JP2021147655A - Binder for producing agglomerate, method for producing agglomerate using the same, and method for producing reduced iron - Google Patents

Abstract

To provide a novel and improved binder for producing agglomerate that can make agglomerate with high reduction efficiency, a method for producing agglomerate using the same, and a method for producing reduced iron.MEANS FOR SOLVING THE PROBLEM: In order to solve the problem, according to a certain point of view of the present invention, a binder for producing agglomerate is provided which is a binder for producing agglomerate that is added to a raw material of agglomerate containing iron oxide raw material, and in which a characteristic that the area ratio of an area of 13C-NMR spectrum from 185 to 165 ppm to the total area of 13C-NMR spectrum obtained by 13C-NMR spectrum measurement is 5% or more, and a characteristic that the area ratio of an area of 13C-NMR spectrum from 240 to 185 ppm to the total area of 13C-NMR spectrum obtained by 13C-NMR spectrum measurement is 2% or more are satisfied.SELECTED DRAWING: Figure 1

Description

The present invention relates to a binder for producing agglomerates, a method for producing agglomerates using the binder, and a method for producing reduced iron.

As a method for producing reduced iron, for example, as disclosed in Patent Documents 1 to 4, a method of producing agglomerates by agglomerating a mixture of an iron oxide raw material and a binder, and reducing the agglomerates. It has been known. In such a method for producing reduced iron, it is possible to use iron ore for sintering (powder ore, fine powder ore, etc.) in addition to dust, scale, etc. generated in the ironmaking or steelmaking process as a raw material for iron oxide. can. Fine powder ore is an iron ore whose iron content has been increased by mineral processing. In recent years, the use of dust, scale, etc. has been recommended from the viewpoint of recycling. In addition, in recent years, the quality of iron ore has deteriorated, so that mineral processing is often performed (that is, the supply of fine powder ore is increasing). For this reason, the use of fine ore is also recommended. Including these viewpoints, a method for producing reduced iron that reduces agglomerates has received much attention.

International Publication No. 2012/049974 Japanese Unexamined Patent Publication No. 2016-108580 Japanese Unexamined Patent Publication No. 2016-160451 Japanese Unexamined Patent Publication No. 2003-129142

By the way, in the above-mentioned method for producing reduced iron, the reduction efficiency (that is, the reduction efficiency of the massive ore) at the time of reducing the agglomerate for the purpose of improving the quality of the reduced iron, increasing the production amount, or reducing the fuel is increased. Is strongly desired. Although Patent Documents 1 to 4 describe a method for reducing agglomerates as described above, there is still room for improvement in reduction efficiency.

The present invention has been made in view of the above problems, and an object of the present invention is a new and improved binder for producing agglomerates capable of producing agglomerates with high reduction efficiency. , A method for producing an agglomerate using the same, and a method for producing reduced iron.

In order to solve the above problems, according to a certain viewpoint of the present invention, it is a binder for agglomerate production added to an agglomerate raw material containing an iron oxide raw material, and ^{was obtained by 13} C-NMR spectrum measurement. ^{The characteristic that the area ratio of the 13} C-NMR spectrum of 185 to 165 ppm to the total ¹³ C-NMR spectrum area is 5% or more, and ^{240 to 240 to the total 13} C-NMR spectrum area ^{obtained by the 13} C-NMR spectrum measurement. Provided is a binder for agglomerate production, which satisfies the property that the area ratio of a ^{13 C-NMR spectrum of 185 ppm is 2% or more.}

Further, ^{the characteristic that the area ratio of the 13 C-NMR spectrum of 185 to 165 ppm to the total 13} C-NMR spectrum area ^{obtained by the 13} C-NMR spectrum measurement is 5% or more, and the characteristic ^{obtained by the 13} C-NMR spectrum measurement. It may contain lignin and / or sugar that satisfy the property that the area ratio ^{of the 13} C-NMR spectrum of 240 to 185 ppm to the total ¹³ C-NMR spectrum area obtained is 2% or more.

