JPH02407B2 - - Google Patents
Info
- Publication number
- JPH02407B2 JPH02407B2 JP60115940A JP11594085A JPH02407B2 JP H02407 B2 JPH02407 B2 JP H02407B2 JP 60115940 A JP60115940 A JP 60115940A JP 11594085 A JP11594085 A JP 11594085A JP H02407 B2 JPH02407 B2 JP H02407B2
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- chromium
- electrode
- arc
- chromium ore
- 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
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/005—Manufacture of stainless steel
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- 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
【発明の詳細な説明】
［産業上の利用分野］
この発明は、取鍋に収納された溶鋼上のスラグ
に電極を浸漬して溶鋼と電極との間にアークを形
成し、溶鋼を加熱するアークプロセスにおいて溶
鋼にクロムを添加するアークプロセスにおける溶
鋼の精錬方法に関する。[Detailed Description of the Invention] [Field of Industrial Application] This invention heats the molten steel by immersing an electrode in slag on molten steel stored in a ladle to form an arc between the molten steel and the electrode. The present invention relates to a method for refining molten steel in an arc process in which chromium is added to molten steel in an arc process.
［従来の技術］
転炉精錬後、溶鋼をアーク加熱するアークプロ
セスを実施することにより、溶鋼の転炉出鋼温度
を下げることができる。これにより、副原料及び
転炉炉体耐火物の使用原単位を低減させ、転炉か
らの溶鋼の出鋼歩留りを上げることができる。こ
のアークプロセスにおける精錬において、溶鋼の
成分調整をするために溶鋼にクロム（Cr）を添
加する場合がある。[Prior Art] After converter refining, the converter tapping temperature of molten steel can be lowered by performing an arc process of arc heating the molten steel. Thereby, it is possible to reduce the usage unit of auxiliary raw materials and converter body refractories, and increase the yield of molten steel from the converter. During refining using this arc process, chromium (Cr) is sometimes added to the molten steel in order to adjust the composition of the molten steel.
従来、溶鋼にクロムを添加する場合には、合金
鉄の代替として取鍋に出鋼した溶鋼にクロム鉱石
を投入し、更に還元剤としてアルミニウム（Al）
又はシリコン（Si）を投入した後、溶鋼を昇温さ
せることによりスラグ中のクロミヤ（Cr2O3）を
Al又はSiで還元し、溶鋼にクロムを添加してい
る。 Conventionally, when adding chromium to molten steel, chromium ore was added to the molten steel tapped into a ladle as a substitute for ferroalloy, and aluminum (Al) was added as a reducing agent.
Alternatively, after adding silicon (Si), chromia (Cr 2 O 3 ) in the slag can be removed by heating the molten steel.
Chromium is added to molten steel by reducing it with Al or Si.
［発明が解決しようとする問題点］
しかしながら、クロム鉱石の還元剤として用い
ているアルミニウム及びシリコンは比較的高価で
あるために、クロムの添加コストが高いという問
題があつた。[Problems to be Solved by the Invention] However, since aluminum and silicon used as reducing agents for chromium ore are relatively expensive, there has been a problem that the cost of adding chromium is high.
［問題を解決するための手段］
この発明は、かかる事情に鑑みてなされたもの
であつて、アークプロセスの特質を利用して溶鋼
にクロムを安価に添加することができるアークプ
ロセスにおける溶鋼の精錬方法を提供することを
目的とする。[Means for Solving the Problem] The present invention has been made in view of the above circumstances, and is a method for refining molten steel in an arc process that makes it possible to inexpensively add chromium to molten steel by utilizing the characteristics of the arc process. The purpose is to provide a method.
