JPS62230950A - Manufacture of medium-or low-carbon ferromanganese - Google Patents
Manufacture of medium-or low-carbon ferromanganeseInfo
- Publication number
- JPS62230950A JPS62230950A JP7532886A JP7532886A JPS62230950A JP S62230950 A JPS62230950 A JP S62230950A JP 7532886 A JP7532886 A JP 7532886A JP 7532886 A JP7532886 A JP 7532886A JP S62230950 A JPS62230950 A JP S62230950A
- Authority
- JP
- Japan
- Prior art keywords
- blowing
- gas
- decarburization
- oxygen
- blown
- 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
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 56
- 229910000616 Ferromanganese Inorganic materials 0.000 title claims abstract description 39
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 title claims abstract description 39
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 238000007664 blowing Methods 0.000 claims abstract description 78
- 239000002184 metal Substances 0.000 claims abstract description 29
- 239000011261 inert gas Substances 0.000 claims abstract description 26
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 43
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 42
- 229910052760 oxygen Inorganic materials 0.000 claims description 42
- 239000001301 oxygen Substances 0.000 claims description 42
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 17
- 229910001882 dioxygen Inorganic materials 0.000 claims description 17
- 230000008685 targeting Effects 0.000 claims 1
- 238000005261 decarburization Methods 0.000 abstract description 40
- 238000000034 method Methods 0.000 abstract description 22
- 239000007789 gas Substances 0.000 abstract description 12
- 229910021332 silicide Inorganic materials 0.000 abstract description 3
- FVBUAEGBCNSCDD-UHFFFAOYSA-N silicide(4-) Chemical compound [Si-4] FVBUAEGBCNSCDD-UHFFFAOYSA-N 0.000 abstract description 3
- 238000007254 oxidation reaction Methods 0.000 description 23
- 230000003647 oxidation Effects 0.000 description 19
- 230000000694 effects Effects 0.000 description 8
- 230000007423 decrease Effects 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 230000008020 evaporation Effects 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- 239000002893 slag Substances 0.000 description 4
- 239000003638 chemical reducing agent Substances 0.000 description 3
- 229910000676 Si alloy Inorganic materials 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 229910002551 Fe-Mn Inorganic materials 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000011449 brick Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- CSJDCSCTVDEHRN-UHFFFAOYSA-N methane;molecular oxygen Chemical compound C.O=O CSJDCSCTVDEHRN-UHFFFAOYSA-N 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は高炭素フェロマンガン溶湯を吹錬して中・低炭
素フェロマンガンを製造する方法に関し、詳細には脱炭
の進行を２段階に分けて制御することにより、Ｍｎ歩留
りに悪影響を与えることなく効率良く目標Ｃ量を達成す
ることのできる中・低炭素フェロマンガンの製造方法に
関するものである。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing medium/low carbon ferromanganese by blowing high carbon ferromanganese molten metal. The present invention relates to a method for producing medium/low carbon ferromanganese that can efficiently achieve a target C content without adversely affecting the Mn yield by separately controlling the Mn yield.
［従来の技術］
中・低炭素フェロマンガンを製造する従来の方法は、所
謂シリサイド法と呼ばれる方法であって、Ｆｅ−Ｍｎ合
金に対するＣ及びＳｉの相互溶解度を利用することによ
って目標Ｃ含有量の５１−Ｍｎｎ溶金製造しく電気炉）
、これにＭｎ鉱石等のＭｎ酸化物を添加して５１−Ｍｎ
中のＳｉを酸化除去するのが常法であった。この方法は
電気炉を使用するものである為電力コストの比重が高い
という経済上の問題を内包する他、上記酸化除去によっ
て大量に副生ずる５ｉｎ２を補足する為の塩基性酸化物
（例えばＣａｂ）を同じく大量に使用する必要があり、
スラグ量が過大になるという操業上の問題もある。しか
も該スラグ中には回収対象となるほどに多くはないけれ
どもそのまま投棄するには公害発生を惹起する程度の量
のＭｎが混入しているので、スラグ処理に細心の注意を
