JP3185394B2 - High-speed production method of spherical metal fine particles - Google Patents
High-speed production method of spherical metal fine particlesInfo
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- JP3185394B2 JP3185394B2 JP23493592A JP23493592A JP3185394B2 JP 3185394 B2 JP3185394 B2 JP 3185394B2 JP 23493592 A JP23493592 A JP 23493592A JP 23493592 A JP23493592 A JP 23493592A JP 3185394 B2 JP3185394 B2 JP 3185394B2
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- particles
- iron
- fine particles
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、各種鉱石または金属酸
化物の粒子から球状の金属微粒子を直接に且つ高速に製
造する方法に関するものである。尚本発明における鉱石
または金属酸化物における金属は、還元性雰囲気によっ
て還元され得るものであり、Ｆｅを始めとして、Ｍｎ，
Ｃｒ，Ｎｉ，Ｓｉ，Ｃｕ等が挙げられるが、以下では鉄
鉱石から鉄の微粒子を製造する場合を主体にして説明を
進める。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing spherical metal fine particles directly and at high speed from various ore or metal oxide particles. The metal in the ore or metal oxide in the present invention can be reduced by a reducing atmosphere, and includes Fe, Mn,
Examples thereof include Cr, Ni, Si, and Cu, but the following description will focus on the case of producing fine iron particles from iron ore.
【０００２】[0002]
【従来の技術】鉄の微粒子を製造するに当たっては、原
料鉄鉱石から、製鉄操業によって、固体状の鉄を一旦製
造した後、これを更に加熱溶融し、溶融金属の状態でガ
スアトマイズ法や水アトマイズ法によって微粒子とする
のが一般的である（例えば特開昭４８−２５７号，同４
９−１０８５９号等）。2. Description of the Related Art In the production of iron fine particles, solid iron is once produced from raw iron ore by an iron-making operation, and is then further heated and melted, and the molten metal is subjected to gas atomization or water atomization. In general, fine particles are formed by a method (for example, see JP-A-48-257 and JP-A-48-257).
No. 9-10859).
【０００３】[0003]
【発明が解決しようとする課題】しかしながら上記の様
な技術では、製鉄操業によって鉄鉱石を溶融還元して固
体状の鉄を一旦製造した後、これを再度加熱溶融して溶
融金属とし、アトマイズ法等の微粒子製造工程を経る必
要がある。即ち、２度に亘る加熱工程が必要となって、
多くのエネルギーを必要とし、不経済である。However, in the above technique, iron ore is melt-reduced to reduce iron ore to once produce solid iron, which is then heated and melted again to form a molten metal, which is then atomized. And the like. That is, two heating steps are required,
It requires a lot of energy and is uneconomical.
【０００４】本発明はこうした技術的課題を解決する為
になされたものであって、その目的は、プロセスの簡略
化を図りつつ、鉱石または金属酸化物の粒子から直接に
且つ高速に金属微粒子を製造し、省エネルギーを達成し
て金属微粒子製造の為のコスト削減が可能な製造方法を
提供することにある。The present invention has been made to solve such technical problems, and an object of the present invention is to directly and quickly produce metal fine particles from ore or metal oxide particles while simplifying the process. An object of the present invention is to provide a manufacturing method capable of manufacturing, achieving energy saving and reducing costs for manufacturing metal fine particles.
【０００５】[0005]
【課題を解決するための手段】上記目的を達成し得た本
発明方法とは、ガス状および／または固体状還元剤によ
って還元性雰囲気を形成した気流中に、鉱石または金属
酸化物の粒子を随伴させ、該粒子を前記気流中にて予熱
・還元および溶融還元しつつ、生成する溶融金属を溶融
スラグ中で球状化せしめ、引き続き冷却して球状の金属
微粒子となす点に要旨を有するものである。The method of the present invention, which has achieved the above objects, comprises the steps of: ore or metal oxide particles are introduced into a gas stream formed by a gaseous and / or solid reducing agent in a reducing atmosphere. The gist of the present invention is that the particles are preheated / reduced and melt-reduced in the gas stream, and the resulting molten metal is spheroidized in a molten slag, followed by cooling to form spherical metal fine particles. is there.
