JP2003267730A - METHOD FOR PRODUCING FeO POWDER - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an FeO powder in a large amount and efficiently by treating a dust containing an iron component as a recycling raw material. <P>SOLUTION: The method comprises a step for pelletizing the dust containing an iron component to obtain pellets, a step for heating the pellets at 600-1,100°C and under a vacuum of 1.33-13.3 kPa to convert the iron component contained in the pellets into FeO, and a step for rapidly cooling the powdered FeO to ≤300°C and under a vacuum of not more than 13.3 kPa. Further the pellets can include a reducing agent (iron powder or the like) having an average particle size of not more than 200 μm. The method can comprise before the step for pelletizing a step for washing the dust with water to remove a chlorine component and a step for removing the washing water containing dissolved chlorine. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently producing a large amount of FeO powder by treating electric furnace dust, blast furnace dust, converter dust, etc. generated in a steelmaking process as a recycling raw material. The FeO powder produced by the present invention is used as an agricultural or horticultural fertilizer for supplying divalent iron ions, a water purification material, a constituent material of an electromagnetic wave absorber, and the like.

[0002]

2. Description of the Related Art Conventionally, FeO powder is manufactured on a small scale in a laboratory or the like. For example, an iron plate having a thickness of about 6 mm is placed in a heating furnace having a low oxygen partial pressure atmosphere and heated at 750 ° C. or higher for 24 hours or longer. In this way, a mass of FeO is obtained, and a powder is obtained by crushing. As another method, there is a method in which iron powder is placed in a heating furnace in a low oxygen partial pressure atmosphere and heated at 750 ° C. or higher for a long time. In this case, since the iron powder is sintered, the FeO powder is obtained by crushing.

[0003]

The raw material of the FeO powder in the above manufacturing method is iron itself, and the electric furnace dust, blast furnace dust, converter dust, etc. generated in the steelmaking process are recycled as the raw material, and the FeO powder is used. And a large amount
It is the actual situation that a method for producing it so as not to be over-oxidized like e ₃ O ₄ and Fe ₂ O ₃ has not been studied yet.

[0004]

Means for Solving the Problems The present inventors have conducted a study on a method for efficiently producing FeO powder in a large amount by treating dust containing an iron component as a recycling raw material, and as a result, completed the present invention. It was That is, FeO of the present invention
The manufacturing method of the powder is a granulation step of granulating dust containing an iron component to manufacture a granulated product, and heating the granulated product in a vacuum,
A heating step in which the iron component contained in the granulated product is FeO;
And a cooling step of rapidly cooling powdered FeO in a vacuum.

Before the granulation step, a dust cleaning step of removing chlorine components by washing the dust with water, and a cleaning water removal step of removing cleaning water in which chlorine is dissolved are provided. be able to.

It is possible that the above dust contains 40% by mass or less (including 0% by mass) of metallic iron with respect to the total amount of iron. Further, the granulated product may further contain a reducing agent having an average particle diameter of 200 μm or less. The reducing agent may include metallic iron. Further, the shortest distance from the center to the surface of the granulated product produced by the granulation step is 2
It can be 5 mm.

The above heating process is performed at 1.33 to 13.3 kP.
It may be heated in the temperature range of 600 to 1,100 ° C. under the vacuum of a. The cooling rate in the cooling step may be 5 to 150 ° C./minute. Further, after the cooling step, a recovery step of recovering the discharged FeO powder can be provided.