According to another aspect of the present invention, ^{the characteristic that the area ratio of the 13 C-NMR spectrum of 185 to 165 ppm to the total 13} C-NMR spectrum area ^{obtained by the 13} C-NMR spectrum measurement is 5% or more, and. ¹³ A step of preparing a binder for agglomerate production that satisfies the characteristic that the area ratio ^{of the 13 C-NMR spectrum of 240 to 185 ppm to the total 13} C-NMR spectrum area obtained by the C-NMR spectrum measurement is 2% or more. And, the step of adding the binder for agglomerate production to the agglomerate raw material containing the iron oxide raw material and mixing, and the agglomerate are prepared by using the mixture of the agglomerate raw material and the agglomerate production binder. A method for producing an agglomerate is provided, which comprises a step.

Here, the step of preparing the agglomerates for producing binder performs ¹³ C-NMR spectrum measurement of agglomerate manufacturing binder for the area of ¹³ C-NMR spectrum of 185~165ppm to total ¹³ C-NMR spectral area The step of determining the ratio and the area ratio ^{of the 13 C-NMR spectrum of 240 to 185 ppm to the total 13} C-NMR spectrum area ^{obtained by the 13} C-NMR spectrum measurement may be included.

According to another aspect of the present invention, there is provided a method for producing reduced iron for producing reduced iron by using the agglomerated product produced by the above-mentioned method for producing agglomerated products.

According to the above viewpoint of the present invention, it is possible to produce an agglomerate having high reduction efficiency.

It is a graph which shows the area ratio ^{of the 13} C-NMR spectrum of organic binders A to D. It is a graph which shows the relationship between the type of agglomerates (tablets), and the CO partial pressure when agglomerates are heated to 720 ° C. It is a graph which shows the difference Δ of the metallization rate of each agglomerate with respect to the metallization rate of agglomerate (tablet) A. It is a graph which shows the relationship between the DO value of organic binders a to i, and the difference of the metallization rate of tablets a to i based on the metallization rate of tablet g. It is a graph which shows the relationship between the SO-1 value of organic binders a to i, and the difference of the metallization rate of tablets a to i based on the metallization rate of tablet g. It is a graph which shows the relationship between the SO-2 value of organic binders a to i, and the difference of the metallization rate of tablets a to i based on the metallization rate of tablet g. It is a graph which shows the relationship between the sum of the DO value and SO-1 value of organic binders a to i, and the difference of the metallization rate of tablets a to i based on the metallization rate of tablet g.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.

<1. Characteristics of binder for agglomerate production>
First, the characteristics of the binder for producing agglomerates according to the present embodiment will be described. The binder for producing agglomerates according to the present embodiment serves as a binder for producing agglomerates, and is added to a agglomerate raw material containing an iron oxide raw material. After that, the mixture of the agglomerated raw material and the binder for producing the agglomerated product is made into an agglomerated product by an appropriate method. The agglomerate is, for example, agglomerate.

The binder for producing agglomerates according to the present embodiment is a kind of organic binder, and ^{the area ratio of 13} C-NMR spectrum of ^{185 to 165 ppm to the total 13} C-NMR spectrum area ^{obtained by 13} C-NMR spectrum measurement. Is 5% or more (hereinafter, also referred to as “first characteristic”), and the ^{area of the 13} C-NMR spectrum of 240 to 185 ppm with respect ^{to the total 13 C-NMR spectrum area obtained by 13} C-NMR spectrum measurement. It satisfies the characteristic that the ratio is 2% or more (hereinafter, also referred to as "second characteristic"). The numerical value represented by the unit "ppm" in the present specification is a chemical shift of the NMR spectrum.

The present inventor considered that it is important to generate a reducing gas at a high temperature in order to increase the reduction efficiency of the agglomerated product. Therefore, the present inventor produced agglomerates using various organic binders. Then, by heating the agglomerate, the reduction reaction of iron oxide was allowed to proceed in the agglomerate. Further, the CO partial pressure (= CO gas pressure / (CO gas pressure + CO ₂ gas pressure)) when the agglomerated product was heated to 720 ° C. was measured. As a result, it was found that the lower the CO partial pressure at 720 ° C., the higher the metallization rate of the reduced iron (that is, the more the reduction is progressing). Here, the metallization rate is the mass ratio of metallic iron to the mass of total iron in the reduced iron. Details will be described in Examples.

