JPS6342301A - Production of decarburized iron powder - Google Patents
Production of decarburized iron powderInfo
- Publication number
- JPS6342301A JPS6342301A JP61185692A JP18569286A JPS6342301A JP S6342301 A JPS6342301 A JP S6342301A JP 61185692 A JP61185692 A JP 61185692A JP 18569286 A JP18569286 A JP 18569286A JP S6342301 A JPS6342301 A JP S6342301A
- Authority
- JP
- Japan
- Prior art keywords
- iron powder
- carbon
- carbon iron
- low
- powder
- 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 55
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 239000000843 powder Substances 0.000 claims abstract description 33
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims abstract description 30
- 238000005261 decarburization Methods 0.000 claims abstract description 25
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000001257 hydrogen Substances 0.000 claims abstract description 7
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 7
- QMQXDJATSGGYDR-UHFFFAOYSA-N methylidyneiron Chemical compound [C].[Fe] QMQXDJATSGGYDR-UHFFFAOYSA-N 0.000 claims description 22
- 239000007789 gas Substances 0.000 claims description 21
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 10
- 239000001301 oxygen Substances 0.000 claims description 10
- 229910052760 oxygen Inorganic materials 0.000 claims description 10
- 238000002485 combustion reaction Methods 0.000 claims description 5
- 239000000446 fuel Substances 0.000 claims description 3
- 230000003647 oxidation Effects 0.000 claims 1
- 238000007254 oxidation reaction Methods 0.000 claims 1
- 229910052799 carbon Inorganic materials 0.000 abstract description 28
- 238000000034 method Methods 0.000 abstract description 24
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 abstract description 11
- 238000005245 sintering Methods 0.000 abstract description 7
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 5
- 239000000203 mixture Substances 0.000 abstract description 3
- 230000001590 oxidative effect Effects 0.000 abstract 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 20
- 238000006243 chemical reaction Methods 0.000 description 15
- 229910052742 iron Inorganic materials 0.000 description 12
- 238000006722 reduction reaction Methods 0.000 description 10
- 238000000889 atomisation Methods 0.000 description 8
- 238000002844 melting Methods 0.000 description 6
- 230000008018 melting Effects 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 239000002994 raw material Substances 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 238000003746 solid phase reaction Methods 0.000 description 2
- 238000010671 solid-state reaction Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000007730 finishing process Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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、高炭素鉄粉を脱炭して低炭素鉄粉を製造する
方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing low carbon iron powder by decarburizing high carbon iron powder.
低炭素鉄粉の製造法は、例えば社団法人日本鉄鋼協会発
行 門出記念技術講座 第８２巻第８３：？！５合併号
ｐ、１１−４２に記載されているように、鉄鉱石。For example, the manufacturing method of low carbon iron powder can be found in the Kadde Memorial Technology Course, Vol. 82, No. 83, published by the Japan Iron and Steel Institute. ! Iron ore, as described in No. 5, p. 11-42.
ミルスケール等の酸化鉄をコークス等で還元し得られた
スポンジ状の純鉄を粉砕する還元法と、溶解炉で得られ
た溶鉄に高圧水を吹付け、そのエネルギーで微粉末を直
接得るアトマイズ法とに大別される。The reduction method involves reducing iron oxide such as mill scale with coke and pulverizing the resulting spongy pure iron, and the atomization method involves spraying high-pressure water onto the molten iron obtained in a melting furnace and using the energy to directly obtain fine powder. It is broadly divided into law.
しかし、前者の還元法は固体反応なので原料中のシリカ
等の不純物の除去は不可能で品質的には必ずしも満足す
べきものが得られず、また反応時間も長くかかり、数１
０時間の処理が必要となり、エネルギー消費の点からも
問題があった。However, since the former reduction method is a solid reaction, it is impossible to remove impurities such as silica from the raw materials, so it is not always possible to obtain a satisfactory product in terms of quality, and the reaction time is long.
The process required 0 hours of processing, and there was also a problem in terms of energy consumption.
