WO1996028381A1

WO1996028381A1 - Process for producing iron carbide and equipment therefor

Info

Publication number: WO1996028381A1
Application number: PCT/JP1996/000608
Authority: WO
Inventors: Eiji Inoue; Yoshio Uchiyama; Junya Nakatani
Original assignee: Kawasaki Jukogyo Kabushiki Kaisha; Mitsubishi Corporation
Priority date: 1995-03-10
Filing date: 1996-03-11
Publication date: 1996-09-19
Also published as: DE19681132T1; JPH08245212A; JP2635945B2; AU695168B2; ATA902096A; AU4891196A

Abstract

A powdery ore is preheated with hot air in a preheating furnace (2) and sent into a fluidized-bed reaction furnace (1). Iron oxide particles contained in the gas discharged from the furnace (2) are recovered in a dust collector (3) and are reduced in a reduction furnace (4). The reduced iron particles are fed into the passage leading to the reaction furnace (1), where they act as a catalyst for accelerating iron carbide formation.

Description

Specification

"Method and apparatus for manufacturing eye anchors" [Technical field]

The present invention relates to a method and an apparatus for producing iron carbide as iron carbide from iron oxide such as hematite.

(Background technology)

To charged with Matthew Bok (F e ₂ 0 ₃₎ particles in a fluidized bed type reaction furnace to produce iron card by de (F e ₃ C) Grain child while fluidized by the reaction gas prior art, for example, Japanese It is disclosed in the Patent Gazette (PCT / US91 / 05198) published in Table 6-6-5019803. In this prior art, was charged with preheated iron ore particles in a fluidized bed type reaction furnace, - carbonized by a reaction gas including carbon oxides (CO), Seme emissions Thai preparative (F e ₃ C) Iron such as Produce carbide particles. If iron ore containing a large amount of iron oxide such as hematite can be efficiently converted to iron carbide, iron ore can be directly used as an iron source in steelmaking furnaces such as electric furnaces. This is a powerful technique for extracting iron from steel.

FIG. 6 shows the change of the composition with the lapse of the reaction time shown in FIG. The ferrate product to be charged at time 0, F e ₃ 0 ₄ is about _{6 0%, F e 2 0} 3 is contained about 4 0%. Iron oxide has been charged is being converted into iron carbide (F e ₃ C), in the latter stage of the reaction (4-6 hours), generation of iron carbide speed de is significantly reduced. Reducing the F e ₃ 0 ₄ or iron oxides such as F e 0, in order to obtain iron carbide (F e ₃ C) at a high conversion rate, furthermore the long It turns out that a reaction is required. In a fluidized bed reactor, a long flow path is required to keep particles in the furnace for a long time. Also, in order to obtain a large amount of iron carbide, the cross-sectional area of the flow channel must be increased. Therefore, in order to obtain a large amount of iron carbide at a high conversion, it is necessary to install a large fluidized bed reactor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for producing an eye anchor binder which can increase the production rate of iron carbide in the latter stage of the reaction and can efficiently produce the fluidized bed reactor without increasing the size of the reactor. _C [Disclosure of the Invention]

In order to achieve the above object, the present invention provides a method for producing an anchor oxide, in which iron oxide particles are charged into a fluidized bed reactor and carbonized while being fluidized by a reaction gas. It is characterized in that iron (F e) particles are injected from the middle of the flow of material particles. In this way, iron oxide particles are charged into a fluidized bed reactor, and iron particles are introduced into the flow path for converting the iron force into one byte, whereby the iron particles are removed from the monoxide contained in the reaction gas. It has an action of a catalyst to promote decomposition to 2 C 0 → C + C 0 2 of the reaction of carbon (C 0), the conversion of iron oxide to iron force one by de iron carbide Promote. Thus, by introducing iron particles as a catalyst in the latter stage of the reaction, the generation rate of eye anchors can be improved.

Further, the present invention is characterized in that the iron particles are charged at a plurality of locations, and the particle size of the iron particles to be charged is reduced toward the downstream side. Iron particles are injected into the flow channel from a plurality of locations, and the particle size of the input iron particles is made smaller toward the downstream side, so that it can easily act as a catalyst even in a short time until the end of the flow channel. After that, it converts itself to iron carbide. Further, the iron particles of the present invention are characterized in that the iron particles are recovered from the exhaust gas when preheating the iron oxide particles, reduced and generated. In this way, iron oxide particles are recovered from the exhaust gas generated when the iron oxide particles charged into the fluidized bed reactor are heated, reduced, and then introduced into the flow path of the fluidized bed reactor. By generating iron particles, the iron oxide particles discharged in the exhaust gas during preheating are smaller in particle size than the iron oxide particles charged into the fluidized bed reactor, and Since the fine particles are reduced and injected from the middle of the flow channel, they can effectively function as a catalyst even in a short time, and then become iron carbide.

