JPH01176005A - Decarbonizing method for carbon contained in iron powder - Google Patents
Decarbonizing method for carbon contained in iron powderInfo
- Publication number
- JPH01176005A JPH01176005A JP62333004A JP33300487A JPH01176005A JP H01176005 A JPH01176005 A JP H01176005A JP 62333004 A JP62333004 A JP 62333004A JP 33300487 A JP33300487 A JP 33300487A JP H01176005 A JPH01176005 A JP H01176005A
- Authority
- JP
- Japan
- Prior art keywords
- iron powder
- fluidized bed
- carbon
- decarburization
- fluidizing gas
- 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 72
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 33
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 11
- 239000007789 gas Substances 0.000 claims abstract description 28
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 7
- 239000001257 hydrogen Substances 0.000 claims abstract description 7
- 239000000843 powder Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- QMQXDJATSGGYDR-UHFFFAOYSA-N methylidyneiron Chemical compound [C].[Fe] QMQXDJATSGGYDR-UHFFFAOYSA-N 0.000 claims description 6
- 238000006243 chemical reaction Methods 0.000 abstract description 15
- 229910052742 iron Inorganic materials 0.000 abstract description 12
- 238000007254 oxidation reaction Methods 0.000 abstract description 10
- 230000003647 oxidation Effects 0.000 abstract description 8
- 239000000203 mixture Substances 0.000 abstract description 4
- 230000001590 oxidative effect Effects 0.000 abstract description 2
- 238000005262 decarbonization Methods 0.000 abstract 2
- 230000002250 progressing effect Effects 0.000 abstract 1
- 238000005261 decarburization Methods 0.000 description 35
- 230000009467 reduction Effects 0.000 description 16
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 8
- 238000005243 fluidization Methods 0.000 description 7
- 239000000428 dust Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 3
- 238000003466 welding Methods 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 241000277269 Oncorhynchus masou Species 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000007885 magnetic separation Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000007704 transition Effects 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、スティッキングを防止しながら流動層方式で
含有炭素鉄粉を脱炭する方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for decarburizing carbon-containing iron powder using a fluidized bed method while preventing sticking.
流動層は、各種粉体の乾燥をはじめとして、酸化、還元
等の化学反応を伴うプロセスに多用されている。たとえ
ば、固体と気体との間の反応を促すプロセスにおいては
、両者の間の接触面積を大きくすることができる。しか
も、粉体表面の反応及び伝熱を律速する境膜の剥離が促
進されることから、境膜抵抗を極めて小さくすることが
でき、反応速度及び伝熱係数が大きくとれる。更に、流
動層内の温度分布及び成分分散が均一化され、反応条件
を支配する雰囲気の制御も容易である。また、設備自体
もコンパクト化することができ、可動部分が少なくメン
テナンスが容易であること等の種々の優れた特性をもっ
ている。Fluidized beds are frequently used in processes involving chemical reactions such as oxidation and reduction, as well as the drying of various powders. For example, in a process that promotes a reaction between a solid and a gas, the contact area between the two can be increased. Moreover, since the peeling of the film that determines the rate of reaction and heat transfer on the powder surface is promoted, the film resistance can be made extremely small, and the reaction rate and heat transfer coefficient can be increased. Furthermore, the temperature distribution and component dispersion within the fluidized bed are made uniform, and the atmosphere governing the reaction conditions can be easily controlled. Moreover, the equipment itself can be made compact and has various excellent characteristics such as having few moving parts and easy maintenance.
このような特性を活かして、たとえば特開昭５７−９８
６１５号公報では、微粉炭と粉粒状鉄鉱石を可動状態で
反応させ、鉄鉱石の還元を行う装置が提案されている。Taking advantage of these characteristics, for example, JP-A-57-98
No. 615 proposes an apparatus for reducing iron ore by reacting pulverized coal and granular iron ore in a movable state.