[0008]

According to the method for producing FeO powder of the present invention,
For example, dust containing iron components is processed as a recycled raw material.
However, it is possible to efficiently produce FeO powder in a large amount.
Wear. According to the method for producing FeO powder of the present invention, dust
Superior to the granulated product obtained by granulating
The uniform thermal conductivity ensures uniform heating,
The reaction proceeds smoothly. Obtained by the heating process
FeO is cooled rapidly under a given vacuum.
Therefore, it is possible to collect it while maintaining its state. Immediately
Then, FeO is further oxidized to another oxidation state such as F
e_ThreeO_Four, Fe_TwoO _ThreeAs powder without
Obtainable. In addition, reduction of metallic iron etc. to the above granulated product
By including an agent, other gold can be added during the above heating process.
Metal components such as zinc are reduced to form metallic state.
And can be collected. Iron-made by dust cleaning process
Can reduce the chlorine concentration in dust containing
It Dust with a low chlorine concentration is dust during vacuum heating.
Are less likely to agglomerate, which causes dusty dust
You can prevent life.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The "dust" according to the present invention is not particularly limited as long as it contains an iron component. The content is not limited either. The shape of the dust is usually powder, but is not limited thereto, and may be small pieces of dust. In the case of powder, the average particle diameter is generally 3 to 10 μm. Examples of the dust include electric furnace dust, blast furnace dust, converter dust, cupola dust, and forged shot dust. The iron component contained in these dusts is usually contained as an oxide or as a mixture of iron oxide and metallic iron.
It is preferable that metallic iron is contained in an amount of 40% by mass or less (including 0% by mass) with respect to the total amount of iron. It is more preferably 30% by mass or less (including 0% by mass). In the FeO powder manufacturing method of the present invention, the dust is 1
They may be used alone or in combination of two or more. The components contained in the dust are generally other metal components such as Zn, Ni, Cu and Mn in addition to the iron component. The existing state of these is not particularly limited.

The above-mentioned "granulated product" produced in the above-mentioned granulating step is molded by vacuum heating so that the following reaction can proceed efficiently. Fe ₂ O ₃ + Fe → 3FeO ... (1) Fe ₃ O ₄ + Fe → 4FeO ... (2) Fe + 1 / 2O ₂ → FeO ... (3) However, the above (1) to ( 3) indicates that the dust contains at least metallic iron. The granulated product is
It may be formed by pressing only dust, or may be formed by pressing a mixture of dust and other processing material. Further, in order to maintain the shape as a granulated product, the above components may be solidified with a binder or the like. The other treatment material is added as necessary in consideration of the existence state and content of the iron component and other metal components contained in the dust. For example, when the content of iron component contained in dust is small, FeO
The total amount of iron can be increased by adding cutting scraps or polishing scraps containing iron components, iron powder, etc. for the purpose of mass production of powder, improvement of efficiency in one operation, and the like. Further, a reducing agent or the like can be added in order to accelerate the reaction and recover other metal components contained in the dust in a metal state. In particular, when the dust contains a zinc component (usually contained as an oxide ZnO) and is recovered as metallic zinc at the same time as the production of the FeO powder, the cutting containing the metallic iron exemplified for the supplementation of the above iron component. In addition to scraps and polishing scraps, it is preferable to use, as a reducing agent, an iron-based reducing agent such as pig iron and steel, and a material containing a large amount of carbon such as tire scraps. Metallic iron is preferable as the reducing agent. The reducing agents may be used alone or in combination of two or more. When the dust contains an oxide of another metal component, for example, zinc oxide, and metallic iron is used as the reducing agent, the reaction (4) proceeds. ZnO + Fe → Zn + FeO (4)

When another processing material such as a reducing agent is used, its shape is not particularly limited as long as it can mold the above-mentioned dust and granulated product, but powder, granular, small pieces and the like are used. be able to. When used as a reducing agent, a powdery material having a high contact rate is preferable in consideration of reaction efficiency and reduction efficiency of other metal oxides contained in the dust. The average particle diameter is preferably 200 μm or less, more preferably 180 μm or less. The lower limit is the fine powder that can be handled.

When the reducing agent is used, the mixing ratio of the dust and the reducing agent is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, when the dust is 100 parts by mass. It is more preferably 80 parts by mass or less. The lower limit is usually 30 parts by mass. 1
If it exceeds 100 parts by mass, the treatment efficiency may decrease, while if it is less than 30 parts by mass, reduction of oxides of other metal components such as zinc oxide may be incomplete.