Further, the present invention provides an apparatus for producing an anchor carbide in which iron oxide particles are charged into a fluidized bed reactor and carbonized while being fluidized by a reaction gas, wherein the preheating means for preheating the iron oxide particles by hot air And a collecting means for collecting the iron oxide particles from the exhaust gas of the preheating means, and a reducing means for reducing the iron oxide particles collected by the collecting means and introducing the reduced iron oxide particles into a fluidized bed reactor. And According to the iron anchor carbide manufacturing apparatus of the present invention having such features, the iron oxide particles preheated by the preheating means are charged into a fluidized bed reactor to manufacture iron carbide. Iron oxide particles are recovered from the exhaust gas of the preheating means by the recovery means, reduced by the reduction means, and fed into the fluidized bed reactor. The iron oxide particles recovered from the exhaust gas have a smaller particle size than the preheated iron oxide particles charged into the fluidized bed reactor. Therefore, the iron particles reduced by the reducing means and fed into the channel of the fluidized-bed reactor have a smaller particle size than the iron oxide particles that react in the fluidized-bed reactor. After accelerating the reaction in a shorter time as a catalyst for the conversion to carbides, the iron itself becomes iron carbide.

Further, the apparatus for producing an eye anchor byte according to the present invention, wherein the reducing means and Classification means for classifying the reduced iron oxide particles into a plurality of classes according to the particle size is provided between the fluidized bed reactor and the iron oxide fed into the fluidized bed reactor. It is characterized in that reduced particles of a grade having a smaller particle diameter toward the downstream side are introduced at a plurality of positions in the middle of the particle flow path. According to the apparatus of the present invention for producing an eye anchor having such characteristics, the iron particles reduced by the reducing means are classified into a plurality of classes according to the particle size by the classification means. Reduced particles having a smaller particle diameter toward the downstream side are introduced into the flow path in the fluidized bed reactor from a plurality of locations. Small-sized iron particles are effective even in a short period of time, and after increasing the rate of iron carbide formation from iron oxide, themselves become iron carbide.

As described above, according to the present invention, it is possible to improve the rate at which iron oxide is generated from iron oxide by introducing iron particles acting as a catalyst in the latter half of the reaction time of a fluidized bed reactor. it can. Since the time required to obtain the composition of the eye anchor is shortened, production efficiency is improved, and equipment such as a fluidized bed reactor can be downsized.

Further, according to the present invention, since the particle size of the iron particles to be charged into the fluidized bed reactor becomes smaller toward the downstream side, it is possible to effectively improve the generation rate of the eye anchor in a short time until the end of the flow path. Can be planned.

According to the present invention, the iron oxide particles contained in the exhaust gas from the preheated iron oxide particles are collected, reduced, and introduced into the flow channel of the fluidized bed reactor. The iron oxide particles recovered from the exhaust gas have a smaller particle size than the iron oxide particles charged into the fluidized bed reactor. Since the particle diameter of the iron particles to be reduced is also smaller than the particle diameter of the iron oxide particles to be charged, the iron fine particles immediately after the reduction are charged to accelerate the reaction rate of the formation of the eye anchor. Can be effectively achieved.

Furthermore, according to the present invention, the iron oxide particles are heated by hot air by preheating means. When preheating, iron oxide particles are collected from the exhaust gas by a recovery means, reduced by a reduction means and put into a fluidized bed reactor. The preheated iron oxide particles charged into the fluidized bed reactor are charged into the fluidized bed reactor, and are carbonized while flowing along the flow path to produce an anchor binder. Since iron particles are injected into this flow channel, the carbonization reaction is promoted by the catalytic action, and the production rate of the eye anchor is increased. As a result, the production time of the eye anchor binder can be shortened, and a large amount of the eye anchor binder can be produced even with a relatively small fluidized bed reactor.

Further, according to the present invention, the iron particles are classified by the classification means provided between the reduction means and the fluidized bed reactor. Iron particles of a small particle size are injected into the downstream side of the flow channel of the fluidized bed reactor, and the carbonization reaction is promoted even in a short time, and the iron particles themselves become iron carbide in a short time. [Brief description of drawings]

FIG. 1 is a block diagram showing a simplified configuration of a manufacturing apparatus according to one embodiment of the present invention.

