JP2018184645A - Slag outflow prevention apparatus - Google Patents

Slag outflow prevention apparatus Download PDF

Info

Publication number
JP2018184645A
JP2018184645A JP2017087579A JP2017087579A JP2018184645A JP 2018184645 A JP2018184645 A JP 2018184645A JP 2017087579 A JP2017087579 A JP 2017087579A JP 2017087579 A JP2017087579 A JP 2017087579A JP 2018184645 A JP2018184645 A JP 2018184645A
Authority
JP
Japan
Prior art keywords
slag
discharge hole
viscosity
substance
dart
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.)
Granted
Application number
JP2017087579A
Other languages
Japanese (ja)
Other versions
JP6874507B2 (en
Inventor
政樹 宮田
Masaki Miyata
政樹 宮田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Corp
Original Assignee
Nippon Steel and Sumitomo Metal Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nippon Steel and Sumitomo Metal Corp filed Critical Nippon Steel and Sumitomo Metal Corp
Priority to JP2017087579A priority Critical patent/JP6874507B2/en
Publication of JP2018184645A publication Critical patent/JP2018184645A/en
Application granted granted Critical
Publication of JP6874507B2 publication Critical patent/JP6874507B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Landscapes

  • Carbon Steel Or Casting Steel Manufacturing (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a slag outflow prevention apparatus capable of suppressing slag flowing out from a discharge hole regardless of the number of operations of a converter.SOLUTION: The apparatus comprises a head part for closing a discharge hole for discharging hot metal or molten steel at the time of tapping or burning out of a converter, and a guide part held when placing the head part into the discharge hole. A substance is attached around the outflow prevention apparatus to increase the viscosity or apparent viscosity of the slag.SELECTED DRAWING: Figure 1

Description

本発明は、炉内で処理された溶銑または溶鋼を転炉から排出する際に、溶銑または溶鋼上に浮遊しているスラグが排出孔から流出するのを防止するためのスラグの流出防止装置に関する。   The present invention relates to a slag outflow prevention device for preventing slag floating on hot metal or molten steel from flowing out from a discharge hole when molten metal or molten steel treated in the furnace is discharged from a converter. .

溶銑の脱りん処理や脱炭処理が終了すると、転炉を傾斜することによって、炉内の溶銑又は溶鋼が転炉の側壁に設けられた出銑孔又は出鋼孔（以下、総称として排出孔と記す）を通して取鍋に移される。ところが、転炉内には溶銑又は溶鋼の上にスラグが浮遊しており、そのスラグが排出孔から流出して取鍋に入ると、脱りん処理効果を実質的に低下させてしまったり、鋼の品質を低下させたりする。従って、出銑又は出鋼が終わった段階でスラグの流出を防止する対策が必要である。そこで、その対策の１つとして、出銑又は出鋼の最終段階で炉内にスラグの流出防止装置（以下、ダーツと称す）を投入して排出孔を閉塞させる方法が知られている（例えば特許文献１参照）。   When the hot metal dephosphorization and decarburization processes are completed, the hot metal or molten steel in the furnace is tilted by tilting the converter, so that the hot metal or hot steel hole provided in the side wall of the converter (hereinafter referred to as a discharge hole as a generic term) Through the ladle). However, slag floats on the hot metal or molten steel in the converter, and if the slag flows out of the discharge hole and enters the ladle, the dephosphorization effect may be substantially reduced, The quality of the product. Therefore, it is necessary to take measures to prevent the outflow of slag at the stage where the tapping or tapping is finished. Therefore, as one of the countermeasures, there is known a method of closing a discharge hole by introducing a slag outflow prevention device (hereinafter referred to as dart) into the furnace at the final stage of tapping or tapping (for example, Patent Document 1).

図３は、出鋼の最終段階における転炉内の様子を縦断面で示した図であり、転炉がほぼ水平状態にされ、溶鋼が転炉内に少し残っている状態を示している。出鋼が最終段階になると、図３に示すように溶鋼２０の上面に浮遊するスラグ３０が排出孔４０から流出することを防止するために、ダーツ５０が転炉内に投入される。   FIG. 3 is a vertical cross-sectional view showing the inside of the converter in the final stage of the steel output, and shows a state where the converter is almost horizontal and a small amount of molten steel remains in the converter. When the steel output is at the final stage, as shown in FIG. 3, the dart 50 is introduced into the converter in order to prevent the slag 30 floating on the upper surface of the molten steel 20 from flowing out from the discharge hole 40.

