JPH01176004A - Manufacture of decarbonized iron powder - Google Patents
Manufacture of decarbonized iron powderInfo
- Publication number
- JPH01176004A JPH01176004A JP62333003A JP33300387A JPH01176004A JP H01176004 A JPH01176004 A JP H01176004A JP 62333003 A JP62333003 A JP 62333003A JP 33300387 A JP33300387 A JP 33300387A JP H01176004 A JPH01176004 A JP H01176004A
- Authority
- JP
- Japan
- Prior art keywords
- iron powder
- fluidized bed
- decarburization
- carbon
- sticking
- 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
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 91
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 22
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 22
- 239000007789 gas Substances 0.000 claims abstract description 18
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 17
- 239000001301 oxygen Substances 0.000 claims abstract description 17
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 17
- 239000011261 inert gas Substances 0.000 claims abstract description 4
- 238000005261 decarburization Methods 0.000 claims description 27
- 238000000227 grinding Methods 0.000 claims description 7
- 230000001603 reducing effect Effects 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 3
- 229910001882 dioxygen Inorganic materials 0.000 claims description 3
- 238000007664 blowing Methods 0.000 claims description 2
- 238000011282 treatment Methods 0.000 abstract description 15
- 238000006243 chemical reaction Methods 0.000 abstract description 10
- 239000002245 particle Substances 0.000 abstract description 9
- 239000000843 powder Substances 0.000 abstract description 8
- 238000000034 method Methods 0.000 description 19
- 229910052742 iron Inorganic materials 0.000 description 9
- 238000007254 oxidation reaction Methods 0.000 description 8
- 238000006722 reduction reaction Methods 0.000 description 8
- 230000003647 oxidation Effects 0.000 description 7
- 239000000047 product Substances 0.000 description 6
- 230000004927 fusion Effects 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- 239000003245 coal Substances 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 229910015191 FeOFe2O3 Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 241000277269 Oncorhynchus masou Species 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 238000007885 magnetic separation Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 239000012264 purified product Substances 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、含炭素鉄粉を流動層方式で脱炭処理する際、
スティッキングを回避しながら短時間で脱炭を行う方法
に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for decarburizing carbon-containing iron powder using a fluidized bed method.
This invention relates to a method for decarburizing in a short time while avoiding sticking.
含炭素鉄粉を脱炭する方法として１．サガ一方式が知ら
れている。この方式においては、含炭素鉄粉を一般にサ
ガーと呼ばれる耐熱金属又は耐火物製の容器に封入し、
均熱炉内で１０００℃以上の高温に長時間保持し、酸化
鉄を脱炭源として含炭素鉄粉の脱炭を行っている。As a method for decarburizing carbon-containing iron powder, 1. Saga one style is known. In this method, carbon-containing iron powder is generally sealed in a container made of heat-resistant metal or refractory material called a sagger.
The carbon-containing iron powder is decarburized by holding it at a high temperature of 1000° C. or higher for a long time in a soaking furnace and using iron oxide as a decarburization source.
ところが、この方法によるとき、容器中で含炭素鉄粉が
高温に加熱されるため、脱炭後の鉄粉は凝集して強固な
ケーキ状となっている。そのため、脱炭された鉄粉を解
砕する工程が必要とされる。However, when using this method, the carbon-containing iron powder is heated to a high temperature in the container, so the iron powder after decarburization aggregates into a strong cake-like shape. Therefore, a process of crushing the decarburized iron powder is required.
また、脱炭中に鉄粉が凝集するため、凝集体の内部に取
り込まれた酸化物に対して還元作用が働かない。そのた
め、残留している酸化物を除去する工程も別途必要にな
る。また、この方法で生産性を上げるためには、大型の
設備が必要となり、設備コストが大きくなる。Furthermore, since the iron powder aggregates during decarburization, the reducing action does not work on the oxides taken into the aggregates. Therefore, a separate process for removing the remaining oxide is required. Furthermore, in order to increase productivity with this method, large-scale equipment is required, which increases equipment cost.
