第２図
は同上における脱りん剤吹込み部の拡大図である。図中
、（１）は高炉、（２）は出銑口、（３）は出銑樋、（
４）はスキンマー、（５）は排滓口、（６−ＩＯ２−２
）は脱りん剤吹込み用非浸漬ランスをそれぞれ示す。FIG. 1 is a schematic view showing an actual tM aspect of the present invention, and FIG. 2 is an enlarged view of the dephosphorizing agent injection section in the same. In the figure, (1) is the blast furnace, (2) is the taphole, (3) is the tapwater, (
4) is a skimmer, (5) is a slag outlet, (6-IO2-2
) indicates a non-immersion lance for injecting dephosphorizing agent.
すなわち、高炉（１）の出銑口（２）より流出する溶銑
（７）は、通常は出銑樋（３）内に設置されているスキ
ンマー（４）にてスラグ（８）が分離され、分離された
スラグは排滓口（５）より排出し、溶銑（７）はスキン
マー（４）を通過してトーピードカー（図示せず）に至
るが、この出銑過程において、この発明ではスキンマー
（４）の下流に脱りん剤吹込み用非浸漬ランス（６−１
）（６−２）を樋長手方向に浴深さの２．５倍以上の間
隔を隔てて配置する。高炉（１）から出銑される溶銑（
刀の脱りん処理を行なう場合は、例えば出銑樋（３）の
上流でサンプリングし、熱起電力式Ｓｉメータ等の測定
装置により溶銑中ｓＬ含有量を測定し、溶銑中Ｓｉ含有
量が０．２０％以下の場合に、スキンマー（４）にて低
塩基性スラブを除滓する。また溶銑中Ｓｉ含有量が０．
２０％以上の場合には、スキンマー（４）の以前で脱Ｓ
ｉ処理を行ない溶銑中Ｓｉ含有量を０．２０％以下とし
スキンマー（４）にて低塩基性スラグを除滓する。しか
る後、スキンマー（４）の下流に多段に配置した脱りん
剤吹込み用非浸漬ランス（６−１）（６−２）にて脱り
ん剤を吹込む。脱りん剤はキャリアガスにて粉体輸送管
内を輸送され、混合流体として溶銑中に吹込まれる。脱
りん剤はまず１段目の非浸漬ランス（６−１）より吹込
み、その吹込まれた脱りん剤（１６−１）が浴面上に浮
上後に２段目の非浸漬ランス（６−２）より脱りん剤（
１６−２）を吹込む。That is, from the hot metal (7) flowing out from the taphole (2) of the blast furnace (1), the slag (8) is separated by a skimmer (4) that is normally installed in the taphole (3). The separated slag is discharged from the slag discharge port (5), and the hot metal (7) passes through the skinmer (4) and reaches the torpedo car (not shown). ) A non-immersion lance (6-1) for injecting dephosphorizing agent is installed downstream of the
) (6-2) are arranged at intervals of at least 2.5 times the bath depth in the longitudinal direction of the gutter. Hot metal tapped from the blast furnace (1) (
When dephosphorizing swords, for example, take a sample upstream of the tap tap (3), measure the sL content in the hot metal using a measuring device such as a thermoelectromotive force Si meter, and confirm that the Si content in the hot metal is 0. .20% or less, the low base slab is removed with a skimmer (4). Also, the Si content in the hot metal is 0.
If it is 20% or more, remove S before the skinmer (4).
I treatment is performed to reduce the Si content in the hot metal to 0.20% or less, and the low basicity slag is removed using a skimmer (4). Thereafter, a dephosphorizing agent is blown into the dephosphorizing agent using non-immersion lances (6-1) and (6-2) arranged in multiple stages downstream of the skinmer (4). The dephosphorizing agent is transported through the powder transport pipe using a carrier gas and blown into the hot metal as a mixed fluid. The dephosphorizing agent is first blown into the first stage non-immersion lance (6-1), and after the blown dephosphorizing agent (16-1) floats on the bath surface, it is blown into the second stage non-immersion lance (6-1). 2) Dephosphorizing agent (
16-2).
２段目のランスは１段目のランスから吹込まれた脱りん
剤が浮上する地点の下流に配置されているので、両ラン
スから吹込まれる脱りん剤が混合することはなく前記ダ
ブルスラグの効果が得られ、脱りん率が高くなる。The second stage lance is located downstream of the point where the dephosphorizing agent injected from the first stage lance floats, so the dephosphorizing agent injected from both lances does not mix and the double slag is The effect is obtained and the dephosphorization rate increases.
