JPWO2011021577A1 - Non-fired carbon-containing agglomerated mineral for blast furnace and method for producing the same - Google Patents

Abstract

This unfired carbon-containing agglomerated mineral has a carbon content (TC) of 18 to 25% by mass, and a ratio CaO / SiO2 of CaO content (% by mass) to SiO2 content (% by mass) is 1. 0-2.0. This non-fired carbon-containing agglomerated mineral is produced by mixing and kneading an iron-containing raw material, a carbon-containing raw material, and a binder, forming a kneaded product to obtain a molded body, and then forming the molded body. A step of curing to obtain a non-fired carbon-containing agglomerated mineral, the carbon content (TC) of the non-fired carbon-containing agglomerated mineral is 18 to 25% by mass, and the CaO content of the gangue component ( (Mass%) and SiO2 content (mass%) ratio CaO / SiO2 is selected from the group consisting of ore brands and binder blending amounts in the forming step of the molded body. Adjust one or more blending conditions.

Description

The present invention relates to a non-fired carbon-containing agglomerated ore for a blast furnace, and more particularly, to a non-fired carbon-containing agglomerated mineral that can lower the lower slag melting point of the blast furnace and reduce the reducing material ratio of the blast furnace.
This application claims priority on August 21, 2009 based on Japanese Patent Application No. 2009-191966 filed in Japan, the contents of which are incorporated herein by reference.

  Conventionally, various iron-containing dust and carbon-containing dust collected from various dust collectors at steelworks, etc., blended with cement-based hydraulic binder, kneaded and molded, 8-16mm diameter unfired lump The ore is produced and used as blast furnace raw material.

  As a method for producing an unfired carbon-containing agglomerated mineral, a method is known in which iron-making dust is granulated into pellets, and then the pellets are cured and cured. In the step of granulating the iron-made dust into pellets, the particle size distribution of the dust is adjusted to an appropriate range, a binder such as quicklime and cement and 5 to 15% of water are added, and the mixture is granulated with a disk pelletizer or the like. I have pellets.

  In the production of such a non-fired carbon-containing agglomerated mineral, it is also required to increase the carbon content (TC) of the non-fired carbon-containing agglomerated mineral for the purpose of reducing the reducing material ratio in blast furnace operation. ing.

For example, in Patent Document 1, a carbon interior non-fired agglomerated mineral is manufactured by blending an iron-containing iron raw material and a carbon-based carbon material, adding a binder, kneading, molding, and curing. This carbon-incorporated non-fired agglomerated mineral has 80 to 120% of the theoretical amount of carbon necessary for reducing the iron oxide contained in the iron-containing iron-containing raw material into metallic iron. Moreover, the binder is selected so that the crushing strength at room temperature is 7850 kN / m ² or more, and mixing, molding, and curing are performed. Since the reduction reaction occurs due to the carbon contained in the iron oxide in the unfired carbon-containing agglomerated mineral, the reduction rate can be improved.

However, in this manufacturing method, the carbon content is limited to ensure strength, and the effect of reducing the reducing material ratio in a sufficient blast furnace cannot be obtained. In order to sufficiently obtain the effect of reducing the reducing material ratio, when a large amount of this unfired carbon-containing agglomerated mineral is used in a blast furnace, the amount of heat absorbed by the dehydration reaction of the binder in the blast furnace increases. Thereby, there existed a fault which forms a low-temperature heat preservation zone and promotes reduction | restoration powdering of a sintered ore.
Moreover, since quick lime and CaO-type cement are often used as a binder, CaO content in a non-baking carbon-containing agglomerated mineral becomes high. For this reason, the viscosity of the melt produced | generated from a non-baking carbon-containing agglomerated mineral in a reaction process becomes high too much. Thereby, aggregation and melt-down of the generated metal are inhibited. As described above, there is a drawback that the ventilation and liquid permeability at the lower part of the blast furnace are deteriorated.

  For example, if the unfired carbon-containing agglomerated material melts and drops at a low temperature, the unfired carbon-containing agglomerated material melts early in the vertical furnace and easily flows down the gap between the raw materials filled in the furnace. . In this case, the period of contact with the coke becomes longer. As a result, the reduction reaction of the powdered iron ore in the unfired carbon-containing agglomerated mineral and the carburization reaction of the generated iron can be promoted.

In Patent Document 2, attention is paid to the fact that the melting temperature can be reduced by coating CaCO ₃ even in the case of powdered iron ore in which surface concentration of SiO ₂ and Al ₂ O ₃ has occurred. And based on this attention point, the non-baking carbon-containing agglomerated mineral in which the pulverized iron ore and the flux were couple | bonded through coal is proposed.

  Patent Document 2 discloses a coal-containing agglomerated mineral containing 23.3 to 24.6% by mass of coal. Generally, the carbon content of coal is about 70%, and the remainder is ash. And volatiles. Therefore, the carbon content in the carbon-containing agglomerated ore corresponds to 16 to 17% by mass.

On the other hand, many reports have been made on the relationship between the dropability of sintered ore and the components.
For example, Non-Patent Document 1, dropping the temperature of sintered ore varies non-linearly with _{CaO / SiO 2, CaO / SiO} 2 = 1.0 near the most dropping temperature decreases, and increases the MgO It has been reported that the dropping temperature decreases.

  Non-Patent Document 2 reports that when 2% of MgO is added to dust cold pellets (cement bond) containing 7% of carbon, the high-temperature ventilation resistance is reduced.

As described above, it is well known to optimize CaO / SiO ₂ and MgO having a gangue composition in order to improve the metal dripping property of sintered ore and dust pellets having a carbon content of less than 10%. However, the metal dripping properties of carbon-containing agglomerates with high carbon content (18-25% by mass) with completely different reduction behaviors, and the appropriate conditions for the slag melting point at the bottom of the furnace to determine the metal dripping properties have been It was not known.

Therefore, the inventors have a carbon-containing agglomerated ore with a high carbon content (total C content 20%, total Fe content 40%, CaO 11%, SiO 6%, Al ₂ O ₃ 2.5%, MgO 0.5 %) Reduction characteristics were investigated. FIG. 8 shows a conventional sintered ore (total Fe content 58.5%, FeO 8%, CaO 10%, SiO ₂ 5%, Al ₂ O ₃ 1.7%, MgO 1.0%) and a large carbon content. The relationship between temperature and reduction rate is shown for carbon-containing agglomerated ores. Referring to FIG. 8, it can be seen that, in the carbon-containing agglomerated ore, the reduction proceeds remarkably in a low temperature region as compared with the conventional sintered ore. This is a major feature of the carbon-containing agglomerates with a high carbon content.