【０００６】[0006]
【作用】本発明者らのこれまでの研究によれば、高温還
元性雰囲気の気流中で浮遊状態にある鉄鉱石粒子は、ま
ずその表面のあちこちでFe2O3 からFe1-xOへの還元が進
みつつ溶融状態になり、引き続きFe1-XOから金属鉄まで
還元された表面上の溶融鉄は中心部に次々と凝集し、中
心部が溶融鉄で構成されその表面が酸化鉄で覆われた状
態になることが分った。[Effects] According to the research conducted by the present inventors, iron ore particles suspended in a stream of high-temperature reducing atmosphere are first converted from Fe 2 O 3 to Fe 1-x O around the surface thereof. The molten iron on the surface, which has been reduced from Fe 1-X O to metallic iron, agglomerates one after another at the center, the central part is composed of molten iron, and the surface is iron oxide. It turned out to be covered with.
【０００７】上記現象が発生するメカニズムは次の様に
考察できた。図１は粒子の表面部分で還元されて生成し
た溶融鉄が中心部へ移行して酸化鉄に被覆された状態を
形成するに至るまでを段階的に示した模式図であり、図
１(a) は溶融鉄が溶融酸化鉄（スラグ）表面に存在する
状態（段階１）、図１(b) は溶融鉄が溶融酸化鉄中に埋
没浸入していく状態（段階２）、図１(c) は溶融鉄が酸
化鉄中に取り込まれた状態（段階３）を夫々示す。段階
１から段階３に至るまでのエネルギー状態（エネルギー
の差ΔＦ）を、溶融鉄の表面張力（γM ）、酸化鉄の表
面張力（γS)、および溶融鉄−酸化鉄間の界面張力（γ
M-S ）の関係で示すと、下記(1) 式の様になる。The mechanism by which the above phenomenon occurs can be considered as follows. FIG. 1 is a schematic diagram showing step by step until molten iron produced by reduction at the surface portion of the particles migrates to the center and forms a state covered with iron oxide. ) Shows the state where the molten iron exists on the surface of the molten iron oxide (slag) (step 1), and FIG. 1 (b) shows the state where the molten iron is buried and infiltrated into the molten iron oxide (step 2). ) Indicates the state in which the molten iron is taken into the iron oxide (step 3). The energy state (energy difference ΔF) from stage 1 to stage 3 is determined by the surface tension of molten iron (γ M ), the surface tension of iron oxide (γ S ), and the interfacial tension between molten iron and iron oxide ( γ
MS ), the following equation (1) is obtained.
【０００８】 ΔＦ＝γS ＋γM-S −γM …(1)ΔF = γ S + γ MS −γ M (1)
【０００９】ここでγS ≒500 ダイン／cm，γM-S ≒30
0 ダイン／cm，γM ≒1200ダイン／cmであることが分か
っているので、エネルギーの差ΔＦは明らかに負の値と
なる。従って、溶融鉄粒子が溶融酸化鉄に覆われた段階
３の状態が最も安定であることが分かる。また段階３で
は、酸化鉄内に取り込まれた溶融鉄は集合して球状化し
更に安定な状態となる。尚段階２は溶融鉄表面への溶融
酸化鉄の流動と見ることもでき、これは表面張力による
移動（いわゆるマランゴニ効果）であり、移動速度は非
常に大きい。以上のことから、溶融した鉄鉱石は還元反
応が進行しても表面が常に酸化鉄に覆われた状態であ
り、還元剤の接触によって、還元反応の急速な進行が期
待される。Here, γ S ≒ 500 dyne / cm, γ MS ≒ 30
Since it is known that 0 dynes / cm and γ M ≒ 1200 dynes / cm, the energy difference ΔF is clearly a negative value. Therefore, it can be seen that the state of stage 3 in which the molten iron particles are covered with the molten iron oxide is the most stable. In addition, in Step 3, the molten iron taken into the iron oxide is aggregated and spheroidized to be in a more stable state. Step 2 can also be regarded as the flow of the molten iron oxide to the surface of the molten iron, which is movement by surface tension (the so-called Marangoni effect), and the movement speed is very high. From the above, the surface of the molten iron ore is always covered with iron oxide even when the reduction reaction proceeds, and rapid progress of the reduction reaction is expected by contact with the reducing agent.