ところで、粉体の加熱、乾燥等の各種処理を行う方法と
して、処理される粉体を流動状態に維持し、この粉体に
処理ガスを接触させる流動層方式が知られている。たと
えば、特開昭５７−９８６１５号公報に示されている石
炭流動層式製鉄装置にあっては、薄型の流動層式還元反
応炉を同様な形状をもつ流動層式燃焼加熱室とサンドウ
ィッチ状に配列し、還元反応炉に粉炭と粉粒状鉄鉱石と
を投入して流動状態に維持し、還元反応に必要な熱量を
燃焼加熱室から供給して、鉄鉱石の還元を行っている。Incidentally, as a method for performing various treatments such as heating and drying powder, a fluidized bed method is known in which the powder to be treated is maintained in a fluidized state and a processing gas is brought into contact with the powder. For example, in the coal fluidized bed type iron manufacturing equipment shown in JP-A-57-98615, a thin fluidized bed reduction reactor is sandwiched with a similarly shaped fluidized bed combustion heating chamber. The iron ore is reduced by putting powdered coal and granular iron ore into the reduction reactor and maintaining it in a fluidized state, and supplying the amount of heat necessary for the reduction reaction from the combustion heating chamber.
このように流動層方式で粉体の処理を行うとき、粉体表
面と処理ガスとの間の接触が充分に確保され、均一に処
理された製品を迅速に得ることができる。When processing powder using the fluidized bed method as described above, sufficient contact between the powder surface and the processing gas is ensured, and uniformly processed products can be quickly obtained.
そこで、この流動層方式によって含炭素鉄粉を脱炭する
ことが考えられる。Therefore, it is possible to decarburize carbon-containing iron powder using this fluidized bed method.
流動層を用いて含炭素鉄粉の脱炭を行う場合、流動層温
度は５５０ ℃以上の高温に保つ必要があることが知ら
れているが、鉄粉内部に右いては、次なる反応（Ｆｅ
Ｏｘ 十ｘ Ｃ→ｘＣＯ＋ Ｆｅ）が進行すると考えら
れる。脱炭の進行とともに鉄の還元も生じ、還元鉄粉の
凝集によるスティッキング現象が生じ流動が停止する。It is known that when decarburizing carbon-containing iron powder using a fluidized bed, it is necessary to maintain the temperature of the fluidized bed at a high temperature of 550 °C or higher, but inside the iron powder, the following reaction ( Fe
It is thought that the process (Ox 1x C→xCO+ Fe) progresses. As decarburization progresses, reduction of iron also occurs, and a sticking phenomenon occurs due to agglomeration of reduced iron powder, causing the flow to stop.
また、例えば脱炭源として酸素を用いた場合、Ｆｅ＋ｘ
／２０ｚ→Ｆｅｄ、となる反応による発熱が大きいため
に、鉄粉表面の融着によりスティッキング現象が生じる
。Furthermore, for example, when oxygen is used as a decarburization source, Fe+x
Since the heat generated by the reaction of /20z→Fed is large, a sticking phenomenon occurs due to fusion of the surface of the iron powder.
そこで、本発明は、スティッキングを回避しながら、均
一に脱炭処理された鉄粉を高い生産性で製造することを
目的とする。Therefore, an object of the present invention is to produce uniformly decarburized iron powder with high productivity while avoiding sticking.
本発明の脱炭鉄粉の製造方法は、その目的を達成するた
めに、流動層の温度を５５０〜９００℃に維持し、酸素
濃度１０％以下となるように酸素ガス又は空気を混入し
、且つ水蒸気を添加した不活性ガスからなる流動化ガス
を前記流動層に吹き込み、流動状態にある含炭素鉄粉を
脱炭することを特徴とする。In order to achieve the objective, the method for producing decarburized iron powder of the present invention maintains the temperature of the fluidized bed at 550 to 900°C, and mixes oxygen gas or air so that the oxygen concentration is 10% or less, In addition, a fluidizing gas made of an inert gas to which water vapor has been added is blown into the fluidized bed to decarburize the carbon-containing iron powder in a fluidized state.