また、アトマイズ法では一般には炭素含有油の低い溶鉄
が対象となるが、その場合、溶融温度が１５００℃を上
回るので、溶解及びアトマイズする間の温度保持に多大
のエネルギーを必要とし、さらに高温の溶鉄に耐える耐
火物も必要となるため、これらのコスト負担は大きい。In addition, the atomization method generally targets molten iron with low carbon content, but in that case, the melting temperature exceeds 1500°C, so a large amount of energy is required to maintain the temperature during melting and atomization, and even higher temperatures Since refractories that can withstand molten iron are also required, these costs are high.
このアトマイズ法における欠点を解消するために、溶鉄
中の炭素含有量を上げる試みも行われているが、後処理
として脱炭工程を採らず仕上ぶ元のみで処理する限り、
炭素含有量が０．０３重置局以下の低炭素鉄粉を得るた
めには、アトマイズするための）容鉄中の炭素含有量は
０．２重量％が限度と思われる。In order to overcome the drawbacks of this atomization method, attempts have been made to increase the carbon content in the molten iron, but as long as the finishing process is done without a decarburization process as a post-treatment,
In order to obtain low carbon iron powder with a carbon content of 0.03 or less, the carbon content in the iron volume (to be atomized) is considered to be at most 0.2% by weight.
このような低炭素鉄粉の製造に際しての問題を解決する
ため、溶融温度の低い高炭素鉄をアトマイズした後、後
工程で脱炭処理を行なう例として、アメリカン・ソサイ
アティ・フォー・メタルス発行メタルス・ハンドブック
・９編 第７巻 粉末冶金ｐ、８６．ρ、８９に記載さ
れている。In order to solve these problems in producing low carbon iron powder, the Metals and Steel Powder published by the American Society for Metals provides an example of decarburizing in the post-process after atomizing high carbon iron with a low melting temperature. Handbook, Volume 9, Volume 7, Powder Metallurgy p, 86. ρ, 89.
この方法は、チタン滓を得た後の溶鉄、又は屑鉄と黒鉛
を溶解した溶鉄を利用する。アトマイズの原料として炭
素含有量が約３重量％の低融点の）容器が使用できる他
に、凝固した鉄粉は硬く脆いため機械的粉砕が容易であ
るという利点があり、通常は粉砕工程を併用してアトマ
イズ工程の生産性を上げている。脱炭工程としては、ア
トマイズの際に空気を吹付は一部を酸化させた鉄粉又は
鉄粉にミルスケール等の酸化鉄粉末を混合したものを１
０００℃前後にＪＪＩ＋熱し、鉄粉中の炭素と酸化鉄の
酸素を反応させ、ＣＯガスとして分離する方法である（
以下これを脱炭法と呼ぶ）。This method utilizes molten iron after obtaining titanium slag, or molten iron obtained by melting scrap iron and graphite. In addition to being able to use a container with a low melting point (with a carbon content of approximately 3% by weight) as a raw material for atomization, the solidified iron powder is hard and brittle, so it has the advantage of being easy to mechanically crush, and a crushing process is usually used in combination. This increases the productivity of the atomization process. In the decarburization process, air is blown during atomization to partially oxidize iron powder or iron powder mixed with iron oxide powder such as mill scale.
This is a method of heating JJI+ to around 000℃, causing the carbon in the iron powder to react with the oxygen in the iron oxide, and separating it as CO gas (
(hereinafter referred to as the decarburization method).
こうして得られた鉄粉は炭素量０．１重量％、酸素約１
重置％が残留し、低炭素鋼を直接アトマイズした鉄わ）
とほぼ同じレベルにある。The iron powder thus obtained has a carbon content of 0.1% by weight and an oxygen content of about 1%.
Iron that is directly atomized from low carbon steel with overlapping percentage remaining)
is at almost the same level.
還元法、アトマイズ法更に脱炭法は、いずれも鉄粉中に
１重量％前後の酸素を含有しており、仕上処理として７
５０℃〜９５０℃の水素雰囲気中にて還元し、酸素含有
量を０．１〜０．３重量％に低減する。この際、残留す
る炭素の一部も除かれ、Ｑｌ的には炭素０．０３重置局
以下の低炭素鉄粉が得られる。The reduction method, atomization method, and decarburization method all contain around 1% by weight of oxygen in the iron powder, and as a finishing treatment,
Reduction is performed in a hydrogen atmosphere at 50°C to 950°C to reduce the oxygen content to 0.1 to 0.3% by weight. At this time, a portion of the remaining carbon is also removed, and a low carbon iron powder having a Ql of 0.03 or less carbon is obtained.