【００１０】本発明は上記メカニズムを効果的に利用し
たものであるが、本発明においては、気流の領域温度を
適切に調整することにより反応状況で区別できる以下の
３つの領域を形成する。即ち、(a) 鉄予熱・還元領域、
(b) 溶融還元領域および(c)冷却領域である。In the present invention, the above mechanism is effectively used. In the present invention, the following three regions which can be distinguished depending on the reaction state are formed by appropriately adjusting the region temperature of the air flow. That is, (a) iron preheating / reduction region,
(b) a smelting reduction region and (c) a cooling region.
【００１１】まず予熱・還元領域では、鉱石（または金
属酸化物）粒子は予熱されると共に、周囲に存在する還
元剤との接触により還元が進行する。例えば固体還元剤
として微粉炭を使用した場合は、微粉炭の熱分解過程で
放出される還元性ガス成分および、タール成分から鉱石
粒子表面へ炭素分析反応が生じる。この場合、該領域中
に微粉炭粒子および鉱石粒子が400 〜800 ℃になる様な
温度域をなるべく大きく取ることにより、鉱石表面への
炭素析出量を増大させ得る。次に、溶融還元領域では、
鉄鉱石の昇温・還元の進行により、溶融ウスタイトが融
出し、これが表面に析出した炭素分や周囲に存在する還
元剤と高速溶融還元反応を生じる。従って、前記予熱・
還元領域での析出炭素量が大きいほど、この領域での溶
融還元量も大きくなる。また溶融還元領域では鉄鉱石粒
子がウスタイトの融点以上に昇温される必要がある。尚
この領域では金属微粒子は球状化する（前記図１参
照）。次に、冷却領域では、溶融還元した粒子を冷却固
化し、外殻部の酸化鉄層（スラグ層）を除去する。図２
は固体還元剤として微粉炭を用いたときの鉄鉱石粒子の
各領域における反応挙動を模式的に示した図である。First, in the preheating / reducing region, the ore (or metal oxide) particles are preheated, and the reduction proceeds by contact with a surrounding reducing agent. For example, when pulverized coal is used as the solid reducing agent, a carbon analysis reaction occurs on the ore particle surface from the reducing gas component and the tar component released in the process of thermal decomposition of the pulverized coal. In this case, the amount of carbon deposited on the ore surface can be increased by setting as large a temperature range as possible in which the pulverized coal particles and the ore particles are in the range of 400 to 800 ° C. Next, in the smelting reduction area,
As the heating or reduction of the iron ore progresses, molten wustite melts, and this causes a high-speed smelting reduction reaction with the carbon component deposited on the surface and the reducing agent present in the surroundings. Therefore, the preheating
The larger the amount of precipitated carbon in the reduction region, the greater the amount of smelting reduction in this region. In the smelting reduction region, the temperature of the iron ore particles needs to be raised to the melting point of wustite or more. In this region, the metal fine particles are sphericalized (see FIG. 1). Next, in the cooling region, the melt-reduced particles are cooled and solidified, and the iron oxide layer (slag layer) in the outer shell is removed. FIG.
FIG. 3 is a diagram schematically showing a reaction behavior in each region of iron ore particles when pulverized coal is used as a solid reducing agent.
