JP2558989B2 - Method for producing low phosphorus molten metal - Google Patents
Method for producing low phosphorus molten metalInfo
- Publication number
- JP2558989B2 JP2558989B2 JP8136992A JP8136992A JP2558989B2 JP 2558989 B2 JP2558989 B2 JP 2558989B2 JP 8136992 A JP8136992 A JP 8136992A JP 8136992 A JP8136992 A JP 8136992A JP 2558989 B2 JP2558989 B2 JP 2558989B2
- Authority
- JP
- Japan
- Prior art keywords
- furnace
- phosphorus
- metal
- carbon
- reducing agent
- 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
Description
【０００１】[0001]
【産業上の利用分野】本発明は、炭素系固体還元剤の充
填層を形成し、下部に設置した羽口から金属酸化物を吹
き込んで低燐溶融金属を製造する方法に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a low phosphorus molten metal by forming a packed bed of a carbon-based solid reducing agent and blowing a metal oxide from a tuyere installed at the bottom.
【０００２】[0002]
【従来の技術】竪型炉を用い、炉内に炭素系固体還元剤
の充填層を形成し、炉下部に設置した羽口から高温空気
または酸素富化された高温空気とともに金属酸化物ある
いは金属酸化物と造滓剤を吹き込み、溶融金属を製造す
る方法については、特開昭57−198205号あるいは特開昭
58-77548号公報等に開示されている。これらの技術は鉄
鋼材料などの原料を製造するときに利用される。このよ
うな炉内に炭素系固体還元剤からなる充填層を有する竪
型炉では、羽口前に生成するレースウェイで発生する高
温によって、吹き込まれた鉱石が、昇温、溶融、還元さ
れることにより溶融金属を得ている。鉱石中に含有され
る燐は、主として燐酸化物として含まれているため、そ
のほとんどは炭素系固体還元剤充填層の強力な還元雰囲
気に晒されて、容易に還元され、生成した溶融金属中に
溶解してしまう。また、もう一方の燐源である炭素系固
体還元剤中の燐はやはり炭素系固体還元剤の灰分中に燐
酸化物として含まれており、炭素系固体還元剤が充填層
中を降下する間に一部分解して気化し炉内ガスに同伴さ
れて上昇するが、炉頂から金属酸化物やスクラップ等の
金属、あるいは塩基性造滓剤が装入されていると、羽口
レベルまで降下する間に溶融金属あるいは溶融スラグと
なり滴下するため、上昇した燐及び燐化合物は溶融金
属、あるいは塩基性造滓剤に溶解して安定化する。この
塩基性造滓剤中に安定化した燐は炉床へ滴下するまでに
溶融金属の炭素と反応して溶融金属中に溶解する。すな
わち、高炉のように炉頂から鉱石及び造滓剤を装入して
製錬を行う方法では、炉下部の高温領域で発生した燐ま
たは燐酸化物の気化物が、融着帯以下の領域で滴下する
溶融金属あるいは溶融スラグにより吸収されて金属中に
移行する。2. Description of the Related Art A vertical furnace is used to form a packed bed of a carbon-based solid reducing agent in the furnace, and metal oxide or metal is mixed with hot air or oxygen-enriched hot air from a tuyere installed at the bottom of the furnace. A method for producing a molten metal by blowing an oxide and a slag-forming agent is described in JP-A-57-198205 or JP-A-
It is disclosed in Japanese Patent Publication No. 58-77548. These techniques are used when manufacturing raw materials such as steel materials. In a vertical furnace having a packed bed made of a carbon-based solid reducing agent in such a furnace, the blown ore is heated, melted, and reduced by the high temperature generated in the raceway in front of the tuyere. By doing so, molten metal is obtained. The phosphorus contained in the ore is mainly contained as a phosphorus oxide, so most of it is exposed to the strong reducing atmosphere of the carbon-based solid reducing agent packed bed, and is easily reduced. It will dissolve. In addition, the phosphorus in the carbon-based solid reducing agent that is the other phosphorus source is also included in the ash content of the carbon-based solid reducing agent as a phosphorus oxide, and while the carbon-based solid reducing agent descends in the packed bed, Partially decomposes and vaporizes and rises along with the gas in the furnace, but if metals such as metal oxides and scraps or basic slag forming agents are charged from the furnace top, it will fall to the tuyere level. Since it becomes molten metal or molten slag and is added dropwise, the increased phosphorus and phosphorus compounds are dissolved and stabilized in the molten metal or the basic slag forming agent. The phosphorus stabilized in this basic slag-forming agent reacts with the carbon of the molten metal and is dissolved in the molten metal by the time it is dropped onto the hearth. That is, in the method of charging ore and slag-forming agent from the furnace top like a blast furnace and performing smelting, the vaporized phosphorus or phosphorous oxide generated in the high temperature region in the lower part of the furnace is in the region below the cohesive zone. It is absorbed by the dripping molten metal or molten slag and moves into the metal.