The granulated product is usually formed by mixing the above dust, or a mixture of the above dust and other processing material with a binder. The binder is not particularly limited, but examples thereof include alumina cement, starch, bentonite, phenol resin, furan resin, water glass and the like. Of these, alumina cement, starch, and bentonite are preferably used because they do not pose a problem of smoke or odor even if they are volatilized during the treatment. The amount of the binder used is preferably 3 when the total amount of the dust or the mixture of the dust and other processing material is 100 parts by mass.
To 20 parts by mass, more preferably 3 to 15 parts by mass, still more preferably 3 to 12 parts by mass. If the amount is less than 3 parts by mass, the amount of the binder is too small to make the molding difficult. If the amount is more than 20 parts by mass, the water content in the granulated product evaporates, the granulated product becomes brittle and the amount of gas generated from the binder increases. It is not preferable because In addition, in order to proceed the reaction efficiently, it is preferable to remove moisture from the produced granulated product by drying or the like before the heating step.

The shape of the granulated product is not particularly limited, and may be spherical, elliptic spherical, hemispherical, cubic, rectangular parallelepiped, cylindrical, briquette-shaped or the like. Further, it may not be densely molded. In order to transfer heat to the entire granulated product by heating, or to maintain the shape of the granulated product during the heating process, considering the heat conduction from the start of heating to the target heating temperature, The shortest distance from the center of the granule to the surface is preferably 25 mm or less, more preferably 1
It is 5 mm or less, more preferably 10 mm or less. However, the lower limit is usually 3 mm. When it exceeds 25 mm, it is difficult to reach the heating temperature inside the granulated product and the reaction does not proceed, which is not preferable. If it is less than 3 mm, adhesion between the dust particles may occur, and the reaction may not proceed even if heated. As an example of the above granulated product, a spherical granulated product having a maximum diameter of 50 mm can be used in the case of a sphere, and a cubic granulated product having a maximum side length of 50 mm in the case of a cube. Can be used. Regarding the heat conduction of the granulated product, the effect due to the radiant heat is better exhibited when the granulated product has a certain amount of voids than when the inside of the granulated product is dense.

The above heating step is an important step involving a reaction for obtaining FeO powder. That is, the granulated product is heated in a vacuum, and the iron component contained in the granulated product is reacted in the reaction (1).
FeO is obtained by at least one of (3) to (3). When the dust contains an oxide of another metal component, for example, zinc oxide, the above reaction (4) proceeds, and the produced zinc evaporates under the condition of 600 ° C. or higher, usually higher than 1.56 kPa. Therefore, it can be recovered in a metal state in the heating step. In this case, a heating step for converting the iron component contained in the dust or the like into FeO and a metal recovery step for recovering the other metal component such as zinc in a metal state can be provided.

In the heating step, the "vacuum degree" is not particularly limited as long as at least one of the reactions (1) to (3) proceeds efficiently. In order to proceed the above reaction efficiently, the degree of vacuum is preferably 0.1 to 13.
It is 3 kPa, more preferably 2.6 to 13.3 kPa, and further preferably 4.0 to 6.7 kPa. If the degree of vacuum is too low, a large amount of iron not used in the reaction tends to remain without being oxidized, while if the degree of vacuum is too high, the generated Fe
O tends to be oxidized to Fe ₃ O ₄ , and further, the reduction reaction of oxides of other metal components, such as zinc oxide, becomes difficult to proceed.

The low vacuum state as described above also means that a small amount of oxygen is present, and the heating may be performed in an inert gas atmosphere having an oxygen partial pressure equivalent to the above preferable vacuum conditions.

