KR101630986B1 - Method of manufacturing low phosphor reduced iron using high phosphor iron ore - Google Patents

Abstract

According to an embodiment of the present invention, the manufacturing method of reduced iron having low phosphorus content comprises: a step of adjusting an amount of moisture in the iron ore powder having high phosphorus content; a step of injecting the iron ore having high phosphorus content and adjusted moisture content to an ore differentiation furnace, and differentiating the same by high speed heating; a step of removing ultrafine powder from the differentiated ore, reducing the same into reduced iron by injecting the differentiated ore to a reduction classification furnace, and providing a reduction gas; and a step of manufacturing compacted iron by compressing the reduced iron.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for producing reduced iron using reduced iron ore,

The present invention relates to a method for producing reduced iron reduced using iron ore.

Iron ore (P) is distributed in the ore and is known to be a very difficult material for the beneficiation. In recent years, the content of iron ore (P) in the ore has been increasing steadily.

Conventional approach to high phosphorus iron ore is performed by drying or crushing ore and then leaching using hydrochloric acid or using specific gravity difference, or by applying ore reducing at high temperature, cooling or crushing ore at high temperature, And the like have been proposed.

However, the wet eneloop method of leaching phosphorus has the disadvantage of requiring extensive facilities for acid treatment and wastewater treatment. In addition, the phosphorus removal efficiency is relatively low as 50 ~ 70% compared with the treatment scale, and avoiding the restriction of environmental treatment in wastewater treatment such as the use of strong acid such as hydrochloric acid and organic acid such as oxalic acid There is a problem that an additional cost is continuously required.

In addition, the method of simultaneously applying magnetic force sorting and sorting after crushing is mainly performed by drying, crushing, heating, reducing, cooling, crushing, sorting (magnetic separation or particle size separation) , Melting, talline, slag separation, etc., and it is disadvantageous in that the removal efficiency is not so large as compared with the input energy because the process is complicated such as requiring a raw material for removing the phosphorus.

Chinese Patent Publication No. 103667694 Chinese Patent No. 102168174 Chinese Patent Publication 200710034844 Chinese public patent 200910088966 Chinese Published Patent 103789477 Chinese Patent Publication No. 102978318 Chinese Patent Publication No. 102978318 Chinese Patent Publication No. 102094115

ISIJ International, Vol. 51, 2011, No.2, pp.220-227

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a process for producing iron (P) ), It is possible to reduce or reduce the iron content of the reduced iron ores, and it is possible to prevent the iron ores from being broken down, dried and wet leached before the iron ores are crushed, And a method for producing the same.

According to an embodiment of the present invention, there is provided a method for producing reduced iron reduced iron, comprising the steps of: controlling the moisture content of iron iron ore; Charging the iron oxide ore having a controlled moisture content into the ore-separating furnace and heating and differentiating the iron ore; Charging the iron ore from which the minuscule is removed from the differentiated iron ores into a reduction classifier, reducing the reduced iron ore by supplying a reducing gas; And compressing the reduced reduced iron to produce a compacted compact.

In the step of controlling the moisture content, the water content of the crude iron ore may be in the range of between 1% and 3%.

The step of differentiating in the ore refining furnace may include heating the iron ores to a temperature of 400 ° C or higher to evaporate water and crystal water in the iron ores; Separating the iron ores into iron minerals of 100 mu m or more and iron minerals of 100 mu m or less having a relatively high phosphorus (P) content than the iron ores of 100 mu m or more; And discharging the minute particles.

The step of separating the minuscule components may be carried out by supplying an oxidizing or reducing gas to the ore-separating furnace to scatter the minuscule components.

And separating the gas discharged with the gas from the gas in a micro-particle collector.

The step of reducing the reduced iron ore to the reduced iron in the reduction classifier may include the steps of further reducing the differentiated iron ores while flowing and reducing the reduced iron ore with the reducing gas; Separating the iron ores into iron minerals of 100 mu m or more and iron minerals of 100 mu m or less having a relatively high phosphorus (P) content than the iron ores of 100 mu m or more; Discharging the minute particles; And reducing the iron ores having a phosphorus content of 100 mu m or more in which the phosphorus content is lowered to produce reduced iron.

The reducing gas may include at least one selected from the group consisting of CO, CO ₂ , H ₂ , H ₂ O and N ₂ .

The step of fabricating the compacted material may include compressing the reduced steel using a pair of rolls provided in a compacted material manufacturing apparatus connected to the reduction classifier.

According to the present invention, it is possible to remove phosphorus components in a process without further processing such as pretreatment of the iron ore, which is not directly utilized in the steel making process, so that not only the process is simplified but also the energy efficiency is high Can be obtained.