FIG. 2 is a simplified plan sectional view of a manufacturing apparatus according to another embodiment of the present invention.

FIG. 3 is a simplified front sectional view of the manufacturing apparatus of the embodiment shown in FIG.

FIG. 4 is a schematic diagram showing an example of operating conditions of the embodiment of FIG. FIG. 5 is a graph showing an example of the particle size distribution of raw materials and products. C FIG. 6 is a graph showing the relationship between the reaction time and the composition of the prior art.

[Best mode for carrying out the invention] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a simplified configuration of an eye anchor binder manufacturing apparatus according to one embodiment of the present invention. In fluidized-bed reactor 1, to Matthew Doo (F e 2 0 ₃₎ particles by entering instrumentation as a raw material of, causing carbonization reaction to obtain particles of iron card by de (F e 3 C). The hematite to be charged is preheated in a preheating furnace 2 by hot air once as powdered ore. The operating conditions in the preheating furnace 2 and the fluidized bed reactor 1 are almost the same as those of the above-mentioned prior art. For example, preheating is performed by hot air at a temperature of 50,000 to 900 ° C. so that the reaction in the fluidized bed reactor 1 can be performed at 50,000 or more.

The hot air preheating the ore in the preheating furnace 2 is discharged as exhaust gas and guided to the dust collector 3. Of the ore preheated by the preheating furnace 2, coarse ore is charged into the fluidized bed reactor 1 through the mouth hopper 5, and fine ore scattered in the exhaust gas is collected by the dust collector 3. The dust collector 3 realized by a cyclone or the like separates fine particles contained in the exhaust gas. These fine particles are iron oxide fine particles contained in the raw material ore, and the dust collector 3 collects the iron oxide fine particles from the exhaust gas as a collecting means. The recovered iron oxide fine particles are fed into a reduction furnace 4 which is a reducing means. In the reduction furnace 4, iron oxide is reduced by a reducing gas containing hydrogen (H ₂ ) or the like to obtain iron (F e). The iron particles reduced by the reducing furnace 4 are introduced into the fluidized bed reactor 1 in the middle of the flow path.

The fluidized bed reactor 1 fluidizes preheated iron oxide particles with a reaction gas, carbonizes them while moving along an internal flow path, and converts them into eye anchor particles. The reaction proceeds along the flow path, and iron particles are injected from the middle of the flow path corresponding to the latter half of the reaction. The carbonization reaction is accelerated and the production rate is improved. Since different atmospheres are used in the fluidized bed reactor 1, the preheating furnace 2, and the reduction furnace 4, lock hoppers 5, 6, and 7 are interposed therebetween to prevent the atmosphere from being mixed. In each of the lock hoppers 5, 6, and 7, the particles are once trapped, the atmosphere is replaced with nitrogen (N ₂ ), and then further replaced with the atmosphere used for downstream devices.

By placing the iron particles, a fluidized bed type reaction furnace 1 of the flow path. Carbon monoxide contained in the reaction gas (CO) is decomposed, 2 C 0 → C tens C 0 ₂ of the reaction is accelerated It is considered something. The effect of such a catalyst is introduced in, for example, METAL URGICAL TRANSACTIONS VOLUME 5, JANUARY 1974 4 p. From Fig. 6, it is considered that iron (F e) decreases in the late stage of the reaction, so that the production rate of iron anchor is reduced. When iron, which acts as a catalyst, is added in the latter half of the reaction, Generation speed was improved.

2 and 3 show a simplified configuration of another embodiment of the present invention. 2 is a plan sectional view, FIG. 3 is a front sectional view, FIG. 2 is a sectional view taken along line II-II in FIG. 3, and FIG. 3 is a sectional line III in FIG. Each corresponds to the state viewed from III. The fluidized bed reactor 10 of the present embodiment is internally partitioned by a partition 11 in order to lengthen a flow path c having a cylindrical outer shape which is advantageous as a pressure vessel. The fluidized bed is fluidized by a reaction gas ejected from a nozzle 13 provided on the dispersion plate 12. The flow path of the fluidized bed is formed between the inlet 14 of the iron oxide particles as the raw material and the outlet 15 of the iron anchor carbide as the carbide. When the iron oxide particles move along this flow path, they are carbonized by the reaction gas. As shown in Fig. 6, immediately after the raw materials are charged, iron (Fe) is generated inside the fluidized bed reactor 10 and the carbide formation reaction is promoted. However, in the second half of the reaction, iron (F e) decreases and catalysis decreases. In the present embodiment, a plurality of inlets 16 and 17 are provided in the latter half of the flow channel to feed iron particles.