脱炭後の鉄粉は、摩鉱により表面の酸化物層が剥離され
た精製品とすることができる。或いは、流動層温度８０
０℃以下で還元ガスによって、脱炭後の鉄粉を部分還元
して精製品とするとも可能である。The iron powder after decarburization can be a refined product from which the oxide layer on the surface has been removed by grinding. Or fluidized bed temperature 80
It is also possible to partially reduce the iron powder after decarburization using a reducing gas at 0° C. or lower to obtain a refined product.
流動層を使用した処理方法においては、固気の接触面積
を大きくとることができ、反応及び伝熱を律速する固気
間の境膜抵抗を極めて小さくすることができる。また、
この方法によるとき、流動層の温度を急速に上げること
ができ、更に所定の温度に流動層全体を均一に維持する
ことが可能である。In a treatment method using a fluidized bed, the contact area of solid gas can be increased, and the film resistance between solid gases that determines the rate of reaction and heat transfer can be made extremely small. Also,
When using this method, the temperature of the fluidized bed can be rapidly raised, and furthermore, it is possible to uniformly maintain the entire fluidized bed at a predetermined temperature.
この流動層によって含炭素鉄粉の脱炭処理を行うにあた
り、本発明においては、流動層の温度を５５０〜９００
℃に維持している。また、空気又は酸素ガスを不活性ガ
スに混入し、脱炭源として必要な酸素の濃度を流動化ガ
スに対して１０％以下に調整する。また、流動層の温度
を調節するため、１０％程度までの適量の水蒸気を添加
する。In decarburizing carbon-containing iron powder using this fluidized bed, in the present invention, the temperature of the fluidized bed is set to 550 to 900.
It is maintained at ℃. Further, air or oxygen gas is mixed with the inert gas, and the concentration of oxygen necessary as a decarburization source is adjusted to 10% or less with respect to the fluidizing gas. Further, in order to adjust the temperature of the fluidized bed, an appropriate amount of water vapor of up to about 10% is added.
この条件下で流動層に含炭素鉄粉が滞留する時間を充分
に確保することにより、たとえば１％程度の炭素を含有
する含炭素鉄粉を１５〜２０分程度の処理で０．１ ％
以下にまで脱炭することができる。By ensuring sufficient time for the carbon-containing iron powder to stay in the fluidized bed under these conditions, for example, carbon-containing iron powder containing about 1% carbon can be reduced to 0.1% by processing for about 15 to 20 minutes.
It is possible to decarburize the following.
ここで、流動化ガスに含まれる酸素の濃度が１０％を超
えるとき、鉄粉粒子の酸化が激しくなり、また酸化発熱
によって鉄粉粒子相互の融着、すなわちスティッキング
が生じる。その結果、流動層内が不安定な流動状態とな
り、鉄粉粒子の表面に生成した酸化被膜によって脱炭反
応も阻害される。Here, when the concentration of oxygen contained in the fluidizing gas exceeds 10%, the oxidation of the iron powder particles becomes intense, and the heat of oxidation causes fusion, that is, sticking, of the iron powder particles. As a result, the interior of the fluidized bed becomes unstable, and the decarburization reaction is also inhibited by the oxide film formed on the surface of the iron powder particles.
これに対し、酸素濃度を１０％以下とするとき、鉄粉粒
子の表面に薄い酸化被膜が形成されるが、この被膜の厚
みは小さなものであるため脱炭反応を妨げることがない
。また、酸化被膜形成時に生じた熱量も僅かなものであ
るため、鉄粉粒子がスティッキングすることもない。On the other hand, when the oxygen concentration is 10% or less, a thin oxide film is formed on the surface of the iron powder particles, but since the thickness of this film is small, it does not interfere with the decarburization reaction. Furthermore, since the amount of heat generated during the formation of the oxide film is small, the iron powder particles do not stick.
また、流動層の温度が５５０℃以下では脱炭反応速度が
極めて遅く、はとんど脱炭が進行しない。Further, if the temperature of the fluidized bed is 550° C. or lower, the decarburization reaction rate is extremely slow, and decarburization hardly progresses.
