WO2019008675A1 - Carbon material interior ore and production method therefor - Google Patents

Abstract

Provided is a carbon material interior ore that can be efficiently produced. The carbon material interior ore is produced without baking by adding an organic binder to an iron oxide-containing feedstock and a carbon material, adjusting the moisture content, and mixing and granulating same. The feedstock is adjusted so that when the amount of carbon derived from the iron oxide-containing feedstock is X and the amount of carbon derived from the carbon material is Y, said carbon material interior ore satisfies the relationship given by 3.5X+Y≥25 and also satisfies the relationship given by 0.2X+Y≤20. By satisfying the relationship given by 3.5X+Y≥25, it is possible to improve reducibility. By satisfying the relationship given by 0.2X+Y≤20, it is possible to ensure the crushing strength necessary for a blast furnace feedstock.

Description

Charcoal-embedded mine and method for producing the same

The present invention relates to a carbon material-containing ore used as a steelmaking material in a blast furnace and a method for producing the same.

BACKGROUND ART In recent years, for the purpose of reducing a reducing material ratio in blast furnace operation, a carbon material-containing ore formed by mixing and granulating a carbon material and an iron oxide-containing raw material has been proposed.

In addition to strength and reducibility and reduction ability in a low temperature range, a carbon material-containing ore used as a raw material for blast furnaces is required to have excellent reducibility.

As a method of producing a non-calcined carbonaceous material interior ore excellent in this kind of crushing strength and reducibility, as shown in Patent Document 1, an iron-containing raw material containing high-crystal water ore having a particle size of 10 μm to 50 μm And a hydraulic binder such as pulverized coke with a particle size of 100 μm or less and cement, etc. to make the carbon content of the carbon material internal ore 18% to 25% by mass, and the porosity 20% or more A method of 30% or less is known.

In addition, as a method for producing a carbon material internal ore excellent in cold crushing strength and reducibility, as shown in Patent Document 2, the specific surface area by BET method is 0.6 m ² / g or more and 10 m ² / g or less There is known a method of forming a mixture of an iron-containing raw material and a carbon material having a softening and melting property by hot working at 250 ° C. or more and 550 ° C. or less.

International Publication No. 2011/021560 JP 2007-77484

However, in the method of Patent Document 1 described above, there is a problem that the primary curing after molding, the secondary curing and the subsequent drying treatment are time-consuming and expensive and can not be efficiently manufactured.

In addition, in the method of Patent Document 2 described above, since it is necessary to heat the raw material to 250 to 550 ° C. and form it hot, the energy loss is large and the equipment is complicated as compared with the case of non-baking. There are problems that can not be manufactured efficiently.

The present invention has been made in view of these points, and it is an object of the present invention to provide a carbon material-containing ore that can be efficiently produced and a method for producing the same.

The carbon material interior mineral described in claim 1 is a carbon material interior mineral formed using an iron oxide-containing material, a carbon material and an organic binder, and the amount of carbon derived from the iron oxide material is X. When the carbon content derived from the carbonaceous material is Y, the relationship shown by 3.5X + Y ≧ 25 is satisfied, and the relationship shown by 0.2X + Y ≦ 20 is satisfied.

The carbon material-containing ore according to claim 2 is the carbon material-containing ore according to claim 1, wherein the iron oxide-containing material has a carbon content of 5% by mass or more and less than 30% by mass.

A carbon material-containing ore according to claim 3 is the carbon material-containing ore according to claim 1 or 2, wherein the carbon material has a carbon content of 70% by mass or more.

The method for producing a carbon material-containing ore according to claim 4 comprises adding an organic binder to the powdery iron oxide-containing raw material and the powdery carbon material, adjusting the water content, mixing and granulating the unfired material. A method for producing a carbon material-containing ore to be produced, where X is the amount of carbon derived from the iron oxide-containing raw material and Y is the amount of carbon derived from the carbon material, the relationship shown by 3.5X + Y ≧ 25 is satisfied, And a raw material is adjusted so that the relationship shown by 0.2X + Y <= 20 is satisfied.

The method for producing a carbon material-containing ore according to a fifth aspect of the present invention is the method for producing a carbon material-containing ore according to the fourth aspect, wherein the iron oxide-containing raw material has a carbon content of 5% by mass to 30% by mass. It is a certain thing.

The method for producing a carbon material-containing ore according to claim 6 is the method for producing a carbon material-containing ore according to claim 4 or 5, wherein the carbon material has a carbon content of 70% by mass or more. .