Next, a change in the slag melting point (CaO—SiO ₂ —Al ₂ O ₃ —MgO—FeO) due to the progress of reduction was simulated by a computer using the reduction rate of FIG. 8 obtained from the result of the reduction test. In addition, slag melting | fusing point was computed from the reduction rate supposing that all unreduced iron exists as FeO among the iron components of a sintered ore and a carbon-containing agglomerated ore. The results are shown in FIG. Here, the melting point means the temperature at which everything becomes a liquid phase, and the melt is generated even below the melting point. However, when the melting point is high, the melt amount is low, so the melting point indirectly represents the melt amount.

Referring to FIG. 9, in the sintered ore, the melting point of the slag substantially coincides with the sample temperature at 1200 to 1400 ° C., and it is considered that a large amount of melt is generated in this temperature range. On the other hand, in the carbon-containing agglomerated ore, the slag melting point remarkably increases from around 900 ° C. and reaches 1600 ° C. or more. Therefore, in a carbon-containing agglomerated ore with a high carbon content, it is considered that the reduction proceeds with a very small amount of melt. For this reason, since a solid phase always exists, the aggregation of the metal is inhibited, which causes dripping deterioration. In the above five-component system (CaO—SiO ₂ —Al ₂ O ₃ —MgO—FeO), in the carbon-containing agglomerated ore with a high carbon content, the influence of FeO on the melting point is extremely large, and the reduction proceeds rapidly at a low temperature. To do. The result shown in FIG. 9 is a phenomenon peculiar to a carbon-containing agglomerated mineral having a high carbon content.

  As described above, the reduction of the carbon-containing agglomerated ore with a high carbon content proceeds remarkably in a low temperature region as compared with the sintered ore, and the reduction proceeds with a very small amount of melt. For this reason, the knowledge about the dripping characteristic in the reduction progress of the sintered ore cannot be applied as it is to the carbon-containing agglomerated ore having a high carbon content.

  When using a carbon-containing agglomerated ore in a blast furnace, if the slag melting point is high, the lower surface of the cohesive zone is lowered, the lower dripping zone is narrowed, and the slag holdup amount between the dripping zone and the furnace core is increased. Specifically, in the dripping zone and the furnace core (the zone where the metal and slag flow down to the puddle while the specific gravity is separated), the flow of the melt is not smooth, and the melt stagnates in the gap (flow path). become. As a result, the gas flow becomes uneven and uniform gas heating cannot be performed. For this reason, a location where heat is insufficient is locally generated, and it becomes difficult to operate with stable furnace bottom air permeability.

JP 2003-342646 A JP-A-2005-325412

ISIJ International 44 (2004), p. 2057 Iron and Steel, 70 (1984), p. S825

  In this invention, the component conditions of the carbon-containing agglomerated mineral which has the optimal slag melting | fusing point for blast furnace use are specified. And based on this research result, this invention aims at provision of the non-baking carbon-containing agglomerated mineral which can lower the slag melting | fusing point and can reduce the reducing material ratio of a blast furnace, and its manufacturing method.

The present inventors can reduce the melting point of the furnace bottom slag by setting CaO / SiO ₂ of the gangue component of the carbon-containing agglomerated mineral to a specific range (1.0 to 2.0), and excellent metal dripping. We found a non-fired carbon-containing agglomerated mineral product that can achieve the desired properties. In order to make CaO / SiO ₂ of the gangue component of the non-fired carbon-containing agglomerated mineral 1.0 to 2.0, as described later, the blending amount of the high SiO ₂ -containing ore and the MgO-containing auxiliary material is adjusted. It has also been found to be preferable.

The non-fired carbon-containing agglomerated ore for a blast furnace according to one aspect of the present invention is obtained by mixing and kneading an iron-containing raw material, a carbon-containing raw material, and a binder, forming a kneaded product, and then obtaining the molded product. The carbon content (TC) is 18 to 25% by mass, and the ratio CaO content (% by mass) of the gangue component to SiO ₂ content (% by mass) is CaO / SiO _2. 1.0 to 2.0.
In the non-fired carbon-containing agglomerated mineral for a blast furnace according to one embodiment of the present invention, the CaO content (% by mass), the SiO ₂ content (% by mass), the Al ₂ O ₃ content (% by mass), and the MgO content Value of gangue amount ((CaO + SiO ₂ + Al ₂ O ₃ + MgO) / (100−carbon content (TC))) expressed by (mass%) and carbon content (TC) (mass%) May be 0.25 or less, and the MgO content may be 0.5 mass% or more.
5-10 mass% may be sufficient as content of the said binder.

A method for producing a non-fired carbon-containing agglomerated ore for a blast furnace according to an aspect of the present invention is a method of mixing a kneaded material, a carbon-containing material, and a binder, kneading, forming a kneaded product, and obtaining a molded product. A forming step and then a step of curing the shaped body to obtain a non-fired carbon-containing agglomerated mineral, wherein the carbon content (TC) of the non-fired carbon-containing agglomerated mineral is 18 to 25% by mass, and as CaO content of gangue ingredient (wt%) and SiO ₂ content ratio CaO / SiO ₂ (mass%) is 1.0 to 2.0, in the step of forming the molded body, ore grade And one or more blending conditions selected from the group consisting of the binder blending amount.
In the method for producing an unfired carbon-containing agglomerated mineral for a blast furnace according to one aspect of the present invention, the CaO content (mass%), the SiO ₂ content (mass%), and Al _{2 of the} unfired carbon-containing agglomerated mineral. Amount of gangue expressed by O ₃ content (mass%), MgO content (mass%) and carbon content (TC) (mass%) ((CaO + SiO ₂ + Al ₂ O ₃ + MgO) / (100− In the forming step of the molded body, the blending conditions are adjusted so that the value of carbon content (TC))) is 0.25 or less and the MgO content is 0.5 mass% or more. May be.
You may adjust the said binder compounding quantity in 5-10 mass%.
In the forming step of the molded body, the auxiliary material selected from quartzite, serpentine, peridotite, dolomite, nickel slag, magnesite, and brucite, and one or both of high-SiO ₂ containing ores are further blended, so that the carbon content of non-calcined carbonaceous mass Naruko (T.C.) is 18 to 25 wt%, and the ratio CaO / SiO ₂ of CaO content and SiO ₂ content is 1.0 to 2.0 to, may be adjusted the amount of the auxiliary materials and high SiO ₂ containing ores.

The non-fired coal-containing agglomerated ore for blast furnaces according to one aspect of the present invention is not only for non-fired carbon-containing agglomerated minerals, but to improve the reduction rate of the main blast furnace iron-containing raw materials such as sintered ores. Has a sufficient carbon content. Furthermore, in the operation of the blast furnace, the slag melting point can be suppressed lower than before, and excellent reduction product slag characteristics (metal dripping properties) can be achieved.
For this reason, when the non-baking carbon-containing agglomerated mineral which concerns on 1 aspect of this invention is used as a part of iron-containing raw material for blast furnaces, favorable air permeability can be implement | achieved in the furnace lower part at the time of blast furnace operation. In addition, the reducing material ratio (coke ratio) can be greatly reduced.