In the heating step, the conditions are not particularly limited as long as the heating is performed while satisfying the vacuum conditions. The heating may be such that the granulated product is placed in the system and heated from room temperature to a target temperature and held at that temperature, or set to a temperature lower than the target temperature. The granulated product may be charged into a certain system, heated to a target temperature and held at that temperature. The granulated product may be charged and held at that temperature. Even if the temperature is required to be raised, the rate of temperature rise is not particularly limited. The heating temperature is preferably 60
It is 0-1100 degreeC, More preferably, it is 800-950 degreeC. If it is less than 600 ° C, the recovery rate as FeO is low,
If it exceeds 1,100 ° C., the above dust may be partially melted, which is not preferable. When a granulated product containing an iron-based reducing agent or the like is treated in order to recover metal components other than iron in a metallic state, it is preferable that the heating temperature is 800 ° C or higher. Further, since the constituent material of the furnace must be expensive and requires heat resistance (particularly refractory and vacuum sealing system), it is preferably 950 ° C. or lower.

The heating time at the preferable temperature is not particularly limited as long as the granulated product is heated to a substantially uniform temperature. Preferably 30 minutes or more, more preferably 3
It is from 0 minutes to 6 hours. If the heating time is short, the above reaction may not proceed sufficiently and the FeO recovery rate may decrease. Moreover, if the heating time exceeds 6 hours, the probability of causing the adhesion of the powders becomes high. Further, the upper limit was set to 6 hours because it is affected by productivity. Further, the combination of the reduction temperature and the heating time is preferably 90 minutes or longer at 800 to 850 ° C, preferably 60 minutes or longer at 850 to 900 ° C, and preferably 30 minutes or longer at 900 to 950 ° C.

The above-mentioned granulated product is usually treated using a heat treatment furnace. The heat treatment furnace is not particularly limited as long as it has at least a heater and can heat the granulated product to be charged uniformly. Examples of this heat treatment furnace include a roller hearth and a rotary kiln. Further, a recovery device for recovering metallic zinc or the like generated by the reduction may be provided. Considering the heat conduction to the whole granulated product processed in the heat treatment furnace, the stacking height of the granulated product is
Usually 100 mm or less, more preferably 80 mm or less,
More preferably, it is 30 mm or less. In this way
The granulated product is heated, and the iron component becomes powdery FeO due to the above reaction and volatilization and evaporation from the inside.

The inside of the collector provided for recovering the metallic zinc or the like is usually preferably in a vacuum state in order to prevent oxidation. Metallic zinc or the like is melted in this collector and then solidified into an ingot.
This is because the ingot is convenient for the subsequent use of the recovered metal.

The cooling step is the most important step for keeping the powdery FeO produced in the heating step in that state. The cooling step is to rapidly cool the FeO in vacuum. The preferred vacuum degree is 13.3k
Pa or less, more preferably 6.7 kPa or less, still more preferably 1.33 kPa or less. If the degree of vacuum is too high, FeO is oxidized and Fe ₃ O ₄ or Fe _{2 is} added.
It may be O ₃ or the like. The rate of temperature decrease is preferably 5 to 150 ° C / min. If the cooling rate is too low,
FeO may be oxidized to Fe ₃ O ₄ or Fe ₂ O ₃ or the like. Furthermore, in the cooling step, it is preferable to cool the temperature to 300 ° C. or lower under the above conditions. still,
More preferably 200 ° C or lower, further preferably 150 ° C
It is the following.

By providing a recovery step subsequent to the cooling step, it is possible to efficiently recover iron without changing the existing state of iron from FeO. In the recovery step, the cooling step may be kept in a vacuum,
You may return to atmospheric pressure in steps.

In the method for producing FeO powder according to the present invention,
In order to obtain higher recovery of FeO, the above reaction (1)
Of (3) to (3), it is preferable to proceed at least two reactions including the above reaction (3). That is, it is preferable that the above-mentioned granulated product as the article to be heated contains metallic iron. The content is preferably 5% by mass or more, and more preferably 5 to 8 with respect to the total amount of iron constituting the granulated product.
It is 5% by mass, more preferably 8 to 50% by mass. With this, in the powder finally obtained in the present production method, the content ratio of FeO converted from the total iron amount can be preferably 85% or more, more preferably 90% or more.