この流動層を使用して含有炭素鉄粉の脱炭を行おうとす
るとき、水蒸気を含んだガスが流動化ガスとして使用さ
れる。流動化ガスに含まれる水蒸気は、次式の反応によ
って含有炭素鉄粉を脱炭する。When attempting to decarburize carbon-containing iron powder using this fluidized bed, a gas containing water vapor is used as a fluidizing gas. The water vapor contained in the fluidizing gas decarburizes the carbon-iron powder by the following reaction.
Ｃ十Ｈｘ Ｏ−ＣＯ＋ Ｈｔ
ところが、この水蒸気は、脱炭反応と共に、次式の反応
によって、含有炭素鉄粉の鉄分を酸化する作用をもつ。C10Hx O-CO+ Ht However, this water vapor has the effect of oxidizing the iron content of the carbon-containing iron powder by the reaction of the following formula as well as the decarburization reaction.
Ｆｅ＋ＨｚＯ→ＦｅＯ＋Ｈｚ
そのため、含有炭素鉄粉の脱炭は進行するものの、同時
に含有炭素鉄粉が酸化され、処理後の鉄粉は黒変し、商
品価値の低いものとなる。Fe+HzO→FeO+Hz Therefore, although the decarburization of the carbon-containing iron powder progresses, the carbon-containing iron powder is oxidized at the same time, and the iron powder after treatment turns black and has low commercial value.
また、脱炭反応を促進させるため、流動層の温度を高め
ようとすると、含有炭素鉄粉粒子相互がスティッキング
して均一な脱炭処理を行うことができなくなる。Furthermore, when attempting to raise the temperature of the fluidized bed in order to promote the decarburization reaction, the carbon-containing iron powder particles stick to each other, making it impossible to perform a uniform decarburization process.
そこで、本発明は、流動層の温度及び流動化ガスの組成
を特定することによって、スティッキング及び酸化を防
止しながら、含有炭素鉄粉を均一に脱炭することを目的
とする。Therefore, an object of the present invention is to uniformly decarburize the carbon-containing iron powder while preventing sticking and oxidation by specifying the temperature of the fluidized bed and the composition of the fluidizing gas.
本発明の脱炭処理方法は、その目的を達成するために、
流動層内の温度を５５０〜８００℃に維持し、水素に対
する水蒸気の分圧比を０．４以上とした流動化ガスを流
動層に吹き込み含有炭素鉄粉を流動状態にすることを特
徴とする。In order to achieve the objective, the decarburization treatment method of the present invention has the following features:
It is characterized in that the temperature in the fluidized bed is maintained at 550 to 800°C, and a fluidizing gas having a partial pressure ratio of water vapor to hydrogen of 0.4 or more is blown into the fluidized bed to bring the carbon-iron powder into a fluidized state.
また、このようにして脱炭された含有炭素鉄粉は、引き
続き温度８００℃以下で水素に対する水蒸気の分圧比を
０．４未満とした流動化ガスにより還元することができ
る。Further, the carbon-containing iron powder thus decarburized can be subsequently reduced by a fluidizing gas having a partial pressure ratio of water vapor to hydrogen of less than 0.4 at a temperature of 800° C. or less.
以下、図面を参照しながら、実施例記より本発明の特徴
を具体的に説明する。EMBODIMENT OF THE INVENTION Hereinafter, the features of the present invention will be specifically explained from Examples with reference to the drawings.
第２図は、本実施例で使用した流動層式〇脱炭処理装置
を示す側断面図である。FIG. 2 is a side sectional view showing the fluidized bed type decarburization treatment apparatus used in this example.
この脱炭処理装置は、処理槽１の内部が流動化板２で仕
切られており、流動化板２より下方がガス供給ヘッダー
３、流動化板２よ゛り上方が流動化室４にされている。In this decarburization treatment equipment, the inside of a treatment tank 1 is partitioned by a fluidization plate 2, a gas supply header 3 is provided below the fluidization plate 2, and a fluidization chamber 4 is provided above the fluidization plate 2. ing.
