JP3067636B2 - Copper removal from molten iron - Google Patents
Copper removal from molten ironInfo
- Publication number
- JP3067636B2 JP3067636B2 JP9678996A JP9678996A JP3067636B2 JP 3067636 B2 JP3067636 B2 JP 3067636B2 JP 9678996 A JP9678996 A JP 9678996A JP 9678996 A JP9678996 A JP 9678996A JP 3067636 B2 JP3067636 B2 JP 3067636B2
- Authority
- JP
- Japan
- Prior art keywords
- molten iron
- oxidizing agent
- reaction
- tin
- amount
- 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 - Lifetime
Links
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
- Treatment Of Steel In Its Molten State (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Description
【0001】[0001]
【発明の属する技術分野】本発明は、溶鉄中の銅および
/または錫を除去する方法に関する。The present invention relates to a method for removing copper and / or tin in molten iron.
【0002】[0002]
【従来の技術】近年、鉄スクラップの発生量の増大とと
もに、鉄スクラップを種々の再溶解法を用いて再利用す
るプロセスまたは鉄スクラップを溶銑や溶鋼と混ぜて使
用するプロセスが一般的に行われている。ところで、こ
れら鉄スクラップ品位は年々低下する傾向にある。例え
ば、自動車解体屑中や廃却モーターコアに含まれる銅線
および錫メッキを処した廃却材料などから銅や錫が混入
するため、スクラップを原料とする鋼材中の銅や錫の含
有量が増加している。2. Description of the Related Art In recent years, along with an increase in the amount of generated iron scrap, a process of recycling iron scrap using various remelting methods or a process of mixing iron scrap with hot metal or molten steel has been generally performed. ing. By the way, these iron scrap grades tend to decrease year by year. For example, copper and tin are mixed in scraps from automobile demolition and copper wire and tin-plated waste materials contained in scrap motor cores, so the content of copper and tin in steel materials from scrap is reduced. It has increased.
【0003】鋼中の銅や錫は一般に鋼質に対して有害不
純物であるので、低濃度に管理することが望まれてい
る。銅が多く含有される鋼では赤熱脆性が生じることか
ら、耐候性鋼等の一部の鋼種を除いては、銅濃度は一般
に0.35wt%ないし0.20wt%以下にすることが必
要とされている。一方、鋼中錫濃度が高いと鋼の熱間加
工性、伸展性および絞り性の低下を招くので、やはり鋼
中錫濃度を0.1wt%以下にすることが必要である。[0003] Since copper and tin in steel are generally harmful impurities to steel quality, it is desired to control them to a low concentration. Since red-hot embrittlement occurs in steel containing a large amount of copper, the copper concentration is generally required to be 0.35 wt% to 0.20 wt% or less except for some steel types such as weathering steel. ing. On the other hand, if the tin concentration in the steel is high, the hot workability, extensibility and drawability of the steel are reduced, so that the tin concentration in the steel must be 0.1 wt% or less.
【0004】ところが、銅や錫は鉄よりも貴な金属であ
り、酸素との親和力が小さいことから通常の製鋼過程で
は溶鉄から銅や錫を除去することが困難であり、これら
を工業的に有効に除去することができる方法が望まれて
いる。However, copper and tin are more noble metals than iron, and have a low affinity for oxygen, so that it is difficult to remove copper and tin from molten iron in a normal steel making process, and these are industrially used. A method that can be effectively removed is desired.
【0005】本発明者の一人は、特開昭61−1196
12号公報および特公平3−72129号公報におい
て、減圧下において脱炭と同時に溶鉄から脱銅および/
または脱錫を行う方法を示した。これら方法は、溶鉄と
溶鉄中の銅および錫との蒸気圧の差を利用して蒸発除去
するものである。除去速度を向上させるために溶鉄を1
0Torr 以下の減圧下におき、酸化鉄のような酸化剤を
粉体上吹きして脱炭することにより脱炭に伴って生じる
蒸発界面を増加させ、脱銅および/または脱錫を行う方
法である。これらにより、比較的大量の溶鉄の処理が可
能な実用的方法が実現された。One of the present inventors is disclosed in Japanese Unexamined Patent Application Publication No.
In Japanese Patent Publication No. 12 and Japanese Patent Publication No. 3-72129, copper removal from molten iron and / or
Or the method of performing tin removal was shown. These methods remove and evaporate by utilizing the difference in vapor pressure between molten iron and copper and tin in the molten iron. Remove molten iron to increase removal rate
A method in which an oxidizing agent such as iron oxide is sprayed on a powder and decarburized by placing the powder under a reduced pressure of 0 Torr or less, thereby increasing an evaporation interface caused by decarburization and removing copper and / or tin. is there. As a result, a practical method capable of treating a relatively large amount of molten iron has been realized.
【0006】本発明者らは、さらに特開平7−1267
28号公報において、減圧下において脱炭と同時に脱銅
および/または脱錫する際に、酸化鉄のような粉体酸化
剤を上吹きしている脱炭反応界面を不活性ガスプラズマ
で加熱する方法を開示した。The present inventors have further disclosed in JP-A-7-1267.
In Japanese Patent Publication No. 28, when decopperizing and / or detinning simultaneously with decarburization under reduced pressure, a decarburization reaction interface in which a powder oxidizing agent such as iron oxide is blown upward is heated with an inert gas plasma. A method has been disclosed.
【0007】しかしながら上記方法のいずれにおいて
も、大量のスクラップをさらに効率良く処理するという
観点からみると、溶鉄からの脱銅および脱錫の速度は充
分ではなく、したがって処理時間の短縮、脱銅率および
脱錫率の向上には限界がある。However, in any of the above methods, the rate of copper removal and tin removal from molten iron is not sufficient from the viewpoint of more efficient processing of a large amount of scrap, so that the processing time and the copper removal rate are reduced. There is a limit to the improvement of the tin removal rate.