この発明に係るアークプロセスにおける溶鋼の
精錬方法は、溶鋼上のスラグに電極を浸漬し、溶
鋼と電極との間にアークを形成して溶鋼を加熱す
るアークプロセスにおける溶鋼の精錬方法におい
て、前記電極にはその下端に開口する通路が形成
されており、この通路を介して、キヤリヤガスに
搬送させたクロム鉱石および炭素材との混合粉体
を溶鋼上に吐出させることによつて溶鋼にクロム
を添加することを特徴とする。 A method for refining molten steel in an arc process according to the present invention is a method for refining molten steel in an arc process in which an electrode is immersed in slag on the molten steel, and an arc is formed between the molten steel and the electrode to heat the molten steel. A passage is formed at the lower end of the molten steel, and chromium is added to the molten steel by discharging the mixed powder of chromium ore and carbon material carried by the carrier gas onto the molten steel through this passage. It is characterized by
［実施例］
以下に添附図面を参照してこの発明の実施例に
ついて詳細に説明する。第１図に示すように、取
鍋２内には転炉から出鋼された溶鋼４が収容さ
れ、溶鋼４上のスラグ６に取鍋２の炉蓋８を挿通
して炉内に挿入された電極１０が浸漬されるよう
になつている。電極１０は、通常、炭素電極でつ
くられており、炉内に３本（図には１本のみ示
す）挿入され、三層交流電源（図示されず）に接
続されている。電極１０には、その長手方向に沿
つて通路１２が形成されており、通路１２は電極
１０の上端および下端で開口している。この電極
１０の上端にはホース１４の一端部が接続され、
このホース１４の他端部は、キヤリヤガスに搬送
させてクロム鉱石及び、還元剤として炭材（炭素
材）を供給するためのパイプ１６に接続されてい
る。[Embodiments] Examples of the present invention will be described in detail below with reference to the accompanying drawings. As shown in FIG. 1, the ladle 2 contains molten steel 4 tapped from a converter, and the slag 6 on the molten steel 4 is inserted into the furnace by passing the furnace lid 8 of the ladle 2. The electrode 10 is adapted to be immersed. The electrodes 10 are typically made of carbon electrodes, three of which are inserted into the furnace (only one shown) and connected to a three-layer AC power source (not shown). A passage 12 is formed in the electrode 10 along its longitudinal direction, and the passage 12 is open at the upper and lower ends of the electrode 10. One end of a hose 14 is connected to the upper end of this electrode 10,
The other end of the hose 14 is connected to a pipe 16 for supplying chromium ore and carbon material as a reducing agent by conveying it to a carrier gas.
パイプ１６は適当なキヤリヤガス供給源、例え
ば、Arガス供給源に連結されている。更に、パ
イプ１６にはその途中の部分に、粉体状の炭材を
貯留したホツパ１８と、粉体状のクロム鉱石を貯
留したホツパ２０とが配置されている。炭材のホ
ツパ１８の底部にはバルブ２２が設けられてお
り、このバルブ２２を介して炭材のホツパ１８と
パイプ１６とが連結されていて、バルブ２２によ
りパイプ１６に供給する炭材の量を調整するよう
になつている。同様に、クロム鉱石のホツパ２０
の底部には、バルブ２４が設けられており、この
バルブ２４を介してクロム鉱石のホツパ２０とパ
イプ１６とが連結されていて、バルブ２４により
パイプ１６に供給するクロム鉱石を調整する。 Pipe 16 is connected to a suitable carrier gas source, for example an Ar gas source. Further, a hopper 18 storing powdered carbonaceous material and a hopper 20 storing powdered chromium ore are arranged in the middle of the pipe 16. A valve 22 is provided at the bottom of the carbon material hopper 18 , and the carbon material hopper 18 and the pipe 16 are connected through this valve 22 , and the amount of carbon material supplied to the pipe 16 is controlled by the valve 22 . is now being adjusted. Similarly, chromium ore hopper 20
A valve 24 is provided at the bottom of the pipe 16, and the chromium ore hopper 20 and the pipe 16 are connected through the valve 24, and the chromium ore supplied to the pipe 16 is adjusted by the valve 24.