In addition, when the produced reduced iron is used in a furnace for producing molten iron, etc., the energy required for manufacturing molten iron can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart schematically showing a method for producing reduced reduced iron from a crude iron ore according to an embodiment of the present invention; FIG.
2 is a graph showing changes in phosphorus (P) component removal rate and content (P) content in ore according to changes in water content of koline iron ore.
3 is a block diagram schematically showing a reduced iron manufacturing system according to an embodiment of the present invention.
4 is a block diagram schematically showing a reduced iron manufacturing system according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below.

Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings may be exaggerated for clarity of description, and the elements denoted by the same reference numerals in the drawings are the same elements. In this specification, terms such as "upper,""upper,""upper,""lower,""lower,""lower,""side," and the like are based on the drawings, It will be possible to change depending on the direction.

1, a method for producing a reduced iron reduced by using iron ore of chrome according to an embodiment of the present invention will be described. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart schematically showing a method for producing reduced reduced iron from a crude iron ore according to an embodiment of the present invention; FIG.

Referring to FIG. 1, a method of manufacturing reduced iron reduced iron using high iron ore according to an embodiment of the present invention includes the steps of adjusting the moisture content of iron iron ore in powder (S10) Charging the reduced iron ore into the reducing classifier and reducing the iron ore to a reduced iron (S30); and a step (S30) of supplying the reduced iron reduced to the reduced iron And a step (S40) of manufacturing a compacted body.

First, the moisture content of the crude iron ore is controlled through a moisture controller (S10). Corinthian iron ore may be in the form of spectra containing more than 0.1% of phosphorus (P) and more than 6% of crystals.

The phosphorus (P) component is mainly bonded to the gangue component of the Al ₂ O ₃ -SiO ₂ system in the iron ore and exhibits a very uniform distribution in the iron ore with a very small size of 5 μm or less. In some cases, CaO and phosphorus are combined in some ore ore, but such iron ore is not effective in the method according to the present invention.

Since the water content plays an important role in the step of differentiating iron ore, proper moisture content control is required. If the water content in the iron ore is small, the moisture content is uniformly dispersed in the iron ore in the form of mist to adjust the water content of the iron ore to 1% to 3%, and the water content is adjusted to 10 to 30 Min so that the moisture in the iron ore can be properly permeated. When the moisture content exceeds 4%, the moisture content is controlled to be in the range of 1% to 3% by supplying air at 200 ° C or higher and drying. If the moisture content exceeds 4%, there is a problem that the process may be adhered to the apparatus during the transportation and charging process, thereby causing a problem in the manufacturing process.

Next, a step of charging the iron oxide ore having a controlled moisture content into the ore-separating furnace and heating and differentiating it may be performed (S20).

The iron ore is charged into the ore differentiation furnace in a state containing a large amount of crystal water and moisture. Then, it is heated to approximately 400 캜 or higher to rapidly evaporate water and crystal water in the iron ores. The volumetric expansion occurring at this time is used to break down and separate the iron ore into the iron ores containing a large amount of phosphorus (P) component and a minute fraction of less than about 100 mu m containing fine gangue and iron ores of about 100 mu m or more.

Minerals with a phosphorus (P) content of less than 100 μm and a large amount of gangue are smaller in particle size and density than iron ores with less gangue. Therefore, when an oxidizing or reducing gas having a proper flow rate is supplied into the ore-separating furnace, it can be separated and separated. In addition, the minute particulate that is scattered and discharged may be discharged together with the gas supplied into the ore-separating furnace, and separated from the gas in the micro-fine particle collector.

The ore differentiation furnace may be a flow furnace type in which powder iron ores flow through an oxidizing or reducing gas of 400 DEG C or more, a furnace type which is maintained at 400 DEG C or higher by using a burner or a microwave oven type to which oxidizing or reducing gas is supplied Lt; / RTI > However, the ore differentiation furnace according to the present invention is not limited thereto.

Next, a step of charging the iron ore, from which the minuscule is removed, into the reducing classifier, and supplying the reducing gas to reduce iron to the reduced iron (S30).

The iron ores having a size of 100 mu m or more, which are weakened by the crystal water and moisture release, are charged into a fluidized-bed reduction reactor maintained at a temperature of about 600 DEG C to 800 DEG C or more. Then, the reducing gas is supplied at a rate of about 0.8 m / s or more to perform fluidized reduction. The reducing gas may include at least one selected from the group consisting of CO, CO ₂ , H ₂ , H ₂ O and N ₂ .

The weakened iron ore is further differentiated by the reduction gas due to friction between the ores and collision with the inner wall of the fluidized-bed reacting classifier during the flow and reduction processes. As a result, the phosphorus (P) component And gangue stones are distributed in a large quantity, so that the density is reduced and scattered by the reducing gas, and the discharge is facilitated. The additional generated minute fraction is discharged together with the reducing gas, and is separated from the reducing gas in the minute particle collector.