そして、処理槽１の下部に設けられているガス吹込み口
５から吹き込まれた流動化ガス６は、偏流防止板７によ
って流動化板２全面にわたって均一な流量分布をもつ流
れとなって、流動化板２に穿設した多数の開口部８から
流動化室４に流入し、流動化室４内にある含有炭素鉄粉
９を流動化させる。なお、処理槽１の炉壁１０は保温材
１１で覆われており、処理槽１内の熱が外部に放散され
ることを防止している。また、処理槽ｌ内の流動状態を
検出する差圧マノメータ１２及び内部温度を検出する熱
電対等の温度計１３が処理槽１の内部に配置されている
。The fluidizing gas 6 blown from the gas blowing port 5 provided at the bottom of the processing tank 1 is turned into a flow with a uniform flow rate distribution over the entire surface of the fluidizing plate 2 by the drift prevention plate 7. It flows into the fluidization chamber 4 through a large number of openings 8 formed in the fluidization plate 2, and the carbon-containing iron powder 9 in the fluidization chamber 4 is fluidized. Note that the furnace wall 10 of the processing tank 1 is covered with a heat insulating material 11 to prevent the heat inside the processing tank 1 from dissipating to the outside. Further, a differential pressure manometer 12 for detecting the flow state in the processing tank 1 and a thermometer 13 such as a thermocouple for detecting the internal temperature are arranged inside the processing tank 1.
処理槽１に投入される含を炭素鉄粉９として、転炉ダス
トから回収した鉄粉を使用した。この回収鉄粉は、転炉
ダストをベンチュリースクラバー等の湿式集塵機で排ガ
スから分離し、磁選、磨鉱等によってスラグ、スケール
等の非金属物質を分離したものである。この回収鉄粉は
、平均粒度が９４．６．Ｌｌｌｌで、次の組成をもつも
のであった。The iron powder collected from converter dust was used as the carbon iron powder 9 to be charged into the treatment tank 1. This recovered iron powder is obtained by separating converter dust from exhaust gas using a wet type dust collector such as a venturi scrubber, and removing nonmetallic substances such as slag and scale by magnetic separation, polishing, etc. This recovered iron powder has an average particle size of 94.6. It had the following composition.
成分 Ｃ金属鉄 ＦｅＯＦｅｚＯ＋含有蓋（
重量％） ０．５０ ９５．８ １．７２ ０．
６７このように回収鉄粉の炭素含有量が高いため、回収
鉄粉を未脱炭のまま溶接棒等に使用すると、溶接中にｃ
ｏ、ｃｏ□ガスの発生を招き、溶接面を乱す等の問題が
ある。そこで、炭素含有量を下げ回収鉄粉の性質を向上
させるため、第２図に示した装置で脱炭処理した。この
とき、水素に対する水蒸気の分圧比Ｐ□。／Ｐ□及び流
動化ガスの温度を種々変更し、それらが脱炭反応にどの
ように影響したかを調べた。Component C Metallic iron FeOFezO+containing lid (
Weight%) 0.50 95.8 1.72 0.
67 Because the carbon content of recovered iron powder is high as described above, if recovered iron powder is used in welding rods etc. without decarburization, carbon will be generated during welding.
There are problems such as generation of o, co□ gas and disturbing the welding surface. Therefore, in order to reduce the carbon content and improve the properties of the recovered iron powder, decarburization treatment was performed using the apparatus shown in FIG. 2. At this time, the partial pressure ratio of water vapor to hydrogen is P□. /P□ and the temperature of the fluidizing gas were variously changed to examine how they affected the decarburization reaction.
第１図は、その結果を表したグラフである。FIG. 1 is a graph showing the results.