According to the present invention, when the carbon content derived from the iron oxide-containing raw material is X and the carbon content derived from the carbon material is Y, the relationship shown by 3.5X + Y ≧ 25 is satisfied, and 0.2X + Y ≦ 20. Since the reducibility can be improved and the crushing strength as a material for blast furnaces can be secured only by adjusting the types and the blending of the iron oxide-containing raw material and the carbon material so as to satisfy the relationship shown in FIG. .

It is a graph which shows the conditions of the reduction test at the time of measuring the reduction rate of a carbon material internal deposit. It is a graph which shows the relationship between a carbon material interior mineral carbon content and a reduction rate. It is a graph which shows the relationship between the carbon content of a carbon material internal deposit, and crushing strength. It is a graph which shows the relationship between the value shown by 3.5X + Y of a carbon material internal deposit, and a reduction rate. It is a graph which shows the relationship between the value shown by 0.2X + Y of a carbon material internal deposit, and crushing strength.

Hereinafter, the configuration of an embodiment of the present invention will be described in detail.

In the carbon material internal ore, a powdery iron oxide-containing raw material and a powdery carbon material are blended at a predetermined ratio, and an organic binder is added, and water is added to adjust the water appropriately, and then mixed and formed. Granulated to be manufactured.

The iron oxide-containing raw material contains iron oxide, and for example, iron ore, dust recovered from a dust collector in an ironworks, and a mixture containing blast furnace gas ash and foreign matter generated in ironworks are used. These raw materials may be used alone or in combination of two or more at a predetermined ratio. Moreover, it is not limited to these raw materials, You may use another iron oxide containing raw material.

The amount of carbon contained in the iron oxide-containing raw material is preferably 5% by mass or more in order to improve the reducibility of the carbonaceous material-containing ore. On the other hand, when the amount of carbon contained in the iron oxide-containing raw material is 30% by mass or more, the crushing strength of the carbon material-containing ore may be reduced. Therefore, the amount of carbon contained in the iron oxide-containing raw material is preferably 5% by mass or more and less than 30% by mass.

As the carbonaceous material, for example, powdered coke, steam coal, anthracite and coke dust are used. These raw materials may be used alone or in combination of two or more at a predetermined ratio. Moreover, it is not limited to these raw materials, You may use another carbonaceous material.

The amount of carbon contained in the carbonaceous material is preferably 70% by mass or more in order to ensure reducibility of the carbonaceous material-containing ore.

As the organic binder, for example, pulp waste solution, molasses, various polymers, starch and carboxymethylcellulose are suitably used. In addition, these may not only be used independently but may mix | blend multiple types by a predetermined | prescribed ratio. Moreover, it is not limited to these organic binders, You may use another organic binder.

Furthermore, as a raw material, in addition to the organic binder, for example, an inorganic binder such as quick lime or bentonite may be added in a range where the amount of slag in the raw material does not increase.

The addition amount of the organic binder can be appropriately determined, but if the ratio of the organic binder in all the various raw materials is less than 1% in terms of solid content, there is a possibility that sufficient crushing strength can not be secured as a material for blast furnaces, If it exceeds 10%, the strength improvement effect saturates, resulting in an increase in material cost. Therefore, the addition amount of the organic binder is preferably 1% to 10% in terms of solid content.

When the raw material is granulated, for example, a compression granulation method for producing a pillow type briquette or an almond type briquette with a briquette machine having a pair of forming rolls, a rolling granulation method for molding into a sphere with a pan pelletizer, etc. Although performed suitably, it is not limited to these methods, You may granulate by another method.

The unfired carbon material-filled ore immediately after molding needs to have a certain strength in order to withstand transportation to the blast furnace and powderization during blast furnace charging. Therefore, the raw carbon material internal ore after molding is subjected to a drying process to improve its strength. It is preferable to carry out such drying treatment with, for example, hot air at 100 ° C. or more and 300 ° C. or less so that the moisture content of the short wood interior mine becomes 3% or less.

Here, the amount of carbon greatly affects the reducibility of the carbonaceous material ore, and as the amount of carbon is larger, the reducibility is improved and the reduction effect of the blast furnace reducing material ratio is increased. On the other hand, when the amount of carbon in the carbonaceous material-containing ore increases, the crushing strength decreases. Therefore, it is manufactured by the amount of carbon which satisfies the crushing strength and reducibility conventionally calculated | required as a carbon material interior ore.

However, the carbon in the carbonaceous material-containing ore includes not only carbon contained in the carbonaceous material, but also those derived from iron oxide-containing raw materials. We examined what kind of influence it has on characteristics such as reducibility.