【００１２】ところで鉄鉱石の溶融還元開始温度は、予
熱・還元領域での還元の進行度合いにより変化する。例
えば予熱・還元領域でFe2O3 からFe1-xOまで還元が進行
（還元率約33％）してしまえば、溶融還元領域で、比較
的低温のウスタイト(Fe1-xO)の融点（1377℃）以上にす
れば溶融還元を開始することができる。即ち、前記予熱
・還元領域での鉄鉱石粒子の固体状での還元を進行させ
ることで、溶融還元領域の温度レベルを下げることがで
きる。また溶融還元領域の温度レベルをヘマタイト(Fe2
O3) の融点（1550℃）以上に保てば、確実に溶融還元が
進行する。The smelting reduction starting temperature of iron ore varies depending on the degree of reduction in the preheating / reduction region. For example, if reduction progresses from Fe 2 O 3 to Fe 1-x O in the preheating / reduction region (reduction rate about 33%), relatively low temperature wustite (Fe 1-x O) in the smelting reduction region If the temperature is higher than the melting point (1377 ° C.), smelting reduction can be started. In other words, the solid state reduction of the iron ore particles in the preheating / reduction region allows the temperature level of the smelting reduction region to be reduced. The temperature level of the smelting reduction region hematite (Fe 2
If the temperature is maintained at or above the melting point of O 3 ) (1550 ° C.), smelting reduction proceeds without fail.
【００１３】一方、冷却領域においては、冷却速度が大
きいほど、粒子外殻の酸化鉄を除去し易くなる。この領
域における冷却速度の目安としては-500℃／秒以上が好
ましい。尚粒子凝固後の気流の線速を上昇させると共
に、サイクロン等を用いて、粒子と障壁との衝突・接触
を促進することは、外殻の酸化鉄除去に極めて有効であ
る。On the other hand, in the cooling region, the higher the cooling rate, the easier it is to remove iron oxide in the outer shell of the particles. As a standard of the cooling rate in this region, -500 ° C./sec or more is preferable. In addition, increasing the linear velocity of the air flow after the solidification of the particles and promoting collision / contact between the particles and the barrier using a cyclone or the like are extremely effective for removing iron oxide from the outer shell.
【００１４】尚本発明で用いる鉱石の粒度は、反応効率
等を考慮すれば１mm以下であることが好ましく、より好
ましくは0.1mm 以下である。また本発明で用いるガス状
還元剤としては、ＣＯ，Ｈ2 等が挙げられ、固体状還元
剤としては、微粉炭やコークス粉等が挙げられるが、こ
れらは併用しても良い。The particle size of the ore used in the present invention is preferably 1 mm or less, and more preferably 0.1 mm or less in consideration of reaction efficiency and the like. Examples of the gaseous reducing agent used in the present invention include CO and H 2 , and examples of the solid reducing agent include pulverized coal and coke powder. These may be used in combination.
【００１５】以下本発明を実施によって更に詳細に説明
するが、下記実施例は本発明を限定する性質のものでは
なく、前・後記の趣旨に徴して設計変更することはいず
れも本発明の技術的範囲に含まれるものである。例え
ば、下記実施例では鉄鉱石から金属鉄微粒子を製造する
場合について示したが、本発明はこの様な場合に限ら
ず、各種鉱石または金属酸化物（例えば予備還元された
もの）から前述した様な各種金属微粒子を製造する為に
適用できることは言う迄もない。Hereinafter, the present invention will be described in more detail with reference to embodiments. However, the following examples are not intended to limit the present invention. Are included in the target range. For example, in the following examples, a case where metal iron fine particles are produced from iron ore is described. However, the present invention is not limited to such a case, and various kinds of ores or metal oxides (for example, pre-reduced ones) may be used as described above. Needless to say, it can be applied to manufacture various kinds of metal fine particles.
【００１６】[0016]
【実施例】図３は本発明を実施する為の装置構成例を示
す概略説明図であり、図中１は電気炉，２は鉄鉱石や微
粉炭の供給器，３は還元性ガス供給口，４は冷却用水
槽，５はサイクロンを夫々示す。尚前記水槽４は冷却を
強化する為のものであり、サイクロン５は金属鉄粒子外
殻に形成される酸化鉄層を補助的に除去すると共に、金
属鉄を採取するためのものである。FIG. 3 is a schematic explanatory view showing an example of an apparatus configuration for carrying out the present invention, wherein 1 is an electric furnace, 2 is a feeder for iron ore or pulverized coal, and 3 is a reducing gas supply port. , 4 indicate a cooling water tank, and 5 indicates a cyclone. The water tank 4 is for strengthening the cooling, and the cyclone 5 is for removing the iron oxide layer formed on the outer shell of the metal iron particles and for collecting the metal iron.