払わなければならないという問題も抱えている。[Prior Art] The conventional method for producing medium- to low-carbon ferromanganese is the so-called silicide method, in which the target C content is achieved by utilizing the mutual solubility of C and Si in Fe-Mn alloy. 51-Mnn molten metal manufacturing electric furnace)
, by adding Mn oxide such as Mn ore to this, 51-Mn
The conventional method was to remove the Si inside by oxidation. Since this method uses an electric furnace, it has the economical problem of high electricity costs, and also uses basic oxides (e.g. Cab) to supplement the 5in2 that is produced as a by-product in large quantities during the oxidation and removal process. It is also necessary to use a large amount of
There is also an operational problem that the amount of slag becomes excessive. Moreover, although the amount of Mn contained in the slag is not large enough to be collected, it does contain enough Mn to cause pollution if it is simply dumped, so the problem is that great care must be taken when disposing of the slag. I also have
［発明が解決しようとする問題点］
そこで特公昭５７−２７１６６号辷開示されている様な
酸素ガス吹錬法、即ち高炭素フェロマンガン溶湯を対象
としてこれに酸素ガスを吹込み、酸素による脱炭を利用
して中・低炭素フェロマンガンに変換するという方法が
提案されている。この方法を更に詳細に検討すると、酸
素吹込みの実施に先立って高炭素フェロマンガンをその
融点より１００℃以上高くまで加熱しておき（炉ガスジ
ャケットノズルを使用する）、酸素の吹込みに当たって
は１９００℃近い高温度に昇温させて脱炭の促進を図り
、一方酸素吹きによって形成されるＭｎ酸化物は石灰お
よび珪素合金の添加によって還元回収するという構成が
採られている。しかしながらＭｎは沸点が比較的低く且
つ蒸気圧も高いので、上記酸化による損失だけでなく蒸
発による損失を考慮する必要があり、電力コストの代り
にＭｎ歩留りが低いという面でコスト高を避けることが
できないと考えられている。これに対し特開昭６０−５
６０５１号では、上底吹きを併行的に実施できる様に構
成された反応容器を用い、上吹き酸素ガスによる脱炭を
、不活性ガスの底吹きによる攪拌効果を利用して促進し
、１８３０℃止まりの温度で高炭素フェロマンガンを吹
錬する方法が提案されている。この方法によると酸素ガ
スの上吹きによる脱炭である為、高炭素領域では大きな
脱炭酸素効率（供給酸素のうち脱炭反応に費やされた酸
素の割合）を期待できるが、中炭素領域から低炭素領域
にかけては炭素拡散律速になる為脱炭酸素効率が低下し
、目標Ｃ濃度へ下る迄の吹錬時間が長くなると共に、そ
の分過剰の酸素が供給されることとなってＭｎの酸化損
失が増大していくという欠点があった。[Problems to be Solved by the Invention] Therefore, the oxygen gas blowing method as disclosed in Japanese Patent Publication No. 57-27166, in which oxygen gas is blown into a high carbon ferromanganese molten metal, is decomposed by oxygen. A method has been proposed that uses charcoal to convert it into medium- to low-carbon ferromanganese. A more detailed study of this method reveals that prior to oxygen injection, high carbon ferromanganese is heated to 100°C or more above its melting point (using a furnace gas jacket nozzle); A configuration is adopted in which decarburization is promoted by raising the temperature to a high temperature close to 1900° C., while Mn oxides formed by oxygen blowing are reduced and recovered by adding lime and a silicon alloy. However, since Mn has a relatively low boiling point and high vapor pressure, it is necessary to consider not only the loss due to oxidation but also the loss due to evaporation, and it is possible to avoid high costs in terms of low Mn yield at the expense of electricity costs. It is thought that it is not possible. On the other hand, JP-A-60-5
In No. 6051, a reaction vessel configured to perform top-bottom blowing in parallel was used, and decarburization by top-blowing oxygen gas was promoted by utilizing the stirring effect of bottom-blowing inert gas. A method of blowing high carbon ferromanganese at a constant temperature has been proposed. According to this method, since decarburization is performed by upward blowing of oxygen gas, a high decarburization oxygen efficiency (ratio of oxygen consumed for decarburization reaction out of supplied oxygen) can be expected in the high carbon region, but in the medium carbon region In the low-carbon region, carbon diffusion becomes rate-limiting, so the decarburization oxygen efficiency decreases, and the blowing time until the target C concentration is reached becomes longer. The disadvantage was that oxidation loss increased.