【0008】[0008]
【発明が解決しようとする課題】本発明は上記課題を解
決するためのものである。本発明の目的は、溶鉄からの
脱銅および/または脱錫の速度を増大させて高効率に短
時間で処理する方法、具体的には30分程度の処理時間
で溶鉄中の銅を0.35wt%以下、錫を0.10wt%以
下に低下させることができる方法を提供することにあ
る。SUMMARY OF THE INVENTION The present invention has been made to solve the above problems. An object of the present invention is to increase the rate of copper removal and / or tin removal from molten iron and to carry out the treatment with high efficiency in a short time, specifically, to reduce the copper in the molten iron to 0.1% in a treatment time of about 30 minutes. It is an object of the present invention to provide a method capable of reducing tin to 35 wt% or less and tin to 0.10 wt% or less.
【0009】[0009]
【課題を解決するための手段】本発明の要旨は次の脱銅
および/または脱錫方法にある。The gist of the present invention resides in the following copper removing and / or tin removing method.
【0010】10Torr 以下の減圧下において、炭素を
含有する溶鉄面に酸化鉄粉体または/および酸化鉄より
も酸化力の低い酸化物粉体からなる酸化剤を吹き付けて
溶鉄の脱炭を行うことにより、この溶鉄中の銅および/
または錫を除去する方法であって、吹き付け1箇所かつ
単位時間あたりの吹き付け量を酸化剤の吸熱量換算で5
00〜1500 kJ/min とすることを特徴とする溶鉄
からの脱銅および/または脱錫方法。Decarbonizing the molten iron by spraying an oxidizing agent comprising iron oxide powder and / or an oxide powder having a lower oxidizing power than iron oxide on the surface of the molten iron containing carbon under a reduced pressure of 10 Torr or less. By this, copper in this molten iron and / or
Or a method of removing tin, wherein the spray amount per spray and per unit time is 5 in terms of the endothermic amount of the oxidizing agent.
A method for removing copper and / or tin from molten iron, which is performed at a rate of 00 to 1500 kJ / min.
【0011】上記方法において、酸化剤の望ましい吹き
付け箇所数は溶鉄面において2箇所以上である。この吹
き付け箇所数の上限は、溶鉄面について各吹き付け箇所
の中心間距離を100mm以上離すことができるかどうか
により決定される。In the above method, the desired number of spraying points of the oxidizing agent is two or more on the molten iron surface. The upper limit of the number of spraying points is determined by whether or not the distance between the centers of the spraying points on the molten iron surface can be separated by 100 mm or more.
【0012】本発明者らは、前記発明に引き続いて、1
0Torr 以下の減圧下で、炭素を含有する溶鉄面に上記
のような酸化剤を吹き付けて脱炭を行うことにより、溶
鉄から脱銅および/または脱銅を行う方法に関して鋭意
研究を続けてきた。その結果、下記〜の新知見を得
た。Following the above invention, the present inventors have set forth the following:
Under a reduced pressure of 0 Torr or less, intensive research has been conducted on a method of removing copper and / or copper from molten iron by spraying the above-mentioned oxidizing agent onto the surface of the molten iron containing carbon to remove carbon. As a result, the following new findings were obtained.
【0013】溶鉄からの脱銅および脱錫の反応は蒸発
反応であるので、反応を促進させるには反応界面積を増
大させ、かつ反応界面温度を極力高く維持する必要があ
ること。Since the reaction of copper removal and tin removal from molten iron is an evaporation reaction, it is necessary to increase the reaction interface area and maintain the reaction interface temperature as high as possible in order to promote the reaction.
【0014】反応界面積をさらに増大させる方法とし
ては、より多量の粉体酸化剤を溶鉄面に吹き付けて、脱
炭反応をより活発に生ぜしめることが考えられた。とこ
ろが、粉体酸化剤の吹き付け速度を過度に増大させて
も、脱銅および/または脱錫の反応は停滞もしくは低下
すること。As a method of further increasing the reaction interface area, it has been considered that a larger amount of a powder oxidizing agent is sprayed on the molten iron surface to more actively cause the decarburization reaction. However, even if the spraying speed of the powder oxidizing agent is excessively increased, the reaction of copper removal and / or tin removal may stagnate or decrease.
【0015】上記の停滞もしくは低下の理由は、粉体
酸化剤を溶鉄面に吹きつけて脱炭反応を行う場合、脱炭
反応自体によって生じる発熱量よりも酸化剤(酸化物)
の解離に伴う吸熱量の方がはるかに大きく、その結果、
脱炭反応が生じる界面の温度がむしろ低下しているから
であること。The reason for the above-mentioned stagnation or decrease is that when a powder oxidizing agent is sprayed on a molten iron surface to carry out a decarburizing reaction, the amount of the oxidizing agent (oxide) is smaller than the amount of heat generated by the decarburizing reaction itself.
The endotherm associated with the dissociation of is much larger,
This is because the temperature at the interface where the decarburization reaction occurs is rather lowered.
【0016】粉体酸化剤を上吹するときの吹き付け箇
所を溶鉄面の2箇所以上とした場合には、反応界面積を
顕著に増大させる効果が得られること。When the powder oxidizing agent is sprayed upward at two or more locations on the molten iron surface, the effect of significantly increasing the reaction interface area can be obtained.
【0017】1箇所かつ単位時間あたりの粉体酸化剤
の吹き付け量を最適化すれば、反応界面温度を極力高く
維持することができること。By optimizing the amount of powder oxidizing agent sprayed at one location and per unit time, the reaction interface temperature can be maintained as high as possible.
【0018】反応界面温度を局所的に低下させること
なく反応界面積を増大させるためには、上記の手段を
用いて粉体酸化剤の吹き付け総量を増大させるととも
に、1箇所あたりの吹き付け量は上記の手段におい
て、脱銅および/または脱錫の反応速度が最大となる量
とすればよいこと。In order to increase the reaction interface area without locally lowering the reaction interface temperature, the spraying amount of the powder oxidizing agent is increased by using the above-mentioned means, and the spraying amount per one place is set as described above. In the means, the amount may be such that the reaction rate of copper removal and / or tin removal becomes the maximum.