図中において、Ｆｅ＋Ｈ，０＝ＦｅＯ＋Ｈｚの曲線より
下でＰ□。／Ｐ□の小さい側の領域と、Ｃ＋Ｈ，ｏ ＝
ＣＯ＋ Ｈｚの曲線より上でＰ□。／Ｐ６の大きい側
の領域の重なる部分が優先脱炭の領域、つまりＦｅの酸
化を抑制しつつ脱炭を進行させることができる。しかし
、過度にＰＭ、。／ＰＭ、の小さい領域で脱炭処理を行
うと、脱炭の進行と同時に急激に還元も進行し、鉄粉に
おいて５５０℃以上の温度条件下では鉄粉同志の付着力
が増大して、凝集、つまりスティッキングを発生し脱炭
終了前に流動層が維持できな（なる。In the figure, P□ below the curve of Fe+H, 0=FeO+Hz. /P□ smaller side area and C+H,o =
P□ above the CO+ Hz curve. The overlapping portion of the region on the larger /P6 side is the region of preferential decarburization, that is, decarburization can proceed while suppressing oxidation of Fe. However, PM too much. /PM, when decarburization is performed in a small region, reduction progresses rapidly at the same time as decarburization progresses, and under temperature conditions of 550°C or higher, the adhesion force between iron powders increases, causing agglomeration. In other words, sticking occurs and the fluidized bed cannot be maintained before decarburization is completed.
また、ＰＨｍ。／Ｐ６の値と共に温度も重要な条件であ
り、第１図に示す如く、温度が高い程平衡する００分圧
が高く、脱炭反応の進行にも有利であると同時に同時に
、Ｐ□。／ｐ、、であればよりＦ ｅ ＋ Ｈｔ Ｏ＝
Ｆ ｅ Ｏ＋ Ｈｔの反応が抑制され還元されやすい
ことになる。また、一般に鉄粉のスティッキングは高温
はど低い還元率で生じることが知られており、当該処理
中にも同様の傾向が確認され、やはり処理温度が高すぎ
ると脱炭終了前にスティッキングによる流動層の停止が
生じることがわかった。さらに低温側で処理を行うと、
第１図より容易に推察されるように脱炭の進行には不利
であり、５５０℃以下ではほとんど脱炭が進行しないこ
とがわかった。Also, PHm. In addition to the value of /P6, temperature is also an important condition; as shown in Figure 1, the higher the temperature, the higher the equilibrium 00 partial pressure, which is advantageous for the progress of the decarburization reaction, and at the same time, P□. /p, , then F e + Ht O=
This means that the reaction of FeO+Ht is suppressed and it is easily reduced. In addition, it is generally known that sticking of iron powder occurs at a low reduction rate at high temperatures, and a similar tendency was confirmed during the treatment. It was found that layer arrest occurs. If processing is performed at a lower temperature,
As can be easily inferred from FIG. 1, it was found that decarburization was disadvantageous to the progress of decarburization, and decarburization hardly progressed at temperatures below 550°C.
発明者らは以上の事実をふまえ、各処理条件を広範囲に
わたり操業を行った結果、Ｐ□。／ＰＭ。Based on the above facts, the inventors conducted operations under a wide range of processing conditions, and as a result, P□. /PM.
を０．４以上、温度計１３で検出される流動層の温度を
５５０〜８００℃に維持することがスティッキングを防
止し、所定の脱炭を行うために必要であることを見出し
た。It has been found that it is necessary to maintain the temperature of the fluidized bed at 550 to 800° C., as detected by the thermometer 13, at 0.4 or more to prevent sticking and perform the desired decarburization.
そこで、前述の含有炭素鉄粉９を、処理槽１の温度を７
００℃に維持し、分圧比Ｐ□。／Ｐ□−〇、８３で脱炭
した場合の操業例を示す、第３図は、このときの炭素含
有量の変化を表す、第３図から明らかなように、処理時
間３０分程度で、目標炭素含有ｉｔｏ、０５％以下に脱
炭することができた。Therefore, the above-mentioned carbon-containing iron powder 9 was heated to a temperature of 7.
Maintained at 00°C, partial pressure ratio P□. Figure 3 shows an example of operation when decarburizing at /P□-〇, 83, and shows the change in carbon content at this time. It was possible to decarburize the target carbon content to below 0.5%.