更に特開昭６０−６７６０８号では底吹きガスの一部を
酸素ガスに変更しく残りは不活性ガスのまま）上からと
底からの酸素吹きを併用することによって初期段階での
脱炭を促進すると共に、所定の中・低炭素領域まで一気
に下げてきた段階で酸素の吹込みを上吹き、底吹き共完
全に停止し、その後は底吹不活性ガスによって溶湯の攪
拌を行なうと共に、上記脱炭プロセスにおいて形成され
たＭｎ酸化物をＳｉ合金やＡＩＬ等の還元剤を投入する
ことによって還元（Ｍｎを回収）し、中・低炭素フェロ
マンガンを製造するという方法が提案されている。しか
しこの方法で使用される底吹酸素ガス量は上吹酸素ガス
量の高々６〜７％止まりである為炭素濃度を中・低炭素
領域まで下げようとするならば、該炭素濃度領域では脱
炭酸素効率が低いことに鑑み、かなりの時間に亘って上
底吹き吹錬を実行しなければならなくなる。従って酸素
吹込総量の増大とこれに伴なうＭｎ酸化ロスの増大とい
う問題が顕著になり、該脱炭プロセスに続いてＳｉ合金
等によるＭｎ酸化物の回収という工程を付加するにして
も、Ｓｉ合金等の還元剤自身が高価効果であるから、全
体として考えれば極めて不経済な方法であると言わざる
を得ない。Furthermore, in JP-A No. 60-67608, part of the bottom blowing gas was changed to oxygen gas, and the rest was left as inert gas). Decarburization was promoted in the initial stage by using oxygen blowing from the top and from the bottom. At the same time, at the stage when the temperature has suddenly decreased to the specified medium/low carbon range, both the top blowing and bottom blowing of oxygen are completely stopped, and then the molten metal is stirred by bottom blowing inert gas, and the above-mentioned desorption process is carried out. A method has been proposed in which Mn oxide formed in a carbon process is reduced (Mn is recovered) by adding a reducing agent such as a Si alloy or AIL to produce medium/low carbon ferromanganese. However, the amount of bottom-blown oxygen gas used in this method is only 6 to 7% of the top-blown oxygen gas amount, so if you are trying to lower the carbon concentration to a medium-low carbon range, it is necessary to In view of the low carbon-oxygen efficiency, top-bottom blowing must be carried out over a considerable period of time. Therefore, the problem of an increase in the total amount of oxygen blown and an accompanying increase in Mn oxidation loss becomes significant. Since the reducing agent itself, such as an alloy, is expensive, it must be said that this is an extremely uneconomical method when considered as a whole.
本発明は従来技術における上記の如き欠点を憂慮してな
されたものであって、安価な高炭素フェロマンガンを原
料しとして吹錬するという点は踏襲するが吹錬中のＭｎ
酸化をできる限り抑制することによって経済的に中・低
炭素フェロマンガンを製造し得る方法を提供しようとす
るものである。The present invention was made in consideration of the above-mentioned drawbacks of the prior art, and although it follows the point of blowing using inexpensive high-carbon ferromanganese as a raw material, Mn during blowing
The present invention aims to provide a method for economically producing medium- to low-carbon ferromanganese by suppressing oxidation as much as possible.
［問題点を解決する為の手段］
本発明者らは、上記従来技術の欠点を分析し、脱炭酸素
効率の大きい前期と、脱炭酸素効率の小さい後期にかけ
て吹錬方式を制御することを骨子とする本発明を完成し
た。即ち本発明に係る中・低炭素フェロマンガンの製造
方法とは、高炭素フェロマンガン溶湯を対象とし、酸素
ガスの上吹きと酸素および不活性ガスの底吹きによって
所定炭素量まで脱炭する第１工程と、酸素ガスの底吹き
と不活性ガスの底吹きを併用し、底吹き酸素ガス１００
容量部に対する不活性ガスの底吹き量を２０容量部以上
とすると共に溶湯温度を１６５０〜１８００℃に制御し
つつ所望の炭素量まで脱炭する第２工程に分けて吹錬す
る様に構成した点に要旨を有するものである。従って本
発明は高炭素フェロマンガンから出発し、比較的高炭素
濃度領域の中炭素フェロマンガン（例えばＣ濃度：３．
０〜２．５％）を経て中炭素フェロマンガン（例えばＣ
濃度＝１．９〜１．６％）に到達（第２工程）する方法
と、同じく高炭素フェロマンガンから出発し、一般的な
中濃度の炭素領域（例えばＣ濃度＝２．５〜１．９％）
を経て低炭素フェロマンガン（例えばＣ濃度： ０．９
５〜０．７０％）に到達（第２工程）する方法を包含し
ている。[Means for Solving the Problems] The present inventors analyzed the drawbacks of the above-mentioned prior art and decided to control the blowing method during the early stage when the decarburization oxygen efficiency is high and the latter stage when the decarburization oxygen efficiency is low. The basic invention has been completed. That is, the method for producing medium/low carbon ferromanganese according to the present invention is a first step in which a high carbon ferromanganese molten metal is decarburized to a predetermined carbon content by top blowing with oxygen gas and bottom blowing with oxygen and inert gas. process, bottom blowing of oxygen gas and bottom blowing of inert gas are used together, bottom blowing oxygen gas 100
The blowing is divided into a second step in which the bottom blowing amount of inert gas is set to 20 parts by volume or more and the temperature of the molten metal is controlled at 1,650 to 1,800°C, and decarburization is performed to a desired carbon content. The main points are the main points. Therefore, the present invention starts from a high carbon ferromanganese, and starts from a medium carbon ferromanganese in a relatively high carbon concentration region (for example, C concentration: 3.