In the method for producing a non-fired carbon-containing agglomerated mineral for a blast furnace according to one embodiment of the present invention, since a non-fired process is applied, it is possible to save energy and reduce CO ₂ compared to the fired process. Further, the dust generated in the iron making process can be recycled as an iron-containing raw material and a carbon material by a relatively inexpensive and simple method.

Binder is a diagram showing a relationship (cement) the amount (and CaO / SiO ₂ ratio) and cold crushing strength. It is a diagram showing the relationship between the sintered ore and non-calcined carbonaceous mass Naruko CaO / SiO ₂ and slag melting point when MgO content is 1.5%. CaO / SiO ₂ is a diagram showing the relationship between the sintered ore and non-calcined carbonaceous MgO content mass Naruko and slag melting point when it is 1.5. It is a diagram showing the relationship between the non-calcined carbonaceous mass Naruko and sinter the CaO / SiO ₂ and metal dropping rate. It is a figure which shows the relationship between MgO content of a non-baking carbon-containing agglomerated mineral and sintered ore, and a metal dripping rate. It is a diagram showing the relationship between the gangue amount _{(CaO + SiO 2 + MgO +} Al 2 O 3) / (100-TC) values and the metal dropping rate. It is a figure which shows the relationship between the carbon content (TC) of a non-baking carbon-containing agglomerated mineral, and a metal dripping rate. It is a figure which shows the relationship between the temperature of the conventional sintered ore, and the non-baking carbon-containing agglomerated mineral with a high carbon content. It is a figure which shows the relationship between the temperature of the conventional sintered ore and the non-baking carbon-containing agglomerated mineral with high carbon content, and the calculated value of slag melting | fusing point.

The unfired carbon-containing agglomerated ore for a blast furnace according to this embodiment is obtained by mixing and kneading an iron-containing raw material, a carbon-containing raw material, and a binder, molding the kneaded material to obtain a molded body, and then curing the molded body. Manufactured by the method. Carbon content (T.C.) is 18 to 25 wt%, CaO / SiO ₂ gangue component is 1.0 to 2.0. As a result, an optimum slag melting point for blast furnace use can be obtained.

In this embodiment, the carbon content (TC) of a non-baking carbon-containing agglomerated mineral is 18-25 mass%, Preferably it is 20-23 mass%.
If the carbon content is less than 18%, even if the gangue component is adjusted, the effect of reducing the reducing material ratio is reduced. When the carbon content exceeds 25% by mass, it becomes impossible to have the minimum cold crushing strength necessary for use in blast furnaces.

The ratio CaO / SiO ₂ (also referred to as basicity) of CaO content (% by mass) and SiO ₂ content (% by mass) of the gangue component of the unfired carbon-containing agglomerated mineral is 1.0 to 2.0. Yes, preferably 1.4 to 1.7.
The metal dripping rate can be improved by setting CaO / SiO ₂ to a low value within the range of 1.0 to 2.0. If CaO / SiO ₂ is more than 2.0, the metal dropping rate is less than 50%. When CaO / SiO ₂ is less than 1.0, the effect of improving the metal dropping rate is saturated.

In the present embodiment, the value of the gangue amount is preferably 0.25 or less, more preferably 0.22 to 0.25. Here, the gangue amount is a value calculated by the following equation.
Amount of gangue = (CaO + SiO ₂ + Al ₂ O ₃ + MgO) / (100-carbon content (TC))
Incidentally, _CaO in the _{formula, SiO 2, Al 2 O 3} , and MgO is, CaO content in the non-calcined carbonaceous mass Naruko respectively (wt%), SiO ₂ content (wt%), _Al 2 _{O 3} Content (mass%) and MgO content (mass%) are shown.
By setting the value of the gangue amount to 0.25 or less, the slag amount can be reduced and the dripping property can be further improved.

  The MgO content is preferably 0.5% by mass or more, more preferably 0.6 to 2.0% by mass. Thereby, melting | fusing point of low FeO slag (slag with little FeO content) falls by MgO, and can improve metal dripping property further.

The method for producing a non-fired carbon-containing agglomerated ore for a blast furnace according to the present embodiment includes a step of forming a molded body to obtain a molded body by mixing and kneading the iron-containing raw material, the carbon-containing raw material, and the binder, and molding the kneaded product. Then, the step of curing the shaped body to obtain a non-fired carbon-containing agglomerated mineral is provided. In the forming step of the compact, the carbon content (TC) of the unfired carbon-containing agglomerated mineral is 18 to 25% by mass, and the CaO content (% by mass) and the SiO ₂ content (mass by mass) of the gangue component. the ratio CaO / SiO ₂ of%) are such that 1.0 to 2.0, adjusting one or more blending conditions selected from the group consisting of ore grade and the binder amount.

As iron-containing raw materials used in this embodiment, sintered dust generated in the iron making process, iron-containing dust such as blast furnace dust, pellet feed smaller in particle size than powdered iron ore for sintering, and powdered iron ore for sintering are crushed And / or fine pulverized iron ore produced by sizing.
Depending on the ore brand to be used, the contents of gangue components such as iron and SiO ₂ vary greatly. Therefore, the CaO / SiO ₂ value can be adjusted by selecting the ore brand to be used. In particular, the CaO / SiO ₂ value is greatly affected by the amount of ore having a high SiO ₂ content.
Examples of ore brands used in the present embodiment include Indian high Siricious, robe river, Yandy Kujina, Rio Doce (Itabira), Mara Mamba, and the like.

  Examples of the carbon-containing raw material used in the present embodiment include blast furnace primary ash, coke dust, fine coke, and anthracite.

  Examples of the binder used in the present embodiment include fine powders mainly composed of blast furnace granulated slag and aging binders composed of alkali stimulants, quicklime, Portland cement, bentonite and the like. The blending amount (addition amount) of the binder can be appropriately determined in consideration of other blending conditions and the like. When the blending amount of the binder is too small, it becomes difficult to sufficiently maintain the cold rolling strength of the unfired carbon-containing agglomerated mineral. Moreover, when there are too many compounding quantities of a binder, the amount of slag of a non-baking carbon-containing agglomerated mineral will increase, and the air permeability of a furnace lower part will become unstable. Thereby, the stable reducing material ratio reduction effect is not acquired.

Therefore, the cold strength of the unfired carbon-containing agglomerated minerals in which CaO / SiO ₂ was changed by adjusting the binder blending amount was investigated. The obtained results are shown in Table 1 and FIG.