逆に、９００ ℃以上の温度では、脱炭は急速に進むが
、鉄粉の焼結温度となり鉄粉の融着が進み、安定な流動
層を維持できないからである。このようなことから流動
層温度を５５０〜９００℃に保つことにより、十分な脱
炭反応速度と安定な流動層が確保される。On the other hand, at a temperature of 900° C. or higher, decarburization progresses rapidly, but the temperature reaches the sintering temperature of the iron powder and the fusion of the iron powder progresses, making it impossible to maintain a stable fluidized bed. For this reason, by maintaining the fluidized bed temperature at 550 to 900°C, a sufficient decarburization reaction rate and a stable fluidized bed can be ensured.
この酸化被膜は、必要に応じて次工程で摩鉱処理を施す
ことにより、容易に地鉄から剥離することができる。或
いは、水素、ＣＯ等の還元ガスを使用して脱炭鉄粉を流
動層内で８００℃以下の温度で処理することにより、酸
化被膜を還元することができる。この還元処理工程は、
脱炭処理用の流動層と同じもの或いは別途設けた流動層
の何れであっても良い。This oxide film can be easily peeled off from the base iron by performing a grinding treatment in the next step if necessary. Alternatively, the oxide film can be reduced by treating the decarburized iron powder in a fluidized bed at a temperature of 800° C. or lower using a reducing gas such as hydrogen or CO. This reduction process is
The fluidized bed may be the same as the fluidized bed for decarburization treatment, or it may be a fluidized bed provided separately.
以下、転炉ダストから回収した鉄粉を原料とした実施例
によって、本発明の特徴を具体的に説明する。Hereinafter, the features of the present invention will be specifically explained using examples using iron powder recovered from converter dust as a raw material.
この回収鉄粉は、転炉で発生したダストを磁選。This recovered iron powder is produced by magnetic separation of dust generated in converters.
摩鉱等によってスラグ、スケール等から分離した平均粒
度９４．６ｍの粉粒体である。また、その組成は、次の
通りである。It is a granular material with an average particle size of 94.6 m separated from slag, scale, etc. by grinding or the like. Moreover, its composition is as follows.
成分 Ｃ金属鉄 Ｆｅ ＯＦｅ２Ｏ３含有量
（重量％） ０．５０ ９５．８ １，７２ ０．
６７この回収鉄粉を脱炭処理槽に投入し、空気及び水蒸
気を添加した窒素ガスを流動化ガスとして空塔速度０．
４〜０．５ （ｍ／ｓ）で吹き込み、６０分間の脱炭処
理を行った。Component C Metallic iron Fe OFe2O3 content (wt%) 0.50 95.8 1,72 0.
67 This recovered iron powder was put into a decarburization treatment tank, and nitrogen gas to which air and water vapor were added was used as a fluidizing gas at a superficial velocity of 0.
The decarburization process was carried out for 60 minutes by blowing at a rate of 4 to 0.5 (m/s).
第１図は、流動化ガスの酸素濃度と回収鉄粉の脱炭率と
流動層の温度との関係を表したグラフである。流動層の
温度に対して６０分間の脱炭処理後の脱炭率（＝６０分
後の鉄粉含有炭素量／処理前の鉄粉含有炭素量） を示
している。酸素濃度１０％以下であれば、５５０〜９０
０℃の間で脱炭処理が可能であることを示す。５５０
℃以下の温度では脱炭反応の進行が遅く酸化のみ進行す
る。FIG. 1 is a graph showing the relationship between the oxygen concentration of the fluidizing gas, the decarburization rate of recovered iron powder, and the temperature of the fluidized bed. The decarburization rate after 60 minutes of decarburization treatment (=carbon content in iron powder after 60 minutes/carbon content in iron powder before treatment) is shown with respect to the temperature of the fluidized bed. If the oxygen concentration is 10% or less, 550-90
This shows that decarburization treatment is possible between 0°C. 550
At temperatures below ℃, the decarburization reaction progresses slowly and only oxidation proceeds.