ただし、脱炭の進行するにつれて、含有炭素鉄粉９の酸
化反応が盛んになり、全鉄分に対する金属鉄の割合が低
下する。そこで、炭素含有量が目標値０．０５％以下に
なった時点を脱炭完了時とし、これ以降では水蒸気を含
有しない流動化ガスによって温度５５０℃で鉄粉の還元
を行った。第３図には、この還元処理工程を含めて、鉄
粉の還元率の推移を示している。However, as decarburization progresses, the oxidation reaction of the carbon-containing iron powder 9 becomes more active, and the ratio of metallic iron to the total iron content decreases. Therefore, the time when the carbon content became the target value of 0.05% or less was defined as the completion of decarburization, and after this point, the iron powder was reduced at a temperature of 550° C. using a fluidizing gas that does not contain water vapor. FIG. 3 shows the transition of the reduction rate of iron powder, including this reduction treatment step.
この還元工程における流動化ガスは、８００℃以下の温
度範囲に維持することが好ましい。還元工程においても
脱炭の場合と同様にスティッキングが発生する。また、
高温であればある程低い還元率でスティッキングが発生
する。脱炭処理終了レベルの還元率まで、鉄粉の品位を
回復するためには、８００℃以下で還元処理することが
好ましい。The fluidizing gas in this reduction step is preferably maintained at a temperature range of 800° C. or lower. Sticking occurs in the reduction process as well as in the case of decarburization. Also,
The higher the temperature, the lower the reduction rate and the more sticking occurs. In order to restore the quality of the iron powder to the reduction rate at the end of the decarburization treatment, it is preferable to carry out the reduction treatment at 800° C. or lower.
すなわち、脱炭工程及び還元工程の何れにおいても、流
動化ガスの温度が８００℃を超えないようにすることが
必要である。この温度が８００℃を超えると、第４図に
示すように処理槽１内にある鉄粉が凝集していわゆるス
ティッキング１４を生じ、流動化板２の開口部８直上に
空筒部１５が形成されると鉄粉は流動しなくなり、流動
層が形成されない。したがってこのようなスティッキン
グ１４が発生すると、ガス吹込み口５から吹き込まれた
流動化ガス６が空筒部１５を通過して、含有炭素鉄粉９
との充分な接触が図れなくなる。That is, in both the decarburization step and the reduction step, it is necessary to prevent the temperature of the fluidizing gas from exceeding 800°C. When this temperature exceeds 800°C, the iron powder in the processing tank 1 aggregates to cause so-called sticking 14, as shown in FIG. When this happens, the iron powder will no longer flow and a fluidized bed will not form. Therefore, when such sticking 14 occurs, the fluidizing gas 6 blown from the gas inlet 5 passes through the hollow cylinder 15 and the carbon-iron powder 9
It becomes impossible to maintain sufficient contact with the person.
第５図は、このとき差圧マノメータ１２で測定された処
理槽１内の圧力変動を示すグラフである。FIG. 5 is a graph showing pressure fluctuations in the processing tank 1 measured by the differential pressure manometer 12 at this time.
スティッキング１４が発生していないとき、流動化され
ている含有炭素鉄粉９を通過する流動化ガス６の圧損は
、大きな幅で変動する。ことろが、スティッキング１４
が発生すると、流動化ガス６が空筒部１５を優先的に流
れるため、差圧マノメータ１２により測定された差圧の
変動幅は小さなものとなり、ついには差圧自体も低値に
安定する。したがって、処理槽ｌ内における流動層前後
の差圧を測定することにより、スティッキング１４発生
の有無を検出することができる。When sticking 14 does not occur, the pressure drop of the fluidizing gas 6 passing through the fluidized carbon-containing iron powder 9 fluctuates over a wide range. Kotoroga Sticking 14
When this occurs, the fluidizing gas 6 preferentially flows through the cavity 15, so that the fluctuation range of the differential pressure measured by the differential pressure manometer 12 becomes small, and eventually the differential pressure itself stabilizes at a low value. Therefore, by measuring the differential pressure before and after the fluidized bed in the treatment tank 1, it is possible to detect whether or not sticking 14 has occurred.