【0019】[0019]
【発明の実施の形態】本発明方法は、10Torr 以下の
減圧下において、炭素を含有する溶鉄面の1箇所または
2箇所以上に酸化鉄または/および酸化鉄よりも酸化力
の低い酸化物粉体からなる酸化剤を適正条件で吹き付け
て溶鉄の脱炭を行うことにより、溶鉄中の銅および/ま
たは錫を除去するものである。BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a method for producing an oxide powder having lower oxidizing power than one or more iron oxides at one or more sites on the surface of a molten iron containing carbon under a reduced pressure of 10 Torr or less. The molten iron is decarburized by spraying an oxidizing agent consisting of the following under appropriate conditions to remove copper and / or tin in the molten iron.
【0020】本発明方法の実施に必要な装置は、溶鉄面
に粉体を吹き付けることが可能で、かつ雰囲気圧力10
Torr 以下が得られような真空精錬設備であれば、特に
限定されない。例えば、溶鋼処理に一般的に用いられる
RH真空脱ガス装置のような炉外精錬装置、VODやV
ADのような取鍋真空脱ガス装置、高周波による加熱が
可能なVIM装置などの現在使用されているものに、粉
体上吹き装置を備えた真空精錬装置である。The apparatus required for carrying out the method of the present invention is capable of spraying powder on the molten iron surface and having an atmospheric pressure of 10
It is not particularly limited as long as it is a vacuum refining facility capable of obtaining Torr or less. For example, out-of-pile refining equipment such as RH vacuum degassing equipment commonly used for molten steel processing, VOD and V
Vacuum refining equipment which is equipped with a powder top blower in addition to currently used equipment such as a ladle vacuum degassing equipment such as AD and a VIM equipment capable of heating by high frequency.
【0021】本発明の対象となる溶鉄の種類は、炭素を
含有するものであれば特に限定されない。例えば、通常
スクラップを溶解して得られる炭素鋼や溶銑は、酸化剤
による脱炭が可能であるから、本発明方法が適用可能で
ある。また、ニッケルやクロムを多量に含むステンレス
溶鋼や高合金溶鋼にも適用可能である。鋼種によって
は、必要に応じて加炭した後に酸化剤を供給、添加して
脱銅、脱錫を行うことも可能である。本発明方法では脱
炭反応を利用するので、溶鉄の炭素含有量が高いほど脱
銅、脱錫の効率は高い。The type of molten iron to be used in the present invention is not particularly limited as long as it contains carbon. For example, the method of the present invention can be applied to carbon steel or hot metal usually obtained by melting scrap, since decarburization with an oxidizing agent is possible. Further, the present invention is also applicable to stainless steel molten steel or high alloy molten steel containing a large amount of nickel or chromium. Depending on the type of steel, it is also possible to supply and add an oxidizing agent after carburizing as needed to remove copper and remove tin. Since the decarburization reaction is used in the method of the present invention, the higher the carbon content of the molten iron, the higher the efficiency of copper removal and tin removal.
【0022】図1に基づいて、本発明方法を適用する装
置の構成例を説明する。図1は、真空高周波誘導加熱溶
解装置を示す概略縦断面図である。この装置は、真空排
気孔6を備えた真空槽1、耐火物5および誘導加熱コイ
ル7を備えた溶鉄8の容器9および真空槽1の上蓋2に
備えた2本の昇降可能な粉体上吹きランス3,4から構
成される。An example of the configuration of an apparatus to which the method of the present invention is applied will be described with reference to FIG. FIG. 1 is a schematic vertical sectional view showing a vacuum high-frequency induction heating and melting apparatus. The apparatus comprises a vacuum chamber 1 having a vacuum exhaust hole 6, a container 9 of molten iron 8 having a refractory 5 and an induction heating coil 7, and two vertically movable powders provided on a top lid 2 of the vacuum chamber 1. It is composed of blowing lances 3 and 4.
【0023】上記のような装置では、真空槽1内の圧力
は、排気孔6を通じて図示しないスチームエジェクター
ポンプなどにより、溶鉄8を保持しかつ粉体酸化剤を吹
き付けた状態で10Torr 以下に保つことができるよう
になされている。In the above-described apparatus, the pressure in the vacuum chamber 1 is maintained at 10 Torr or less while holding the molten iron 8 and spraying the powder oxidizing agent by a steam ejector pump (not shown) through the exhaust hole 6. Has been made possible.
【0024】粉体酸化剤は、粉体上吹きランス3,4か
らキャリアガスとともに溶鉄8面に吹き付ける。The powder oxidizing agent is sprayed from the powder blowing lances 3 and 4 together with the carrier gas onto the molten iron 8 surface.
【0025】キャリアガスについては、通常は溶鉄に対
して不活性なアルゴンガスが好ましいが、特に制限を設
ける必要はなく、例えば窒素濃度に制限のない溶鉄では
窒素ガスも使用可能である。キャリアガス量について
も、粉体酸化剤の吹き付けには減圧によって生じる差圧
を利用するため特に制限はない。しかし、例えば吹き付
け1箇所あたりのキャリアガス量の範囲が100〜10
00Nリットル/min であれば、吹き付けの安定性が向
上する。As the carrier gas, an argon gas which is generally inert to the molten iron is preferably used. However, there is no particular limitation. For example, nitrogen gas can be used for molten iron having no limitation in nitrogen concentration. The amount of the carrier gas is not particularly limited because the pressure difference generated by the reduced pressure is used for spraying the powder oxidizing agent. However, for example, the range of the carrier gas amount per one spraying is 100 to 10
If it is 00 Nl / min, the spraying stability is improved.