The iron charged from the multiple inlets 16 and 17 reduces the iron oxide particles recovered in the reduction furnace 4 and further classifies the particles according to the particle size using a classifier 20 realized by a cyclone, etc. Classify. For example, when Matthew Bok (F e ₂ 03) you input instrumentation with a grain size from 1 to 0.1 negation of the from charging hole 1 4, iron is reduced is recovered (F e) is 0.1 5 Design to have a particle size of 0.1 The classifier 20 classifies the iron (F e) particles into a class of 0.15 to 0.13 mm and a class of 0.13 to 0.1 concealed, and the smaller particles of iron (F e) on the downstream side. From the inlet 17 of. The downstream input port 1Ί is closer to the discharge port 15 at the end of the flow path than the upstream input port 16 and effectively acts as a catalyst in a short period of time. It is preferable to input iron particles having a particle size.

As shown in Fig. 3, in the fluidized bed reactor 10, a reaction gas containing carbon monoxide (CO) is introduced from a lower reaction gas inlet 21 and discharged from an upper reaction gas outlet 22. . A wind box part 23 is formed below the dispersion plate 12 and temporarily stores the introduced reaction gas. The reaction gas in the wind box section 23 is blown out through a nozzle 13 provided on the dispersion plate 12 to form a fluidized bed 24 above the dispersion plate 12. The partition 11 is higher than the height of the fluidized bed 24 to be formed. The upper wind tower section 25 increases the cross-sectional area, reduces the flow rate of the reaction gas, and prevents particles from being scattered from the fluidized bed 24 c

Figure 4 shows the amount of F e ₂ 0 ₃ which is charged as a raw material, the operating conditions relating to the amount of you put F e later. In Fig. 4 (1), enter Fe 6%, and in Fig. 4 (2), enter Fe 10%. Since the inside of the fluidized bed reactor 10 is partitioned into five spaces, The amount of Fe added is

6/2

X 1 0 0 = 1 6 (.¾)… (1)

1 8.8

1 0/2

X 1 0 0 = 2 8 (%)… (2) 1 8

Becomes It is desirable that the amount of Fe added be within a range of 50% at the maximum and 10% at the minimum.

Figure 5 is a F e ₂ 0 ₃ of particle size distribution to be introduced as a raw material in a solid line, shows an example of particle size distribution of the conversion has been iron card by de by a two-dot chain line, F e ₂ 03 is 0.1 It is distributed in the range of ~ 1 mm. If it is 10%, it is 0.15 mm or less, and if it is 6%, it is 0.15 mm or less.

In each of the embodiments described above, iron particles to be fed into a fluidized bed reactor are generated by reducing a part of iron oxide particles to be charged as a raw material. You may make it throw in. When iron particles immediately after reduction are used as in this example, particles close to pure iron with little oxidation can be introduced, and even if the amount is small, the catalytic action is sufficiently exhibited and the eye anchor is efficiently used. A byte can be manufactured. [Industrial applicability]

Since the present invention is configured as described above, it is possible to improve the iron carbide generation rate in the latter stage of the reaction and to perform iron production efficiently without increasing the size of the fluidized bed reactor. Suitable for carbide manufacturing equipment.

Claims

Scope of request In a method for producing an iron carbide in which iron oxide particles are charged into a fluidized bed reactor and carbonized while being fluidized by a reaction gas,

A method for manufacturing an iron force byte, comprising: charging iron particles from the middle of the flow path of the charged iron oxide particles.

The method of claim 1, wherein the iron particles are charged at a plurality of locations, and the particle size of the iron particles is reduced toward the downstream side.

The method according to claim 1 or 2, wherein the iron particles are recovered from exhaust gas when preheating the iron oxide particles, and are generated by reduction. .

The iron oxide particles are charged into a fluidized bed reactor, and the iron oxide particles are carbonized while being fluidized by the reaction gas.

A preheating means for preheating the iron oxide particles by hot air;

A recovery means for recovering the iron oxide particles from the exhaust gas of the preheating means, and a reduction means for reducing the iron oxide particles recovered by the recovery means and introducing the reduced iron oxide particles into a fluidized bed reactor. Iron carbide manufacturing equipment.

Classification means for classifying the reduced iron oxide particles into a plurality of grades according to the particle size is provided between the reducing means and the fluidized bed type reactor, and iron fed into the fluidized bed type reactor is provided. The production of an iron carbide according to claim 4, wherein reduced particles of a grade having a smaller particle diameter toward the downstream side are introduced at a plurality of places in the flow path of the oxide particles. apparatus.