第１図には、このようにして検出されたスティッキング
の発注状況を、流動層内の温度及び分圧比Ｐ□。／Ｐ□
との関係において表している。すなわち、スティッキン
グの発生を防止するには前述のように流動層内の温度を
８００℃以下とすると共に、分圧比Ｐ□。／Ｐ□、を０
．４以上とすることがを効である。それはスティッキン
グは温度が上昇し、還元が進行した時に生じる。第１図
に示すように、８００℃以下でＰ□ｏ／Ｐ□を０．４以
上にすることにより、脱炭とＦｅの酸化の同時進行領域
となり、過度の還元の進行を防止でき、また〔Ｃ〕＝Ｏ
，ＯＳ％程度まではＦｅ酸化もほとんど進行しない。と
ころが、８００℃以上の温度では第１図に示す如く、０
．４以上でもスティッキングが生じる。FIG. 1 shows the order status of sticking detected in this way, as well as the temperature and partial pressure ratio P□ in the fluidized bed. /P□
It is expressed in relation to. That is, in order to prevent the occurrence of sticking, the temperature in the fluidized bed should be kept at 800°C or less as described above, and the partial pressure ratio P□. /P□, 0
．． It is effective to set it to 4 or more. Sticking occurs when the temperature increases and reduction progresses. As shown in Figure 1, by setting P□o/P□ to 0.4 or more at 800°C or lower, decarburization and Fe oxidation occur simultaneously, and excessive reduction can be prevented. [C]=O
, OS%, Fe oxidation hardly progresses. However, at temperatures above 800°C, as shown in Figure 1,
．． Sticking occurs even when the number is 4 or more.
また、Ｐ□。／Ｐ□を０．４以下とすると、第１図に示
すように、脱炭反応の平衡する００分圧が下がり脱炭が
進行し難い。Also, P□. When /P□ is 0.4 or less, as shown in FIG. 1, the 00 partial pressure at which the decarburization reaction is balanced decreases, making it difficult for decarburization to proceed.
このようにして、スティッキング及び酸化反応を抑制し
ながら、含有炭素鉄粉９をＯ，ＯＳ％以下の炭素含有量
に脱炭することができた。この脱炭終了後の鉄粉は、鉄
粉同志の凝集もほどんどなく、脱炭源として酸化鉄粉を
別途ブレンドする必要もないため、鉄品位の低下がない
等において優れたものである。また、この脱炭に続いて
さらに還元を行うことによって、鉄粉の還元率を９９．
７５％以上とし、サガ一方式で製造された鉄粉の品位を
超える極めて高品位の製品を得ることができた。In this way, it was possible to decarburize the carbon-containing iron powder 9 to a carbon content of O,OS% or less while suppressing sticking and oxidation reactions. The iron powder after this decarburization is excellent in that there is almost no aggregation of the iron powder, and there is no need to separately blend iron oxide powder as a decarburization source, so that the iron quality does not deteriorate. Furthermore, by performing further reduction following this decarburization, the reduction rate of iron powder can be increased to 99.
It was possible to obtain an extremely high-quality product with a ratio of 75% or more, which exceeded the quality of iron powder produced by the Saga method.
なお、以上においては、転炉ダストから回収された鉄粉
を脱炭する場合を例にとって説明した。Note that the above description has been made by taking as an example the case where iron powder recovered from converter dust is decarburized.
しかし、本発明は、これに拘束されるものではなく、た
とえば鉄鉱石やミル・スケールをコークスや石炭等の炭
材を還元剤として還元した粗還元鉄粉等の含有炭素鉄粉
に対しても同様に適用することができるのは勿論である
。However, the present invention is not limited to this, and can also be applied to carbon-containing iron powder such as crude reduced iron powder obtained by reducing iron ore or mill scale using carbonaceous materials such as coke or coal as a reducing agent. Of course, the same can be applied.
以上に説明したように、本発明においては、流動化ガス
の温度を８００℃以下とし、分圧比Ｐ□。／Ｐ０を０．
４以上とすることによって、酸化及びスティッキングを
防ぎながら含有炭素鉄粉を極めて低炭素レベルまで脱炭
することができる。また、この脱炭時に、鉄粉表面に酸
化被膜の形成がないため、脱炭反応を律速する境膜がな
く、迅速な脱炭が可能となる。また、このようにして脱
炭された鉄粉を分圧比Ｐ□。／ Ｐ Ｈ−を０．４未満
の流動化ガスで還元することによって、還元率９９．７
５％以上の極めて高品位の製品を得ることができる。As explained above, in the present invention, the temperature of the fluidizing gas is set to 800°C or lower, and the partial pressure ratio P□. /P0 to 0.