【0026】本発明方法は、上記のような装置および方
法における脱銅および/または脱錫の条件について、真
空槽内圧力(以下、真空度という)は10Torr 以下の
減圧下、吹きつける粉体酸化剤は酸化鉄または/および
酸化鉄よりも酸化力の低い酸化物粉体からなる酸化剤、
ならびに吹き付け1箇所かつ単位時間あたりの吹き付け
量の範囲を酸化剤の吸熱量換算で500〜1500 kJ
/min とするものである。以下に、上記各条件の限定理
由を詳述する。According to the method of the present invention, the conditions for copper removal and / or tin removal in the above-described apparatus and method are as follows: the pressure in the vacuum chamber (hereinafter referred to as the degree of vacuum) is blown under a reduced pressure of 10 Torr or less. The agent is an oxidizing agent composed of iron oxide or an oxide powder having a lower oxidizing power than iron oxide,
And the range of the spray amount per unit time and the spray time per unit time is 500 to 1500 kJ in terms of the endothermic amount of the oxidizing agent.
/ Min. Hereinafter, the reasons for limiting the above conditions will be described in detail.
【0027】真空度が10Torr を超えて悪化すると、
粉体酸化剤を吹き付けて脱炭する際においても、脱銅、
脱錫は本来蒸発反応であるため、それらの反応速度が低
下する。When the degree of vacuum deteriorates beyond 10 Torr,
Even when decarburizing by spraying a powder oxidizer, copper removal,
Since detinning is an evaporation reaction in nature, the reaction speed thereof decreases.
【0028】次に、粉体酸化剤の種類およびその吹きつ
け条件について説明する。Next, the type of the powder oxidizing agent and the spraying conditions thereof will be described.
【0029】前述のように従来方法では、さらなる鉄ス
クラップの大量処理を想定した場合には脱銅、脱錫の速
度は充分ではなく、処理時間の短縮、脱銅率および脱錫
率の向上には限界がある。すなわち、脱銅、脱錫の反応
速度を向上させるために、単に粉体酸化剤の吹き付け速
度を過度に増大させても、脱銅、脱錫反応は停滞もしく
は低下する。この理由は、粉体酸化剤を溶鉄面に吹きつ
けて脱炭反応を行う場合、脱炭反応自体によって生じる
発熱量よりも、酸化剤(酸化物)の解離に伴う吸熱量の
方がはるかに大きく、その結果、酸化剤を過剰に吹き付
けた場合、脱炭反応が生じる界面の温度がむしろ局所的
に低下しているからである。As described above, in the conventional method, when a large amount of iron scrap is to be treated, the speeds of copper removal and tin removal are not sufficient, so that the processing time is reduced and the copper removal rate and the tin removal rate are improved. Has limitations. That is, even if the spraying speed of the powder oxidizing agent is simply increased excessively in order to increase the reaction rate of copper removal and tin removal, the copper removal and tin removal reactions stagnate or decrease. The reason is that when a powder oxidizing agent is sprayed on the surface of molten iron to perform a decarburizing reaction, the amount of heat absorbed by the dissociation of the oxidizing agent (oxide) is much larger than the amount of heat generated by the decarburizing reaction itself. This is because, when the oxidizing agent is sprayed excessively, the temperature of the interface where the decarburization reaction occurs is rather lowered locally.
【0030】上記の問題を解決するには、粉体酸化剤を
吹き付ける箇所を1箇所以上、望ましくは2箇所以上と
し、脱炭が生じる反応箇所をできるだけ増加させること
によって反応界面積の飛躍的な増大を得ることが必要で
ある。吹き付け箇所を2箇所以上に分散すれば、さらに
蒸発反応が生じる反応界面での局所的な温度低下を抑制
することができ、脱銅、脱錫速度が向上する。In order to solve the above problem, the number of reaction sites where decarburization occurs is increased as much as possible at one or more, preferably at least two sites where the powder oxidizing agent is sprayed, so that the reaction interface area is dramatically increased. It is necessary to gain an increase. By dispersing the spraying locations at two or more locations, it is possible to further suppress a local decrease in temperature at the reaction interface where the evaporation reaction occurs, and to improve the copper removal and tin removal rates.
【0031】粉体酸化剤の種類および吹き付け1箇所あ
たりの粉体酸化剤吹き付け量については、以下のように
考えることができる。The type of the powder oxidizing agent and the amount of the powder oxidizing agent sprayed per one spraying can be considered as follows.
【0032】酸化剤を、酸化鉄または/および酸化鉄よ
りも酸化力の低い酸化物とした理由は、反応界面積の増
大効果をもたらす脱炭反応を、より低酸素ポテンシャル
下で生じさせるためである。このような低酸素ポテンシ
ャル下では、界面活性元素である酸素が反応界面に少な
い状態となるので、蒸発反応である脱銅、脱錫反応は阻
害されにくくなる。The reason why the oxidizing agent is iron oxide and / or an oxide having a lower oxidizing power than iron oxide is to cause a decarburization reaction having an effect of increasing a reaction interface area under a lower oxygen potential. is there. Under such a low oxygen potential, oxygen, which is a surface active element, is reduced at the reaction interface, so that the copper removal and tin removal reactions, which are evaporation reactions, are less likely to be inhibited.
【0033】このような酸化剤としては、解離して脱炭
のための酸素を供給し得る酸化鉄(Fe2 O3 )または
/およびこの酸化鉄よりも酸化力の低い酸化物、例えば
酸化クロム(Cr2 O3 )、酸化マンガン(MnO)、
二酸化珪素(SiO2 )および酸化マグネシウム(Mg
O)などの金属酸化物を用いるのが適切である。As such an oxidizing agent, iron oxide (Fe 2 O 3 ) capable of dissociating and supplying oxygen for decarburization or / and an oxide having a lower oxidizing power than this iron oxide, for example, chromium oxide (Cr 2 O 3 ), manganese oxide (MnO),
Silicon dioxide (SiO 2 ) and magnesium oxide (Mg
It is appropriate to use a metal oxide such as O).
【0034】金属(Me)の粉体酸化物Mex Oy を吹
き付けて炭素を含有する溶鉄を脱炭するとき、炭素1モ
ルあたりの反応は次式(1) で表される。When the molten iron containing carbon is decarburized by spraying a metal (Me) powder oxide Me x O y , the reaction per mole of carbon is represented by the following formula (1).