上記高炭素鉄粉の脱炭工程は、基本的にはＦｅＯ＋ ［
Ｃ］ Ｆｅ＋ＣＯ
（但し、［Ｃ］は鉄粉中の炭素量）
の反応式で表される固体反応ではないかともいわれてい
るが、以下のような問題が存在する。The decarburization process of the above-mentioned high carbon iron powder is basically FeO+ [
C] Fe+CO (where [C] is the amount of carbon in the iron powder) It is said that this is a solid reaction represented by the reaction formula, but there are the following problems.
この固体反応は６５０℃程度の低温でも炭素と酸素源の
接触部分での反応が始まるが各原子の粒内の移動が追い
つかず、反応が途絶え脱炭は止まってしまう。この反応
を持続させるには１０００℃以上に反応系を加熱して、
炭素及び酸素原子の固体内の移動を活発化することが必
要である。This solid-state reaction starts even at a low temperature of about 650°C at the contact area between the carbon and oxygen source, but the movement of each atom within the grains cannot keep up, and the reaction stops and decarburization stops. To sustain this reaction, the reaction system must be heated to over 1000°C.
It is necessary to activate the movement of carbon and oxygen atoms within the solid.
しかしながら、このような高温の処理は鉄粉を焼結せし
め、後工程の水素還元処理には一旦冷却して機械的な粉
砕を必要とする。このように、脱炭及び仕上還元の工程
毎に加熱冷却を繰返すため、多量のエネルギーを消費す
る。However, such high-temperature treatment causes the iron powder to sinter, and the subsequent hydrogen reduction treatment requires cooling and mechanical pulverization. In this way, heating and cooling are repeated for each step of decarburization and final reduction, consuming a large amount of energy.
更に脱炭後の鉄粉は、焼結塊の状態でしか得られないの
で、鉄粉を乗せたトレイ （容器）又はスチールヘルド
を移動させるマンフル炉による効率の悪い操業に頼らざ
るを得ない。Furthermore, since the iron powder after decarburization can only be obtained in the form of sintered lumps, it is necessary to rely on the inefficient operation of a manful furnace in which the tray (container) carrying the iron powder or the steel heald is moved.
若し、高炭素鉄粉からの脱炭鉄粉が焼結せずに粉状のま
まで得られれば、赤熱状態で仕上還元工程に送り込むこ
とができ、脱炭後の冷却、＄ｎ伜、更に仕上還元時の加
熱が不要となる。If decarburized iron powder from high carbon iron powder is obtained in powder form without sintering, it can be sent to the finishing reduction process in a red-hot state, and the cooling after decarburization, $n＄＄, Furthermore, heating during final reduction becomes unnecessary.
本発明の目的は、高炭素鉄粉を脱炭して仕上還元前の相
似炭素鉄粉を得るための脱炭工程における上記焼結の問
題を解消し、効率良く低炭素鉄粉を得ることにある。The purpose of the present invention is to solve the above-mentioned sintering problem in the decarburization process for decarburizing high carbon iron powder to obtain similar carbon iron powder before final reduction, and to efficiently obtain low carbon iron powder. be.
本発明は、上記固体反応による高炭素鉄粉の脱炭は粒子
間の直接反応ではな（Ｇｏ ＋ ＣＯ２ガスを媒体とし
た間接反応であり、雰囲気中のＣＯガスの分圧を高く維
持すれば鉄粉の焼結が起こらない比較的低温下で脱炭が
進むという知見に基づく。In the present invention, the decarburization of high carbon iron powder by the above-mentioned solid-state reaction is not a direct reaction between particles (it is an indirect reaction using Go + CO2 gas as a medium, and if the partial pressure of CO gas in the atmosphere is maintained high). This is based on the knowledge that decarburization progresses at relatively low temperatures where iron powder sintering does not occur.