In order to confirm the influence on the reducibility of the carbon material internal ore by the difference in the carbon content and the difference in the blending amount of the iron oxide-containing raw material, the carbon content and the carbon content from each carbon source are changed The internal ore was manufactured and the crushing strength and the reduction rate were measured.

First, four types of iron oxide-containing raw materials were blended at the ratio shown in Table 1.

In addition, powdery coke, which is a carbonaceous material, and steam coal were blended at a ratio shown in Table 2.

Two types of organic binders shown in Table 3 are added to the iron oxide-containing raw material and the carbon material compounded in these various proportions, mixed while adding water, and then compression molded using a briquette machine to obtain a carbon material interior ore Made. The charcoal-lined ore (raw briquette) is an almond type of 25 mm × 18 mm × 10 mm.

And after making a raw briquette dry at 105 degreeC for 2 hours or more, while measuring crushing strength, it used for the reduction test. The crushing strength was measured according to JIS M 8718. Moreover, the reduction test was performed by the temperature and gas history shown in FIG. 1, and the reduction rate was measured from the components after the test.

FIG. 2 shows the carbon material-containing ore in each of the case of using iron ore A containing no carbon as the iron oxide-containing raw material and the case of using in-house dust containing 8% by mass of carbon as the iron oxide-containing raw material. The relationship between the carbon content and the reduction rate is shown.

When iron ore A containing no carbon is used as the iron oxide-containing raw material, the reduction rate increases as the carbon content increases. On the other hand, when the in-house dust containing carbon is used as the iron oxide-containing material, the reduction ratio is 100% regardless of the carbon content, and the reduction ratio is higher than when iron ore A is used became. In addition, when the same carbon content was compared, the reduction rate was higher when using in-house dust containing carbon as the iron oxide-containing raw material.

That is, it is understood that the carbon contained in the iron oxide-containing raw material is more effective in improving the reducibility of the carbon material-containing ore.

In FIG. 3, the carbon material-containing ore in the case of using iron ore A containing no carbon as the iron oxide-containing raw material and the case of using in-house dust containing 8% by mass of carbon as the iron oxide-containing raw material The relationship between carbon content and crushing strength is shown.

When iron ore A containing no carbon is used as the iron oxide-containing raw material and when both internal dust containing carbon is used, the crushing strength drops sharply when the amount of carbon exceeds a predetermined amount.

In addition, the amount of carbon in which the crushing strength sharply decreases differs between the case where iron ore A is used and the case where in-house dust is used, and in the case where in-house dust is used, the strength decreases due to the high carbon amount.

That is, the carbon contained in the carbonaceous material has a smaller adverse effect of reducing the crushing strength of the carbonaceous material-containing ore than the carbon contained in the iron oxide-containing raw material.

As described above, since the influence on the crushing strength and the reducibility is different between the carbon derived from the iron oxide-containing raw material and the carbon derived from the carbon material, in order to produce the carbonaceous material interior ore having excellent crushing strength and reducibility It is necessary to optimize the blending ratio of raw materials in consideration of the difference in the influence of carbon sources.

Therefore, the relationship between the crushing strength and reducibility, the amount of carbon (X) derived from the iron oxide-containing raw material, and the amount of carbon derived from the carbonaceous material (Y) was confirmed.

The carbon content (%) derived from the iron oxide-containing raw material is a value obtained by multiplying the amount of C in the iron oxide-containing raw material with the blending ratio of the iron oxide-containing raw material in the carbon material interior ore. Y which is the amount of carbon derived from (%) is a value obtained by multiplying the amount of C in the carbon material and the blending ratio of the carbon material in the carbon material-containing ore.

It was found that the reduction ratio was correlated with the value shown by 3.5X + Y as shown in FIG. 4, and the crushing strength was correlated with the value shown by 0.2X + Y as shown in FIG.

Specifically, regardless of the type of iron oxide-containing raw material, the reduction rate of the carbon material-containing ore increases with the increase of the value shown by 3.5X + Y, and the value of 3.5X + Y is 25 or more. It reaches about 100%.

On the other hand, when the value shown by 0.2X + Y exceeds 20, crushing strength will fall large also by any iron oxide containing raw material.

From the above results, the carbon amount (X) derived from the iron oxide-containing raw material and the carbon amount (Y) derived from the carbonaceous material satisfy the relationship shown by 3.5X + Y ≧ 25, and are shown by 0.2X + Y ≦ 20. By adjusting the blending of the raw materials so as to satisfy the relationship, it is possible to produce a carbon material interior ore excellent in crushing strength and reducibility.