0-2.5%) through medium carbon ferromanganese (e.g. C
concentration = 1.9-1.6%) (second step), and also starting from high carbon ferromanganese and achieving a general medium concentration carbon range (e.g. C concentration = 2.5-1.6%). 9%)
Low carbon ferromanganese (e.g. C concentration: 0.9
5 to 0.70%) (second step).
［作用］
高炭素フェロマンガンを酸素吹錬によって脱炭しようと
する場合の酸化反応を熱力学的に考察してみると、低温
ではＭｎの酸化が優先し、高温ではＣの酸化が優先する
という傾向が認められる。[Effect] When we consider thermodynamically the oxidation reaction when high carbon ferromanganese is decarburized by oxygen blowing, it is found that at low temperatures, oxidation of Mn takes priority, and at high temperatures, oxidation of C takes priority. A trend is observed.
またＣの活量が高いぼどＣの酸化が優先する傾向も認め
られる。しかしＣの酸化によって発生し溶湯の表面に存
在するＣＯの影響を、例えばＰｏ。There is also a tendency for oxidation of C to take precedence in cases where C has a high activity. However, the influence of CO generated by the oxidation of C and present on the surface of the molten metal, such as Po.
（ｃｏの分圧）という観点から見ると、低温であっても
Ｐ ｃｏが低ければＣの酸化が優先するという傾向も認
められる。尚温度に関連して述べると、高温側になるほ
どＭｎの蒸発ロスが顕著になるという傾向がある。これ
らの傾向を総括すると、高炭素フェロマンガンの脱炭吹
錬は、低温側で実施した方が安全であり、低温吹錬にお
けるＣ酸化の低迷はＰｃ、。の低減によって解消する方
が有利であるという指針が得られる。From the viewpoint of (partial pressure of co), there is also a tendency that oxidation of C takes precedence if P co is low even at low temperatures. Regarding temperature, there is a tendency that the higher the temperature, the more significant the evaporation loss of Mn becomes. To summarize these trends, decarburization blowing of high carbon ferromanganese is safer when carried out at low temperatures, and the stagnation of C oxidation in low temperature blowing is Pc. This provides guidance that it is more advantageous to eliminate the problem by reducing it.
ところで原料となる高炭素フェロマンガンの温度は、還
元電気炉やシャフト炉で製造する場合はこれらからの出
湯温度、或は誘導炉やアーク炉による再溶解で製造する
場合は溶は落ち温度によって夫々窓められるが、いずれ
にしても必要以上の高温はＭｎの蒸発ロスを招くので可
及的に低温であることが望ましく、一般的には１３００
〜１４００℃程度で行なわれることになる。従って吹錬
の初期には溶湯温度が低く、また炭素の活量も高いので
この点では前記指針に沿りているという利点がある。し
かし低温吹錬におけるＭｎの酸化反応は必ずしも十分低
いという訳ではなく、本発明第１工程では酸素ガスの上
下吹きを併用することとしているので、初期の吹錬では
Ｃの酸化とＭｎの酸化がいずれも顕著に進行する。そし
てこれらの酸化反応による発熱は溶湯温度の上昇をもた
らし、それに従フて脱炭酸素効率も６０〜９０％に上昇
する。By the way, the temperature of high-carbon ferromanganese, which is the raw material, depends on the temperature at which the molten metal comes out when manufactured in a reduction electric furnace or shaft furnace, or the temperature at which the molten metal falls when manufactured by remelting in an induction furnace or arc furnace. However, in any case, higher temperatures than necessary will result in evaporation loss of Mn, so it is desirable to keep the temperature as low as possible, and generally 1300
It will be carried out at about ~1400°C. Therefore, at the beginning of blowing, the temperature of the molten metal is low and the carbon activity is high, so there is an advantage that the above guideline is met in this respect. However, the oxidation reaction of Mn in low-temperature blowing is not necessarily sufficiently low, and since the first step of the present invention uses both upper and lower blowing of oxygen gas, the oxidation of C and the oxidation of Mn occur in the initial blowing. Both cases progress markedly. The heat generated by these oxidation reactions causes the temperature of the molten metal to rise, and the oxygen decarburization efficiency increases accordingly to 60 to 90%.
こうして脱炭反応が進行し、フェロマンガン中のＣ濃度
が２％前後まで下ってくる（Ｃの活量が低下してくる）
と、溶湯温度が高温であるにもかかわらず脱炭酸素効率
が低下しはじめ、相対的にＭｎの酸化反応が顕著に進行
する。In this way, the decarburization reaction progresses, and the C concentration in ferromanganese drops to around 2% (the activity of C decreases).