実 施 例
高炉から出銑された溶銑の浴深さ０．５ｍ、脱Ｐ処理前
［Ｓｊ］ ＝ ０．１０ ＋ ０．０２％の溶銑に対し
、３０ＣａＯ−１０ＣａＦ２−６０Ｆａ２０：＋の成分
を有する脱りん剤をキャリアガス（空気）と共に８０ｋ
ｉ／Ｔ吹込んだ。その際、溶銑中の高炉滓および脱珪滓
は脱りん処理ゾーンの上流に設置したスキンマーにて１
０ｋＣＪ／Ｐ−Ｔ以下まで除滓した。Example The bath depth of hot metal tapped from a blast furnace is 0.5 m, and the hot metal has a composition of 30CaO-10CaF2-60Fa20:+ before deP treatment [Sj] = 0.10 + 0.02%. 80k of dephosphorizing agent with carrier gas (air)
I/T was injected. At that time, the blast furnace slag and desiliconization slag in the hot metal are removed by a skimmer installed upstream of the dephosphorization treatment zone.
Sludge was removed to below 0kCJ/PT.
本実施例では、２本の非浸漬ランスを２．５ｍ。In this example, two non-immersed lances are 2.5 m long.
１、Ｏｒｒ＋、 Ｏｎの間隔で設置して脱りん剤を吹
込み、それぞれの間隔で吹込んだ結果を第３図に示す。The dephosphorizer was installed at intervals of 1, Orr+, and On, and the dephosphorizing agent was injected, and the results of injecting at each interval are shown in Figure 3.
第３図の結果より、ランス間隔がＯｍと１．０ｍでも同
一の挙動を示し処理後［Ｐｌ ＞ ０．０３％であった
。一方、吹込まれたフラックスが浮上するだけの距離を
充分に確保したランス間隔２．５ｍ （ランス間隔／浴
深さ＝ ５．０）の場合、２段にわたって脱りんが進み
［Ｐｌ ＝ ０．０２％を得た。From the results shown in FIG. 3, the same behavior was observed even when the lance spacing was Om and 1.0 m, and [Pl > 0.03% after treatment. On the other hand, in the case of a lance spacing of 2.5 m (lance spacing/bath depth = 5.0), which provides a sufficient distance for the injected flux to float, dephosphorization proceeds in two stages [Pl = 0.02 I got %.
発明の詳細
な説明したごとく、この発明は出銑樋において脱りん剤
の粉体をキャリアガスにて混合流体として非浸漬ランス
より溶銑中に吹込む際、溶銑中Ｓｉ含有量が０．２０％
以下で低塩基性スラグを１０ｋｇ／Ｐ−Ｔ以下まで除滓
した後、吹込まれる脱りん剤が混合しない間隔を隔てて
多段に配置したランスより脱りん剤を吹込んで脱りんす
る方法でおり、ダブルスラグ法の効果が得られることに
よって脱りん反応が著しく高められ、０．０３％以下ま
で出銑樋上で脱りんできる効果を有する。従って、この
発明方法によれば、取鍋やトーピード等での■脱りん処
理が不要となり、溶銑の脱りん処理を工程増なく行なう
ことができる効果を秦する。As described in detail, the present invention is capable of reducing the Si content of the hot metal to 0.20% when the powder of the dephosphorizing agent is blown into the hot metal from a non-immersed lance as a mixed fluid using a carrier gas in the tap runner.
After the low basicity slag is removed to below 10 kg/PT, dephosphorization is carried out by injecting dephosphorizing agent through lances arranged in multiple stages at intervals where the dephosphorizing agent is not mixed. By obtaining the effects of the double slug method, the dephosphorization reaction is significantly enhanced, and it has the effect of dephosphorizing up to 0.03% or less on the tap runner. Therefore, according to the method of the present invention, the dephosphorization treatment using a ladle, torpedo, etc. is not necessary, and the dephosphorization treatment of hot metal can be carried out without increasing the number of steps.