また、第２図は、６０分間の脱炭処理中のスティッキン
グの発生状況を流動層温度と酸素容量濃度（％）で示す
。９００ ℃以上では鉄粉の融着が発生し、スティッキ
ングを生ずる。また、温度を９００℃以下としても酸素
濃度を１０％超とすると鉄粉の酸化が大きく、鉄粉表面
の酸化熱により鉄粉の融着が進み、スティッキングが発
生し流動層を維持することができない。Furthermore, FIG. 2 shows the occurrence of sticking during the 60-minute decarburization treatment in terms of fluidized bed temperature and oxygen capacity concentration (%). At temperatures above 900°C, fusion of iron powder occurs, resulting in sticking. Furthermore, even if the temperature is below 900°C, if the oxygen concentration exceeds 10%, the oxidation of the iron powder will be large, and the heat of oxidation on the surface of the iron powder will advance the fusion of the iron powder, causing sticking and making it difficult to maintain the fluidized bed. Can not.
たとえば、流動層温度７００ ℃の下で酸素濃度１％の
流動化ガスにより脱炭された鉄粉は、次の組成をもつも
のとなった。For example, iron powder decarburized by fluidizing gas with an oxygen concentration of 1% at a fluidized bed temperature of 700° C. had the following composition.
成分 Ｃ金属鉄 ＦｅＯＦｅ２Ｏ３含有量
（重量％） ０．０５ ９６．４ １．４ ０
．９この脱炭鉄粉の表面には、厚み１虜以下の極めて薄
い酸化被膜が付着していた。そこで、次に示す摩鉱或い
は還元処理によって、脱炭鉄粉から酸化被膜を除去し、
精製品とした。Component C Metallic iron FeOFe2O3 content (wt%) 0.05 96.4 1.4 0
．． 9. On the surface of this decarburized iron powder, an extremely thin oxide film with a thickness of less than 1 mm was adhered. Therefore, the oxide film is removed from the decarburized iron powder by the following grinding or reduction treatment,
It was made into a refined product.
摩鉱による酸化被膜除去
当該脱炭処理を行った鉄粉をボールミルで摩鉱し、湿式
分離によって摩鉱工程で剥離した酸化膜を除去した後、
乾燥した鉄粉は、金属鉄９７．１％。Removal of oxide film by grinding The decarburized iron powder is ground in a ball mill, and the oxide film peeled off during the grinding process is removed by wet separation.
Dry iron powder is 97.1% metallic iron.
ＦｅＯＯ，３４％、 Ｆｅ２０ｎ ０．０７％の極め
て高品位の脱炭鉄粉であった。It was an extremely high-grade decarburized iron powder containing 34% FeOO and 0.07% Fe20n.
還元処理による酸化被膜除去
脱炭処理を行った鉄粉を同一流動層において温度を５５
０℃、Ｈ２濃度８０ ％、窒素濃度２０％の還元処理を
行った結果、得られた精製品は、Ｆｅ純度９７％以上の
極めて高品位なものであり、しかも炭素含有量が０．０
５％の低いものであった。また、還元により、多孔質の
表面層が鉄粉粒子の表面に形成されていた。この還元鉄
粉を粉末冶金用原料として使用したとき、寸法精度及び
加工性に優れた焼結体が得られた。また、鉄粉の焼結性
も優れたものであった。Iron powder that has been subjected to oxide film removal and decarburization treatment by reduction treatment is heated to 55% in the same fluidized bed.
As a result of reduction treatment at 0°C, H2 concentration of 80%, and nitrogen concentration of 20%, the purified product obtained is of extremely high quality with Fe purity of 97% or more, and has a carbon content of 0.0%.
It was as low as 5%. Furthermore, due to the reduction, a porous surface layer was formed on the surface of the iron powder particles. When this reduced iron powder was used as a raw material for powder metallurgy, a sintered body with excellent dimensional accuracy and workability was obtained. Moreover, the sinterability of the iron powder was also excellent.
なお、以上の例においては、転炉ダストから回収された
鉄粉を脱炭する場合について説明した。In addition, in the above example, the case where iron powder recovered from converter dust was decarburized was explained.