Then, even though the molten metal temperature is high, the decarburization oxygen efficiency begins to decrease, and the oxidation reaction of Mn progresses relatively significantly.
従って本発明ではこの段階で酸素の上吹きを中止し、そ
れ以上の脱炭は底吹酸素に主役を荷なわせることとする
。即ちＣの活量が低下した状態での脱炭はＣの拡散律速
で進行するので第２工程では酸素の底吹きと不活性ガス
の緒きによる穏やかな脱炭を行なわせることとし、脱炭
の進行に応じて酸素比率（酸素ガス量／不活性ガス量）
を低下させる。最後には不活性ガスの単独底吹きでしめ
くくることもある。酸素比率が低下した分は不活性ガス
吹込量の相対的増大又は絶対的増大によって不活性ガス
比率の増大となって現われ、脱炭酸素効率が比較的高レ
ベルに保持されるので、Ｍｎ酸化の少ない状態で脱炭が
促進され、目標とする炭素レベルまで吹錬を続行する。Therefore, in the present invention, the top blowing of oxygen is stopped at this stage, and the main role for further decarburization is caused by the bottom blowing oxygen. In other words, decarburization in a state where the activity of C is reduced progresses at a diffusion rate of C, so in the second step, gentle decarburization is performed by bottom blowing oxygen and introduction of inert gas. The oxygen ratio (oxygen gas amount/inert gas amount) changes depending on the progress of
decrease. The process may end with a single bottom blow of inert gas. The decrease in the oxygen ratio appears as an increase in the inert gas ratio due to a relative or absolute increase in the amount of inert gas blown in, and the decarburization oxygen efficiency is maintained at a relatively high level, resulting in a reduction in Mn oxidation. Decarburization is promoted in low carbon conditions, and blowing continues to reach the target carbon level.
尚本発明で使用される不活性ガスとしては一般にＡｒや
Ｎ２が汎用されるが、底吹ノズルの保護という観点から
は炭化水素系ガスの使用も可能であり、もとよりその種
類は本発明を制限するものではない。又酸素底吹きと不
活性ガス底吹きは、単管ノズルを介して行なっても良い
が、２重管以上の複層ノズルを使用し、内管から酸素ガ
スを、外管から不活性ガスを夫々吹込む様に構成してお
けば、ノズルの焦損防止という意味で好結果が得られる
。In general, Ar and N2 are commonly used as inert gases used in the present invention, but from the viewpoint of protecting the bottom blowing nozzle, hydrocarbon gases can also be used, and the type of gas is not limited to the present invention. It's not something you do. Oxygen bottom blowing and inert gas bottom blowing may be performed through a single tube nozzle, but a multilayer nozzle with double or more tubes may be used to supply oxygen gas from the inner tube and inert gas from the outer tube. If the configuration is such that the nozzles are blown into each other, good results can be obtained in terms of preventing burnout of the nozzles.
ところで脱炭の第２工程における不活性ガスの底吹量は
、底吹き酸素ガス１００容量部に対して２０容量部以上
とすることが好ましく、２０容量部未満であると攪拌効
果の不十分によって脱炭酸素効率の増大が望めず、その
結果として脱炭の進行が抑制され、結果的にＭｎの酸化
ロスが増大する。従ってより好ましい量は５０容量部以
上である。しかし不活性ガス量が過剰になると溶湯温度
を低下させ、前述の如＜Ｍｎの酸化が促進される。従っ
て好ましい上限は４００容量部であり、更に好ましい上
限は２００容量部である。上記は本発明を総括して述べ
る場合であって、目的とするフェロマンガン中の目標Ｃ
量に応じて増減することが望まれる。例えば中炭素フェ
ロマンガン（たとえばＣ濃度＝１．９〜１．６％）を目
標とする場合は、第１工程における目標Ｃ濃度をたとえ
ば３．０〜２．５％とし、第２工程における不活性ガス
の底吹量を２０〜１００容量部（対酸素底吹量１００容
量部）に制御し、一方低炭素フエロマンガン（たとえば
Ｃ濃度： ０．９５〜０．７０％）を目標とする場合は
第１工程における目標Ｃ濃度をたとえば２．５〜１．９
％とし、第２工程における不活性ガスの吹込量を５０〜
２００容量部（同）に制御することが例示される。By the way, the amount of bottom-blown inert gas in the second step of decarburization is preferably 20 parts by volume or more per 100 parts by volume of bottom-blown oxygen gas, and if it is less than 20 parts by volume, the stirring effect may be insufficient. An increase in the decarburization oxygen efficiency cannot be expected, and as a result, the progress of decarburization is suppressed, and as a result, the oxidation loss of Mn increases. Therefore, a more preferable amount is 50 parts by volume or more. However, when the amount of inert gas becomes excessive, the temperature of the molten metal is lowered, and the oxidation of <Mn as described above is promoted. Therefore, a preferable upper limit is 400 parts by volume, and a more preferable upper limit is 200 parts by volume. The above is a general description of the present invention, and the target C in the target ferromanganese is
It is desirable to increase or decrease the amount depending on the amount. For example, if the target is medium carbon ferromanganese (for example, C concentration = 1.9 to 1.6%), the target C concentration in the first step is set to 3.0 to 2.5%, and the target C concentration in the second step is set to 3.0 to 2.5%. When controlling the bottom blowing amount of active gas to 20 to 100 parts by volume (bottom blowing amount to oxygen 100 parts by volume) and aiming for low carbon ferromanganese (for example, C concentration: 0.95 to 0.70%), For example, the target C concentration in the first step is 2.5 to 1.9.