By the way, the organic binder in the agglomerate is thermally decomposed by heating to generate _{CO 2 gas.} Therefore, it is considered that if a large amount of the organic binder is thermally decomposed in the temperature range of 720 ° C., the partial pressure of CO at 720 ° C. is lowered and the reduction reaction of iron oxide is more likely to proceed. Therefore, the present inventor thinks that an organic binder that hardly causes thermal decomposition up to at least about 500 ° C. can be thermally decomposed in a large amount in the temperature range of 720 ° C. to reduce the CO partial pressure. Thought. Here, various forms of covalent bonds (carboxylic acids, ethers, aldehydes, etc.) are present in the organic binder. Of these, carboxylic acids and aldehydes are thermally decomposed in a temperature range of 500 ° C. or higher to generate _{CO 2 gas.} Therefore, it can be said that it is preferable that the binder for producing agglomerates has as many of these functional groups as possible. Here, the ¹³ C-NMR spectrum of carboxylic acid is observed at 185 to 165 ppm, and the ¹³ C-NMR spectrum of aldehyde is observed at 240 to 185 ppm. Therefore, it is preferable that the area of these spectra is large. Therefore, it is considered that an organic binder having as many covalent bonds as possible can be thermally decomposed in a large amount in the temperature range of 720 ° C. to reduce the CO partial pressure. Based on this finding, the present inventor states that ^{the area ratio of the 13 C-NMR spectrum of 185 to 165 ppm to the total 13} C-NMR spectrum area ^{obtained by 13} C-NMR spectrum measurement is 5% or more. It ^{satisfies the characteristic and the characteristic that the area ratio of the 13 C-NMR spectrum of 240 to 185 ppm to the total 13} C-NMR spectrum area ^{obtained by the 13} C-NMR spectrum measurement is 2% or more (that is, the first and second). The organic binders were arranged under the condition of "satisfying the characteristics)". As a result, it was found that by using an organic binder satisfying the above conditions, the partial pressure of CO at 720 ° C. can be lowered, and by extension, reduced iron having an extremely high metallization rate can be produced.

Based on these findings, the binder for producing agglomerates according to the present embodiment reduces the agglomerates by producing agglomerates using the binders for producing agglomerates satisfying the first and second characteristics. Efficiency can be increased. That is, by reducing such agglomerates, reduced iron having a higher metallization rate can be produced.

Here, the total ¹³ C-NMR spectrum area is the total area of ^{all 13} C-NMR spectra measured in the range of 0 to 240 ppm. This total area is the area of the region surrounded by the baseline measured from 0 to 240 ppm and the measured spectral curve and the perpendicular to the baseline at 0 ppm and 240 ppm. Area ratio of ¹³ C-NMR spectrum of 185～165Ppm is obtained by dividing the total ¹³ C-NMR spectral area and the area of the ¹³ C-NMR spectrum of 185～165Ppm. The area of the ¹³ C-NMR spectrum at 185 to 165 ppm is the area of the region surrounded by the baseline at 185 to 165 ppm and the measured spectral curve and the perpendicular to the baseline at 185 ppm and 240 ppm. Area ratio of ¹³ C-NMR spectrum of 240～185Ppm is obtained by dividing the total ¹³ C-NMR spectral area and the area of the ¹³ C-NMR spectrum of 240～185Ppm. The area of the ¹³ C-NMR spectrum at 240-185 ppm is the area of the region surrounded by the baseline at 240-185 ppm and the measured spectral curve and the perpendicular to the baseline at 240 ppm and 185 ppm. The area can be determined, for example, by the dedicated software Delta. In the examples described later, each area ratio was determined by this method. The upper limit of the ¹³ C-NMR spectrum area ratio of the 185～165Ppm, the upper limit of the ¹³ C-NMR spectrum area ratio of 240~185ppm is not particularly limited, for example, 30% may be used as the upper limit value.