しかし、本発明は、この回収鉄粉に限らず、鉄鉱石やミ
ル・スケールをコークス、石炭等の炭材で還元して得ら
れる粗還元品等の炭素含有量が高い鉄粉の脱炭に対して
も適用することができる。However, the present invention is applicable not only to the recovered iron powder but also to the decarburization of iron powder with a high carbon content, such as crude reduced products obtained by reducing iron ore and mill scale with carbon materials such as coke and coal. It can also be applied to
以上に説明したように、本発明においては、流動層の温
度及び流動化ガスの酸素濃度を特定することにより、過
剰な酸化を防止しながら、含炭素鉄粉をたとえば約０．
１％以下のレベルにまで脱炭することができる。このと
き、酸素濃度の特定により鉄粉の酸化が抑制されている
ので、酸化反応に基づく発熱が少なく、流動層にスティ
ッキングを発生させることがない。しかも、流動層方式
であるため、個々の鉄粉粒子が均一に処理され、得られ
た製品の品質は安定したものとなる。As explained above, in the present invention, by specifying the temperature of the fluidized bed and the oxygen concentration of the fluidizing gas, the carbon-containing iron powder is heated, for example, at a temperature of about 0.0% while preventing excessive oxidation.
It is possible to decarburize to a level of 1% or less. At this time, since the oxidation of the iron powder is suppressed by specifying the oxygen concentration, there is little heat generated due to the oxidation reaction, and no sticking occurs in the fluidized bed. Moreover, since it is a fluidized bed method, each iron powder particle is treated uniformly, and the quality of the obtained product is stable.
第１図及び第２図は、本発明の効果を具体的に表したグ
ラフである。
特許出願人 新日本製鐵 株式會社代理人
手掘 益（ほか２名）
第１図
温度（”Ｃ）
第２図
１崖（・Ｃ］FIGS. 1 and 2 are graphs specifically showing the effects of the present invention. Patent applicant: Nippon Steel Corporation Agent
Masu Tegori (and 2 others) Figure 1 Temperature ('C) Figure 2 1 Cliff (・C]
Claims (1)
度１０％以下となるように酸素ガス又は空気を混入し、
且つ水蒸気を添加した不活性ガスからなる流動化ガスを
前記流動層に吹き込み、流動状態にある含炭素鉄粉を脱
炭することを特徴とする脱炭鉄粉の製造方法。 ２、脱炭後の鉄粉を摩鉱することにより、表面の酸化物
層を剥離することを特徴とする特許請求の範囲第１項記
載の脱炭鉄粉の製造方法。 ３、脱炭後の鉄粉を、流動層温度８００℃以下で還元ガ
スによって部分還元することを特徴とする特許請求の範
囲第１項記載の脱炭鉄粉の製造方法。[Claims] 1. Maintaining the temperature of the fluidized bed at 550 to 900°C and mixing oxygen gas or air so that the oxygen concentration is 10% or less,
A method for producing decarburized iron powder, which further comprises blowing a fluidizing gas made of an inert gas to which water vapor is added into the fluidized bed to decarburize the carbon-containing iron powder in a fluidized state. 2. The method for producing decarburized iron powder according to claim 1, wherein the oxide layer on the surface is peeled off by grinding the iron powder after decarburization. 3. The method for producing decarburized iron powder according to claim 1, wherein the iron powder after decarburization is partially reduced with a reducing gas at a fluidized bed temperature of 800° C. or lower.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62333003A JPH01176004A (en) | 1987-12-28 | 1987-12-28 | Manufacture of decarbonized iron powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62333003A JPH01176004A (en) | 1987-12-28 | 1987-12-28 | Manufacture of decarbonized iron powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01176004A true JPH01176004A (en) | 1989-07-12 |
Family
ID=18261201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62333003A Pending JPH01176004A (en) | 1987-12-28 | 1987-12-28 | Manufacture of decarbonized iron powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01176004A (en) |
-
1987
- 1987-12-28 JP JP62333003A patent/JPH01176004A/en active Pending
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