%, and the amount of inert gas blown in the second step is 50~
For example, it is controlled to 200 capacity parts (same).
次に該第２工程における溶湯温度の制御を説明する。本
発明は目標Ｃ濃度を２段階に分けて吹き下げる様に制御
しており、第１工程においては中間目標として掲げる所
定量の炭素濃度まで一気に脱炭しているので、第２工程
において更に所望の炭素濃度まで吹下げる為の負荷が軽
減されている。従って第２工程では溶湯温度を必要以上
に高める必要はなく、１８００℃以下で十分である。Next, control of the molten metal temperature in the second step will be explained. In the present invention, the target C concentration is controlled to be blown down in two stages, and in the first step, the carbon concentration is decarburized all at once to a predetermined amount of carbon concentration, which is set as an intermediate target. The load to blow down to the carbon concentration is reduced. Therefore, in the second step, there is no need to increase the temperature of the molten metal more than necessary, and a temperature of 1800° C. or lower is sufficient.
１８００℃を超えるとＭｎの蒸発が盛んになるので回避
しなければならない。但し低温になり過ぎると、前述の
如＜Ｍｎの酸化が進行し易くなるのでできる限り高温側
、具体的には１６５０℃以上にして脱炭酸素効率の維持
を図り、脱炭の進行に寄与せしめるべきである。If the temperature exceeds 1800°C, the evaporation of Mn will increase, so it must be avoided. However, if the temperature becomes too low, the oxidation of Mn will easily proceed as described above, so the temperature should be kept as high as possible, specifically 1650°C or higher, to maintain decarburization oxygen efficiency and contribute to the progress of decarburization. Should.
上記説明における第１工程から第２工程への切り換えポ
イントは、Ｃ濃度が所定値になることを一応の基準とし
たが、第１工程の吹錬中に脱炭酸素効率の推移をチェッ
クしておき、ある値以下（例えば４０〜２５％）になれ
ば第２工程への制御に切り替えるという風に制御するこ
とも本発明の技術的範囲に含まれる。In the above explanation, the point of switching from the first step to the second step is that the C concentration reaches a predetermined value, but the change in decarburization oxygen efficiency during blowing in the first step is checked. It is also within the technical scope of the present invention to perform control in such a manner that the temperature is increased, and when the value falls below a certain value (for example, 40 to 25%), the control is switched to the second step.
以上の様に第１工程は上吹酸素を中心とする脱炭を行な
い、第２工程では底吹酸素と底吹不活性ガスの協力によ
る脱炭操業を行なう方法を採用したので、第１図に示す
様に、第２工程における脱炭酸素効率を４０〜５０％の
レベル（破線）に維持することも可能であり、従来の様
に１段で最終目標濃度まで脱炭していた場合（第１図の
実線最終段、脱炭酸素効率：５〜１５％）に比べて効率
の良い脱炭を行なうことができる。従ってＭｎの酸化も
少なく、高価な還元剤を用いてＭｎの回収を行なうとい
った不経済且つ繁雑な手間をかける必要がない。但し最
終的な成分調整を目的として合金元素を添加することま
で排除するものではない。As mentioned above, in the first step, decarburization is performed mainly using top-blown oxygen, and in the second step, decarburization is performed using the cooperation of bottom-blown oxygen and bottom-blown inert gas. As shown in , it is possible to maintain the decarburization oxygen efficiency in the second step at a level of 40 to 50% (dashed line), and if decarburization was done in one stage as in the past to the final target concentration ( Decarburization can be carried out more efficiently than in the final stage shown by the solid line in FIG. 1 (decarburization oxygen efficiency: 5 to 15%). Therefore, there is little oxidation of Mn, and there is no need to take the uneconomical and complicated effort of recovering Mn using an expensive reducing agent. However, this does not exclude the addition of alloying elements for the purpose of final component adjustment.