図４は、図３に示す排出孔４０の周辺を拡大した図である。図４に示すように、ダーツ５０はヘッド部５０ａとガイド部５０ｂとを備えており、ヘッド部５０ａの上方の中央には把持棒５０ｃが設けられている。この把持棒５０ｃは、例えば特許文献２に記載の投入設備などでダーツ５０を転炉内に投入する場合に用いられる。出鋼が最終段階に入り、炉内の溶鋼が少なくなった段階でダーツ５０が炉内に装入され、排出孔４０の直上に投下される。ダーツ５０は、図４に示すようにそのガイド部５０ｂが排出孔４０内に侵入することによりダーツ５０の溶鋼上での移動が規制される。このようにして、炉内の溶鋼が無くなる直前にヘッド部５０ａが排出孔４０の溶鋼入口部に覆い被さり、本来的にはスラグ３０の流出が防止される。なお、ヘッド部５０ａは、溶鋼とスラグとの界面に浮遊させておく必要があるので、ヘッド部５０ａの比重は溶鋼の比重とスラグの比重との間の値となるような材料で構成されている。   4 is an enlarged view of the periphery of the discharge hole 40 shown in FIG. As shown in FIG. 4, the dart 50 includes a head portion 50a and a guide portion 50b, and a gripping rod 50c is provided at the center above the head portion 50a. This gripping rod 50c is used, for example, when the dart 50 is thrown into the converter using the charging equipment described in Patent Document 2. The dart 50 is inserted into the furnace at the stage where the outgoing steel enters the final stage and the molten steel in the furnace is low, and dropped onto the discharge hole 40. As shown in FIG. 4, the dart 50 is restricted from moving on the molten steel when the guide portion 50 b enters the discharge hole 40. In this way, the head portion 50a covers the molten steel inlet portion of the discharge hole 40 immediately before the molten steel in the furnace disappears, and the outflow of the slag 30 is essentially prevented. In addition, since it is necessary to make the head part 50a float at the interface between the molten steel and the slag, the specific gravity of the head part 50a is made of a material having a value between the specific gravity of the molten steel and the specific gravity of the slag. Yes.

特開２００３−９６５１２号公報JP 2003-96512 A 実開平６−６９２５９号公報Japanese Utility Model Publication No. 6-69259

転炉の排出孔入り側の耐火物６０は、転炉の操業回数を重ねると溶損し、歪な形になってくる。すると、転炉からのスラグ流出をダーツによって安定して抑制することは困難になる。それは、耐火物が消耗することによって排出孔入り側とダーツとの間に大きな隙間が生じ、そこからスラグが多量に流出してしまうためである。図５は、出鋼が完了した時のダーツ５０の状態を示す図である。図５に示すように、排出孔入り側に溶損部位７０があると、ダーツ５０が傾いてしまい、ダーツ５０と排出孔入り側との隙間からスラグ３０が流出してしまう場合がある。   The refractory 60 on the outlet side of the converter is melted and becomes distorted when the number of operations of the converter is repeated. Then, it becomes difficult to stably suppress the slag outflow from the converter by the dart. This is because the refractory is consumed, so that a large gap is generated between the discharge hole entering side and the dart, and a large amount of slag flows out therefrom. FIG. 5 is a diagram illustrating a state of the dart 50 when the steel output is completed. As shown in FIG. 5, if there is a melted portion 70 on the discharge hole entering side, the dart 50 is inclined, and the slag 30 may flow out from the gap between the dart 50 and the discharge hole containing side.

また、転炉は２０００回以上使用し、排出孔入り側の煉瓦（耐火物）が溶損して歪な形状になってから使用する回数の方が圧倒的に多い。そのため、転炉の操業回数によらず排出孔から流出するスラグ量を抑制する手段が強く要望されていた。   In addition, the converter is used 2000 times or more, and the number of times of use after the brick (refractory) on the discharge hole side is melted and becomes a distorted shape is overwhelmingly larger. Therefore, there has been a strong demand for means for suppressing the amount of slag flowing out from the discharge hole regardless of the number of converter operations.

本発明は前述の問題点を鑑み、転炉の操業回数によらず排出孔から流出するスラグ量を抑制できるスラグの流出防止装置を提供することを目的とする。   In view of the above-described problems, an object of the present invention is to provide a slag outflow prevention device capable of suppressing the amount of slag flowing out from a discharge hole regardless of the number of converter operations.

本発明者は、排出孔からスラグが流出するのを抑制する方法について鋭意検討し、排出孔入り側付近のスラグの流動性を低下させる方法に着目した。出銑又は出鋼の末期では、一般的に、排出孔から排出される溶銑又は溶鋼が渦を形成してその渦にスラグが巻き込まれる現象が発生する。このとき、排出孔の直上にダーツのヘッド部があると、そのヘッド部の存在によりスラグの巻き込みが抑制される。しかし、排出孔入り側付近の溶損部位が存在すると、ダーツのヘッド部と排出孔入り側との隙間がいびつに大きくなり、排出孔へ流れる溶銑又は溶鋼に引きずられて流出するスラグが多くなり易い。また、ダーツのヘッド部が排出孔の入口に接した後も排出孔入口の溶損部位には隙間が残っているため、その隙間からスラグが流出し続けてしまうことになる。そこで、ダーツ周辺に存在するスラグの流動性を低下させれば、たとえ排出孔入り側付近に溶損部位があろうとも、溶銑又は溶鋼に引きずられて流出するスラグの量を低減できることを見出した。   The present inventor has intensively studied a method for suppressing the slag from flowing out from the discharge hole, and has focused on a method for reducing the fluidity of the slag near the discharge hole entering side. In the final stage of the tapping or tapping steel, generally, a phenomenon occurs in which molten iron or molten steel discharged from the discharge hole forms a vortex and slag is caught in the vortex. At this time, if there is a dart head portion directly above the discharge hole, the presence of the head portion prevents slag from being caught. However, if there is a melted part near the discharge hole entry side, the gap between the dart head and the discharge hole entry side becomes distorted, increasing the amount of slag that flows out of the hot metal or molten steel flowing into the discharge hole. easy. Further, even after the head part of the dart comes into contact with the inlet of the discharge hole, a gap remains in the melted portion of the discharge hole inlet, and thus the slag continues to flow out from the gap. Therefore, it has been found that if the fluidity of the slag existing around the darts is lowered, the amount of slag that is dragged out of the hot metal or molten steel can be reduced even if there is a melted part near the discharge hole entrance side. .