【0035】 (1/y)Mex Oy +〔C〕 → (1/y)〔Me〕+CO(g) ・・ (1) 金属酸化物がFe2 O3 、Cr2 O3 、MnO、SiO
2 およびMgOの場合、溶鉄中の炭素:1wt%、溶鉄中
のMe:1wt%としたときの1873Kにおける反応の
自由エネルギー変化およびそのときの炭素1モルあたり
の吸熱量を計算すると、表1のようになる。ただし、F
e2 O3 では、分解すれば溶鉄自体になるので99wt%
Feとして計算した。(1 / y) Me x O y + [C] → (1 / y) [Me] + CO (g) (1) The metal oxide is Fe 2 O 3 , Cr 2 O 3 , MnO, SiO
In the case of 2 and MgO, the change in the free energy of the reaction at 1873K and the endothermic amount per mole of carbon when the carbon in the molten iron: 1 wt% and the Me in the molten iron: 1 wt% were calculated. Become like Where F
With e 2 O 3 , 99% by weight
Calculated as Fe.
【0036】[0036]
【表1】 [Table 1]
【0037】表1に示すように、酸化鉄(Fe2 O3 )
よりも前記(1) 式の自由エネルギー変化が大きい値を持
つ酸化物は、減圧下でCO分圧が低下したときに、より
活発に前記(1) 式の反応が進む。本発明方法でいう「酸
化鉄よりも酸化力の弱い酸化剤」とは、このような性質
を持つ酸化物である。As shown in Table 1, iron oxide (Fe 2 O 3 )
In the oxide having a larger free energy change in the formula (1), the reaction in the formula (1) proceeds more actively when the partial pressure of CO is reduced under reduced pressure. The “oxidizing agent having a lower oxidizing power than iron oxide” in the method of the present invention is an oxide having such properties.
【0038】このような、酸化鉄よりも酸化力の弱い酸
化剤による減圧下での脱炭反応は、その速度が充分に速
い一方で、反応界面での酸素ポテンシャルが充分に低い
ことから界面活性な酸素濃度を下げ、その結果、前述の
ように溶鉄からの銅および錫の蒸発を妨げないという効
果をもたらすのである。Such a decarburization reaction under reduced pressure using an oxidizing agent having a weaker oxidizing power than iron oxide has a sufficiently high rate, while the oxygen potential at the reaction interface is sufficiently low. As a result, the effect of not hindering the evaporation of copper and tin from the molten iron is obtained.
【0039】以上の理由により、本発明方法で用いる酸
化剤を酸化鉄、または酸化鉄よりも酸化力の低い酸化物
から選んだ1種以上、もしくはこれらの混合物とした。
1種以上の混合物とする場合に各酸化物の比率は特に限
定しない。For the above reasons, the oxidizing agent used in the method of the present invention is at least one selected from iron oxide or an oxide having lower oxidizing power than iron oxide, or a mixture thereof.
When one or more mixtures are used, the ratio of each oxide is not particularly limited.
【0040】酸化鉄よりも酸化力の低い酸化物は、先に
例示したもの以外でも、酸化鉄よりも前記(1) 式の反応
自由エネルギーが大きくなるものであればよい。天然に
産出するものでも、合成されたものでも使用できる。各
酸化物に含有される不純物は少ない方が粉体酸化剤供給
量の決定には好ましいが、不純物含有量がわかる酸化物
であればよい。例えば、不純物含有量が10wt%未満の
酸化物であれば、本発明方法をそのまま適用できる。The oxide having a lower oxidizing power than iron oxide is not limited to the above-described examples, as long as it has a higher reaction free energy in the above formula (1) than iron oxide. Both naturally occurring and synthetic ones can be used. It is preferable that the amount of impurities contained in each oxide is small in determining the supply amount of the powder oxidizing agent. For example, if the oxide content is less than 10 wt%, the method of the present invention can be applied as it is.
【0041】粉体酸化剤の粒径は特に限定しないが、例
えば平均粒径が10μm から1mm程度の範囲ものが取扱
い上望ましい。The particle size of the powder oxidizing agent is not particularly limited, but for example, an average particle size in the range of 10 μm to 1 mm is desirable for handling.
【0042】また表1に示したように、各酸化物は解離
反応に大きなエネルギーを要するため、各反応も大きな
吸熱反応であることがわかる。この吸熱反応によって、
脱炭が生じる反応界面近傍の温度は局所的に低下し、こ
の低下が大であると反応界面積の増大効果を上回り、脱
銅、脱錫の反応速度はかえって低下する。Further, as shown in Table 1, since each oxide requires a large amount of energy for the dissociation reaction, it can be seen that each reaction is also a large endothermic reaction. By this endothermic reaction,
The temperature near the reaction interface where decarburization occurs decreases locally, and if this decrease is large, it exceeds the effect of increasing the reaction interface area, and the reaction rates of copper removal and tin removal decrease rather.
【0043】すなわち、脱炭反応に伴う脱銅、脱錫反応
の促進方法を考えるならば、粉体酸化剤の吹き付け速度
を増大するほど脱炭反応は進行し、蒸発反応が生じる反
応界面積を増大させる一方、過剰な酸化剤の吹き付けは
吸熱反応にともなう反応界面温度の低下を招き、蒸発に
よる脱銅率および脱錫率の低下が生じる。したがって、
吹き付け1箇所あたりの粉体酸化剤の吹き付け量を最適
化すること、さらには反応界面積の増大を図るために吹
き付け箇所をできるだけ増加させることにより、脱銅、
脱錫速度の向上を図ることができる。That is, considering a method of accelerating the decopperization and detinization reactions accompanying the decarburization reaction, the decarburization reaction proceeds as the spraying speed of the powder oxidizing agent increases, and the reaction interface area where the evaporation reaction occurs is reduced. On the other hand, excessive oxidizing agent spraying causes a decrease in the reaction interface temperature due to the endothermic reaction, resulting in a reduction in the copper removal rate and tin removal rate due to evaporation. Therefore,
By optimizing the amount of powder oxidizing agent sprayed per point, and further increasing the number of spray points as much as possible to increase the reaction area, copper removal,
The tin removal speed can be improved.