As the binder (cement) content decreased (CaO / SiO ₂ decreased), the cold strength decreased. Then, CaO / SiO ₂ is of less than 1.0 (Binder (cement) amount is less than 5 wt%), has become difficult to maintain the crush strength 100 kg / cm ² between cold. When the cold crushing strength of the non-fired carbon-containing agglomerated mineral is less than 100 kg / cm ² , pulverization of the non-fired carbon-containing agglomerated mineral may be caused at the time of conveyance to the blast furnace and charging. In order to maintain the cold crushing strength at 100 kg / cm ² or more, the binder (cement) content is preferably 5% by mass or more. On the other hand, if the amount of the binder (cement) exceeds 10% by mass, the amount of gangue may be increased. For this reason, it is preferable to make a binder (cement) compounding quantity into 10 mass% or less. Therefore, the blending amount of the binder is preferably 5 to 10% by mass.

In addition, in the mixing, kneading, molding, and curing production processes, free water is taken into the hydrates in the carbon-containing agglomerated minerals by curing the cement during the curing. For this reason, when going through the manufacturing process, the total blending amount of the raw materials slightly changes, but the amount of change is minute and may be considered to hardly change. For this reason, the compounding quantity of a binder becomes substantially the same as the binder content in the non-baking carbon-containing agglomerated mineral produced, for example. Similarly, for other components, the blending amount in the production process and the content in the unfired carbon-containing agglomerated mineral are almost the same.
Accordingly, in the unfired carbon-containing agglomerated mineral of this embodiment, the binder content is preferably 5 to 10% by mass, and as described above, a cold crushing strength of 100 kg / cm ² or more can be achieved. .

In this embodiment, it is preferable to further mix the auxiliary material and the high SiO ₂ content ore. Thereby, component adjustment can be performed more strictly. In particular, the CaO / SiO ₂ value can be adjusted without being influenced by the amount of the binder.
Examples of the auxiliary material include quartzite mainly composed of SiO ₂ , serpentinite mainly composed of MgO, peridotite, dolomite, nickel slag, magnesite, and brucite. The high SiO ₂ content ore, SiO ₂ content of 3.5 mass% or more ore.

Generally, when the chemical composition of the target non-fired carbon-containing agglomerated mineral is specified, the blending amounts of these auxiliary raw materials and high SiO ₂ -containing ore are automatically determined. Therefore, the amount of these auxiliary materials and high SiO ₂ containing ore is not particularly limited, is suitably determined according to the chemical composition of non-calcined carbonaceous mass Naruko.

Next, a method for adjusting CaO / SiO ₂ , MgO content and gangue amount will be described in more detail.
CaO / SiO ₂ is determined by the amount of CaO and the amount of SiO ₂ contained in the raw material to be blended.

CaO is mainly contained in binders, blast furnace primary ash used as a carbon-containing raw material, sintered dust and converter dust used as an iron-containing raw material, and the amount of these should be adjusted appropriately. The CaO content can be adjusted. However, when a cement-based binder having a high CaO content is used as the binder, in order to adjust the CaO content so that CaO / SiO ₂ is 1.0 to 2.0, the blending amount of the binder itself is decreased. There is a need. For this reason, it is necessary to consider whether sufficient cold crushing strength is obtained.

SiO ₂ and MgO are mainly contained in binders, blast furnace primary ash used as a carbon-containing raw material, sintered dust used as an iron-containing raw material, ash in carbon-based weight loss, and the like.
In the present embodiment, if CaO / SiO ₂ in the non-calcined carbonaceous mass Naruko is familiar with 1.0 to 2.0, regardless of the mode of addition of SiO ₂ (the form of raw material containing SiO _2), a constant Can have an effect. Further, regarding MgO, if the MgO content is 0.5 mass% or more, a certain effect can be brought about regardless of the addition form of MgO (form of raw material containing MgO).
When actively reducing the value of CaO / SiO ₂ or making the MgO content 0.5 mass% or more, such as silica, serpentine, peridotite, dolomite, nickel slag, magnesite, brucite, etc. It is preferable to mix an auxiliary raw material or a high SiO ₂ content ore. Thereby, as described above, the value of CaO / SiO ₂ and the MgO content can be adjusted without being influenced by the amount of the binder. However, when these auxiliary materials and high SiO ₂ -containing ores are blended in a large amount, the amount of gangue will increase. For this reason, it is preferable to adjust CaO / SiO ₂ and MgO so that the amount of gangue is 0.25 or less.

In the present embodiment, as described above, the numerical ranges of the carbon content (TC), CaO / SiO ₂ , gangue amount, and MgO content are defined. Experimental results showing the critical significance of these numerical ranges are shown below.
The reduction rate at 1400 ° C. of a sintered ore and an unfired carbon-containing agglomerated mineral with CaO / SiO ₂ of 1.5 and MgO content of 1.5% was measured. Then, assuming that all unreduced iron is present in the slag as FeO, the FeO concentration in the slag was calculated from the obtained reduction rate. As a result, it was found that the FeO concentration in the slag was 34% when the sintered ore was used and 2% when the unfired carbon-containing agglomerated mineral was used. Using this FeO concentration, the relationship between the CaO / SiO ₂ value or MgO content and the slag melting point was investigated for sintered ore and unfired carbon-containing agglomerated ore. The slag melting point (CaO—SiO ₂ —Al ₂ O ₃ —MgO—FeO) was determined from computer simulation.

FIG. 2 shows the relationship between CaO / SiO ₂ and slag melting point when the MgO content is 1.5%. FIG. 3 shows the relationship between the MgO content and the slag melting point when CaO / SiO ₂ is 1.5.
As is apparent from FIG. 2, the degree of influence of CaO / SiO ₂ on the slag melting point differs between sintered ore and unfired carbon-containing agglomerated ore. This is due to the difference in the reduction rate at high temperature (that is, the FeO concentration in the slag). Specifically, in the sintered ore, when CaO / SiO ₂ decreases by 1.0, the slag melting point decreases by 278 ° C. In contrast, in the non-calcined carbonaceous mass Naruko, the CaO / SiO ₂ is 1.0 drops, slag melting point is lowered 620 ° C.. For this reason, the influence of CaO / SiO ₂ in the unfired carbon-containing agglomerated mineral is twice or more larger than the influence of CaO / SiO ₂ in the sintered ore.

The unburned carbon-containing agglomerated ore has a high reduction rate at low temperatures. When using a non-calcined carbon-containing agglomerate with a high carbon content as compared with a calcined agglomerate with a low carbon content, it is reduced earlier in the upper part of the blast furnace. Then, the amount of the unreduced iron component (the amount of FeO) remaining in the slag that is reduced at the top and moves to the bottom decreases. When the amount of FeO in the slag decreases, the slag melting point increases. As described above, the melting point of slag depends on the basicity (CaO / SiO ₂ ). For this reason, it is thought that slag melting point changes greatly with the basicity in a non-baking carbon-containing agglomerated mineral. Moreover, when the basicity in a non-baking carbon-containing agglomerated mineral is large, it is thought that slag melting | fusing point will become very high.