By the way, in ¹³ C-NMR, a covalent bond (for example, ether) whose spectrum is observed at 90 to 50 ppm is often thermally decomposed in a temperature range of less than 500 ° C. Therefore, it is considered that an organic binder having as few covalent bonds as possible can be thermally decomposed in a large amount in the temperature range of 720 ° C. to reduce the CO partial pressure. Therefore, it can be said that it is preferable that the area of the spectrum observed at 90 to 50 ppm is as small as possible. More specifically, in the agglomerate production binder, ^{the area ratio of the 13 C-NMR spectrum of 90 to 50 ppm to the total 13} C-NMR spectrum area ^{obtained by the 13} C-NMR spectrum measurement is 60% or less. It is preferable to further satisfy the above-mentioned characteristic (hereinafter, also referred to as "third characteristic"). ^{The lower limit of the area ratio of the 13} C-NMR spectrum of 90 to 50 ppm is not particularly limited and may include 0 in theory, but 0 may be used as the lower limit in practice.

By producing an agglomerate using a binder for producing an agglomerate that satisfies the first and second characteristics and further satisfies the third characteristic, an agglomerate having a higher reduction efficiency can be produced.

The type of organic binder that can be used as the binder for producing agglomerates is not particularly limited, and any organic binder having the above-mentioned characteristics can be used. The binder for producing agglomerates may be composed of a single type of organic binder, or may be a mixture of a plurality of types of organic binders. However, it is necessary that the binder for producing agglomerates as a whole satisfies at least the first and second properties.

Typical examples of the organic binder that can be used as the binder for producing agglomerates according to the present embodiment include lignin and molasses. However, any lignin and molasses may be used, and the characteristics of lignin and molasses may vary greatly depending on differences in the production process, refining process, etc. of lignin and molasses. That is, some lignin and molasses can be used as a binder for producing agglomerates according to the present embodiment, and some are not. The same applies to other organic binders.

^{Therefore, if the 13} C-NMR spectrum of the obtained organic binder is unknown, first, the ¹³ C-NMR spectrum of the organic binder may be measured to evaluate whether or not the organic binder has the above-mentioned characteristics. Then, when the organic binder satisfies at least the first and second properties, the organic binder can be used as the binder for producing agglomerates according to the present embodiment. The organic binder preferably further satisfies the third property.

The binder for producing agglomerates is preferably a lignin that satisfies the first and second properties. The lignin preferably further satisfies the third property. The binder for producing agglomerates may contain an organic binder other than the lignin, but the binder for producing agglomerates as a whole must satisfy at least the first and second properties.

<3. Manufacturing method of agglomerates ＞
Next, a method for producing an agglomerate using the above-mentioned binder for producing an agglomerate will be described. In this production method, the above-mentioned step of preparing a binder for agglomerate production (first step) and a step of adding a binder for agglomerate production to an agglomerate raw material containing an iron oxide raw material and mixing them (second step). Step) and a step (third step) of producing an agglomerate using a mixture of the agglomerate raw material and a binder for producing the agglomerate.

(3-1. First step)
In the first step, a binder for producing agglomerates is prepared. For example, obtain a commercially available organic binder. Alternatively, an organic binder is produced by a known production method. ^{Then, the 13} C-NMR spectrum of the obtained organic binder is measured. ^{If the 13} C-NMR spectrum of the organic binder is known, it is not always necessary to perform the measurement. Then, it is determined whether or not the organic binder satisfies the above-mentioned first and second properties, and if the organic binder satisfies the first and second properties, the organic binder can be used as a binder for producing agglomerates. .. The organic binder preferably further satisfies not only the first and second properties but also the third property.

(3-2. Second step)
In the second step, a binder for producing agglomerates is added to a agglomerate raw material containing an iron oxide raw material and mixed. The type of iron oxide raw material is not particularly limited, and any material that can be used as a raw material for agglomerates can be used in this embodiment without particular limitation. Examples of the iron oxide raw material include dust, scale, etc. generated in the ironmaking or steelmaking process, as well as iron ore for sintering. The iron ore for sintering is, for example, powder ore or fine powder ore. Fine powder ore is obtained by increasing the iron content by mineral processing. The agglomerate is, for example, agglomerate.