［実施例］
１直■±
Ｍｇ０−Ｃ系レンガを内張すした内径６００ＩｌｌＩ１
１の反応容器の容器底部中央に設置した２重管ノズルよ
り、内外管合計０．５Ｎｍ３／分のＡｒを吹きながら高
炭素フェロマンガン溶湯（第１表参照）５００ Ｋｇを
装入した。装入後の溶湯温度は１４００℃であった。そ
の後底吹きノズル外管よりＡｒを０．２Ｎｍ’／分、内
管より酸素０．３Ｎｍ”７分の速度で吹き込むと同時に
、容器の上部に設置した水冷ランスより酸素を１．３８
ｍ’／分の速度で吹き込み２５分間吹錬を行なった。そ
の後上吹き酸素を停止し底吹き酸素を０．５Ｎｍ’／分
、底吹きＡｒを０．３Ｎｍ’／分に増加して底吹き吹錬
のみを１５分間続は最終的に底吹き酸素を０．４Ｎｍ’
／分、底吹きＡｒを０．４Ｎｍ’／分になるように調整
して吹錬を終了し、その後５分間はＡｒを底吹きノズル
の内・外管から合計０．５Ｎｍ’／分の速度で吹き込み
除滓。[Example] 1 diameter ± Mg0-C brick lined with inner diameter 600IllI1
500 kg of high carbon ferromanganese molten metal (see Table 1) was charged into the reaction vessel No. 1 from a double tube nozzle installed at the center of the bottom of the vessel while blowing Ar at a total rate of 0.5 Nm 3 /min into the inner and outer tubes. The temperature of the molten metal after charging was 1400°C. After that, Ar is blown into the bottom blowing nozzle at a rate of 0.2 Nm'/min from the outer pipe and oxygen is blown into the inner pipe at a rate of 0.3 Nm'/min, while at the same time oxygen is blown at 1.38 Nm'/min from the water-cooled lance installed at the top of the container.
Blowing was carried out for 25 minutes by blowing at a speed of m'/min. After that, the top blowing oxygen was stopped, the bottom blowing oxygen was increased to 0.5 Nm'/min, the bottom blowing Ar was increased to 0.3 Nm'/min, and only the bottom blowing was continued for 15 minutes. .4Nm'
/min, and the blowing was completed by adjusting the bottom blowing Ar to 0.4Nm'/min, and for the next 5 minutes, Ar was blown at a total rate of 0.5Nm'/min from the inner and outer tubes of the bottom blowing nozzle. Blow in to remove slag.
出渇しメタルを鋳造した。なお上吹き終了前後に高炭素
フェロマンガンのふるい下品３０にｇを分割して投入し
た。上吹終了時、吹錬終了時、Ａｒリンス終了時の溶湯
の成分組成及び温度は第２表に示す通りであった。また
鋳造したメタルは４８８にｇであり、歩留は９２．１％
であった。Forged out of dry metal. Before and after the completion of top blowing, 30 g of high carbon ferromanganese was added in portions to a 30 ml sieve. The composition and temperature of the molten metal at the end of top blowing, at the end of blowing, and at the end of Ar rinsing were as shown in Table 2. The weight of the cast metal is 488g, and the yield is 92.1%.
Met.
（以下余白）
実施例２
実施例１と同様の反応容器をもちいて脱炭精錬を行なう
にあたり、底吹き２重管ノズルより０．５Ｎｍ’／分の
Ａｒを吹きながら第１表に示した高炭素フェロマンガン
溶湯５００にｇを容器内に装入した。装入後の溶湯温度
は１３５０℃であった。(Left below) Example 2 When performing decarburization refining using the same reaction vessel as in Example 1, the heights shown in Table 1 were carried out while blowing Ar at 0.5 Nm'/min from a bottom-blowing double pipe nozzle. 500 g of carbon ferromanganese molten metal was charged into a container. The temperature of the molten metal after charging was 1350°C.
その後底吹きノズルの外管よりＡｒを０．２５Ｎｍ３／
分、内管より酸素を０．５Ｎｍ３／分の速度で吹き込む
と同時に容器上部に設置した水冷ランスより酸素を１．
１Ｎｍ’／分の速度で吹き込み２０分間吹錬を続行した
。その後上吹き酸素を停止し、酸素０．５Ｎｍ３／分で
２０分間、 ０．４Ｎｍ’／分で５分間夫々底吹きを行
い、Ａｒは０．２５Ｎ１１’ ／分で１０分間。After that, Ar was applied at 0.25Nm3/ from the outer tube of the bottom blowing nozzle.