具体的には、ダーツと一緒に、スラグ中に固相として分散して見掛けのスラグ粘度を高める高融点物質、熱分解してスラグを冷却してスラグ粘度を高める物質、又はスラグの組成を変えてスラグの粘度を増加させる物質を添加できるようにする。上記物質としては、ＣａＯ、ＣａＣＯ3、ＭｇＯ、ＭｇＣＯ3、ドロマイト、煉瓦屑、転炉スラグなどがある。なお、上記物質の粒径は５０ｍｍ以下が望ましい。 Specifically, together with darts, a high melting point material that disperses as a solid phase in the slag to increase the apparent slag viscosity, a material that thermally decomposes to cool the slag to increase the slag viscosity, or changes the composition of the slag Allowing the addition of substances that increase the viscosity of the slag. Examples of the substance include CaO, CaCO 3 , MgO, MgCO 3 , dolomite, brick waste, and converter slag. The particle size of the substance is desirably 50 mm or less.

以上のことから本発明は以下のとおりである。
（１）転炉の出銑又は出鋼時に、溶銑又は溶鋼を排出する排出孔を閉塞するためのヘッド部と、前記ヘッド部を前記排出孔に導くためのガイド部とを少なくとも備えた流出防止具の周りに、スラグの粘度又は見かけの粘度を高める物質を付帯したことを特徴とするスラグの流出防止装置。
（２）前記スラグの粘度を高める物質は、前記スラグの組成を変える物質、又は前記スラグを冷却する物質であることを特徴とする上記（１）に記載のスラグの流出防止装置。
（３）前記スラグの粘度又は見かけの粘度を高める物質は、ＣａＯ、ＣａＣＯ3、ＭｇＯ、ＭｇＣＯ3、ドロマイト、煉瓦屑、及び転炉スラグからなる群から選ばれる１種又は２種以上であることを特徴とする上記（１）又は（２）に記載のスラグの流出防止装置。
（４）前記スラグの粘度又は見かけの粘度を高める物質の最大粒径が５０ｍｍ以下であることを特徴とする上記（１）〜（３）のいずれかに記載のスラグの流出防止装置。 From the above, the present invention is as follows.
(1) Outflow prevention provided with at least a head part for closing a discharge hole for discharging molten iron or molten steel and a guide part for guiding the head part to the discharge hole at the time of unloading or steeling of a converter A slag outflow prevention device, characterized in that a substance that increases the viscosity of the slag or the apparent viscosity is attached around the tool.
(2) The slag outflow prevention device according to (1), wherein the substance that increases the viscosity of the slag is a substance that changes a composition of the slag or a substance that cools the slag.
(3) The substance that increases the viscosity or apparent viscosity of the slag is one or more selected from the group consisting of CaO, CaCO 3 , MgO, MgCO 3 , dolomite, brick waste, and converter slag. The slag outflow prevention device according to (1) or (2) above, wherein
(4) The slag outflow prevention device according to any one of the above (1) to (3), wherein the maximum particle size of the substance that increases the viscosity or apparent viscosity of the slag is 50 mm or less.

本発明によれば、転炉の操業回数によらず排出孔から流出するスラグ量を抑制できるスラグの流出防止装置を提供することができる。   ADVANTAGE OF THE INVENTION According to this invention, the slag outflow prevention apparatus which can suppress the slag amount which flows out from a discharge hole irrespective of the frequency | count of operation of a converter can be provided.

本発明に係るスラグの流出防止装置の一例を示す図である。It is a figure which shows an example of the slag outflow prevention apparatus which concerns on this invention. 本発明に係るスラグ流出装置を用いてスラグの流出を防止する様子を説明するための図である。It is a figure for demonstrating a mode that the outflow of slag is prevented using the slag outflow apparatus which concerns on this invention. 出鋼時にダーツが排出孔に収まる様子を説明するための図である。It is a figure for demonstrating a mode that a dart is settled in a discharge hole at the time of steel extraction. 出鋼時における排出孔付近を拡大した図である。It is the figure which expanded the discharge hole vicinity at the time of steel extraction. 溶損部位がある場合のスラグの流出形態を説明するための図である。It is a figure for demonstrating the outflow form of slag in case there exists a erosion site | part.