【０００３】一般に金属材料中の燐は不純物と考えら
れ、例えば鉄鋼材料においてはその組成中に燐を含有す
ることによって、結晶粒界での強度を弱め、靭性を低下
させることが知られており、材料規格にはその材料の用
途に応じて、燐含有量を低位に抑制することが決められ
ている。したがって、こうした製品の製造に当たっては
その原料中の燐濃度には厳しい制限が与えられている。
本発明で用いる竪型炉もこのような製品の原料を製造す
るための製錬炉であるので、その製造する溶融金属にお
ける燐の含有量は低ければ低いほど、それだけその後の
製造工程の原料選択の自由度が大きくなるので、好都合
である。したがって、上記金属製錬炉で製造する溶融金
属においても燐の含有量をできる限り低位に保持するこ
とが求められているため、その操業において原料中の燐
濃度を制限することになり、金属製錬炉の原料選択の自
由度を著しく狭めている。Phosphorus in metal materials is generally considered to be an impurity, and it is known that, for example, in steel materials, the inclusion of phosphorus in the composition weakens the strength at grain boundaries and lowers the toughness. The material standard stipulates that the phosphorus content be suppressed to a low level depending on the use of the material. Therefore, in the production of such products, there are severe restrictions on the phosphorus concentration in the raw materials.
Since the vertical furnace used in the present invention is also a smelting furnace for producing raw materials for such products, the lower the phosphorus content in the molten metal to be produced, the more the raw material selection for the subsequent production process. This is convenient because it increases the degree of freedom of. Therefore, even in the molten metal produced in the metal smelting furnace, it is required to keep the phosphorus content as low as possible, so that the phosphorus concentration in the raw material is limited in the operation, and The degree of freedom in selecting raw materials for the smelting furnace is significantly narrowed.
【０００４】[0004]
【発明が解決しようとする課題】本発明は、上記に示し
たような炭素系固体還元剤充填層を有する竪型炉におい
て製造する溶融金属が、原料に含まれる燐のほとんどを
溶融してしまうので、低燐溶融金属を得るためには原料
の燐含有量を低位にするしかないという現状にかんが
み、製錬過程において脱燐を行うことによって、より広
い範囲の原料条件で低燐溶融金属を製造する方法を提供
するものである。According to the present invention, the molten metal produced in the vertical furnace having the carbon-based solid reducing agent packed bed as described above melts most of the phosphorus contained in the raw material. Therefore, in view of the present situation that the phosphorus content of the raw material must be lowered in order to obtain the low phosphorus molten metal, dephosphorization is performed in the smelting process to obtain the low phosphorus molten metal in a wider range of raw material conditions. A method of manufacturing is provided.
【０００５】[0005]
【課題を解決するための手段】本発明者らは、上述のよ
うな炭素系固体還元剤を炉内に保持する金属製錬炉の問
題点に関して長年にわたり研究を行なったところ、発生
ガス中から捕集したダストに燐または燐化合物が含まれ
る現象があることに気がついた。このような現象が表れ
る条件を解析した結果、つぎの知見をえた。 (1) 炭素系固体還元剤の充填層中の1500℃以上となる領
域から羽口レベルまでの滞留時間を１時間以上保つこと
によって、炭素系固体還元剤に含まれる燐の多くが、気
化し炭素系固体還元剤と分離する。 (2) 炉頂から金属酸化物あるいは造滓剤を装入しないこ
とにより、炉上方に気化した燐が安定に固定される物質
をなくすことになり、燐がダストとして炉外へ排出する
ことを促進してやることができる。本発明は以上の知見
にもとづいてなされたものである。The inventors of the present invention have studied for many years about the problems of the metal smelting furnace in which the carbon-based solid reducing agent as described above is held in the furnace. I noticed that there is a phenomenon that the collected dust contains phosphorus or phosphorus compounds. As a result of analyzing the conditions in which such a phenomenon appears, the following findings were obtained. (1) Most of the phosphorus contained in the carbon-based solid reducing agent is vaporized by keeping the residence time in the packed bed of the carbon-based solid reducing agent from the temperature range of 1500 ° C or higher to the tuyere level for 1 hour or more. Separated from carbon-based solid reducing agent. (2) By not charging metal oxides or slag forming agents from the top of the furnace, the vaporized phosphorus in the upper part of the furnace does not have a substance that is stably fixed, and phosphorus is discharged as dust to the outside of the furnace. Can be promoted. The present invention has been made based on the above findings.