Examples of the constituent raw materials of the granulated product containing iron in the metallic state as described above include the following. The binder and the like are omitted. (A) Electric furnace dust + metal state iron (iron powder, etc.) (b) Blast furnace dust + metal state iron (iron powder, etc.) (c) Converter dust only (d) Forging shot dust only, (o) ) Forged shot dust + metal iron (iron powder, etc.)

In the dust cleaning step, the method of washing the dust with water is not particularly limited. It is sufficient that the chlorine component contained in the dust is sufficiently dissolved by water by washing with water. Examples thereof include a method in which dust is put into a container filled with water and stirred, and a method in which water is continuously flown into a container containing dust. Considering the amount of water used and the chlorine component removal efficiency, a method of washing with water in a rotary of a rotary mixer car is preferable. The mass ratio of the dust to the cleaning water in the dust cleaning step is not particularly limited. Moreover, the cleaning time is not particularly limited.

In the washing water removing step, the method of removing water from the washed dust is not particularly limited, but examples thereof include draining by filtration, filter pressing, centrifugation and the like. Of these, the method using a filter press is preferably used. The chlorine component contained in the dust after the washing water removal step is preferably 0.5% by mass or less, more preferably 0.4% by mass or less,
More preferably, it can be reduced to 0.3% by mass or less. Further, in the cleaning water removing step, water may or may not be completely removed. When the water remains, it can be effectively utilized when forming a granulated product in the granulating step. When water remains, the upper limit of the amount of water is preferably 20% by mass, more preferably 15% by mass, and particularly preferably 12% by mass, based on 100% by mass of the dust after the washing water removal step.

According to the production method of the present invention, the FeO content converted from the total iron content can be preferably 85% or more, more preferably 90% or more. Further, by changing the manufacturing conditions of the FeO powder in which powders having a particle diameter of 5000 μm or less and powders of various particle sizes are mixed,
It is also possible to obtain a porous powder. The porous FeO powder can be used as a water purification material or the like by using it in combination with SiO ₂ , MgO, CaO or the like.

[0029]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 As a raw material, electric furnace dust whose composition is shown as "A" in Table 1 was used. The average particle size is 10 μm. 1 t of this electric furnace dust is put in a tank filled with 10 t of water
Washed for hours. After that, squeeze the water with a filter press,
The electric furnace dust was a clay-like cake containing 12 to 30% water. The composition at this time is shown as "B" in Table 1. In the table, “T.Fe” represents the total iron content in the sample, and “M.Fe” represents the pure iron content. Each component was quantified by a chemical analysis method, and metallic iron and FeO were distinguished by an X-ray diffraction method. The same applies below. The cake and a powder having a composition of “C” were passed through a 1 mm mesh sieve so that the mass ratio of the dry mass of the electric furnace dust was 1: 1, and iron powder (made by Kawasaki Steel) was put into a mix muller. Further, 5% by mass of the dry mass of the electric furnace dust was added to the alumina cement. This mixture was kneaded for 1 minute, the water content was adjusted to 9 to 11%, and the mixture was discharged. A columnar granulated product having a diameter of 8 mm and a length of about 20 mm was produced from this mixture by a vertical extrusion molding machine. This granulated product was placed in a drying oven and dried at 400 ° C. for 60 minutes. Total 41 of this granulated product
0t was continuously processed using the apparatus shown in FIG.