以下、本発明の詳細について図面を参照しながら説明する。本発明は、脱りん処理後の出銑、脱炭処理後の出鋼のどちらにも適用できる。以下、代表して脱炭処理後の出鋼時に適用する例について説明する。   Hereinafter, the details of the present invention will be described with reference to the drawings. The present invention can be applied to both tapping after dephosphorization and tapping steel after decarburization. Hereinafter, as an example, an example applied at the time of steel output after decarburization will be described.

本発明のスラグの流出防止装置（以下、ダーツ）は、出鋼（出銑）の最終段階で投入されると、出鋼（出銑）の最終段階でダーツ周囲のスラグの流動性を低下させることによって排出孔から流出するスラグの量を抑制する。スラグの流動性を低下させる方法、すなわち粘度を増加させる方法としては、（１）液相スラグに固体粒を分散させる方法、（２）スラグを冷却する方法、及び（３）スラグの組成を変える方法がある。   When the slag outflow prevention device of the present invention (hereinafter referred to as dart) is introduced at the final stage of tapping (developing), the fluidity of the slag around the dart is reduced at the final stage of tapping (developing). This suppresses the amount of slag flowing out from the discharge hole. As a method of reducing the fluidity of slag, that is, a method of increasing the viscosity, (1) a method of dispersing solid particles in liquid phase slag, (2) a method of cooling slag, and (3) changing the composition of slag There is a way.

（１）液相スラグに固体粒を分散させる方法は、スラグに溶解し難い高融点の物質を固相粒子として添加して分散させ、スラグの見掛けの粘度を増加させる方法である。液相スラグへ固相粒子を分散させると、見掛けの粘度が増加することが知られている。固相粒子としては、ＭｇＯ、ドロマイト、煉瓦屑、転炉スラグなどが考えられる。   (1) The method of dispersing solid particles in liquid phase slag is a method of increasing the apparent viscosity of slag by adding and dispersing as a solid phase a substance having a high melting point that is difficult to dissolve in slag. It is known that when the solid phase particles are dispersed in the liquid phase slag, the apparent viscosity increases. As solid phase particles, MgO, dolomite, brick waste, converter slag, and the like are conceivable.

（２）スラグを冷却する方法は、スラグを冷却することによってスラグそのものの粘度を増加させる方法である。この方法では、冷却時にスラグ中に固相が晶出して固相と液相とが分散し、前述した見掛けの粘度が増加することもある。冷却方法としては、スラグへ添加後に熱分解して熱を奪う吸熱反応が起こる物質を添加する方法が考えられる。このような物質としては、例えばＣａＣＯ3、ＭｇＣＯ3、ドロマイトなどが考えられる。 (2) The method for cooling the slag is a method for increasing the viscosity of the slag itself by cooling the slag. In this method, the solid phase crystallizes in the slag during cooling, and the solid phase and the liquid phase are dispersed, and the apparent viscosity described above may increase. As a cooling method, a method of adding a substance that undergoes an endothermic reaction that thermally decomposes and takes heat away after addition to the slag can be considered. Examples of such substances include CaCO 3 , MgCO 3 , and dolomite.

（３）スラグの組成を変える方法は、スラグに溶解する物質を添加してスラグの組成を変えることによって、スラグそのものの粘度を増加させる方法である。例えば、ＣａＯを添加すると、スラグ中の（ＣａＯ）濃度を高くなり、塩基度（ＣａＯ／ＳｉＯ2比）が上昇し、スラグの粘度が増加する。 (3) The method of changing the composition of the slag is a method of increasing the viscosity of the slag itself by adding a substance that dissolves in the slag and changing the composition of the slag. For example, when CaO is added, the (CaO) concentration in the slag increases, the basicity (CaO / SiO 2 ratio) increases, and the viscosity of the slag increases.

以上のようにスラグの粘度又は見かけの粘度を増加させる方法が考えられる。そこで、本発明者らは、ダーツの投入時にこれらの物質を添加するために、これらの物質を付帯できるようにしたダーツを見出した。例えば図１に示すように、スラグ粘度を増加させるための物質２を入れた袋１をダーツ１０に付帯するようにする。出鋼が最終段階に入り、炉内の溶鋼が少なくなった段階で図１に示すようなダーツが炉内に装入され、排出孔の直上に投下される。そして、ダーツが投下されてスラグが流出し始める迄に、その袋１が破れて上記物質がダーツ周辺のスラグに添加され、スラグ中へ分散することによってスラグの粘度または見かけの粘度が高められるため、スラグ流出抑制効果が十分に発揮される。つまり、図２に示すように、排出孔付近のスラグ３は粘度または見かけの粘度が増加するため、溶損部位があることによってダーツが排出孔を十分に閉塞できない場合にも、スラグの流出を抑えることができる。   As described above, a method of increasing the viscosity of the slag or the apparent viscosity can be considered. Therefore, the present inventors have found darts that can be supplemented with these substances in order to add these substances when the darts are introduced. For example, as shown in FIG. 1, a bag 1 containing a substance 2 for increasing slag viscosity is attached to a dart 10. The darts as shown in FIG. 1 are inserted into the furnace at the stage where the steel output enters the final stage and the molten steel in the furnace is low, and dropped onto the discharge hole. By the time the dart is dropped and the slag begins to flow out, the bag 1 is torn and the substance is added to the slag around the dart, and the viscosity of the slag or apparent viscosity is increased by dispersing in the slag. The slag outflow suppressing effect is sufficiently exhibited. That is, as shown in FIG. 2, since the slag 3 near the discharge hole increases in viscosity or apparent viscosity, even if the dart cannot sufficiently close the discharge hole due to the melted portion, the slag flows out. Can be suppressed.