また、取鍋２の炉底にはポーラスプラグ２６が
設けられており、このポーラスプラグ２６を介し
て溶鋼４に不活性ガス（Arガス）を導入し、溶
鋼を撹拌できるようになつている。 Further, a porous plug 26 is provided at the bottom of the ladle 2, and an inert gas (Ar gas) is introduced into the molten steel 4 through the porous plug 26 so that the molten steel can be stirred.
このように構成されたアークプロセスにおける
溶鋼のアーク加熱装置においては、先ず、ポーラ
スプラグ２４からArガスを吐出しつつ、溶鋼４
を転炉から取鍋２に出鋼し、炉内に電極１０を挿
入する。次に、電極１０に通電し、電極１０と溶
鋼４との間にアークを形成し、溶鋼をアーク加熱
する。電極１０の通電と同時に、パイプ１６にキ
ヤリヤガスとしてArガスを供給するとともに、
炭材ホツパ１８のバルブ２２及びクロム鉱石用の
ホツパ２０のバルブ２４を開き、炭材とクロム鉱
石とを所定の混合比、例えばモル比１：３に設定
してホツパから切出し、パイプ１６に供給する。
粉体状の炭材と粉体状のクロム鉱石は、このパイ
プ１６内において、搬送されつつ略均一に混合さ
れる。この混合粉体は、キヤリヤガスに搬送さ
れ、通路１２を介して電極１０の先端部の開口か
ら溶鋼４に向けて連続的に吐出される。 In the arc heating device for molten steel in the arc process configured as described above, first, the molten steel 4 is heated while discharging Ar gas from the porous plug 24.
is tapped from a converter into a ladle 2, and an electrode 10 is inserted into the furnace. Next, the electrode 10 is energized, an arc is formed between the electrode 10 and the molten steel 4, and the molten steel is heated by the arc. At the same time as the electrode 10 is energized, Ar gas is supplied as a carrier gas to the pipe 16,
The valve 22 of the carbon material hopper 18 and the valve 24 of the chromium ore hopper 20 are opened, and the carbon material and chromium ore are cut out from the hopper at a predetermined mixing ratio, for example, a molar ratio of 1:3, and are supplied to the pipe 16. do.
Powdered carbonaceous material and powdered chromium ore are mixed substantially uniformly within this pipe 16 while being conveyed. This mixed powder is carried by the carrier gas and continuously discharged from the opening at the tip of the electrode 10 toward the molten steel 4 via the passage 12.
電極の先端から供給された混合粉体は、電極と
溶鋼との間に形成されているアークの熱（2000乃
至3000℃）により次のように反応すると考えられ
る。 It is thought that the mixed powder supplied from the tip of the electrode reacts as follows due to the heat (2000 to 3000°C) of the arc formed between the electrode and the molten steel.
Cr2O3＋3C→2Cr＋3CO
この反応式は、従来のように1600乃至1700℃の
温度の溶鋼内では、その自由エネルギが低いため
に、容易に進行せず、反応速度が遅い。このた
め、このような温度域では、ＣによるCr2O3の還
元は事実上不可能である。ところが、この発明に
よれば、アークの温度が2000乃至3000℃の高温で
あるため、上記反応が迅速に進行し、Cr2O3がＣ
により還元される。 Cr 2 O 3 +3C→2Cr+3CO This reaction formula does not proceed easily in molten steel at a temperature of 1,600 to 1,700°C, as in the past, because its free energy is low, and the reaction rate is slow. Therefore, reduction of Cr 2 O 3 by C is virtually impossible in such a temperature range. However, according to the present invention, since the arc temperature is as high as 2,000 to 3,000°C, the above reaction proceeds quickly, and Cr 2 O 3 is converted to C.
will be reduced by
次に、第２及び第３図を参照してこの発明の効
果を説明する。 Next, the effects of this invention will be explained with reference to FIGS. 2 and 3.