The agglomerated raw material may be composed of only the iron oxide raw material, or may be a mixture of the iron oxide raw material and other raw materials. Examples of other raw materials include coke powder, anthracite, coke dust, blast furnace primary ash, and reducing agents such as coal. Other raw materials may be added to the iron oxide raw material in advance, or may be added to the iron oxide raw material together with the binder for producing agglomerates. The amount of the binder for producing the agglomerate is not particularly limited, and may be appropriately adjusted according to the characteristics required for the agglomerate. As an example, the addition amount may be about 0.5 to 10% by mass with respect to the total mass of the agglomerated raw material.

A binder other than the binder for producing the agglomerate, for example, an inorganic binder may be added to the agglomerate raw material. An organic binder other than the binder for producing the agglomerated product may be added to the agglomerated raw material, but in order to obtain the effect of the present embodiment more effectively, the organic binder added to the agglomerated raw material Is preferably only the binder for producing agglomerates according to the present embodiment.

(3-3. Third step)
In the third step, a lump product is produced using a mixture of the lump product raw material and a binder for producing the lump product. The specific method for producing the agglomerate is not particularly limited. For example, agglomerates may be produced by granulating the mixture using a granulator such as a drum mixer or a pan pelletizer. Further, the agglomerated product may be produced by molding the mixture using a double roll compressor, an extrusion molding machine, a briquette machine or the like. By the above steps, an agglomerate can be produced. In the second step or the third step, water may be added to the raw material as appropriate.

<4. Method for producing reduced iron using agglomerates>
The method for producing reduced iron using agglomerates is also not particularly limited. For example, the agglomerates may be charged into a reduction furnace such as a blast furnace, a shaft furnace, a rotary hearth furnace, or a rotary kiln, and the agglomerates may be reduced in these reduction furnaces. In the present embodiment, since the agglomerate contains the above-mentioned binder for producing agglomerate, the reduction efficiency is very high. Therefore, reduced iron having a high metallization rate can be produced.

<1. Example 1>
Next, an embodiment of the present embodiment will be described. In Example 1, the effect of the binder for producing agglomerates according to the present embodiment was verified by conducting the test described below.

First, organic binders A to D were prepared. The organic binder A is starch, the organic binder B is molasses, the organic binder C is the produced lignin left for half a year, and the organic binder D is the lignin immediately after being produced by the same production method as the organic binder C.

^{Then, the 13} C-NMR spectra of the organic binders A to D were measured. ¹³ The measurement of the C-NMR spectrum was performed using an INOVA500 device manufactured by VARIAN with a static magnetic field strength of 11.75T. The pulse sequence used the Han-Echo method, which was a combination of a 90 ° pulse and a 180 ° pulse, and the measurement was performed while tilting the sample to a magic angle and rotating it at 22 kHz. The pulse repetition time was set to 100 seconds to measure a quantitative spectrum. The total number of times was 4096. ^{Then, the area ratio of the 13} C-NMR spectrum (area ratio to the total ¹³ C-NMR spectrum area) at each chemical shift of the organic binders A to D was measured. Here, the total ¹³ C-NMR spectrum area is the total area of ^{all 13} C-NMR spectra measured in the range of 0 to 240 ppm. The results are shown in FIG. The horizontal axis of FIG. 1 shows the range of chemical shift, and the vertical axis shows the area ratio of the spectrum detected within that range.

As is clear from FIG. 1, the organic binder B to D, the area ratio of the ¹³ C-NMR spectrum of 185~165ppm becomes 5% or more, the area ratio of the ¹³ C-NMR spectrum of 240~185ppm becomes 2% or more (That is, both the first characteristic and the second characteristic are satisfied).

Further, in the organic binders B to D, ^{the area ratio of the 13} C-NMR spectrum of 90 to 50 ppm is 60% or less (that is, the third characteristic is satisfied). In the organic binders B to D, ^{the area ratio of the 13} C-NMR spectrum of 90 to 50 ppm is 40% or less. On the other hand, the organic binder A, the area ratio of the ¹³ C-NMR spectrum of 185~165ppm is less than 5%, the area ratio of the ¹³ C-NMR spectrum of 240~185ppm has become less than 2% (i.e. the first characteristic And neither of the second characteristics is satisfied). Further, in the organic binder A, ^{the area ratio of the 13} C-NMR spectrum of 90 to 50 ppm exceeds 60% (that is, the third characteristic is not satisfied). Therefore, the organic binders B to D correspond to the binder for producing agglomerates according to the present embodiment.