以上のようにダーツ１０本体は少なくともヘッド部１０ａとガイド部１０ｂとを備えているが、溶銑（又は溶鋼）上に浮かんで最終的には排出孔の入口を閉塞するように、ダーツ１０のヘッド部１０ａの比重は溶銑（又は溶鋼）よりも小さく、スラグより大きい材質のものを用いる。ダーツそのものについては公知のものを用いてもよい。   As described above, the main body of the dart 10 includes at least the head portion 10a and the guide portion 10b, but the head of the dart 10 so as to float on the hot metal (or molten steel) and finally close the inlet of the discharge hole. The specific gravity of the part 10a is smaller than that of hot metal (or molten steel) and is made of a material larger than slag. A known dart may be used.

スラグの粘度または見かけの粘度を増加させるための物質をダーツとともに投下可能であれば、袋以外の物や容器で付帯するようにしてもよい。袋を用いる場合には、例えば、ダーツのヘッド部１０ａ上方の把持棒１０ｃから４方に４つの袋を吊り下げ、４つの袋内へ上記物質を装入する。このようなダーツを排出孔の直上に投下すれば、簡便で、確実に前述した効果を享受できる。袋を用いる以外に、適当な容器に上記物質を装入して把持棒に括りつける方法でも良い。   If the substance for increasing the viscosity of the slag or the apparent viscosity can be dropped together with the dart, it may be attached with an object other than the bag or a container. In the case of using bags, for example, four bags are suspended in four directions from the gripping rod 10c above the head part 10a of the dart, and the substance is loaded into the four bags. If such a dart is dropped directly above the discharge hole, the effects described above can be easily and reliably obtained. In addition to using a bag, a method of charging the above substance into a suitable container and binding it to a gripping rod may be used.

なお、袋や容器の材質は、排出孔の真上からダーツを溶鋼へ投下する前段階で溶鋼及びスラグから発せられる熱によって溶解又は燃焼してしまわない材料であれば特に限定されない。袋や容器の材質としては、ダーツを投下する前段階では溶解または燃焼等により破損してしまわず、ダーツが排出孔の直上に運ばれた後の投下される直前、またはダーツが投下されて溶鋼とスラグとの間に位置しているときに破れて、内容物がスラグに添加されるような材質であることが望ましい。
具体的には、ダーツを排出孔直上まで運ぶのに要する時間に応じて適宜決めればよいことであり、袋であれば難燃・防炎素材や薄手の金網等が例示できるし、容器であれば厚手のボール紙等が例示できる。 The material of the bag or container is not particularly limited as long as it does not melt or burn by the heat generated from the molten steel and slag before dropping the dart into the molten steel from directly above the discharge hole. As for the material of the bag or container, it will not be damaged by melting or combustion in the stage before dropping the dart, but immediately after the dart is transported directly above the discharge hole or just before it is dropped, or the dart is dropped and molten steel It is desirable that the material be broken when it is positioned between the slag and the contents added to the slag.
Specifically, it may be determined as appropriate according to the time required to carry the dart to just above the discharge hole. For a bag, a flame retardant / flame proof material, a thin wire mesh, etc. An example is thick cardboard.

スラグの粘度（又は見かけの粘度）を増加させる物質は、前述した（１）〜（３）の少なくともいずれかの効果を有する物質が挙げられる。もちろん、上記（１）〜（３）の効果を同時に複数発揮できる物質もあり、その方が効果は大きい。ドロマイトなどはそれに相当する。さらに前述した物質を２種類以上混合して用いてもよい。   Examples of the substance that increases the viscosity (or apparent viscosity) of the slag include substances having at least one of the effects (1) to (3) described above. Of course, there are substances that can simultaneously exhibit a plurality of the effects (1) to (3), and the effect is greater. Dolomite is equivalent to that. Further, two or more kinds of the aforementioned substances may be mixed and used.

なお、上記物質の最大粒径は５０ｍｍ以下が望ましい。但し、粒径が５ｍｍ未満である物質の割合が多過ぎると、界面張力の影響が強く出て、固相粒がスラグ浴内へ侵入して分散しにくくなる。そのため、粒径が５ｍｍ未満の割合（重量割合）は、２０％以下が望ましい。一方、最大粒径が５０ｍｍ超だと固相粒添加量が一定の場合、スラグとの接触面積が小さく、スラグへ溶解しにくくなり分散しにくくなる。   The maximum particle size of the substance is desirably 50 mm or less. However, if the proportion of the substance having a particle size of less than 5 mm is too large, the influence of the interfacial tension is strong, and the solid phase particles enter the slag bath and are difficult to disperse. Therefore, the ratio (weight ratio) of the particle size of less than 5 mm is desirably 20% or less. On the other hand, when the maximum particle size exceeds 50 mm, when the amount of solid phase particles added is constant, the contact area with the slag is small, and it is difficult to dissolve and disperse in the slag.