すなわち、高炭素鉄粉の脱炭過程において、雰囲気中の
ＣＯガスは酸化鉄と接触して００２ガスを生じ、さらに
Ｃ０２ガスは鉄粉中の炭素と反応してＣＯガスを発生し
なから脱炭は進行する。換言すれば脱炭反応は次の２条
件が必要である。That is, during the decarburization process of high-carbon iron powder, CO gas in the atmosphere comes into contact with iron oxide to generate 002 gas, and the CO2 gas further reacts with carbon in the iron powder to generate CO gas and is decarburized. Charcoal progresses. In other words, the following two conditions are required for the decarburization reaction.
＋１１ 発生するＣＯガスを逃さず装入物との接触を
良くする。+11 Make good contact with the charge without letting the generated CO gas escape.
（２）装入物中に酸化鉄が存在する。(2) Iron oxide is present in the charge.
酸化鉄は直ちにぷ元されｃｏ２を作るが、酸化鉄が不足
すれば脱炭に必要なＣ０２ができず、脱炭反応は終息す
る。Iron oxide is immediately converted into CO2 to produce CO2, but if iron oxide is insufficient, CO2 required for decarburization cannot be produced, and the decarburization reaction ends.
従って脱炭反応が持続する条件、即ち成品の炭素含有量
はＣＯガス及び酸化鉄の存在、即ちｃｏ ＋ ｃｏ２ガ
ス分圧によって決定される。Therefore, the conditions under which the decarburization reaction continues, ie, the carbon content of the product, are determined by the presence of CO gas and iron oxide, ie, the co + co2 gas partial pressure.
しかし、従来の工程では発生したＣＯガスをＮ２ガス等
の不活性ガスで置換したり、減圧除去する例があり、こ
れらの操作はｃｏ 士ｃｏ２ガス分圧を下げるので脱炭
反応の面からは不利な条件と言える。However, in conventional processes, there are examples in which the generated CO gas is replaced with an inert gas such as N2 gas or removed under reduced pressure.These operations lower the partial pressure of the CO2 gas, so they are not effective in terms of the decarburization reaction. This can be said to be a disadvantageous condition.
その結果、脱炭を進めるには鉄粉の焼結が進行する１０
００℃程度の高温処理を行なわせざるを得なかった。As a result, in order to advance decarburization, sintering of iron powder must proceed10
There was no choice but to perform high-temperature treatment at around 00°C.
本発明における雰囲気中のＣｏ ＋ ＣＯ２ガス分圧を
、４０％以上とくに、低温操業で低炭素鉄粉を得る点か
らは、６０％以上に維持することが望ましい。In the present invention, it is desirable to maintain the partial pressure of Co + CO2 gas in the atmosphere at 40% or more, particularly at 60% or more from the viewpoint of obtaining low carbon iron powder at low temperature operation.
かかる分圧は、装入物から発生するＣＯガスを逃さず、
外部からの窒素の混入を許さぬ炉によって得ることがで
きる。Such a partial pressure prevents CO gas generated from the charge from escaping,
It can be obtained in a furnace that does not allow nitrogen to enter from the outside.
驚くべきことに、このような謂いｃｏ ＋ ｃｏ２濃度
の雰囲気を保てば７００℃程度の低温でも脱炭反応は長
時間継続し、低炭素鉄粉が得られる。しかし、処理温度
が低いと反応速度が下がり生産性の点で得策でなく、鉄
粉が焼結しない範囲での高温、即ち９５０℃〜８００℃
の温度域が適切である。Surprisingly, if an atmosphere with such a so-called co + co2 concentration is maintained, the decarburization reaction will continue for a long time even at a low temperature of about 700°C, and a low carbon iron powder can be obtained. However, if the processing temperature is low, the reaction rate decreases and it is not a good idea in terms of productivity.
The temperature range is appropriate.
本発明の場合のように、脱炭がわ〕体の焼結が起きない
条件で行われれば、粉体に下からガスを送り１ｇ動させ
る流動層型の炉等、高効率な粉体反応炉が考えられる。As in the case of the present invention, if the decarburization is carried out under conditions that do not cause sintering of the powder, a highly efficient powder reaction can be achieved, such as in a fluidized bed furnace in which gas is fed from below to the powder and the powder is moved by 1 g. A furnace can be considered.
しかしながら、実際の適用に際しては保守の容易さ、操
業性の点からロータリーキルンが最適である。However, for actual application, rotary kilns are most suitable from the viewpoint of ease of maintenance and operability.