In FIG. 1, the granulated product is put into the hopper 11 of the material supply system 1, replaced with a vacuum atmosphere, and sent to the vacuum heating furnace 21 of the vacuum heating system 2. Vacuum heating furnace 21
Has four chambers, each of which is partitioned by a bottom portion 24, and each chamber has a heater 25 for heating the granulated product 5 mainly by radiation heat transfer. An opening for dropping the granulated product 5 into the lower chamber is provided at an appropriate position on the bottom portion 24. Also,
The stirrer 23 has a function of rotating, extends through the four-stage chamber of the vacuum heating furnace 21, and stirs the granulated product 5 on the bottom 24 of each stage. The stirrer 23 is continuously rotated by the rotation driving means of the motor 234. Stirrer 23
Has a shaft 231, a rotary blade 232 attached to the shaft 231, a stirring member 233 extending from the rotary blade 232 toward the bottom portion 24 of the vacuum heating furnace 21, and a motor 234. Inside the vacuum heating furnace 21, the internal pressure is set to 1.3 to 2 kPa using a vacuum pump, the heater temperature of the upper first-stage chamber 211 is set to 800 ° C., and the heater temperature of the second-stage chamber 212 is 850. Is set to ℃, lower third and fourth tier chambers (213, 214) and fourth tier chamber 21
The temperature of the heater 25 of the lower chamber 215 of 4 is set to 900 ° C. The granulated product 5 stays while being stirred in each chamber for 30 minutes by adjusting the rotation speed of the stirrer, and sequentially drops into the lower chamber. Therefore, the granulated product is heated at 800 ° C. for 30 minutes, 850 ° C. for 30 minutes, and 900 ° C. for 1 hour. The granulated product changes into powder during stirring.

The obtained powder is vacuumed in a vacuum heating furnace 2
Cooling system 26 by means of the discharge feeder 22 connected to 1.
Discharged to. Then, the powder was vacuum-cooled to 400 ° C. in the cooling system 26 at a temperature lowering rate of 20 ° C./min.
Then, the cooling system 26 is replaced with nitrogen gas, and the cooling rate is set to 13
Cooled to 200 ° C at 0 ° C. After that, the temperature is further lowered and discharged,
Recovered. The composition of the obtained powder is designated as "D". Also,
At the same time, zinc was evaporated in the above heating and recovered as metallic zinc.

[0032]

[Table 1]

Example 2 The same as Example 1 except that the iron powder having the composition “C” used in Example 1 was replaced with the forged shot dust having the composition “E” in Table 2. To produce FeO powder. The "forged shot dust" is a powder obtained when the surface of the heat-treated forged product is ground with shot balls, and has an average particle diameter of 100 µm. The composition of the obtained powder is designated as "F".

[0034]

[Table 2]

Example 3 An FeO powder was produced in the same manner as in Example 1 except that the forged shot dust collected in Example 2 was used as a raw material. The composition of the granulated product obtained using alumina cement is "G", and the composition of the finally obtained powder is "H".
The composition is shown in Table 3.

[0036]

[Table 3]

Reference Example As the raw material, converter dust having a composition shown in Table 4 as "I" was used. 10 g of this converter dust was sampled in a quartz tube, the internal pressure was adjusted to 0.1 kPa using a vacuum pump, and then heated in a resistance heating furnace at 900 ° C. for 1 hour. After that, the quartz tube was taken out of the furnace while being kept in a vacuum, and naturally cooled by air (an air cooling fan or the like may be used). The composition of the obtained powder was designated as "J", and its composition is shown in Table 4.

[0038]

[Table 4]

Effect of Example When comparing A and B in Table 1, the chlorine content was reduced to 0.5 mass% by washing the electric furnace dust with water, so that large lumps were generated in the subsequent vacuum heat treatment. I was able to continue the operation to the end without doing.
Example 1 is an example in which B and C (iron powder) were mixed and heated in vacuum. The iron powder has two purposes of supplying the iron component to the object to be treated and acting as a reducing agent. In the obtained D, it can be seen that the content ratio of FeO to the total iron content is high and the zinc component is recovered as metallic zinc. Example 2 (Table 2) is an example in which B and E (forged shot dust containing metal iron and other iron components in the existing state) were mixed and heated in vacuum, and F obtained later was It can be seen that the content ratio of FeO and the recovery ratio of metallic zinc with respect to the total iron amount are higher than those in Example 1 described above. Example 3 is an example in which the above-mentioned forged shot dust is used as the object to be treated, and since it does not contain a zinc component, zinc metal is not recovered and the main purpose is to produce FeO.
From H in Table 3, the content ratio of FeO to the total iron content is 90.
It turns out that it is excellent with%.