また、ダーツとともに付帯する上記物質の量は、０．０７〜１．０ｋｇ／溶鋼ｔｏｎ（ｏｒ 溶銑ｔｏｎ）とすることが望ましい。上記物質の量が下限値を下回ると、粘度が増加したスラグでダーツ周辺を覆いきれないため、効果が低下してしまう恐れがある。また、上記物質の量が上限を超えると、効果が飽和し、コスト上不利である。より望ましくは０．２〜０．７ｋｇ／溶鋼ｔｏｎ（ｏｒ 溶銑ｔｏｎ）である。   Moreover, it is desirable that the amount of the substance attached together with the dart is 0.07 to 1.0 kg / molten steel ton (or molten iron ton). If the amount of the substance is lower than the lower limit value, the dart periphery cannot be covered with the slag having increased viscosity, which may reduce the effect. Moreover, when the amount of the substance exceeds the upper limit, the effect is saturated, which is disadvantageous in cost. More desirably, it is 0.2 to 0.7 kg / molten steel ton (or molten iron ton).

以上のようにスラグ粘度を増加させるための物質をダーツとともに投入することによって、少量の固相粒でも、転炉の炉回数によらず排出孔から流出するスラグ量を抑制できる。なお、脱りん処理後の出銑に適用すれば、その後の脱炭炉への燐持込量が減って、脱炭炉で脱りんするためのＣａＯ添加量を減らすことができる。脱炭炉へ適用すれば、取鍋へ流出するＦｅＯ等の低級酸化物量を減らせるので、二次精錬（脱酸、脱硫）の負荷を大幅に軽減できる。更には、ＦｅＯをＡｌで還元する際に生成するＡｌ2Ｏ3系介在物量も減らせるため、鉄鋼製品の品質が向上する。 As described above, by introducing the substance for increasing the slag viscosity together with the dart, the amount of slag flowing out from the discharge hole can be suppressed even with a small amount of solid phase grains regardless of the number of converters. In addition, if it applies to the tapping after a dephosphorization process, the amount of phosphorus brought into a subsequent decarburization furnace can reduce, and the CaO addition amount for dephosphorization in a decarburization furnace can be reduced. If applied to a decarburization furnace, the amount of lower oxide such as FeO flowing out to the ladle can be reduced, so the load of secondary refining (deoxidation, desulfurization) can be greatly reduced. Furthermore, since the amount of Al 2 O 3 inclusions produced when FeO is reduced with Al can be reduced, the quality of the steel product is improved.

次に、本発明の実施例について説明するが、実施例での条件は、本発明の実施可能性及び効果を確認するために採用した一条件例であり、本発明は、この一条件例に限定されるものではない。本発明は、本発明の要旨を逸脱せず、本発明の目的を達成する限りにおいて、種々の条件を採用し得るものである。   Next, examples of the present invention will be described. The conditions in the examples are one example of conditions used for confirming the feasibility and effects of the present invention, and the present invention is based on this one example of conditions. It is not limited. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

（実施例）
流出防止具として、ヘッド部の主要組成が、質量％でＣｒ2Ｏ3：４０％、Ｆｅ2Ｏ3：２５％、ＭｇＯ：１０％、ＳｉＯ2：１０％、Ａｌ2Ｏ3：１０％であり、ガイド部の主要組成が、Ａｌ2Ｏ3：７０％、ＳｉＯ2：２０％のダーツを用いた。
一方、操業回数が１５００回以上の転炉で溶銑２５０ｔｏｎを脱りん吹錬した。脱りん吹錬終了後のスラグは、塩基度（ＣａＯ／ＳｉＯ2）１．３、４０ｋｇ／溶銑ｔｏｎで、脱りん後の溶銑の温度は１３５０℃だった。その後、炉体を傾動して出銑を開始し、出銑末期に、前述した組成のダーツに最大粒径が５０ｍｍ以下のドロマイトを各１０ｋｇ（０．０４ｋｇ／溶銑ｔｏｎ）装入した４つの段ボール製容器をガイド部の四方に括りつけたダーツを作製し、投入装置のアームで把持棒を保持しながら排出孔の真上に当該ダーツを移動させて投下した。ダーツを転炉内に入れてから排出孔直上まで移動させるのに要した時間は５〜１０秒間であり、ダーツのガイド部を溶銑中へ投下してから出銑が完了するまでの時間は約１分であった。
スラグ流出量は、取鍋内のスラグ厚さから流出量を算出し、その量を溶銑量で割って、溶銑１ｔｏｎ当たりのスラグ流出量を求めた。
同様の実験を１００回行ったところ、スラグ流出量は平均で３ｋｇ／溶銑ｔｏｎであった。 (Example)
As an outflow prevention tool, the main composition of the head part is Cr 2 O 3 : 40%, Fe 2 O 3 : 25%, MgO: 10%, SiO 2 : 10%, Al 2 O 3 : 10% by mass%. Yes, darts having a main composition of Al 2 O 3 : 70% and SiO 2 : 20% were used.
On the other hand, 250 ton of hot metal was dephosphorized and blown in a converter having 1500 operations or more. The slag after completion of dephosphorization was basicity (CaO / SiO 2 ) 1.3, 40 kg / molten ton, and the molten iron temperature after dephosphorization was 1350 ° C. Thereafter, the furnace body was tilted to start brewing, and at the end of brewing, four pieces of corrugated cardboard were charged with 10 kg (0.04 kg / molten ton) of dolomite having a maximum particle size of 50 mm or less in the dart having the composition described above. A dart having a container made around the guide part was produced, and the dart was moved and dropped directly above the discharge hole while holding the gripping rod with the arm of the input device. The time required to move the dart from the converter to the position immediately above the discharge hole is 5 to 10 seconds, and the time from dropping the dart guide portion into the hot metal until completion of the extraction is about It was 1 minute.
The amount of slag outflow was calculated from the slag thickness in the ladle, and the amount was divided by the amount of hot metal to determine the amount of slag outflow per ton of hot metal.
When the same experiment was performed 100 times, the slag outflow amount was 3 kg / molten ton on average.