Then, the organic binders A to D were added to dust, which is a kind of iron oxide raw material, and mixed, and the mixture was granulated (kneaded) together with water to prepare agglomerates (tablets A to D).

Then, the tablets A to D were individually put into a heating furnace whose temperature in the furnace was preheated to 1250 ° C. and held for 6 minutes. At this time, the temperature inside the furnace was maintained at 1250 ° C. As a result, the iron oxide reduction reaction was allowed to proceed in the tablets A to D. Here, since the temperature of the tablets A to D is raised in the furnace, the temperatures of the tablets A to D were measured with time, and the CO partial pressure in the furnace at each temperature of the tablets A to D was further measured. Specifically, a part of the atmosphere inside the furnace was sampled, and the partial pressure of CO in the furnace was measured by performing FT-IR measurement. Here, the CO partial pressure was determined as CO gas pressure / (CO gas pressure + CO ₂ gas pressure). FIG. 2 shows the CO partial pressure when the tablets A to D reach 720 ° C. As is clear from FIG. 2, the CO partial pressure of tablets B to D at 720 ° C. is lower than the CO partial pressure of tablets A at 720 ° C.

Then, the tablets A to D were returned to room temperature in the heating furnace, and the tablets A to D were taken out. Then, in order to measure the metallization rate of the tablets A to D, T-Fe, which is the total Fe mass in the tablets A to D, is quantified by the ICP method, and M-Fe, which is the mass of the reduced metallic iron, is obtained. It was quantified by the bromine-methanol method. Based on these results and the following formula (1), the metallization rate (%) of tablets A to D was calculated. The results are shown in FIG. In addition, FIG. 3 shows the difference Δ (the metallization rate of tablets A to D-the metallization rate of tablet A) based on the metallization rate of tablet A.
Metallization rate (%) = M-Fe / T-Fe x 100 (1)

As is clear from FIG. 3, the metallization rate of the tablets B to D using the organic binders B to D (that is, the binder for producing agglomerates according to the present embodiment) was higher than that of the tablet A. Therefore, by using the binder for producing agglomerates according to the present embodiment, reduced iron having a high metallization rate can be obtained. In particular, since the organic binders B to D also satisfy the third property, the metallization rate is particularly high. Further, since the CO partial pressure of the organic binders B to D at 720 ° C. is lower than the CO partial pressure of the organic binder A at 720 ° C., the lower the CO partial pressure at this temperature, the higher the metallization rate of the reduced iron. It turns out (ie, the reduction is more advanced).

<2. Example 2>
In Example 2, a plurality of types of organic binders a to i having different raw materials or production methods were prepared, and their characteristics were verified. The organic binders a to g are lignins produced by different production methods. The organic binder h is starch and the organic binder i is molasses.

^{Then, the 13} C-NMR spectra of the organic binders a to i were measured by the same method as in Example 1. The results are shown in Table 1. In Table 1, DO (%) the area ratio of the ¹³ C-NMR spectrum of 240~185ppm, SO-1 (%) the area ratio of the ¹³ C-NMR spectrum of 185～165Ppm, ¹³ C-NMR of 90~50ppm The area ratio of the spectrum is shown as SO-2 (%). As is clear from Table 1, the organic binders a to f and i have a DO of 2% or more and an SO-1 of 5% or more (that is, satisfy the first and second characteristics), and thus the organic binders a to f. , I correspond to the binder for producing agglomerates of the present embodiment. Since the SO-2 of the organic binders a to f and i is 60% or less, the organic binders a to f and i also satisfy the third characteristic.

Further, tablets a to i were prepared and the metallization rate was measured by the same method as in Example 1. Regarding the metallization rate, the difference Δ of the metallization rate (%) based on the tablet g (tablet produced using the organic binder g) was determined. The results are shown in Table 1 and FIGS. 4 to 7. In FIGS. 4 to 6, the results of Table 1 are plotted on an XY plane in which the horizontal axis is any of DO, SO-1, and SO-2, and the vertical axis is the difference Δ of the metallization rate (%). Is. FIG. 7 is a plot of the results of Table 1 on an XY plane in which the horizontal axis is the sum of the DO value and the SO-1 value and the vertical axis is the difference Δ of the metallization rate (%).