【0044】種々の粉体酸化剤を用いて実験を行ったと
ころ、溶鉄1t以上を収容できる容器であれば酸化剤の
種類および吹き付け箇所数にかかわらず、酸化剤の吹き
付け1箇所あたりかつ単位時間あたりの吸熱量の範囲を
500〜1500 kJ/minにすれば、脱炭による反応
界面積の増大効果を充分享受しながら、反応界面の局所
温度低下を最小限にすることによって、脱銅および/ま
たは脱錫速度を向上させることができた。すなわち、3
0分程度の処理時間で溶鉄中の銅を0.35wt%以下、
錫を0.10wt%以下にすることができた。Experiments were carried out using various powder oxidizing agents. As long as the container can hold 1 ton or more of molten iron, irrespective of the type of oxidizing agent and the number of spraying points, per oxidizing agent is sprayed per unit time and per unit time. When the range of the heat absorption per unit is set to 500 to 1500 kJ / min, while the effect of increasing the reaction interface area by the decarburization is sufficiently enjoyed, the local temperature decrease at the reaction interface is minimized, so that copper removal and / or copper removal can be achieved. Alternatively, the tin removal rate could be improved. That is, 3
0.30 wt% or less of copper in the molten iron in a processing time of about 0 minutes,
Tin could be reduced to 0.10 wt% or less.
【0045】このように、吸熱量500 kJ/min 以上
で、脱炭反応は充分に生じさせることができ、反応界面
積の増大効果を得ることができる。一方、吸熱量150
0 kJ/min 以下で、反応界面の局所温度低下は脱銅お
よび脱錫反応を阻害することがない程度となる。As described above, at an endothermic amount of 500 kJ / min or more, the decarburization reaction can be sufficiently caused, and the effect of increasing the reaction interface area can be obtained. On the other hand, the heat absorption 150
At 0 kJ / min or less, the decrease in local temperature at the reaction interface does not hinder the decopperization and tin removal reactions.
【0046】上記の吸熱量の範囲を各酸化物粉体の単位
時間あたりの供給量に換算すると吹き付け1箇所あた
り、Fe2 O3 では160〜482g/min 、Cr2 O
3 では90〜270g/min 、MnOでは123〜37
0g/min 、SiO2 では106〜320g/min 、M
gOでは83〜249g/min に相当する。[0046] per spot spraying and converted into the supply amount per unit time of the heat absorption amount of each oxide powder within the above range, Fe 2 in O 3 160~482g / min, Cr 2 O
3 is 90 to 270 g / min, and MnO is 123 to 37 g / min.
0 g / min, 106 to 320 g / min for SiO 2 , M
In gO, it corresponds to 83 to 249 g / min.
【0047】溶鉄量が1t未満の場合は、溶鉄自身の熱
余裕の制限もあることから、溶鉄量に応じて吹き付け1
箇所あたりの酸化剤量を減じる必要がある。この場合、
酸化剤量は、吸熱量に換算して溶鉄量(t)で割った値
を用いる。すなわち、溶鉄量α(t)(ただしα<1)
のとき、酸化剤量の範囲は吸熱量換算で500×α〜1
500×α(kJ/min)とする。When the amount of molten iron is less than 1 ton, there is a limitation on the heat margin of the molten iron itself.
It is necessary to reduce the amount of oxidizer per site. in this case,
As the oxidizing agent amount, a value obtained by converting the amount of heat absorption and dividing by the amount of molten iron (t) is used. That is, the amount of molten iron α (t) (where α <1)
In this case, the range of the amount of the oxidizing agent is 500 × α to 1
500 x α (kJ / min).
【0048】吹き付け箇所数は、原理的には多ければ多
いほど良いことになるが、実質的には吹き付け箇所数の
上限は、溶鉄容器の容積、その形状および粉体吹き付け
装置とその設置方法によって制約を受ける。例えば、外
部から加熱できる高周波炉で1.5tの溶鉄に処理を施
す場合には、4箇所は可能である。このとき吹き付け箇
所間の距離は、それぞれの溶鉄面における吹き付け中心
が100mm以上離れているように配置するのが望まし
い。すなわち、図1に示すように粉体上吹きランス3,
4は傾斜させてもまたは垂直でもよいが、上記中心が1
00mm未満になって吹き付け箇所が近づくと、吹き付け
箇所は実質同一箇所となり、反応界面積の増大効果が減
少する。In principle, the larger the number of spraying points, the better. However, the upper limit of the number of spraying points is practically limited by the volume of the molten iron container, its shape, the powder spraying apparatus and its installation method. Be restricted. For example, when a process is performed on molten iron of 1.5 tons in a high-frequency furnace that can be heated from the outside, four places are possible. At this time, it is desirable to arrange the distance between the spraying points such that the spraying center on each molten iron surface is separated by 100 mm or more. That is, as shown in FIG.
4 may be inclined or vertical, but the center is 1
When the diameter is less than 00 mm and the spray point approaches, the spray point becomes substantially the same point, and the effect of increasing the reaction interface area decreases.
【0049】粉体上吹きランスは、上記条件を満たすこ
とができる場合、多孔構造とすることも可能である。If the above conditions can be satisfied, the powder upper blowing lance may have a porous structure.
【0050】[0050]
(試験1)図1に示す構成の真空高周波誘導加熱溶解装
置を用い、酸化剤の種類および吹き付け速度を変えて脱
銅および脱錫処理を行った。条件を下記に示す。(Test 1) Copper removal and tin removal treatment were performed using a vacuum high-frequency induction heating and melting apparatus having the configuration shown in FIG. The conditions are shown below.