【０００６】本発明は、炉内に燐元素を含有する炭素固
体還元剤の充填層を形成し、炉の下方羽口部から高温空
気または酸素を富化した高温空気とともに、金属酸化物
または金属酸化物と造滓剤とを竪型炉内に吹き込むこと
によって、溶融金属を得る金属製錬方法において、炭素
系固体還元剤の充填層の炉頂部からは金属酸化物やスク
ラップなどの金属あるいは塩基性造滓剤を装入すること
なく、炭素系固体還元剤を装入し、1500℃以上となる領
域から吹き込み羽口部に至るまでの滞留時間を１時間以
上保持することを特徴とする低燐溶融金属の製造方法で
ある。According to the present invention, a packed bed of a carbon solid reducing agent containing elemental phosphorus is formed in a furnace, and a high temperature air or high temperature air enriched with oxygen from the lower tuyere of the furnace is used together with a metal oxide or a metal oxide. By blowing an oxide and a slag forming agent into a vertical furnace, in a metal smelting method for obtaining molten metal, a metal such as a metal oxide or scrap or a base from the furnace top of a packed bed of a carbon-based solid reducing agent. It is characterized by charging the carbon-based solid reducing agent without charging the slag forming agent, and maintaining the residence time from the region of 1500 ° C or higher to the blowing tuyere for 1 hour or more. This is a method for producing a molten phosphorus metal.
【０００７】[0007]
【作用】以下に本発明をなすに至った経過および作用に
ついて説明する。コークスを高温雰囲気に晒しておくと
灰分中の無機燐として存在しているP2O5が還元されて気
化脱燐することが知られている。本発明で用いる金属製
錬炉では炭素系固体還元剤の充填層を形成しているシャ
フト部には高温の炭素系固体還元剤が滞留しており、こ
の領域は燐の還元気化脱燐がおこる条件下にある。本発
明者らの実験によると、炉内での1500℃以上になる領域
に炭素系固体還元剤が１時間以上滞留することによっ
て、炭素系固体還元剤の種類により50〜80％の燐が気化
脱燐することが判った。また気化脱燐した燐あるいは燐
化合物が、炉内ガスに同伴して上昇する時に、その途中
に溶融金属が存在すると、燐蒸気は溶融金属に溶解し、
また燐化合物は溶融金属中に含まれる炭素により還元さ
れて、やはり溶融金属中に溶解する。さらに途中に塩基
性造滓剤が存在すると、気相中燐は、塩基性造滓剤中の
塩基性化合物との反応により、スラグ中に安定化するこ
とも判った。The operation and operation of the present invention will be described below. It is known that when the coke is exposed to a high temperature atmosphere, P 2 O 5 existing as inorganic phosphorus in the ash is reduced and vaporized and dephosphorized. In the metal smelting furnace used in the present invention, the high temperature carbon-based solid reducing agent is retained in the shaft portion forming the packed bed of the carbon-based solid reducing agent, and the reduction vaporization and dephosphorization of phosphorus occurs in this region. Under conditions. According to the experiments conducted by the present inventors, the carbon-based solid reducing agent stays in the furnace at a temperature of 1500 ° C. or higher for 1 hour or more, so that 50 to 80% of phosphorus is vaporized depending on the kind of the carbon-based solid reducing agent. It turned out to dephosphorize. Further, when vaporized and dephosphorized phosphorus or a phosphorus compound is accompanied by ascending gas in the furnace and rises, if molten metal is present, phosphorus vapor is dissolved in the molten metal,
Further, the phosphorus compound is reduced by carbon contained in the molten metal and is also dissolved in the molten metal. Further, it was also found that when a basic slag-forming agent was present on the way, phosphorus in the gas phase was stabilized in the slag by the reaction with the basic compound in the basic slag-forming agent.