The reason why the carbon contained in the iron oxide-containing raw material has a greater effect of improving reducibility is considered to be that the distance between the iron oxide and the carbon material is short and the effect of improving the reductability by the carbon material is large. . Further, the reason why the carbon contained in the iron oxide-containing raw material is apt to reduce the crushing strength is considered to be because the particle diameter of the carbonaceous material is smaller than that of the iron oxide-containing raw material.

Next, effects and the like of the above-described embodiment will be described.

According to the above embodiment, when the carbon content derived from the iron oxide-containing raw material is X and the carbon content derived from the carbon material is Y, the relationship shown by 3.5X + Y + 25 is satisfied, and 0. The reducibility can be improved and the crushing strength as a blast furnace raw material can be secured only by adjusting the type and the combination of the iron oxide-containing raw material and the carbon material so as to satisfy the relationship 2X + Y ≦ 20. Therefore, it is possible to efficiently produce a carbon material-containing ore excellent in crushing strength and reducibility without performing post-processing and firing after molding.

Moreover, by using an iron oxide-containing raw material having a carbon content of 5% by mass or more and less than 30% by mass, the reducibility is easily improved and the crushing strength is easily secured.

Furthermore, by using a carbon material having a carbon content of 70% by mass or more, reducibility can be easily secured.

Hereinafter, Examples and Comparative Examples will be described.

First, it knead | mixed while adding a water | moisture content to the raw material of the mixing | blending shown in Table 4, and it compression-molded using the briquette machine, and shape | molded the raw briquette of 25 mm x 18 mm x 10 mm almond type.

Moreover, after making a raw briquette dry at 105 degreeC for 2 hours or more, while performing crushing strength measurement according to JISM 8718, it used for the reduction test.

Table 5 shows the amount of carbon (X) derived from the iron oxide-containing raw material, the amount of carbon derived from the carbonaceous material (Y), the various relational expressions of X and Y, and the experimental results in each Example and each Comparative Example. Show.

In the embodiment Nos. 1 and 2 in which the value indicated by 3.5X + Y is 25 or more and the value indicated by 0.2X + Y is 20 or less. 1 to No. In all cases 6, when the crushing strength was 0.7 kN or more, sufficient crushing strength as a raw material for blast furnace could be secured, and the reduction ratio was 100%, and the reducibility was good.

On the other hand, No. 1 which is a comparative example. 7 had a value of not more than 20 indicated by 0.2X + Y and a high crushing strength, but a value of not less than 25 indicated by 3.5X + Y, the reduction ratio was as low as 90.3% and the reducibility was inferior. .

Moreover, No. 1 which is a comparative example. 8 and No. 9 has a value of 25 or more as 3.5X + Y and good reducibility, but since the value as 0.2X + Y exceeds 20, the crushing strength is lower than 0.7 kN and sufficient as a material for blast furnaces The strength could not be secured.

INDUSTRIAL APPLICABILITY The present invention can be used as a carbon material-containing ore which is a steelmaking material in a blast furnace.

Claims (6)

1. A carbon material-containing ore formed by using an iron oxide-containing raw material, a carbon material and an organic binder,
   Assuming that the amount of carbon derived from the iron oxide-containing raw material is X and the amount of carbon derived from the carbonaceous material is Y,
   A carbon material-containing ore characterized by satisfying the relationship shown by 3.5X + Y ≧ 25 and satisfying the relationship shown by 0.2X + YY20.
2. The carbonaceous material-containing ore according to claim 1, wherein the iron oxide-containing raw material has a carbon content of 5% by mass or more and less than 30% by mass.
3. The carbonaceous material-containing ore according to claim 1 or 2, wherein the carbonaceous material has a carbon content of 70% by mass or more.
4. An organic binder is added to a powdery iron oxide-containing raw material and a powdery carbonaceous material, and a moisture is adjusted, mixed and granulated, and a method for producing a carbon material-containing ore prepared by non-calcining,
   Assuming that the amount of carbon derived from the iron oxide-containing raw material is X and the amount of carbon derived from the carbonaceous material is Y,
   A raw material is adjusted so as to satisfy the relation shown by 3.5X + Y 満 足 25 and to satisfy the relation shown by 0.2X + Y ≦ 20.
5. The method for producing a carbon material-containing ore according to claim 4, wherein the iron oxide-containing raw material has a carbon content of 5% by mass or more and less than 30% by mass.
6. The method for producing a carbon material-containing ore according to claim 4 or 5, wherein the carbon material has a carbon content of 70% by mass or more.

Images