【0051】溶鉄組成:Cu=0.40wt%、 Sn=
0.11wt%、炭素=0.5〜1wt%、Si=0.03
wt%、Mn=0.01wt%、 P=0.008〜0.0
18wt%、残部=鉄および不可避的不純物 溶鉄量:1.5t 溶鉄温度:1650℃ 耐火物の主成分:マグネシアクロマイト 真空度:処理開始前は1Torr 、処理中は1〜9Torr 酸化剤:(1) 酸化鉄粉体(平均粒径90μm) (2) 酸化クロム粉体(平均粒径120μm) (3) 酸化マンガン粉体(平均粒径60μm) (4) 二酸化珪素粉体(平均粒径110μm) (5) 酸化マグネシウム粉体(平均粒径100μm) キャリアガス:Ar(流量は400〜700リットル/
min ) 吹き付け箇所:1箇所 処理時間:30分間 図2および図3に上記試験の結果を示す。Iron composition: Cu = 0.40 wt%, Sn =
0.11 wt%, carbon = 0.5-1 wt%, Si = 0.03
wt%, Mn = 0.01 wt%, P = 0.008-0.0
18 wt%, balance = iron and unavoidable impurities Molten iron content: 1.5 t Molten iron temperature: 1650 ° C Main component of refractory: magnesia chromite Vacuum degree: 1 Torr before starting treatment, 1 to 9 Torr during treatment Oxidizing agent: (1) Iron oxide powder (average particle size 90 μm) (2) Chromium oxide powder (average particle size 120 μm) (3) Manganese oxide powder (average particle size 60 μm) (4) Silicon dioxide powder (average particle size 110 μm) ( 5) Magnesium oxide powder (average particle size 100 μm) Carrier gas: Ar (flow rate is 400 to 700 liters /
min) Spraying location: 1 location Processing time: 30 minutes FIGS. 2 and 3 show the results of the above test.
【0052】図2は、吹き付け速度を酸化剤の単位時間
あたりの吸熱量(kJ/min)で表したときの吸熱量が、
〔%Cu〕の減少量(%)に及ぼす影響を示す図であ
る。図3は、同じく吸熱量が、〔%Sn〕の減少量に及
ぼす影響を示す図である。図および以下において%はwt
%である。FIG. 2 shows that when the spraying speed is represented by the endothermic amount of the oxidizing agent per unit time (kJ / min),
It is a figure which shows the influence which [% Cu] has on reduction (%). FIG. 3 is a diagram showing the effect of the amount of heat absorption on the decrease in [% Sn]. In figures and below,% is wt
%.
【0053】図2に示すように〔%Cu〕の減少量は、
いずれの酸化剤においても、上記吸熱量の範囲が500
〜1500 kJ/min で10%以上となった。図3に示
すように〔%Sn〕の減少量は、いずれの酸化剤におい
ても、同上範囲が500〜1500 kJ/mi nで10%
以上となった。As shown in FIG. 2, the decrease of [% Cu]
In any oxidizing agent, the range of the above-mentioned endothermic amount is 500
It became 10% or more at 101500 kJ / min. As shown in FIG. 3, the amount of reduction of [% Sn] was 10% at 500 to 1500 kJ / min for all oxidizing agents.
That's all.
【0054】(試験2)図1に示す構成の真空高周波誘
導加熱溶解装置を用い、吹き付け箇所数および吹き付け
速度を変えて脱銅および脱錫処理を行った。条件を下記
に示す。(Test 2) Copper removal and tin removal treatment were performed using a vacuum high-frequency induction heating melting apparatus having the configuration shown in FIG. 1 while changing the number of spraying points and the spraying speed. The conditions are shown below.
【0055】溶鉄組成:Cu=0.40%、 Sn=
0.11%、炭素=0.5〜1%、Si=0.03%、
Mn=0.01%、 P=0.008〜0.018%、
残部=鉄および不可避的不純物 溶鉄量:1.5t 溶鉄温度:1650℃ 耐火物の主成分:マグネシアクロマイト 真空度:処理開始前は1Torr 、処理中は1〜9Torr 酸化剤:前記(4) 二酸化珪素粉体(平均粒径110μm) キャリアガス:Ar(流量は1箇所あたり400リット
ル/min) 吹き付け箇所:(1) 単孔ランス1本を用いて1箇所 (2) 単孔ランス2本を用いて2箇所 2本のランスは鉛直下向き 吹き付け箇所中心間距離は500mm (3) 単孔ランス1本と2孔ランス(分岐角度3°)とを
用いて3箇所。2孔ランスの吹き付け箇所中心間距離は
300mm(ランス高さを調整) (4) 2孔ランス(分岐角度3°)2本を用いて4箇所 吹き付け箇所中心間距離は300mm(ランス高さを調
整) 処理時間:30分間 図4および図5に上記試験の結果を示す。Iron composition: Cu = 0.40%, Sn =
0.11%, carbon = 0.5-1%, Si = 0.03%,
Mn = 0.01%, P = 0.008 to 0.018%,
Balance = iron and unavoidable impurities amount of molten iron: 1.5 t molten iron temperature: 1650 ° C main component of refractory: magnesia chromite Vacuum degree: 1 Torr before treatment, 1 to 9 Torr during treatment Oxidizing agent: (4) silicon dioxide Powder (average particle size: 110 μm) Carrier gas: Ar (flow rate is 400 liters / min per location) Blowing location: (1) One location with one single lance (2) Two single lances Two locations Two lances point vertically downward The distance between the centers of the spraying points is 500 mm (3) Three locations using one single-hole lance and two-hole lance (branch angle 3 °). The distance between the centers of the two lance spray points is 300mm (adjust the height of the lance). (4) The distance between the centers of the spray points is 300mm (adjust the lance height) using two two-hole lances (branch angle 3 °). Processing time: 30 minutes FIGS. 4 and 5 show the results of the above test.