Iron ores having a content of phosphorus (P) of 100 mu m or more are reduced in the fluidized-bed fractionation furnace to produce reduced iron. The phosphorus (P) content in the reduced iron thus reduced may be about 0.8% or less, and the reduction ratio of the iron component may be about 50% or more and less than 80%.

Next, a step of compacting the reduced reduced iron to produce a compacted material may be performed (S40).

Reduced iron having a reduced phosphorus (P) content in the fluidized-bed reduction classifier is produced as a compacted material at a high temperature of approximately 500 ° C or higher in a compacted material manufacturing apparatus connected to the fluidized-bed fractionation furnace. The compacted material producing apparatus may include a hopper and a pair of rolls.

In the compacted material manufacturing apparatus, the reduced iron is compressed by the pair of rolls to be a compacted material. The compacted material produced may have the form of briquettes.

In addition, the compacted material may have a long connected shape. In this case, the compacted material may be crushed to have a uniform particle size. Therefore, the compacted material producing apparatus may further comprise a crusher in addition to the hopper and the pair of rolls. The particle size of the crushed compacted material can be adjusted to be about 5 mm or more and 30 mm or less, which is a particle size suitable for use in blast furnace and steelmaking processes in a blast furnace shape.

As described above, the phosphorus reduced iron produced by using the red iron ore has a phosphorus (P) content of 0.8% or less and a phosphorus (P) content similar to the phosphorus content in the general iron ores can be obtained in the blast furnace such as the blast furnace . The removal rate of phosphorus (P) from the initial iron ore is about 30% ~ 60%, which is similar to that of conventional iron ore. However, the process is simple, and the process of cooling after heating, The energy loss is small.

Hereinafter, an embodiment according to the present invention will be described. The following examples are for the understanding of the present invention and are not intended to limit the present invention.

(Example 1)

According to the present invention, the water content of the crude iron ore powder containing a large amount of crystal water was controlled under the conditions simulating the ore burning furnace, and the results are shown in FIG.

The grain size of the iron ore was 8 mm or less, and the representative composition thereof is shown in Table 1. The ore differentiation furnace was maintained at 500 ° C and air was supplied at a flow rate of 0.8 m / s. As the water content of ore increased, the differentiation rate of ore increased and the fraction of less than 100 ㎛ increased. The minute fraction was scattered by gas and discharged to the outside.

As a result, as the water content in the ore was increased, the amount of phosphorus (P) in the ore remaining in the ore was increased and the phosphorus (P) removal rate was increased as the amount of generated minuscule increased. The removal rate of phosphorus (P) in the ore burning furnace was 28% ~ 40%.

When the moisture content was maintained more than 4%, the adhesion of ore greatly increased and the amount of adhering light was increased before charging into the ore burning furnace, and the transferring and charging efficiencies were very low. It can be seen from Table 2 that the gangue component of the differentiated ores before charging into the fluidized-bed reactors is also reduced. The gangue can be partially removed. Therefore, when the reduced iron produced through the present invention is applied to a blast furnace such as a blast furnace, it can be seen that the slag volume is reduced and the energy required is reduced as compared with the case where the reduced iron is not applied.

The composition (wt%) of the iron ore used in the present invention T-Fe SiO2 Al2O3 P Number of Crystals 60.89 3.70 2.23 0.12 7.40

Composition (wt%) of ore mined from mining furnace and minus minerals removed Ore moisture content (%) T-Fe SiO2 Al2O3 P 0 62.73 3.48 2.16 0.096 One 62.96 3.22 2.04 0.084 2 63.32 3.01 1.97 0.079 3 63.46 2.91 1.79 0.074

(Example 2)

In the case where the water content before charging into the ore-separating furnace of Example 1 is 2%, the ore obtained from the ore-separating furnace is charged into the fluidized-bed fractionation furnace after the discharge of the minute fraction, and the CO 2, Reduced gas was supplied at a rate of 0.8 m / s or more to produce reduced iron at a temperature of 700 to 800 ° C, and further the minute minute particles were discharged together with the gas. Reduction was carried out for 20 to 40 minutes.

The reduction ratio of reduced iron after discharge was 50 ~ 80%. In addition, the amount of extra minute fraction discharged from the fluidized-bed reactor was 3 ~ 8% of that of the fluidized-bed fractionation furnace, and the additional phosphorus removal rate was 2 ~ 5%.

(Example 3)

It was confirmed that the compacted iron obtained from the above Example 2 was heated to a temperature of 400 to 600 ° C and the compacted material could be produced through the compacted material manufacturing apparatus. Also, as the reduction ratio increased, the higher the temperature of the reduced iron, the easier it was to produce compacted irons.