  Referring to FIG. 3, in the sintered ore, when the MgO content is increased by 1.0%, the slag melting point is lowered by 50 ° C. On the other hand, in a non-baking carbon-containing agglomerated mineral, when MgO content increases 1.0%, slag melting | fusing point falls by 22 degreeC. For this reason, the influence of MgO content in a non-baking carbon-containing agglomerated mineral is about half compared with the influence of MgO content in a sintered ore.

  However, strictly speaking, the dropping behavior is not determined only by the slag melting point, but also depends on the amount of slag and other slag physical properties (viscosity, wettability with metal, etc.). For this reason, the dropping behavior is a complicated phenomenon and has not been completely elucidated at present. However, it is clear that the sintered ore and non-fired carbon-containing agglomerated minerals have different component conditions for promoting the metal dropping by lowering the slag melting point.

Then, the dripping characteristic of the non-baking carbon-containing agglomerated mineral which has various gangue components was investigated using the load softening test apparatus.
The iron-containing raw material and the carbon-containing raw material were pulverized, mixed with a binder and auxiliary raw materials, and kneaded to obtain a kneaded product. Next, the kneaded product was molded, and the molded body was cured for a predetermined period to produce an unfired carbon-containing agglomerated mineral. Carbon content of unfired carbon-containing agglomerated minerals C (total carbon) was 20 mass%. Further, the mixing ratio of the iron-containing raw material and the auxiliary raw material was adjusted so that the contents of CaO / SiO ₂ and MgO became predetermined values. The blending amount of the binder (cement) was 10% by mass.
Specifically, the gangue amount ((CaO + SiO ₂ + Al ₂ O ₃ + MgO) / (100-carbon content (TC))) is constant at 0.22, and the MgO content is 0.9% by mass. As a constant, the blending amount of Portland cement and fine silica was adjusted so that CaO / SiO ₂ was a predetermined value in the range of 0.5 to 2.5. Thus, CaO / SiO ₂ of gangue components were produced different non-calcined carbonaceous mass Naruko in the range of 0.5 to 2.5.
Further, a constant CaO / SiO ₂ at 2.0, to prepare a non-sintered carbonaceous mass Naruko with different MgO content.

First, CaO / SiO ₂ of gangue component is carried load softening test for each different non-calcined carbonaceous mass Naruko in the range of 0.5 to 2.5.
Assuming actual blast furnace use, unfired carbon-containing agglomerated minerals were mixed at a rate of 10% with respect to ordinary sintered ore (CaO / SiO ₂ = 1.8). At the stage of heating to 1600 ° C. and reduction, the amount (rate) of metal dropped from the crucible was measured. And the metal dripping rate (%) defined by the following formula | equation was calculated.
Metal dripping rate (%) = Drip metal amount / (Total amount of Fe charged × 0.95) × 100
Moreover, the metal dripping rate was similarly measured about only the sintered ore. In addition, when the metal dripping rate of sintered ore is less than 50%, the lower surface of the fusion band is lowered, and the lower dripping band region is narrowed. For this reason, lower air permeability deteriorates and stable operation becomes difficult.
The obtained results are shown in Table 2 and FIG.

As can be seen from FIG. 4, the higher the CaO / SiO ₂ of the unfired carbon-containing agglomerated mineral, the lower the metal dripping rate. In particular, when the CaO / SiO ₂ of the unfired carbon-containing agglomerated mineral exceeds 2.0, it becomes difficult to maintain a metal dropping rate of 50%. By using the unfired carbon-containing agglomerated indirect reduction, the indirect reduction proceeds from the low temperature region, so that the FeO content in the slag coexisting with the metal in the fusion layer is lowered, and the slag melting point is raised. Generally, the iron melt produced by reduction includes coke carbon when descending to the bottom of the blast furnace, and the carbon content increases (reduction produced metal carburization). It is considered that the increase in the slag melting point hindered the aggregation of iron melts after carburization of the reduced-product metal, and the results shown in FIG. 4 were obtained. When CaO / SiO ₂ was less than 1.0, the slag dropping rate was less than 50% even though the coexistence slag melting point was sufficiently low. This is because the proportion of the SiO ₂ that is the network former increases, so that the viscosity of the coexistence slag increases and the metal aggregation is inhibited.
FIG. 4 also shows the measurement results representing the relationship between CaO / SiO ₂ and metal dripping rate of sintered ore with an MgO content of 1.5%. Also in the sintered ore, the metal dripping rate tends to decrease as CaO / SiO ₂ increases. However, the change is gradual. Also from the result of FIG. 4, it can confirm that the component conditions which should be comprised in order to achieve the outstanding metal dripping property differ in a non-baking carbon-containing agglomerated ore and sintered ore.
As described above, CaO / SiO ₂ needs to be 1.0 to 2.0 in order to improve the metal dropping rate. CaO / SiO ₂ is preferably 1.4 to 1.7, the metal dropping rate of over 60% can be achieved.

Further, CaO / SiO ₂ is 2.0, and for non-calcined carbonaceous mass Naruko with different MgO content was carried load softening test in the same manner. And the relationship between MgO content in a non-baking carbon-containing agglomerated mineral and a metal dripping rate when a non-baking carbon-containing agglomerated mineral was mixed in the ratio of 10% with respect to the sintered ore was investigated. The obtained results are shown in Table 3 and FIG.

As can be seen from FIG. 5, in order to improve the metal dripping rate, it is also effective to increase the MgO content in the unfired carbon-containing agglomerated mineral. From the change in the metal dripping rate when mixing unsintered carbon-containing agglomerated CaO / SiO ₂ = 2.0 into the sintered ore at a rate of 10%, when the MgO content is 0.5% by mass or more, It can be seen that the metal dripping rate can be maintained at 50%. The higher the MgO content, the higher the metal dripping rate. However, it can be seen that the effect is saturated when the MgO content is around 2.0%. This is because the melting point of the above-mentioned low FeO slag (slag with low FeO content) is lowered by MgO. The higher the CaO / SiO ₂ , the more effectively the effect of MgO can be obtained.
Therefore, the MgO content is preferably 0.5% by mass or more. There is no particular upper limit.

FIG. 5 also shows a measurement result representing the relationship between the MgO content of the sintered ore with a CaO / SiO ₂ of 2.0 and the metal dripping rate (%). Also in the sintered ore, the metal dripping rate tends to increase as the MgO content increases. However, the change (influence) is larger than that of unfired carbon-containing agglomerated minerals. Also from the result of FIG. 5, it can confirm that the component conditions which should be comprised in order to achieve the outstanding metal dripping property differ in a non-baking carbon-containing agglomerated ore and sintered ore.