（比較例）
流出防止具として、ヘッド部の主要組成が、質量％でＣｒ2Ｏ3：４０％、Ｆｅ2Ｏ3：２５％、ＭｇＯ：１０％、ＳｉＯ2：１０％、Ａｌ2Ｏ3：１０％であり、ガイド部の主要組成が、Ａｌ2Ｏ3：７０％、ＳｉＯ2：２０％のダーツを用いた。
一方、操業回数１５００回以上の転炉で溶銑２５０ｔｏｎを脱りん吹錬した。脱りん吹錬終了後のスラグは、塩基度（ＣａＯ／ＳｉＯ2）１．３、４０ｋｇ／溶銑ｔｏｎで、脱りん後の溶銑の温度は１３４５℃だった。その後、炉体を傾動して出銑を開始し、出銑末期に、投入装置のアームで前述した組成のダーツの把持棒を保持しながら排出孔の真上に当該ダーツを移動させて投下した。ダーツを転炉内に投下してから出銑が完了するまでの時間は約１分であった。
スラグ流出量は、取鍋内のスラグ厚さから流出量を算出し、その量を溶銑量で割って、溶銑１ｔｏｎ当たりのスラグ流出量を求めた。
同様の実験を１００回行ったところ、スラグ流出量は平均で６ｋｇ／溶銑ｔｏｎであった。 (Comparative example)
As an outflow prevention tool, the main composition of the head part is Cr 2 O 3 : 40%, Fe 2 O 3 : 25%, MgO: 10%, SiO 2 : 10%, Al 2 O 3 : 10% by mass%. Yes, darts having a main composition of Al 2 O 3 : 70% and SiO 2 : 20% were used.
On the other hand, 250 ton of hot metal was dephosphorized and blown in a converter with 1500 or more operations. The slag after the dephosphorization blowing was basicity (CaO / SiO 2 ) 1.3, 40 kg / molten ton, and the molten iron temperature after dephosphorization was 1345 ° C. Thereafter, the furnace body was tilted to start tapping, and at the end of tapping, the dart was moved and dropped directly above the discharge hole while holding the gripping rod of the dart having the composition described above with the arm of the charging device. . The time from dropping the dart into the converter to completing the tapping was about 1 minute.
The amount of slag outflow was calculated from the slag thickness in the ladle, and the amount was divided by the amount of hot metal to determine the amount of slag outflow per ton of hot metal.
When the same experiment was performed 100 times, the slag outflow amount was 6 kg / molten ton on average.

１ 袋
２ 物質
１０ ダーツ 1 bag 2 material 10 darts

Claims (4)

転炉の出銑又は出鋼時に、溶銑又は溶鋼を排出する排出孔を閉塞するためのヘッド部と、前記ヘッド部を前記排出孔に導くためのガイド部とを少なくとも備えた流出防止具の周りに、スラグの粘度又は見かけの粘度を高める物質を付帯したことを特徴とするスラグの流出防止装置。   Around a spill preventer including at least a head part for closing a discharge hole for discharging molten iron or molten steel and a guide part for guiding the head part to the discharge hole at the time of unloading or steeling of a converter Further, a slag outflow prevention device characterized in that a substance for increasing the viscosity of the slag or the apparent viscosity is attached. 前記スラグの粘度を高める物質は、前記スラグの組成を変える物質、又は前記スラグを冷却する物質であることを特徴とする請求項１に記載のスラグの流出防止装置。   The slag outflow prevention device according to claim 1, wherein the substance that increases the viscosity of the slag is a substance that changes a composition of the slag or a substance that cools the slag. 前記スラグの粘度又は見かけの粘度を高める物質は、ＣａＯ、ＣａＣＯ3、ＭｇＯ、ＭｇＣＯ3、ドロマイト、煉瓦屑、及び転炉スラグからなる群から選ばれる１種又は２種以上であることを特徴とする請求項１又は２に記載のスラグの流出防止装置。 The substance that increases the viscosity or apparent viscosity of the slag is one or more selected from the group consisting of CaO, CaCO 3 , MgO, MgCO 3 , dolomite, brick waste, and converter slag. The slag outflow prevention device according to claim 1 or 2. 前記スラグの粘度又は見かけの粘度を高める物質の最大粒径が５０ｍｍ以下であることを特徴とする請求項１〜３のいずれか１項に記載のスラグの流出防止装置。   The slag outflow prevention device according to any one of claims 1 to 3, wherein the maximum particle size of the substance that increases the viscosity or apparent viscosity of the slag is 50 mm or less.
JP2017087579A 2017-04-26 2017-04-26 Slag outflow prevention device Active JP6874507B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2017087579A JP6874507B2 (en) 2017-04-26 2017-04-26 Slag outflow prevention device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2017087579A JP6874507B2 (en) 2017-04-26 2017-04-26 Slag outflow prevention device