第１図はこの発明の一実施態様を示す概略図、第２図は
同上における脱りん剤吹込み部を拡大して示す概略図、
第３図はこの発明の実施例における脱りん挙動の変化を
示す図、第４図〜第８図はこの発明者の行なった実験デ
ータを示し、第４図はＰ分配比とＣａＯ／ ５ｉ０２
（塩基度）の関係を示す図、第５図は高炉出銑樋で脱珪
、脱りんを行なった時の［Ｐ］の推移を示す図、第６図
は高炉出銑樋での１段吹込みと２段吹込みの場合のスラ
グ量と到達［Ｐ］の関係を示す図、第７図は脱りん処理
前［Ｓｉ］と脱りん率の関係を示す図、第８図は低塩基
性スラグ流人量と２段吹込み直後とスキンマー除滓直前
の間での復りん量を示す図である。
１・・・高炉、２・・・出銑口、３・・・出銑樋、４・
・・スキンマー、５・・・排滓口、６−１．６−２・・
・脱りん剤吹込み用非浸漬ランス、７・・・溶銑、８・
・・スラグ。
第７図
０ α１ α２ ｏ、３ α４
α５脱Ｐ処理前〔ｓｌ〕（％）
、 第８図
一
低塩基度スラグ流入は（にＦ／、、ｇ、Ｔ）１１３図
ｏ ｚｏ ｔｏ ａ
、。
ＣａＯ／５ｉ０２
第５図
第６図
スラグＩｔ（にｇ／Ｔ）FIG. 1 is a schematic diagram showing one embodiment of the present invention, FIG. 2 is a schematic diagram showing an enlarged dephosphorizing agent injection part in the same as above,
Fig. 3 is a diagram showing changes in dephosphorization behavior in an example of the present invention, Figs. 4 to 8 show experimental data conducted by the inventor, and Fig. 4 shows changes in P distribution ratio and CaO/5i02
(Basicity) Figure 5 is a diagram showing the change in [P] when desiliconization and dephosphorization are performed in the blast furnace tap runner, Figure 6 is the graph showing the change in [P] when desiliconizing and dephosphorizing in the blast furnace tap runner. Figure 7 shows the relationship between slag amount and attained [P] in the case of blowing and two-stage blowing, Figure 7 shows the relationship between [Si] before dephosphorization treatment and dephosphorization rate, Figure 8 shows the relationship between low base FIG. 2 is a diagram showing the amount of slag flow and the amount of return slag between immediately after second-stage blowing and immediately before skimmer removal. 1...Blast furnace, 2...Tapping port, 3...Tapping sluice, 4...
...Skinmer, 5...Slag outlet, 6-1.6-2...
・Non-immersion lance for injecting dephosphorizing agent, 7... Hot metal, 8.
...Slag. Figure 7 0 α1 α2 o, 3 α4
α5 Before deP treatment [sl] (%), Fig. 8 - Low basicity slag inflow (to F/,, g, T) Fig. 113 o zo to a
,. CaO/5i02 Fig. 5 Fig. 6 Slag It (nig/T)
Claims (1)
スにより脱りん剤をキャリアガスと共に溶銑中に吹込む
際、溶銑中のＳｉ含有量が０．２０％以下で、低塩基性
スラグを１０ｋｇ／Ｐ−Ｔ以下まで除滓した後、樋長手
方向に少なくとも浴深さの２．５倍以上の間隔を隔てて
多段配置した非浸漬上吹ランスにて脱りん剤を吹込むこ
とを特徴とする溶銑の脱りん方法。In the method of dephosphorizing using a blast furnace tap runner, when a dephosphorizing agent is blown into hot metal with a carrier gas using a non-immersed top blowing lance, the Si content in the hot metal is 0.20% or less and low basicity slag is used. After removing slag to 10 kg/PT or less, a dephosphorizing agent is injected using non-immersion top blowing lances arranged in multiple stages at intervals of at least 2.5 times the bath depth in the longitudinal direction of the gutter. A method for dephosphorizing hot metal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19012986A JPS6347321A (en) | 1986-08-13 | 1986-08-13 | Dephosphorization of molten pig iron |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19012986A JPS6347321A (en) | 1986-08-13 | 1986-08-13 | Dephosphorization of molten pig iron |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6347321A true JPS6347321A (en) | 1988-02-29 |
Family
ID=16252875
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19012986A Pending JPS6347321A (en) | 1986-08-13 | 1986-08-13 | Dephosphorization of molten pig iron |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6347321A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5947702A (en) * | 1982-09-10 | 1984-03-17 | 株式会社富士通ゼネラル | Moisture sensitive element and method of producing same |
-
1986
- 1986-08-13 JP JP19012986A patent/JPS6347321A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5947702A (en) * | 1982-09-10 | 1984-03-17 | 株式会社富士通ゼネラル | Moisture sensitive element and method of producing same |
| JPH0153483B2 (en) * | 1982-09-10 | 1989-11-14 | Fujitsu General Ltd |
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