【００１７】図３に示した装置を用い、本発明方法によ
って鉄鉱石粒子から金属鉄粒子が製造される過程を調査
した。その際、電気炉の炉芯管中央部の温度を1550℃に
維持し、還元性ガスと一緒に、鉄鉱石粒子および、微粉
炭と混合した鉄鉱石粒子のそれぞれを供給した。尚ガス
流中の固体濃度は0.1 〜1.0kg/Nm3 とした。Using the apparatus shown in FIG. 3, the process of producing metallic iron particles from iron ore particles by the method of the present invention was investigated. At that time, the temperature of the central portion of the furnace core tube of the electric furnace was maintained at 1550 ° C., and iron ore particles and iron ore particles mixed with pulverized coal were supplied together with the reducing gas. The solid concentration in the gas stream was 0.1 to 1.0 kg / Nm 3 .
【００１８】鉄鉱石粒子は電気炉１上部を落下中に昇温
が進行し、還元される（電気炉１の入口より約０〜0.5
ｍの部分）。尚電気炉１の上部において鉄鉱石粒子温度
が400 〜800 ℃となる範囲ができるだけ広く取る様な温
度分布を形成することで、鉄鉱石粒子表面における微粉
炭の熱分解由来の炭素析出量を増大させる様にした。The temperature of the iron ore particles is reduced while falling down the upper part of the electric furnace 1 and the iron ore particles are reduced (about 0 to 0.5 from the inlet of the electric furnace 1).
m part). By forming a temperature distribution in the upper part of the electric furnace 1 such that the temperature range of the iron ore particle temperature of 400 to 800 ° C. is as wide as possible, the amount of carbon deposition due to the thermal decomposition of pulverized coal on the iron ore particle surface is increased. I tried to do it.
【００１９】鉄鉱石粒子は更に炉内を落下して、昇温・
還元が進行し、電気炉１の中央部の最高温度域で溶融球
状化し、周囲の還元剤と溶融還元反応を生じる（電気炉
１の入口より約0.5 〜0.6 ｍの部分）。尚溶融還元が開
始する時点で、鉄鉱石粒子は約1400〜1500℃以上に昇温
されていた。The iron ore particles further fall in the furnace, and
The reduction proceeds, and melts and spheroidizes in the highest temperature range in the central part of the electric furnace 1 to cause a smelting reduction reaction with the surrounding reducing agent (a part of about 0.5 to 0.6 m from the inlet of the electric furnace 1). When the smelting reduction started, the iron ore particles had been heated to about 1400 to 1500 ° C. or higher.
【００２０】金属鉄粒子が生成させた後、鉄鉱石粒子は
更に落下して電気炉１下部の冷却域において急冷される
（電気炉１の入口より約0.6 〜1.0 ｍの部分）。尚この
とき冷却速度は約-500℃／秒であった。After the metallic iron particles are generated, the iron ore particles further fall and are rapidly cooled in a cooling zone below the electric furnace 1 (a portion approximately 0.6 to 1.0 m from the inlet of the electric furnace 1). At this time, the cooling rate was about -500 ° C / sec.
【００２１】上記の様な条件で本発明を実施したとこ
ろ、鉄鉱石粒子を供給した場合と、微粉炭と混合した鉄
鉱石粒子を供給した場合において、還元率が若干異な
り、後者の方が良好であったが、いずれの場合も良好な
金属鉄粒子が得られていた。When the present invention was carried out under the above conditions, the reduction ratio was slightly different between the case where iron ore particles were supplied and the case where iron ore particles mixed with pulverized coal were supplied, and the latter was better. However, in each case, good metallic iron particles were obtained.