The amount of coexisting slag (the amount of gangue + the amount of unreduced FeO) is also an important factor that determines the dripping property. Therefore, non-fired carbon-containing agglomerated minerals having CaO / SiO ₂ of 1.5, MgO of 1.0% and different gangue amounts were produced. And the metal dripping rate was measured and the dripping characteristic was investigated.
As described above, the gangue amount was calculated by the following equation.
Amount of gangue = (CaO + SiO ₂ + Al ₂ O ₃ + MgO) / (100-carbon content (TC))
The obtained results are shown in Table 4 and FIG.

As described above, since the FeO concentration in the slag has already decreased to 2% at a relatively low temperature portion, the influence of the FeO concentration is small. As a result, when the gangue amount was 0.25 or less, good metal dripping property was exhibited regardless of the slag amount. When the amount of gangue is in the range of 0.25 or less, it is considered that slag physical properties such as solid phase ratio, viscosity, wettability with metal, etc. become the controlling factors of metal dripping property rather than slag amount. However, when the gangue amount exceeded 0.25, the influence of the slag amount could not be ignored, and the dripping property deteriorated. Furthermore, when the amount of gangue is at this level (above 0.25), when using a large amount of unfired carbon-containing agglomerated ore in a blast furnace, the amount of hearth slag is significantly increased, and the tapping work becomes unstable. Causes fluctuations in ventilation.
From the above results, it is preferable to adjust the components of the unfired carbon-containing agglomerated mineral so that the gangue amount ((CaO + SiO ₂ + MgO + Al ₂ O ₃ ) / (100-TC)) is 0.25 or less.

Furthermore, the influence of the carbon content (TC) in the unfired carbon-containing agglomerated mineral on the metal dripping rate was investigated.
MgO is constant at 1.0% by mass, gangue amount is constant at 0.22, CaO / SiO ₂ is 0.5, 1.0, 1.5, 2.0, or 2.5, The unfired carbon-containing agglomerated mineral was manufactured by adjusting the mixing ratio of the raw materials so that the carbon content (TC) was 10, 15, 18, 25, or 30% by mass.
The amount (rate) of metal dripping was measured in the same manner as described above. The obtained results are shown in FIG.

From the results of FIG. 7, it can be seen that the metal dripping rate decreases as the carbon content (TC) increases. This is because the FeO concentration in the slag coexisting with the metal decreases as the carbon content (TC) increases as described above.
As described above, in order to achieve stable operation in the blast furnace, the metal dripping rate needs to be 50% or more. In CaO / SiO ₂ is 1.0 to 2.0, when the carbon content (T.C.) is less than 25 wt%, it can be seen that achieve metal dropping rate of 50% or more. Therefore, the upper limit of the carbon content (TC) needs to be 25% by mass.

  In this embodiment, the amount of the non-fired carbon-containing agglomerated mineral and the gangue is adjusted to a predetermined range, but the molding method, shape, and physical structure of the non-fired carbon-containing agglomerated mineral (pores / voids) Rate) is not limited. Various forms such as pellets and briquettes can be applied as long as they are non-fired carbon-containing agglomerated blast furnaces. Various molding methods such as extrusion molding can be applied, and equivalent effects can be obtained.

In the blast furnace, the charge moves from the upper part to the lower part, and the reducing gas moves from the lower part to the upper part, thereby causing heat exchange and reaction to proceed. For this reason, the blast furnace is a countercurrent reactor. In general, in continuous operation of a blast furnace, the reducing power of the reducing gas is lost in the upper layer of the ore layer, and the reduction may not proceed sufficiently. In particular, the calcined agglomerated mineral does not contain carbon and does not have a self-reducing ability. For this reason, when a calcined agglomerated mineral is used, the calcined agglomerated mineral is not sufficiently reduced at the upper part of the ore layer. When the calcined agglomerated ore moves to the lower part of the blast furnace in an incomplete reduction state, it is reduced at the dropping zone and the furnace core of the blast furnace, causing direct reduction. In such a case, there is a problem that the load on the blast furnace increases and the air permeability deteriorates.
On the other hand, when using the non-fired carbon-containing agglomerated mineral of this embodiment, the presence of the non-fired carbon-containing agglomerated mineral of this embodiment together with the iron ore in the blast furnace, particularly in the upper layer of the ore layer. Reduction efficiency can be greatly improved.
However, in the non-fired carbon-containing agglomerated mineral having a high carbon content, as described above, the influence of the basicity (CaO / SiO ₂ ) on the slag melting point is particularly large (FIG. 2). In this embodiment, favorable metal dripping property is achieved by prescribing the carbon content (TC) and CaO / SiO ₂ based on the above-described research results of the inventors. For this reason, the amount of slag hold-up between the dripping zone and the furnace core portion is reduced, and good air permeability can be secured.
Furthermore, as described above, the presence of the non-fired carbon-containing agglomerated mineral of the present embodiment together with the iron ore in the blast furnace can greatly improve the reduction efficiency particularly in the upper layer of the ore layer. Since the reduction efficiency in the upper layer of the ore layer that is difficult to be reduced can be greatly improved, the reduction efficiency in the entire blast furnace is greatly improved. For this reason, it is possible to reduce the amount of reducing material larger than the amount of coke equivalent to the excess amount of carbon in the unfired carbon-containing agglomerated mineral of this embodiment.

Fine iron-containing materials (sintered dust and iron ore) were prepared as iron-containing materials, and carbonaceous materials (coke dust, powder coke, and blast furnace primary ash) were prepared as carbon-containing materials. Moreover, cement (early strong Portland cement) was prepared as a binder. In some examples, an auxiliary material having a high SiO ₂ content was also used.
The blending ratio of the raw materials was adjusted so that the blending ratio of cement (early strong Portland cement) was 4 to 9% by mass and the blending ratios of the carbonaceous material and the finely divided iron-containing raw material were various values. These raw materials were mixed with moisture and kneaded with an Eirich mixer. The obtained kneaded product was granulated (molded) with a pan pelletizer to obtain raw pellets. Next, the raw pellets were subjected to sun curing for 2 weeks to produce unfired carbon-containing agglomerated minerals. In addition, the water | moisture content of the raw pellet was adjusted to 10-14 mass% according to the cement amount to mix | blend.