Publications (2)

Publication Number Publication Date
JP2018184645A true JP2018184645A (en) 2018-11-22
JP6874507B2 JP6874507B2 (en) 2021-05-19

Family

ID=64355904

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2017087579A Active JP6874507B2 (en) 2017-04-26 2017-04-26 Slag outflow prevention device

Country Status (1)

Country Link
JP (1) JP6874507B2 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2020094232A (en) * 2018-12-11 2020-06-18 日本製鉄株式会社 Method of preventing outflow of slag in converter
JP2020111772A (en) * 2019-01-10 2020-07-27 日本製鉄株式会社 Method of preventing converter slag from flowing out
JP2020180311A (en) * 2019-04-23 2020-11-05 日本製鉄株式会社 Method for preventing slag outflow in converter
JP2021155770A (en) * 2020-03-25 2021-10-07 日本製鉄株式会社 Outflow prevention method for slag in ladle

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60190505A (en) * 1984-03-09 1985-09-28 Nippon Steel Corp Slag cutting method during tapping of molten steel
KR20160076343A (en) * 2014-12-22 2016-06-30 주식회사 인텍 Slag dart

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60190505A (en) * 1984-03-09 1985-09-28 Nippon Steel Corp Slag cutting method during tapping of molten steel
KR20160076343A (en) * 2014-12-22 2016-06-30 주식회사 인텍 Slag dart

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2020094232A (en) * 2018-12-11 2020-06-18 日本製鉄株式会社 Method of preventing outflow of slag in converter
JP2020111772A (en) * 2019-01-10 2020-07-27 日本製鉄株式会社 Method of preventing converter slag from flowing out
JP7206923B2 (en) 2019-01-10 2023-01-18 日本製鉄株式会社 Method for preventing outflow of slag in converter
JP2020180311A (en) * 2019-04-23 2020-11-05 日本製鉄株式会社 Method for preventing slag outflow in converter
JP7307319B2 (en) 2019-04-23 2023-07-12 日本製鉄株式会社 Method for preventing outflow of slag in converter
JP2021155770A (en) * 2020-03-25 2021-10-07 日本製鉄株式会社 Outflow prevention method for slag in ladle
JP7453525B2 (en) 2020-03-25 2024-03-21 日本製鉄株式会社 Method for preventing slag from flowing out in the ladle

Also Published As

Publication number Publication date
JP6874507B2 (en) 2021-05-19

Similar Documents

Publication Publication Date Title
JP5772339B2 (en) Reuse method of slag in ladle
JP2018184645A (en) Slag outflow prevention apparatus
JP5573424B2 (en) Desulfurization treatment method for molten steel
WO2013145686A1 (en) Method for refining hot metal in converter
CA3046587A1 (en) Electric furnace
JP5292870B2 (en) Reuse method of slag in ladle
JP6028755B2 (en) Method for melting low-sulfur steel
JP6421634B2 (en) Manufacturing method of molten steel
TW201800583A (en) Molten iron desulfurization method and desulfurization apparatus
JP6547734B2 (en) Method of manufacturing low-sulfur steel
JP5895887B2 (en) Desulfurization treatment method for molten steel
JP5928094B2 (en) Method for refining molten iron
JP2014159632A (en) Method for pre-treating molten iron
JP2003155516A (en) Method for desulfurizing molten steel with ladle- refining
JP2005187901A (en) Refining method for molten steel
JP5962156B2 (en) Method for refining molten iron
JP6806288B2 (en) Steel manufacturing method
JP2020094232A (en) Method of preventing outflow of slag in converter
JP6323688B2 (en) Desulfurization method for molten steel
JP6281708B2 (en) Desulfurization method for molten steel
JP5289906B2 (en) Forming suppression method in dephosphorization process
JP7067279B2 (en) Ladle refining method for molten steel
JP5289907B2 (en) Method of charging iron oxide source to suppress slag forming
JP2012122134A (en) Dephosphorizing treatment method of molten iron using calcium ferrite
JP7307319B2 (en) Method for preventing outflow of slag in converter

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20191204

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20201117

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20201124

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20201210

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20210323

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20210405

R151 Written notification of patent or utility model registration

Ref document number: 6874507

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151