(Example 4)

Fig. 3 schematically shows a reduced iron manufacturing system according to an embodiment of the present invention. As shown in FIG. 3, by using the conditions obtained from Examples 1, 2, and 3, the iron oxide ore was charged into the moisture controller 10 to adjust the water content to 1 to 3% 20 to discharge the minerals, and the remaining ores of 100 μm or more are charged again into the fluidized-bed fractionation furnace 30 to produce reduced iron, and the produced reduced iron is fed to the reduced- Compacted bodies were prepared.

At this time, a reducing gas containing CO, H ₂ , N ₂ , CO ₂ and the like was supplied to the fluidized bed reforming furnace 30 at a rate of 0.8 m / s or higher, and the gas discharged from the fluidized- So that the final minute fractional discharge is discharged together with the exhaust gas only in the ore fractionation furnace 20.

The P removal rate was up to 40% and the reduction ratio could be up to 75%, which was sufficient to produce the compacted material.

On the other hand, reference numeral 50, which is not described, is a minute particle collector, 402 a hopper, 404 a roll, and 406 a crusher.

(Example 5)

4 schematically shows a reduced iron manufacturing system according to another embodiment of the present invention. As shown in FIG. 4, by applying the conditions obtained from the above Examples 1, 2, and 3, the crude iron ore powder was charged into the water conditioner 10 to adjust the water content to 2 to 4% 20) to discharge the minerals and discharging the remaining minus 100 mu m or more into the fluidized-bed fractionation furnace (30) to produce the reduced iron while discharging the generated minerals, The reduced iron compacted material was produced through the manufacturing apparatus 40.

At this time, air was supplied to the ore fractionation furnace 10 at 0.8 m / s or more, and the minute fraction was removed from the ore fractionation furnace 10. A reducing gas containing CO, H ₂ , N ₂ , CO ₂ or the like is supplied to the fluidized-bed classifying furnace 30 at a rate of 0.8 m / s or higher and the minute fraction generated in the fluidized- And discharged from the fluidized-bed fractionation furnace (30).

The P removal rate was up to 45% and the reduction ratio was up to 75%.

On the other hand, reference numeral 50, which is not described, is a minute particle collector, 402 a hopper, 404 a roll, and 406 a crusher.

Although the embodiments of the present invention have been described in detail, it is to be understood that the scope of the present invention is not limited thereto and that various modifications and changes may be made thereto without departing from the scope of the present invention. It will be obvious to those of ordinary skill in the art.

10 ... moisture regulator
20 ... ore eruption furnace
30 ... fluidized-bed fractionation furnace
40 ... compactor manufacturing equipment
402 ... hopper
404 ... roller
406 ... crusher
50 ... the minute particle collector

Claims (8)

Adjusting the moisture content of the crude iron ore in the powder;
Charging the iron oxide ore having a controlled moisture content into the ore-separating furnace and heating and differentiating the iron ore;
Charging the iron ore from which the minuscule is removed from the differentiated iron ores into a reduction classifier, reducing the reduced iron ore by supplying a reducing gas; And
Compressing the reduced reduced iron to produce compacted irons;
By weight.
The method according to claim 1,
Wherein the step of controlling the moisture content is such that the water content of the crude iron ore is in the range of between 1% and 3%.
The method according to claim 1,
The step of differentiating in the ore-
Heating the iron ores at a temperature of 400 ° C or higher to evaporate water and crystal water in the iron ores;
Separating the iron ores into iron minerals of 100 mu m or more and iron minerals of 100 mu m or less having a relatively high phosphorus (P) content than the iron ores of 100 mu m or more; And
Discharging the minute particles;
Wherein the reduced reduced iron has an average particle size of less than 100 nm.
The method of claim 3,
Wherein the step of separating the minuscule fraction comprises supplying an oxidizing or reducing gas to the ore-separating furnace to separate and separate the minuscule minus fractions.
5. The method of claim 4,
Further comprising the step of separating the minute fraction discharged together with the gas from the gas in a minute particle collector.
The method according to claim 1,
In the reducing classifying step,
Further reducing the differentiated iron ores while flowing and reducing them with the reducing gas;
Separating the iron ores into iron minerals of 100 mu m or more and iron minerals of 100 mu m or less having a relatively high phosphorus (P) content than the iron ores of 100 mu m or more;
Discharging the minute particles; And
A step of reducing iron ores having a phosphorus content of 100 mu m or more and reducing iron to produce reduced iron;
Wherein the reduced reduced iron has an average particle size of less than 100 nm.
The method according to claim 6,
Wherein the reducing gas comprises at least one selected from the group consisting of CO, CO ₂ , H ₂ , H ₂ O and N ₂ .
The method according to claim 1,
The step of manufacturing the compacted material may include:
And a step of compressing the reduced iron using a pair of rolls provided in a compacted material manufacturing apparatus connected to the reduction classifier.

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