About the obtained unbaked carbon-containing agglomerated mineral, cold crushing strength was measured by the following method according to JISM8718. A compressive load was applied to one sample at a specified pressure rate, and the load value when the sample broke was measured. The load value (kg / cm ² ) per unit cross-sectional area was determined. Then, an average value of 100 samples was calculated and used as an intensity index.
By the method mentioned above, the slag melting | fusing point and metal dripping rate of the non-baking carbon-containing agglomerated mineral were measured.
Further, in a blast furnace having an effective volume of 5500 m ^3, the blast furnace was operated using a non-fired carbon-containing agglomerated mineral of 50 kg / tp as a part of the raw material. And the upper K value in the operation of the blast furnace, the lower K value, the wind pressure fluctuation | variation, and the reducing material ratio were measured, and the average value of the operation result for about one month was calculated | required. The results are shown in Table 6.

Referring to Table 6, in Example 1, the components were optimized, CaO / SiO ₂ was 2.0, MgO was 0.6%, and the gangue amount was 0.22. When used in a blast furnace, the air permeability at the bottom of the furnace was improved, and the reducing material ratio decreased to 470 kg / tp. For this reason, the effect using the non-baking carbon-containing agglomerated mineral with high carbon content was exhibited.

In Example 2, it was blended with a high SiO ₂ content adjuncts, was further reduced to 1.0 to CaO / SiO ₂ enhances the SiO ₂ content. In Example 2, since the CaO / SiO ₂ and MgO contents were within the appropriate ranges, the slag melting point could be lowered. However, since the amount of gangue increased to 0.28, the metal dripping property was slightly lowered, and the reducing material ratio was not lowered so much.

In Example 3, the binder amount was reduced to 4% in order to reduce the amount of gangue. However, since the chemical component content was appropriate, the metal dripping rate was improved. However, since the amount of the binder was small, the cold crushing strength was insufficient at 85 kg / cm ² . For this reason, when it was used in a blast furnace, the amount of powder in the furnace increased, thereby lowering the upper air permeability, and the reducing material ratio was slightly higher.

  In Example 4, the content of the chemical component was adjusted by blending the auxiliary material without reducing the binder amount. As a result, an unfired carbon-containing agglomerated mineral with good metal dripping properties could be produced without impairing the cold crushing strength. When used in a blast furnace, the reducing material ratio was the lowest.

In Example 5, the CaO / SiO ₂ and the gangue amount are within the ranges defined in the present embodiment (CaO / SiO ₂ : 1.0 to 2.0, the gangue amount: 0.25 or less). The MgO content was set as low as 0.4%. For this reason, the metal dripping rate remained at 52% and the reducing material ratio was reduced, but the effect of reducing the reducing material ratio was relatively small.

On the other hand, in Comparative Example 1, the carbon content (TC) is as low as 17% by mass, the CaO / SiO ₂ is as low as 1.9, and the MgO content is as high as 1.0%. Agglomerate was produced. Since the carbon content (TC) was low, the slag melting point was sufficiently low, and there was no problem with dripping. However, when used in a blast furnace, since the carbon content is low, it has been difficult to reduce the reducing material ratio.

In Comparative Example 2, an unfired carbon-containing agglomerated mineral having a carbon content (TC) increased to 20% and CaO / SiO ₂ increased to 2.2 was produced. Since the reduction rate at low temperature was improved, the slag melting point was significantly increased. Since it is more CaO / SiO ₂ is 2.0 greater than the metal dropping property deteriorate. However, when used in a blast furnace, the air permeability in the lower part of the furnace deteriorated and the fluctuation of the wind pressure significantly increased. This destabilized the operation. For this reason, the effect by having high carbon content was not fully received, and the reducing material ratio remained at the 500 kg / tp level.

In Comparative Example 3, a high carbon non-fired carbon-containing agglomerated mineral having a carbon content of 30% and exceeding the upper limit of 25% by mass within the range defined in the present embodiment was produced. Since the content of other components was within an appropriate range, the dropping rate was improved to 65%. However, the cold strength was as low as 60 kg / cm ^2, and the minimum strength required for use in a blast furnace could not be obtained. For this reason, the amount of powder charged into the blast furnace increased, making long-term stable operation difficult.

As described above, in the unfired carbon-containing agglomerated mineral, the carbon content (TC) is 18 to 25% by mass, and CaO / SiO ₂ is within the range of 1.0 to 2.0. It turns out that dripping property is favorable and can reduce the reducing material ratio at the time of using in a blast furnace. In particular, when the value of the gangue amount (CaO + SiO ₂ + Al ₂ O ₃ + MgO) / (100−carbon content (TC)) is 0.25 or less and the MgO content is 0.5 mass% or more This effect is remarkable. Moreover, cold crushing strength can also be maintained by performing such component adjustment by adding an auxiliary material and setting the binder content to 5 to 10%.

When used in a blast furnace, the non-fired carbon-containing agglomerated ore for blast furnace according to one embodiment of the present invention is not only covered with non-fired carbon-containing agglomerated ore, but also the main blast furnace iron-containing raw material such as sintered ore. It has a sufficient carbon content to improve the reduction rate. Furthermore, in the operation of the blast furnace, the slag melting point can be suppressed lower than before, and excellent reduction product slag characteristics (metal dripping properties) can be achieved.
For this reason, when the unfired carbon-containing agglomerated ore according to one aspect of the present invention is used as a part of the iron-containing raw material for blast furnace, good air permeability can be realized in the lower part of the furnace during blast furnace operation, and the reducing material ratio (coke Ratio) can be greatly reduced.

In the method for producing a non-fired carbon-containing agglomerated mineral for a blast furnace according to one embodiment of the present invention, since a non-fired process is applied, it is possible to save energy and reduce CO ₂ compared to the fired process. Further, the dust generated in the iron making process can be recycled as an iron-containing raw material and a carbon material by a relatively inexpensive and simple method.
Therefore, one embodiment of the present invention can be suitably applied to the technical field related to a carbon-containing agglomerated mineral used in a blast furnace.

The non-calcined carbon-containing agglomerated mineral for a blast furnace according to one aspect of the present invention is a mixture of kneaded material and 4-10% by mass of a binder containing iron-containing raw material, carbon-containing raw material, and all raw materials. The molded body is then cured, and the molded body is cured, and the carbon content (TC) is 18 to 25% by mass, and the gangue component SiO ₂ content (% by mass) is 5.1. The ratio CaO / SiO _{2 of} the CaO content (mass%) and the SiO ₂ content (mass%) is 1.0 to 2.0%.
The non-calcined carbon-containing agglomerated mineral for a blast furnace according to one aspect of the present invention is a mixture of kneaded material and 4-10% by mass of a binder containing iron-containing raw material, carbon-containing raw material, and all raw materials. The molded body is then cured, and then the molded body is cured. The carbon content (TC) is 18 to 25% by mass, and the CaO content (mass%) of the gangue component is 6 to 10%. The ratio CaO / SiO ₂ between the CaO content (mass%) and the SiO ₂ content (mass%) may be 1.0 to 2.0.
In the non-fired carbon-containing agglomerated mineral for a blast furnace according to one embodiment of the present invention, the CaO content (% by mass), the SiO ₂ content (% by mass), the Al ₂ O ₃ content (% by mass), and the MgO content Value of gangue amount ((CaO + SiO ₂ + Al ₂ O ₃ + MgO) / (100−carbon content (TC))) expressed by (mass%) and carbon content (TC) (mass%) there is 0.25 or less, and MgO content but it may also be more than 0.5 mass%.