ロータリーキルンによる酸化鉄の還元法として、５Ｌｌ
ＲＮ法と呼ばれる方法がある。As a method for reducing iron oxide using a rotary kiln, 5Ll
There is a method called the RN method.
これは炉内に空気を吹き込み炉内で石炭の一部を燃焼し
、残りの炭素で酸化鉄を還元する方法であって、エクス
トラクション・メタラジ−（ＥｘｔｒＭｅｔａｌｌ）
８１ （ｐ１９３−２０１ ’８１）によると、炉内
のガス成分は装入物層内ではｃｏ ＋ ｃｏ２は９０％
以上になるが、フリーボード部では約７０％が空気から
の窒素でｃｏ ＋ ｃｏ２は２５％程度に過ぎない。This is a method in which air is blown into the furnace, part of the coal is burned in the furnace, and the remaining carbon is used to reduce iron oxide.
81 (p193-201 '81), the gas composition in the furnace is 90% CO + CO2 in the charge layer.
As mentioned above, in the freeboard part, about 70% is nitrogen from the air, and CO + CO2 is only about 25%.
これは、装入物内から発生したｃｏ ＋ ｃｏ２はフリ
ーボードを通り炉外へ排出されていることを示している
。This indicates that the CO + CO2 generated from inside the charge is discharged to the outside of the furnace through the freeboard.
この条件で低炭素域まで脱炭を進行させるには、成品に
残留する酸素含有量を５重量％前後と高くしなければな
らない。In order to progress decarburization to the low carbon range under these conditions, the oxygen content remaining in the product must be as high as around 5% by weight.
換言すればこの様な高酸素の成品ならば空気を使用した
内燃式のロータリーキルンで充分と言える。In other words, for such high oxygen products, an internal combustion type rotary kiln using air is sufficient.
然るに成品の酸素を１Ｎ量％以下に押え、炭素を０．１
重量％以下にするには、フリーボード内の雰囲気のＣｏ
＋ ＣＯ２ガス分圧を４０％、好ましくは６０％以上
に保つ必要があり、外部から加熱する外熱式か、燃焼用
に窒素ガスの少ない燃料および酸素ガスを用いる内燃式
にしなければならない。However, the oxygen content in the finished product is kept below 1N%, and the carbon content is kept at 0.1%.
To reduce the amount of Co in the freeboard atmosphere to below % by weight,
+ It is necessary to maintain the partial pressure of CO2 gas at 40%, preferably 60% or more, and it is necessary to use either an external heating type that is heated from the outside, or an internal combustion type that uses fuel with little nitrogen gas and oxygen gas for combustion.
酸化鉄の還元反応においては、石炭等の固型炭素源に較
べると、鉄粉中の固溶炭素はｃｏ２との反応性が極めて
良好で、１００℃〜２００℃も操業温度を下げられ、且
つ還元鉄粉製造の場合に比して高炭素鉄粉の脱炭には酸
化鉄の還元量はほぼ１０分の１と少なくて済み、従って
設備もコンパクトになるので外熱式又は酸素および低窒
素燃料の吹込みによる内燃式のロータリーキルンの使用
が工業的に可能となった。In the reduction reaction of iron oxide, compared to solid carbon sources such as coal, the solid solution carbon in iron powder has extremely good reactivity with CO2, and the operating temperature can be lowered by 100 to 200 °C. Compared to the production of reduced iron powder, decarburization of high carbon iron powder requires approximately one-tenth the reduction amount of iron oxide, and the equipment is therefore compact, so external heating or oxygen and low nitrogen is required. The use of internal combustion rotary kilns with fuel injection became industrially possible.
直径２００關、長さ３ｍの外熱式ロータリーキルンを用
い、第１表に示す高炭素鉄粉とミルスケールを高炭素鉄
粉に対する比率を重量比で０．１８とした混合粉を作り
原料とした。Using an externally heated rotary kiln with a diameter of 200 cm and a length of 3 m, a mixed powder was prepared using the high carbon iron powder shown in Table 1 and mill scale at a weight ratio of 0.18 to the high carbon iron powder and used as the raw material. .