By setting it to 4 or more, the carbon-containing iron powder can be decarburized to an extremely low carbon level while preventing oxidation and sticking. Furthermore, since no oxide film is formed on the surface of the iron powder during decarburization, there is no barrier film that limits the rate of the decarburization reaction, and rapid decarburization is possible. Moreover, the partial pressure ratio of the iron powder decarburized in this way is P□. /PH- with a fluidizing gas less than 0.4, the reduction rate is 99.7
A product of extremely high quality of 5% or more can be obtained.
第１図は本発明の条件がもつ意義を具体的に表したグラ
フであり、第２図は本発明実施例で使用した脱炭処理装
置を示し、第３図はその実施例における炭素含有量及び
還元率の変化を示すグラフである。他方、第４図はステ
ィッキングが発生した場合の処理槽の内部状況を示し、
第５図はそのときの圧損の変化を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）Fig. 1 is a graph specifically expressing the significance of the conditions of the present invention, Fig. 2 shows the decarburization treatment equipment used in the embodiment of the present invention, and Fig. 3 shows the carbon content in the embodiment. and a graph showing changes in the reduction rate. On the other hand, Figure 4 shows the internal situation of the treatment tank when sticking occurs,
FIG. 5 is a graph showing the change in pressure loss at that time. Patent applicant: Nippon Steel Corporation Agent: Masu Tebori (and 2 others)
Claims (1)
に対する水蒸気の分圧比を０．４以上とした流動化ガス
を流動層に吹き込み含有炭素鉄粉を流動状態にすること
を特徴とする含有炭素鉄粉の脱炭処理方法。 ２、流動層内の温度を５５０〜８００℃に維持し、水素
に対する水蒸気の分圧比を０．４以上とした流動化ガス
を流動層に吹き込み含有炭素鉄粉を流動状態で脱炭し、
引き続き温度８００℃以下で水素に対する水蒸気の分圧
比を０．４未満とした流動化ガスにより前記含有炭素鉄
粉を還元することを特徴とする含有炭素鉄粉の脱炭処理
方法。[Claims] 1. The temperature in the fluidized bed is maintained at 550 to 800°C, and a fluidizing gas with a partial pressure ratio of water vapor to hydrogen of 0.4 or more is blown into the fluidized bed to bring the carbon-iron powder into a fluidized state. A method for decarburizing iron powder containing carbon. 2. The temperature in the fluidized bed is maintained at 550 to 800°C, and a fluidizing gas with a partial pressure ratio of water vapor to hydrogen of 0.4 or more is blown into the fluidized bed to decarburize the carbon-iron powder in a fluidized state.
A method for decarburizing carbon-containing iron powder, characterized in that the carbon-containing iron powder is subsequently reduced with a fluidizing gas having a partial pressure ratio of water vapor to hydrogen of less than 0.4 at a temperature of 800° C. or lower.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62333004A JPH01176005A (en) | 1987-12-28 | 1987-12-28 | Decarbonizing method for carbon contained in iron powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62333004A JPH01176005A (en) | 1987-12-28 | 1987-12-28 | Decarbonizing method for carbon contained in iron powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01176005A true JPH01176005A (en) | 1989-07-12 |
Family
ID=18261213
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62333004A Pending JPH01176005A (en) | 1987-12-28 | 1987-12-28 | Decarbonizing method for carbon contained in iron powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01176005A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6027544A (en) * | 1996-07-22 | 2000-02-22 | Hoganas Ab | Process for the preparation of an iron-based powder |
-
1987
- 1987-12-28 JP JP62333004A patent/JPH01176005A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6027544A (en) * | 1996-07-22 | 2000-02-22 | Hoganas Ab | Process for the preparation of an iron-based powder |
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