The method for producing a non-fired carbon-containing agglomerated ore for a blast furnace according to one aspect of the present invention comprises mixing and kneading 4 to 10% by mass of a binder containing iron-containing raw material, carbon-containing raw material, and all raw materials, and kneaded product Forming a molded body to obtain a molded body, and then curing the molded body to obtain a non-fired carbon-containing agglomerated carbon, TC) is 18 to 25% by mass, and the SiO ₂ content (% by mass) of the gangue component is 5.1 to 10%, and the ratio of CaO content (% by mass) to SiO ₂ content (% by mass) In the forming step of the molded body, one or more blending conditions selected from the group consisting of an ore brand and a binder blending amount are adjusted so that CaO / SiO ₂ is 1.0 to 2.0.
The method for producing a non-fired carbon-containing agglomerated ore for a blast furnace according to one aspect of the present invention comprises mixing and kneading 4 to 10% by mass of a binder containing iron-containing raw material, carbon-containing raw material, and all raw materials, and kneaded product Forming a molded body to obtain a molded body, and then curing the molded body to obtain a non-fired carbon-containing agglomerated carbon, TC) is 18 to 25% by mass, the CaO content (mass%) of the gangue component is 6 to 10%, and the ratio of CaO content (mass%) to SiO ₂ content (mass%) CaO / SiO _In the forming step of the molded body, one or more blending conditions selected from the group consisting of an ore brand and a binder blending amount may be adjusted so that ₂ is 1.0 to 2.0.
In the method for producing an unfired carbon-containing agglomerated mineral for a blast furnace according to one aspect of the present invention, the CaO content (mass%), the SiO ₂ content (mass%), and Al _{2 of the} unfired carbon-containing agglomerated mineral. Amount of gangue expressed by O ₃ content (mass%), MgO content (mass%) and carbon content (TC) (mass%) ((CaO + SiO ₂ + Al ₂ O ₃ + MgO) / (100− In the forming step of the molded body, the blending conditions are adjusted so that the value of carbon content (TC))) is 0.25 or less and the MgO content is 0.5 mass% or more. even if the good.
In the forming step of the molded body, the auxiliary material selected from quartzite, serpentine, peridotite, dolomite, nickel slag, magnesite, and brucite, and one or both of high-SiO ₂ containing ores are further blended, Carbon content (TC) of the unfired carbon-containing agglomerated mineral is 18 to 25% by mass , SiO ₂ content (mass%) of the gangue component is 5.1 to 10%, and CaO content and SiO as the ratio CaO / SiO ₂ of ₂ content is 1.0 to 2.0, the may adjust the amount of either or both of the auxiliary materials and high SiO ₂ containing ores.
In the forming step of the molded body, the auxiliary material selected from quartzite, serpentine, peridotite, dolomite, nickel slag, magnesite, and brucite, and one or both of high-SiO ₂ containing ores are further blended, Carbon content (TC) of the unfired carbon-containing agglomerated mineral is 18 to 25% by mass, CaO content (mass%) of the gangue component is 6 to 10%, and CaO content and SiO ₂ content. as the ratio CaO / SiO ₂ is 1.0 to 2.0 of the may be adjusted the amount of either or both of the auxiliary materials and high SiO ₂ containing ores.

Claims (7)

Iron-containing raw material, carbon-containing raw material, and a binder are mixed, kneaded, a kneaded product is molded to obtain a molded body, and then the molded body is cured and manufactured.
Carbon content (T.C.) is 18 to 25 mass%, and CaO content of gangue ingredient (wt%) and SiO ₂ content ratio CaO / SiO ₂ (mass%) 1.0 to 2.0 A non-fired carbon-containing agglomerated mineral for blast furnaces. Table by CaO content (% by mass), SiO ₂ content (% by mass), Al ₂ O ₃ content (% by mass), MgO content (% by mass) and carbon content (TC) (% by mass) The value of the gangue amount ((CaO + SiO ₂ + Al ₂ O ₃ + MgO) / (100-carbon content (TC))) is 0.25 or less, and the MgO content is 0.5% by mass or more The uncalcined carbon-containing agglomerated mineral for a blast furnace according to claim 1.   The unburned carbon-containing agglomerated mineral for a blast furnace according to claim 1, wherein the content of the binder is 5 to 10% by mass. A step of forming a molded body to obtain a molded body by mixing and kneading the iron-containing raw material, the carbon-containing raw material, and the binder, and molding the kneaded product;
Next, curing the molded body to obtain a non-fired carbon-containing agglomerated mineral,
The carbon content (TC) of the unfired carbon-containing agglomerated mineral is 18 to 25% by mass, and the ratio of CaO content (% by mass) and SiO ₂ content (% by mass) of the gangue component is CaO / SiO. _The blast furnace is characterized by adjusting one or more blending conditions selected from the group consisting of an ore brand and a binder blending amount so that ₂ is 1.0 to 2.0. For producing non-fired carbon-containing agglomerated minerals. CaO content (% by mass), SiO ₂ content (% by mass), Al ₂ O ₃ content (% by mass), MgO content (% by mass) and carbon content (T The value of the gangue amount ((CaO + SiO ₂ + Al ₂ O ₃ + MgO) / (100−carbon content (TC))) expressed by (C) (mass%) is 0.25 or less, and MgO The manufacturing method of the non-baking carbon-containing agglomerated mineral for blast furnaces of Claim 4 which adjusts the said mixing conditions in the formation process of the said molded object so that content may be 0.5 mass% or more.   The manufacturing method of the non-baking carbon-containing agglomerated mineral for blast furnaces of Claim 4 which adjusts the said binder compounding quantity in 5-10 mass%. In the forming step of the molded body, the auxiliary material selected from quartzite, serpentine, peridotite, dolomite, nickel slag, magnesite, and brucite, and one or both of high-SiO ₂ containing ores are further blended,
So that the carbon content of non-calcined carbonaceous mass Naruko (T.C.) is 18 to 25 wt%, and the ratio CaO / SiO ₂ of CaO content and SiO ₂ content is 1.0 to 2.0 , the non-calcined carbonaceous mass Naruko manufacturing method for a blast furnace according to claim 4, characterized in that adjusting the amount of the auxiliary materials and high SiO ₂ containing ores.

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