第２図は横軸にアーク加熱処理時間（分）、縦
軸に溶鋼中のクロム（Cr）の濃度［Cr］をとつ
て、この発明によるクロムの歩留を示すグラフで
ある。尚このグラフにおいてクロム鉱石と炭材の
モル比は１：３に設定し、これらの混合粉体を吐
出量が93〓／分で20分間供給した。グラフにおい
て破線は歩留が100％である場合を示している。
このグラフから明らかなように、この発明の方法
によれば、常に破線で示す100％歩留に近い値で
クロム鉱石を還元することができる。また、混合
粉体が吐出されると極めて迅速に反応が生じるこ
とがわかる。更に、混合粉体の吐出量に応じて溶
鋼中のクロム濃度を簡単に調節することができ
る。 FIG. 2 is a graph showing the chromium yield according to the present invention, with the horizontal axis representing the arc heat treatment time (minutes) and the vertical axis representing the chromium (Cr) concentration [Cr] in molten steel. In this graph, the molar ratio of chromium ore and carbonaceous material was set at 1:3, and the mixed powder was supplied at a discharge rate of 93/min for 20 minutes. In the graph, the broken line indicates the case where the yield is 100%.
As is clear from this graph, according to the method of the present invention, chromium ore can always be reduced at a yield close to 100%, which is indicated by the broken line. It can also be seen that a reaction occurs extremely quickly when the mixed powder is discharged. Furthermore, the chromium concentration in the molten steel can be easily adjusted depending on the amount of mixed powder discharged.
また、第３図は、クロム鉱石と炭材との混合モ
ル比を変化させた場合の還元率を示したグラフで
ある。横軸にクロム鉱石と炭材との混合モル比を
とり、縦軸に還元率をとつた。このグラフから明
らかなようにモル比が3.0までは還元率がモル比
に比例しているが、3.0以上の場合は混合粉体の
炭材が過剰であるために還元率はほぼ一定になつ
ている。即ちこのグラフから明らかなようにモル
比を3.0に設定すればほぼ100％に近い還元率を得
ることができる。 Moreover, FIG. 3 is a graph showing the reduction rate when the mixing molar ratio of chromium ore and carbonaceous material is changed. The horizontal axis shows the mixing molar ratio of chromium ore and carbonaceous material, and the vertical axis shows the reduction rate. As is clear from this graph, the reduction rate is proportional to the molar ratio up to 3.0, but when it is over 3.0, the reduction rate becomes almost constant because there is an excess of carbonaceous material in the mixed powder. There is. That is, as is clear from this graph, if the molar ratio is set to 3.0, a reduction rate close to 100% can be obtained.
この発明は上述した実施例に限定されることな
く、この発明の要旨を逸脱しない範囲で種々変形
可能である。 This invention is not limited to the embodiments described above, and can be modified in various ways without departing from the gist of the invention.
例えば、クロム鉱石と炭材との混合粉体を搬送
するためのキヤリヤガスはアルゴンガスに限らず
N2ガス等の不活性ガスを用いても良い。 For example, the carrier gas used to transport mixed powder of chromium ore and carbonaceous material is not limited to argon gas.
An inert gas such as N 2 gas may also be used.
また、炭材とクロム鉱石とを個別的にホツパに
貯留しパイプ内で両方を混合しているが、炭材と
クロム鉱石とを予め混合しておき、この混合粉体
を１個のホツパに貯留しておいてもよい。また、
各炭材及びクロム鉱石を貯留するホツパを一本の
パイプに直列に配置する場合に限らず、並列に配
置してもよい。この場合夫々の粉体を搬送するキ
ヤリヤガスは２本のパイプで別々に供給される。 In addition, carbonaceous material and chromium ore are stored separately in hoppers and both are mixed in a pipe, but the carbonaceous material and chromium ore are mixed in advance and this mixed powder is poured into one hopper. It may be stored. Also,
The hoppers for storing each carbonaceous material and chromium ore are not limited to being arranged in series in one pipe, but may be arranged in parallel. In this case, the carrier gas for transporting each powder is supplied separately through two pipes.
［発明の効果］
この発明によれば、安価な炭素材を使用してク
ロム鉱石を還元し、溶鋼中にクロムを添加するこ
とができるから、処理コストが低い。[Effects of the Invention] According to the present invention, chromium ore can be reduced using an inexpensive carbon material and chromium can be added to molten steel, resulting in low processing costs.