【００２２】[0022]
【発明の効果】本発明は以上の様に構成されており、還
元性気流中に粉鉱石や金属酸化物の粒子を随伴させ、該
気流中で前記粒子を予熱・還元および溶融還元並びに冷
却を行なうことによって、直接にしかも球状の金属微粒
子を高速に製造することができ、プロセスの簡略化およ
び粒子製造コストの削減が可能になった。The present invention is constituted as described above, in which particles of fine ore or metal oxide are accompanied in a reducing gas stream, and the particles are preheated / reduced, melt-reduced and cooled in the gas stream. By doing so, spherical metal fine particles can be directly produced at a high speed, and the process can be simplified and the particle production cost can be reduced.
【図１】還元されて生成した溶融鉄が酸化鉄に被覆され
るに至るまでを段階的に示した模式図である。FIG. 1 is a schematic view showing step by step until molten iron produced by reduction is coated with iron oxide.
【図２】固体還元剤として微粉炭を用いたときの鉄鉱石
粒子の各領域における反応挙動を模式的に示した図であ
る。FIG. 2 is a diagram schematically showing a reaction behavior in each region of iron ore particles when pulverized coal is used as a solid reducing agent.
【図３】本発明を実施する為の装置構成例を示す概略説
明図である。FIG. 3 is a schematic explanatory view showing an example of a device configuration for implementing the present invention.
１ 電気炉 ２ 供給器 ３ 還元性ガス供給口 ４ 冷却用水槽 ５ サイクロン DESCRIPTION OF SYMBOLS 1 Electric furnace 2 Supply device 3 Reducing gas supply port 4 Cooling water tank 5 Cyclone
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭59−85804（ＪＰ，Ａ) 特開 平１−191705（ＪＰ，Ａ) 特開 平４−210411（ＪＰ，Ａ) 特開 平３−31401（ＪＰ，Ａ) 特公 昭32−6612（ＪＰ，Ｂ１) (58)調査した分野(Int.Cl.7，ＤＢ名) B22F 9/26 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-59-85804 (JP, A) JP-A-1-191705 (JP, A) JP-A-4-210411 (JP, A) JP-A-3- 31401 (JP, A) JP-B 32-6612 (JP, B1) (58) Fields investigated (Int. Cl. 7 , DB name) B22F 9/26
Claims (1)
って還元性雰囲気を形成した気流中に、鉱石または金属
酸化物の粒子を随伴させ、該粒子を前記気流中にて予熱
・還元および溶融還元しつつ、生成する溶融金属を溶融
スラグ中で球状化せしめ、引き続き冷却して球状の金属
微粒子となすことを特徴とする球状金属微粒子の高速製
造方法。An ore or metal oxide particle is made to accompany a gas stream formed with a reducing atmosphere by a gaseous and / or solid reducing agent, and the particles are preheated / reduced and melt-reduced in the gas stream. While melting the generated molten metal
A method for producing spherical metal fine particles at a high speed , comprising spheroidizing in slag and subsequently cooling to form spherical metal fine particles.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23493592A JP3185394B2 (en) | 1992-09-02 | 1992-09-02 | High-speed production method of spherical metal fine particles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23493592A JP3185394B2 (en) | 1992-09-02 | 1992-09-02 | High-speed production method of spherical metal fine particles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0681012A JPH0681012A (en) | 1994-03-22 |
| JP3185394B2 true JP3185394B2 (en) | 2001-07-09 |
Family
ID=16978582
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23493592A Expired - Lifetime JP3185394B2 (en) | 1992-09-02 | 1992-09-02 | High-speed production method of spherical metal fine particles |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3185394B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3772967B2 (en) * | 2001-05-30 | 2006-05-10 | Ｔｄｋ株式会社 | Method for producing magnetic metal powder |
| KR102642963B1 (en) * | 2021-09-07 | 2024-03-05 | 한국생산기술연구원 | Method of manufacturing metal nanopowder using vapor synthesis |
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1992
- 1992-09-02 JP JP23493592A patent/JP3185394B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0681012A (en) | 1994-03-22 |
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