【0056】図4は、吹き付け速度を酸化剤の単位時間
あたりの吸熱量(kJ/min)で表したときの吹き付け箇所
数が、〔%Cu〕の減少量に及ぼす影響を示す図であ
る。図5は、同じく吹き付け箇所数が、〔%Sn〕の減
少量に及ぼす影響を示す図である。FIG. 4 is a diagram showing the effect of the number of spraying points on the reduction of [% Cu] when the spraying speed is expressed by the amount of heat absorbed per unit time of the oxidizing agent (kJ / min). FIG. 5 is a diagram showing the effect of the number of spraying points on the decrease in [% Sn].
【0057】図4に示すように〔%Cu〕の減少量は、
上記吸熱量の範囲が500〜1500 kJ/min で、か
つ吹き付け箇所が増加するほど大きくなった。図5に示
すように〔%Sn〕の減少量は、同上吸熱量の範囲が5
00〜1500 kJ/min で、かつ吹き付け箇所が増加
するほど大きくなった。As shown in FIG. 4, the decrease of [% Cu] is
The range of the above-mentioned heat absorption was 500 to 1500 kJ / min, and it became larger as the number of spraying points increased. As shown in FIG. 5, the amount of decrease in [% Sn]
It increased from 00 to 1500 kJ / min and increased as the number of spray points increased.
【0058】[0058]
【発明の効果】本発明方法によれば、溶鉄からの脱銅お
よび/または脱錫の速度を増大させ、短時間で高効率に
処理することができる。According to the method of the present invention, the rate of copper removal and / or tin removal from molten iron can be increased, and the treatment can be performed efficiently in a short time.
【図1】本発明方法を実施するための真空高周波誘導加
熱溶解装置の例を示す概略縦断面図である。FIG. 1 is a schematic longitudinal sectional view showing an example of a vacuum high-frequency induction heating / melting apparatus for carrying out the method of the present invention.
【図2】吹き付け箇所が1箇所の場合、吹き付け速度を
酸化剤の単位時間あたりの吸熱量(kJ/min)で表したと
きの吸熱量が、〔Cu〕の減少量に及ぼす影響を示す図
である。FIG. 2 is a diagram showing the effect of the endothermic amount on the reduction amount of [Cu] when the spraying speed is represented by the endothermic amount per unit time (kJ / min) of the oxidizing agent when the number of spraying points is one; It is.
【図3】吹き付け箇所が1箇所の場合、吹き付け速度を
酸化剤の単位時間あたりの吸熱量(kJ/min)で表したと
きの吸熱量が、〔Sn〕の減少量に及ぼす影響を示す図
である。FIG. 3 is a graph showing the effect of the endothermic amount on the decrease in [Sn] when the spraying speed is represented by the endothermic amount per unit time (kJ / min) of the oxidizing agent when the number of spraying points is one; It is.
【図4】吹き付け速度を酸化剤の単位時間あたりの吸熱
量(kJ/min)で表したときの吹き付け箇所数が、〔C
u〕の減少量に及ぼす影響を示す図である。FIG. 4 shows that the number of spraying points when the spraying speed is represented by the amount of heat absorbed per unit time (kJ / min) of the oxidizing agent is [C
u] is a diagram showing the effect on the amount of decrease.
【図5】吹き付け速度を酸化剤の単位時間あたりの吸熱
量(kJ/min)で表したときの吹き付け箇所数が、〔S
n〕の減少量に及ぼす影響を示す図である。FIG. 5 shows that the number of spraying points when the spraying speed is represented by the endothermic amount (kJ / min) of the oxidizing agent per unit time is [S
[n] is a diagram showing the effect on the amount of decrease.
1:真空槽、 2:真空槽上蓋、3,4:
粉体上吹きランス、5:耐火物、6:排気孔、
7:誘導加熱コイル、8:溶鉄、
9:容器1: vacuum tank, 2: vacuum tank top lid, 3, 4:
Powder top blowing lance, 5: refractory, 6: exhaust hole,
7: induction heating coil, 8: molten iron,
9: Container
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平7−126726(JP,A) 特開 平7−126727(JP,A) 特開 平1−195241(JP,A) 特開 平6−10026(JP,A) 特開 昭61−190011(JP,A) (58)調査した分野(Int.Cl.7,DB名) C21C 1/04,7/04 C21C 7/068,7/10 ────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-7-126726 (JP, A) JP-A-7-126727 (JP, A) JP-A-1-195241 (JP, A) JP-A-6-126 10026 (JP, A) JP-A-61-190011 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C21C 1 / 04,7 / 04 C21C 7 / 068,7 / 10
Claims (1)
含有する溶鉄面に酸化鉄粉体または/および酸化鉄より
も酸化力の低い酸化物粉体からなる酸化剤を吹き付けて
溶鉄の脱炭を行うことにより、この溶鉄中の銅および/
または錫を除去する方法であって、吹き付け1箇所かつ
単位時間あたりの吹き付け量を酸化剤の吸熱量換算で5
00〜1500 kJ/min とすることを特徴とする溶鉄
からの脱銅および/または脱錫方法。An oxidizing agent comprising iron oxide powder and / or an oxide powder having a lower oxidizing power than iron oxide is sprayed on the surface of the molten iron containing carbon under a reduced pressure of 10 Torr or less to decarbonize the molten iron. By doing so, the copper and / or
Or a method of removing tin, wherein the spray amount per spray and per unit time is 5 in terms of the endothermic amount of the oxidizing agent.
A method for removing copper and / or tin from molten iron, which is performed at a rate of 00 to 1500 kJ / min.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9678996A JP3067636B2 (en) | 1996-04-18 | 1996-04-18 | Copper removal from molten iron |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9678996A JP3067636B2 (en) | 1996-04-18 | 1996-04-18 | Copper removal from molten iron |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH09279220A JPH09279220A (en) | 1997-10-28 |
JP3067636B2 true JP3067636B2 (en) | 2000-07-17 |
Family
ID=14174415
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP9678996A Expired - Lifetime JP3067636B2 (en) | 1996-04-18 | 1996-04-18 | Copper removal from molten iron |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP3067636B2 (en) |
-
1996
- 1996-04-18 JP JP9678996A patent/JP3067636B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPH09279220A (en) | 1997-10-28 |
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