As is clear from Tables 1 and 4 to 7, the tablets a to f and i using the organic binders a to f and i (that is, the binder for producing agglomerates according to the present embodiment) are more than the tablets g and h. The metallization rate also increased. Tablets g, h do not meet either or both of the first and second properties. Therefore, by using the binder for producing agglomerates according to the present embodiment, reduced iron having a high metallization rate can be obtained. In particular, since the organic binders a to f and i also satisfy the third characteristic, the metallization rate is particularly high.

Furthermore, according to FIGS. 4, 5 and 7, it was found that there is a positive correlation between the DO value, the SO-1 value, and the sum of these and the difference Δ of the metallization rate (%) (FIG. 4). R ^{2 in it} indicates the correlation coefficient). In particular, it was also found that the correlation between the sum of the DO value and the SO-1 value and the difference Δ of the metallization rate (%) was the best. Therefore, it can be said that the metallization rate increases if the first and second characteristics are satisfied (that is, if DO is 2% or more and SO-1 is 5% or more). On the other hand, according to FIG. 6, it was found that there is a negative correlation between the difference of the SO-2 value and metallization degree (%) △ (R ² in the figure shows the correlation coefficient) .. Therefore, it can be said that the metallization rate is further increased if the first and second characteristics are satisfied and the third characteristic is further satisfied (that is, if the SO-2 value is 60% or less).

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person having ordinary knowledge in the field of technology to which the present invention belongs can come up with various modifications or modifications within the scope of the technical ideas described in the claims. , These are also naturally understood to belong to the technical scope of the present invention.

Claims (5)

A binder for producing agglomerates that is added to a agglomerate raw material containing an iron oxide raw material.
^{The characteristic that the area ratio of the 13 C-NMR spectrum of 185 to 165 ppm to the total 13} C-NMR spectrum area ^{obtained by the 13} C-NMR spectrum measurement is 5% or more, and the property ^{obtained by the 13} C-NMR spectrum measurement. A binder for producing agglomerates, which satisfies the characteristic that the area ratio ^{of the 13} C-NMR spectrum of 240 to 185 ppm to the ^{total 13 C-NMR spectrum area is 2% or more. The characteristic that the area ratio of the 13 C-NMR spectrum of 185 to 165 ppm to the total 13} C-NMR spectrum area ^{obtained by the 13} C-NMR spectrum measurement is 5% or more, and the property ^{obtained by the 13} C-NMR spectrum measurement. The mass according to claim 1, wherein the clump contains lignin and / or ^{sugar that satisfies the property that the area ratio of the 13} C-NMR spectrum of 240 to 185 ppm to the total ^{13 C-NMR spectrum area is 2% or more.} Binder for product production. ^{The characteristic that the area ratio of the 13 C-NMR spectrum of 185 to 165 ppm to the total 13} C-NMR spectrum area ^{obtained by the 13} C-NMR spectrum measurement is 5% or more, and the property ^{obtained by the 13} C-NMR spectrum measurement. A step of preparing a binder for agglomerate production that satisfies the characteristic that the area ratio ^{of the 13} C-NMR spectrum of 240 to 185 ppm to the total ^{13 C-NMR spectrum area is 2% or more.}
A step of adding and mixing the binder for producing agglomerates to a agglomerate raw material containing an iron oxide raw material, and
A method for producing an agglomerate, which comprises a step of producing an agglomerate using a mixture of the agglomerate raw material and the binder for producing the agglomerate. The step of preparing the agglomerate production binder is to ^{measure the 13} C-NMR spectrum ^{of the agglomerate production binder, and the area ratio of the 13} C-NMR spectrum to 185 to 165 ppm with respect ^{to the total 13 C-NMR spectrum area.} The agglomeration according to claim 3, further comprising the step ^{of obtaining the area ratio of the 13} C-NMR spectrum of 240 to 185 ppm with respect ^{to the total 13 C-NMR spectrum area obtained by the 13} C-NMR spectrum measurement. Method of manufacturing the product. A method for producing reduced iron by using the agglomerated product produced by the method for producing an agglomerated product according to claim 3 or 4.

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