【０００８】したがって炭素系固体還元剤を炉内に保持
する金属製錬炉において、その炭素系固体還元剤の炉内
での1500℃以上の領域に１時間以上滞留させると共に炉
頂から金属酸化物や塩基性造滓剤を装入しないことによ
って、炭素系固体還元剤中の燐化合物から還元気化した
燐、あるいは燐化合物は炉内ガスに同伴して炉頂から系
外へ排出される。これによって生成する溶融金属中への
燐の移行を妨げることが可能であり、低燐溶融金属を製
造することができる。Therefore, in a metal smelting furnace in which the carbon-based solid reducing agent is held in the furnace, the carbon-based solid reducing agent is allowed to stay in the furnace at a temperature of 1500 ° C. or higher for 1 hour or more, and the metal oxide is discharged from the furnace top. By not charging the slag and the basic slag-forming agent, phosphorus vaporized from the phosphorus compound in the carbon-based solid reducing agent, or phosphorus compound, is entrained in the furnace gas and discharged from the furnace top to the outside of the system. This makes it possible to prevent the migration of phosphorus into the generated molten metal, and it is possible to produce a low phosphorus molten metal.
【０００９】[0009]
【実施例】図１は、炭素系固体還元剤としてコークスを
用いて竪型金属製錬炉により鉄鉱石の還元試験を実施し
た時の炉内の温度分布を測定した結果を示す。操業条件
は表１中に実施例として示した。この操業条件では１時
間に約 700kgのコークスが消費されるため、コークスの
降下速度は約0.6m/hであるが、上段羽口上約１ｍより下
のレベルでは炉内温度は1500℃を超えており、したがっ
て炉内のコークスは１時間以上1500℃以上の雰囲気に晒
されていたことが判る。この時製造された溶融金属中の
燐濃度は、表１に示したように 0.008％まで低下してい
た。EXAMPLE FIG. 1 shows the results of measuring the temperature distribution in the furnace when a reduction test of iron ore was carried out in a vertical metal smelting furnace using coke as a carbon-based solid reducing agent. The operating conditions are shown in Table 1 as an example. Under this operating condition, about 700 kg of coke is consumed per hour, so the coke descent rate is about 0.6 m / h, but at temperatures below about 1 m above the upper tuyeres, the furnace temperature exceeds 1500 ° C. Therefore, it can be seen that the coke in the furnace was exposed to an atmosphere of 1500 ° C or higher for 1 hour or longer. The phosphorus concentration in the molten metal produced at this time was as low as 0.008% as shown in Table 1.
【００１０】一方、表１の比較例１として示したように
コークス中の水分が12％と高い条件で操業したところ、
図２に比較例１と示したように炉内の温度分布は炉頂部
での水分の蒸発に熱を消費した結果、全体的に下方向に
ずれて上段羽口上の1500℃以上の高温部が上段羽口より
0.5ｍ下のレベルとなっており、コークスの1500℃以上
の滞留時間が約50分程度であった。この結果製造した溶
融金属中の燐は 0.015％程度であり、脱燐の効果は小さ
かった。これは既述したようにコークスの1500℃以上の
領域の滞留時間が短かったため十分にコークス中の燐の
気化分離ができなかったためである。On the other hand, as shown as Comparative Example 1 in Table 1, when the coke was operated under the condition of high water content of 12%,
As shown in Comparative Example 1 in FIG. 2, the temperature distribution inside the furnace was shifted downward as a result of consuming heat to evaporate the water at the top of the furnace. From the upper tuyeres
The level was 0.5 m below, and the residence time of coke at 1500 ° C or higher was about 50 minutes. As a result, phosphorus in the molten metal produced was about 0.015%, and the effect of dephosphorization was small. This is because, as described above, the residence time of the coke at a temperature of 1500 ° C. or higher was short, and the vaporization and separation of phosphorus in the coke could not be sufficiently performed.