In Examples 1 to 3, among the iron components contained in the object to be treated, the ratio of the content of metallic iron to the total iron content is shown in Table 5. As compared with Example 1 in which the ratio of the content of metallic iron to the total amount of iron was 63.1% by mass before the treatment, which was high, Examples 2 and 3 having smaller values were
Due to the vacuum heat treatment, F for a small amount of total iron
The content of eO is high and the content of metallic iron is low. The reason why a large amount of metallic iron remained in Example 1 is considered to be that the oxidation did not proceed to the inside of the particle size because the metallic iron powder as a reducing agent contained a powder having a large particle size as compared with the other Examples. . In addition, in the data shown in Table 4 as a reference example, the content of metallic iron before treatment is about 40% by mass, and although the manufacturing conditions are completely different, the content of metallic iron with respect to the total amount of iron by vacuum heating treatment Was as low as 0.7% by mass, and the FeO content relative to the total iron content was 99% by mass, which was remarkably excellent. In this reference example, since the purpose of recovering metallic zinc was not intended, it was still evaporated by vacuum heating and was not recovered.

The present invention is not limited to the above embodiments, but can be variously modified within the scope of the present invention depending on the purpose and application. For example, an Erich rear-flow high-speed mixer can be used instead of the mix muller for mixing the dust cake with the reducing agent.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an apparatus for producing FeO powder used in Example 1.

Continued front page    (72) Inventor Hirohiko Sasamoto             1 Wano Wari, Arao-cho, Tokai-shi, Aichi Made in Aichi             Within Steel Co., Ltd. F-term (reference) 4D004 AA37 AC04 BA04 BA10 CA14                       CA15 CA22 CA32 CA37 CA40                       CA42 CB27 CB31 CB45 CC11                       DA03 DA06 DA07 DA20                 4G002 AA02 AB02 AC03 AD04 AE05                 4K001 AA10 BA14 CA11 CA17 EA02

Claims (9)

[Claims] 1. A granulation step of granulating dust containing an iron component to produce a granulated product, and heating the granulated product in a vacuum so that the iron component contained in the granulated product is FeO. A method for producing FeO powder, comprising: a heating step; and a cooling step of rapidly cooling powdered FeO in a vacuum. 2. A dust washing step of removing chlorine components by washing the dust with water, and a wash water removing step of removing wash water in which chlorine is dissolved, before the granulating step. Item 2. A method for producing FeO powder according to Item 1. 3. The method for producing FeO powder according to claim 1, wherein the dust contains 40% by mass or less (including 0% by mass) of metallic iron with respect to the total amount of iron. 4. The granulated product further has an average particle size of 20.
The method for producing FeO powder according to claim 1, wherein a reducing agent having a particle size of 0 μm or less is contained. 5. The method for producing FeO powder according to claim 4, wherein the reducing agent contains metallic iron. 6. The method for producing FeO powder according to claim 1, wherein the shortest distance from the center to the surface of the granulated product produced by the granulating step is 25 mm. 7. The heating step comprises 1.33 to 13.3 k
The method for producing FeO powder according to claim 1, wherein the FeO powder is heated to a temperature range of 600 to 1,100 ° C. under a vacuum of Pa. 8. The cooling rate in the cooling step is 5 to 1
The F according to any one of claims 1 to 7, which is 50 ° C / min.
Method for producing eO powder. 9. The method for producing FeO powder according to claim 1, further comprising a recovery step of recovering discharged FeO powder after the cooling step.