５ ｒｐｖａで回転する該キルンに１２０ ｇ ／ 分
の８４合で原料を供給し、約１．．５ ｍに渡り４００
℃〜９ｏｏ′ｃに加熱され、最終末端部５００ ａｍは
外部より冷却している。The kiln, rotating at 5 rpva, was fed with 120 g/min of feedstock at a rate of about 1. ．． 400 over 5 m
℃~9oo'C, and the final end 500 am is cooled from the outside.
その間フリーボードの雰囲気はｃｏ ＋ ＣＯ２ガス分
圧を６５％に保持した。During this period, the atmosphere in the freeboard was maintained at a co+CO2 gas partial pressure of 65%.
装入後、１４０分後に脱炭された低炭素鉄粉は粉末の状
態で排出され、直ちに後続の水素７５暇星％、窒素２５
重量％の雰囲気を有する前記と同一条件のロータリーキ
ルンに連続的に送り込み、９００ ’Ｃで３０分処理し
た後冷却すると、第１表に示す低炭素鉄粉が得られた。After 140 minutes of charging, the decarburized low carbon iron powder is discharged in powder form, immediately followed by 75% hydrogen and 25% nitrogen.
When the powder was continuously fed into a rotary kiln under the same conditions as above and having an atmosphere of % by weight, treated at 900'C for 30 minutes, and then cooled, the low carbon iron powder shown in Table 1 was obtained.
第１表 原料及び成品の分析
※単位−重世％
〔発明の効果〕
本発明の方法によって、高炭素鉄粉は何等焼結を生しる
ことなく脱炭が可能になり、しかも後の還元工程に熱間
状態での供給が可能となるために、製造のためのエネル
ギーが大幅に節減できる。Table 1 Analysis of raw materials and finished products *Unit: % [Effects of the invention] By the method of the present invention, high carbon iron powder can be decarburized without any sintering, and furthermore, it can be reduced afterward. Since the process can be supplied in a hot state, energy for manufacturing can be significantly reduced.
Claims (1)
＿２ガス分圧の雰囲気下で９５０℃以下の温度で脱炭処
理した後、そのまま水素還元処理することを特徴とする
脱炭鉄粉の製造方法。 ２、ＣＯ＋ＣＯ＿２ガス分圧が４０％以上であることを
特徴とする特許請求の範囲第１項に記載の脱炭鉄粉の製
造方法。 ３、脱炭処理を外部加熱型又は窒素の少ない燃料及び酸
素を用いた内燃型のロータリー炉内で行なうことを特徴
とする特許請求の範囲第１項に記載の脱炭鉄粉の製造方
法。[Claims] 1. Oxidation sources such as high carbon iron powder and iron oxide powder are
A method for producing decarburized iron powder, which comprises decarburizing the iron powder at a temperature of 950° C. or lower in an atmosphere of _2 gas partial pressure, and then directly subjecting it to hydrogen reduction treatment. 2. The method for producing decarburized iron powder according to claim 1, wherein the CO+CO_2 gas partial pressure is 40% or more. 3. The method for producing decarburized iron powder according to claim 1, wherein the decarburization treatment is carried out in an externally heated rotary furnace or an internal combustion rotary furnace using nitrogen-poor fuel and oxygen.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61185692A JPS6342301A (en) | 1986-08-06 | 1986-08-06 | Production of decarburized iron powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61185692A JPS6342301A (en) | 1986-08-06 | 1986-08-06 | Production of decarburized iron powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6342301A true JPS6342301A (en) | 1988-02-23 |
Family
ID=16175190
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61185692A Pending JPS6342301A (en) | 1986-08-06 | 1986-08-06 | Production of decarburized iron powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6342301A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62162153A (en) * | 1986-12-27 | 1987-07-18 | Fujitsu Ltd | Data-replace control system for buffer memory device |
| US5234489A (en) * | 1992-05-27 | 1993-08-10 | L'air Liquide | Process for reducing oxides contained in iron powder without substantial decarburization thereof |
-
1986
- 1986-08-06 JP JP61185692A patent/JPS6342301A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62162153A (en) * | 1986-12-27 | 1987-07-18 | Fujitsu Ltd | Data-replace control system for buffer memory device |
| US5234489A (en) * | 1992-05-27 | 1993-08-10 | L'air Liquide | Process for reducing oxides contained in iron powder without substantial decarburization thereof |
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