【００１１】また、表１の他の比較例２では実施例の操
業条件に比べて、吹き込み鉱石の37.5％にあたる 300kg
/hを炉頂から装入した。図２にこの時の炉内温度分布を
比較例２として示した。炉頂から装入した鉱石の還元に
よってシャフト上部で温度停滞部が生じているが、1500
℃以上の高温部は上段羽口以上約１ｍであり、コークス
の1500℃以上の高温部での滞留時間も１時間以上を確保
している。しかしながら表１に示すように製造した溶融
金属中の燐濃度は0.02％と高い値となっている。これは
既述したように1500℃以上の高温領域でコークスから還
元気化した燐あるいは燐酸化物が、炉頂から装入して還
元滴下してきた溶融物に捕集されて安定化したため、溶
融金属中に含まれてしまったものである。Further, in another comparative example 2 of Table 1, 300 kg, which is 37.5% of blown ore, is compared with the operating conditions of the example.
/ h was charged from the furnace top. FIG. 2 shows the temperature distribution in the furnace at this time as Comparative Example 2. There is a temperature stagnation in the upper part of the shaft due to the reduction of the ore charged from the furnace top.
The high temperature part above ℃ is about 1m above the tuyere of the upper stage, and the retention time of the coke in the high temperature part above 1500 ° C is also more than 1 hour. However, as shown in Table 1, the concentration of phosphorus in the molten metal produced is as high as 0.02%. As described above, this is because phosphorus or phosphorus oxides reduced and vaporized from coke in the high temperature region of 1500 ° C or higher is stabilized by being collected in the molten material charged from the furnace top and reduced and dropped. Has been included in.
【００１２】[0012]
【表１】 [Table 1]
【００１３】[0013]
【発明の効果】以上説明したように、本発明によれば炭
素系固体還元剤充填層金属製錬炉による溶融金属の製造
過程において原料中の燐を効果的に除去することが可能
となり、後工程となる金属製錬の操業自由度を拡大する
ことができた。As described above, according to the present invention, phosphorus in the raw material can be effectively removed in the process of producing molten metal in the carbon-based solid reducing agent packed bed metal smelting furnace. We were able to expand the operational flexibility of the metal smelting process.
【図１】本発明の実施例を示す試験操業における炉内温
度分布を示す特性図。FIG. 1 is a characteristic diagram showing a temperature distribution in a furnace in a test operation showing an example of the present invention.
【図２】本発明の比較例を示す試験操業における炉内温
度分布を示す特性図。FIG. 2 is a characteristic diagram showing a temperature distribution in a furnace in a test operation showing a comparative example of the present invention.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭62−227015（ＪＰ，Ａ) 特開 昭64−47820（ＪＰ，Ａ) 特開 平５−247549（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 62-227015 (JP, A) JP 64-47820 (JP, A) JP 5-247549 (JP, A)
Claims (1)
の充填層を形成し、炉の下方羽口部から高温空気または
酸素を富化した高温空気とともに、金属酸化物または金
属酸化物と造滓剤とを竪型炉内に吹き込むことによっ
て、溶融金属をえる金属製錬方法において、 炭素系固体還元剤の充填層の炉頂部からは金属酸化物や
スクラップなどの金属あるいは塩基性造滓剤を装入する
ことなく、炭素系固体還元剤を装入し、1500℃以上とな
る領域から吹き込み羽口部に至るまでの滞留時間を１時
間以上保持することを特徴とする低燐溶融金属の製造方
法。1. A packed bed of a carbon solid reducing agent containing elemental phosphorus is formed in a furnace, and a metal oxide or a metal oxide is formed together with hot air or hot air enriched with oxygen from the lower tuyere of the furnace. In a metal smelting method in which molten metal is obtained by blowing a slag and a slag forming agent into a vertical furnace, metal such as metal oxides and scraps or basic forming from the furnace top of the packed bed of carbon-based solid reducing agent A low phosphorus melting characterized by charging a carbon-based solid reducing agent without charging a slag agent and maintaining the residence time from the region of 1500 ° C or higher to the blowing tuyere for 1 hour or more. Metal manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8136992A JP2558989B2 (en) | 1992-03-04 | 1992-03-04 | Method for producing low phosphorus molten metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8136992A JP2558989B2 (en) | 1992-03-04 | 1992-03-04 | Method for producing low phosphorus molten metal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05247548A JPH05247548A (en) | 1993-09-24 |
| JP2558989B2 true JP2558989B2 (en) | 1996-11-27 |
Family
ID=13744403
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8136992A Expired - Lifetime JP2558989B2 (en) | 1992-03-04 | 1992-03-04 | Method for producing low phosphorus molten metal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2558989B2 (en) |
-
1992
- 1992-03-04 JP JP8136992A patent/JP2558989B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05247548A (en) | 1993-09-24 |
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