第１図はこの発明の実施例に係るアークプロセ
スにおける溶鋼の精錬方法の実施状態を示す概略
断面図、第２図はクロム歩留を示す図、第３図は
クロム還元率を示す図である。
２……取鍋、４……溶鋼、６……スラグ、１０
……電極、１２……通路、１８，２０……ホツ
パ。
FIG. 1 is a schematic cross-sectional view showing the implementation state of a method for refining molten steel in an arc process according to an embodiment of the present invention, FIG. 2 is a view showing chromium yield, and FIG. 3 is a view showing chromium reduction rate. . 2... Ladle, 4... Molten steel, 6... Slag, 10
...electrode, 12...passage, 18,20...hopper.
Claims (1)
との間にアークを形成して溶鋼を加熱するアーク
プロセスにおける溶鋼の精錬方法において、前記
電極にはその下端に開口する通路が形成されてお
り、この通路を介して、キヤリヤガスに搬送させ
たクロム鉱石と炭素材との混合粉体を溶鋼上に吐
出することによつて溶鋼にクロムを添加すること
を特徴とするアークプロセスにおける溶鋼の精錬
方法。1. In a method for refining molten steel in an arc process in which an electrode is immersed in slag on molten steel and an arc is formed between the molten steel and the electrode to heat the molten steel, the electrode is provided with a passageway opening at its lower end. Refining of molten steel in an arc process characterized by adding chromium to molten steel by discharging a mixed powder of chromium ore and carbon material carried by a carrier gas onto the molten steel through this passage. Method.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60115940A JPS61272309A (en) | 1985-05-29 | 1985-05-29 | Method for refining molten steel in arc process |
| KR1019860003926A KR900004159B1 (en) | 1985-05-29 | 1986-05-20 | Method of heating molten steel by arc process |
| DE8686106973T DE3677059D1 (en) | 1985-05-29 | 1986-05-22 | METHOD FOR HEATING MOLTEN STEEL BY ARC. |
| EP86106973A EP0203533B1 (en) | 1985-05-29 | 1986-05-22 | Method of heating molten steel by arc process |
| ZA863975A ZA863975B (en) | 1985-05-29 | 1986-05-28 | Method of heating molten steel by arc process |
| CA000510202A CA1242325A (en) | 1985-05-29 | 1986-05-28 | Method of heating molten steel by arc process |
| US06/868,807 US4650517A (en) | 1985-05-29 | 1986-05-29 | Method of heating molten steel by arc process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60115940A JPS61272309A (en) | 1985-05-29 | 1985-05-29 | Method for refining molten steel in arc process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61272309A JPS61272309A (en) | 1986-12-02 |
| JPH02407B2 true JPH02407B2 (en) | 1990-01-08 |
Family
ID=14674943
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60115940A Granted JPS61272309A (en) | 1985-05-29 | 1985-05-29 | Method for refining molten steel in arc process |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS61272309A (en) |
| ZA (1) | ZA863975B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63128147A (en) * | 1986-11-19 | 1988-05-31 | Nkk Corp | Manufacture of steel containing chromium in electric furnace |
| JPS63203712A (en) * | 1987-02-19 | 1988-08-23 | Daido Steel Co Ltd | Melting method of chromium-containing steel |
| JPS6425938A (en) * | 1987-07-20 | 1989-01-27 | Daido Steel Co Ltd | Refining method for molten steel by arc furnace |
| JP2564604B2 (en) * | 1988-05-19 | 1996-12-18 | 日本鋼管株式会社 | Electric furnace refining method for chromium-containing steel |
-
1985
- 1985-05-29 JP JP60115940A patent/JPS61272309A/en active Granted
-
1986
- 1986-05-28 ZA ZA863975A patent/ZA863975B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| ZA863975B (en) | 1987-01-28 |
| JPS61272309A (en) | 1986-12-02 |
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