At the same time, oxygen was blown into the inner tube at a rate of 0.5 Nm3/min, and at the same time oxygen was blown into the container from a water-cooled lance installed at the top of the container.
Blowing was continued at a rate of 1 Nm'/min for 20 minutes. After that, top blowing oxygen was stopped, and bottom blowing was performed at 0.5 Nm3/min of oxygen for 20 minutes and 5 minutes at 0.4 Nm'/min, and for 10 minutes at 0.25 Nm'/min of Ar.
その後０．３Ｎｍ３／分で１０分間、 ０．４８ｍ３／
分で５分間行なった。吹錬終了後底吹きノズルよりＡｒ
のみを内外管合計０．５Ｎｍ３／分で５分間吹き込んで
除滓後出湯、鋳造した。上吹き終了後５分経過時点から
２０分後までの間に高炭素フェロマンガンのふるい下品
３５Ｋｇを分割投入した。上吹終了時、吹錬終了時、Ａ
ｒリンス終了時の溶湯の成分及び温度は第３表に示すと
おりであり、鋳造したメタルは４８７Ｋｇで歩留は９１
％であった。Then 0.3Nm3/min for 10 minutes, 0.48m3/
I did it for 5 minutes. After blowing, use Ar from the bottom blowing nozzle.
After removing the sludge by blowing water into the inner and outer tubes at a total rate of 0.5 Nm3/min for 5 minutes, the molten metal was tapped and cast. 35 kg of high carbon ferromanganese sifted material was added in portions between 5 minutes and 20 minutes after the end of top blowing. At the end of top blowing, at the end of blowing, A
The composition and temperature of the molten metal at the end of rinsing are shown in Table 3, and the cast metal weighs 487 kg and the yield is 91.
%Met.
（以下余白）
［発明の効果］
本発明は上記の様に構成されているので、脱炭の進行を
効果的に制御することができ、従来のシリサイド法や他
の酸素脱炭法より経済的に中・低炭素フェロマンガンを
製造できる様になった。(Left below) [Effects of the Invention] Since the present invention is configured as described above, it is possible to effectively control the progress of decarburization, and it is more economical than the conventional silicide method or other oxygen decarburization methods. It became possible to produce medium- to low-carbon ferromanganese.
第１図は上底吹きによる脱炭酸素効率の変化を示す図で
ある。
第１図
プ４吋閃−FIG. 1 is a diagram showing changes in decarburization oxygen efficiency due to top-bottom blowing. Figure 1 4-inch flash
Claims (1)
きと酸素および不活性ガスの底吹きによって所定炭素量
まで脱炭する第１工程と、酸素ガスの底吹きと不活性ガ
スの底吹きを併用し、底吹き酸素ガス１００容量部に対
する不活性ガスの底吹き量を２０容量部以上とすると共
に溶湯温度を１６５０〜１８００℃に制御しつつ所望の
炭素量まで脱炭する第２工程からなることを特徴とする
中・低炭素フェロマンガンの製造方法。Targeting high carbon ferromanganese molten metal, the first step is to decarburize to a predetermined carbon content by top blowing with oxygen gas and bottom blowing with oxygen and inert gas, and a combination of bottom blowing with oxygen gas and bottom blowing with inert gas. and a second step of decarburizing to a desired carbon content while controlling the molten metal temperature to 1,650 to 1,800° C. while controlling the bottom-blown amount of inert gas to 20 parts by volume or more with respect to 100 parts by volume of bottom-blown oxygen gas. A method for producing medium/low carbon ferromanganese.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7532886A JPS62230950A (en) | 1986-03-31 | 1986-03-31 | Manufacture of medium-or low-carbon ferromanganese |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7532886A JPS62230950A (en) | 1986-03-31 | 1986-03-31 | Manufacture of medium-or low-carbon ferromanganese |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62230950A true JPS62230950A (en) | 1987-10-09 |
Family
ID=13573081
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7532886A Pending JPS62230950A (en) | 1986-03-31 | 1986-03-31 | Manufacture of medium-or low-carbon ferromanganese |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62230950A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008531840A (en) * | 2005-12-02 | 2008-08-14 | エス・エム・エス・デマーク・アクチエンゲゼルシャフト | Method and melting apparatus for producing high manganese low carbon steel |
-
1986
- 1986-03-31 JP JP7532886A patent/JPS62230950A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008531840A (en) * | 2005-12-02 | 2008-08-14 | エス・エム・エス・デマーク・アクチエンゲゼルシャフト | Method and melting apparatus for producing high manganese low carbon steel |
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