JP5308711B2 - Granulation method for sintered raw materials for iron making - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pelletization-processing method for a sintering raw material for iron making which is effective for pelletization of the sintering raw material for iron making such as powdery iron ore in production of the sintered ore as the raw material to be charged into a blast furnace in an iron making process and which, even when the pelletization property of the sintering raw material for iron making is remarkably enhanced, actualizes the sufficient productivity of the sintered ore without incurring sticking of the fine iron ore powder to fuel such as powdery coke with the level of the ignitability and combustibility to the powdery coke kept high, and which reduces quantity of fats and oils discharged into exhaust gas. <P>SOLUTION: The pelletization-processing method for the sintering raw material for iron making in the presence of the powdery coke and/or anthracite, includes a step of subjecting the fuel containing the powdery coke and/or the anthracite to hydrophobic treatment with water-based emulsion of a hydrophobic material, then subjecting the fuel having undergone the hydrophobic treatment to pelletization-processing together with a part or the whole of the remaining sintering raw material for iron making. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a method for granulating a sintering raw material for iron making. More specifically, the present invention relates to a method for granulating a sintered raw material for iron making that can be suitably applied to granulate fine iron ore and the like in the production of sintered ore as a raw material for charging a blast furnace in the iron making process.

The iron making process is generally performed by charging sintered ore made of iron ore, lump ore, and pellets together with coke into a blast furnace. This sintered ore is prepared by pre-treating sintered raw materials including iron ore, auxiliary raw materials, fuel, etc., filling the sintering machine to a specific height to form a sintered part bed, and then igniting the surface layer Manufactured by firing. As a sintering machine, a downward suction type is usually adopted, and air necessary for sintering is circulated by suctioning from below the sintering raw material, and fuel is supplied downward from above the sintering raw material. By burning, the sintering raw material is sintered. For this reason, if the sintering raw material contains a lot of fine powder, the air permeability decreases due to clogging and the like, and the combustion rate of the powdered coke as the fuel becomes slow, so the production efficiency of the sintered ore decreases. It will be.

As a means for suppressing the influence of fine powder of the sintering raw material, a method using an iron ore granulating binder such as a polymer binder is known (for example, see Patent Documents 1 and 2). However, in the treatment using these granulating binders, iron ore fine powder adheres and granulates on the surface of the powdered coke and anthracite as fuel, and the combustibility of these fuels may not be sufficient.
Therefore, a method for treating powder coke and anthracite with a hydrophobic substance in advance has been disclosed as a countermeasure means for preventing adhesion of iron ore fine powder to such fuel (see, for example, Patent Document 3). In this method, a hydrophobic substance such as liquid paraffin is attached in advance to the surface of the fuel particles, thereby making it difficult for iron ore fine powder having moisture to adhere in the subsequent granulation step of the sintered raw material. It is an effective technique for improving the combustibility of powdered coke and anthracite. However, there has been room for improvement to more suitably apply to the granulation treatment of the sintered raw material.
JP 59-50129 A Japanese Patent No. 3703769 JP 2005-154823 A

The present invention has been made in view of the above situation, and is effective for granulating a sintered raw material for iron making, such as fine iron ore, in the production of sintered ore as a raw material for charging a blast furnace in the iron making process, Even when the granulation properties of the sintering raw material for iron making are significantly improved, sufficient sintering is achieved while maintaining high ignitability and flammability to the powdered coke without attaching iron ore fine powder to fuel such as powdered coke. It is an object of the present invention to provide a method for granulating a sintered raw material for iron making that can realize ore productivity and can also reduce the amount of oil and fat discharged into the exhaust gas. In addition, another object is to provide a powdered coke for iron making and / or an anthracite treatment agent that can be suitably used for such a granulation treatment.

The present inventors have studied various methods for granulating the sintering raw material for iron making, and when granulating the sintering raw material for iron making, fuel such as powdered coke and anthracite is also granulated, and their surface First, paying attention to the fact that the iron ore fine powder adheres to the surface, the ignitability and combustibility are not sufficient, and after treating part or all of the powdered coke and anthracite as a fuel with a hydrophobic substance, We found a phenomenon in which the adhesion of ore to the surface of powdered coke and anthracite coal markedly decreases when fuel is added to iron ore and granulated. However, in such treatment, although the combustibility of powder coke and anthracite coal is improved, the used hydrophobic substance is not combusted in the sintering machine and may be discharged into the exhaust gas of the sintering machine. Pay attention. In particular, when oils and fats such as liquid paraffin are used as hydrophobic substances, if the oils and fats increase in the exhaust gas, the oils and fats may accumulate inside the electric dust collector for exhaust gas treatment. In order to proceed with the work, in a normal sintering machine, the amount of oil and fat is controlled, and it is necessary to reduce the processing amount of the hydrophobic substance as much as possible.

Therefore, the present inventors have emulsified the hydrophobic substance as a means for effectively adhering the hydrophobic substance to the fuel surface such as powdered coke and anthracite while reducing the amount of fat and oil discharged into the exhaust gas. The present inventors have found a method for hydrophobizing a fuel containing fine coke and anthracite, such as kneading with a fuel containing coke and anthracite and then drying the fuel. This method makes it possible to deposit the hydrophobic substance thinly and uniformly on the surface of the fuel, so that the amount of the hydrophobic substance used is reduced to about 1/10 compared to the conventional method of directly kneading the fuel and the hydrophobic substance. We have found that the above problems can be solved brilliantly. In addition, when a specific compound is used as a hydrophobic substance and an emulsion of the compound is used for the hydrophobic treatment, adhesion of ore fine powder to the fuel surface is more effectively suppressed during granulation treatment of the sintered raw material. It has been found that such a treatment agent composed of an aqueous emulsion of a hydrophobic substance is particularly useful as a hydrophobic treatment for fuel containing powdered coke and anthracite. It has been reached.

That is, the present invention is a method of granulating a sintered raw material for iron making in the presence of powdered coke and / or anthracite, and the granulating method of the sintered raw material for iron making comprises: coking powder and / or anthracite. Hydrophobic treatment of the containing fuel with an aqueous emulsion of a hydrophobic substance, followed by granulation treatment of the fuel after the hydrophobic treatment together with a part or all of the remaining sintering raw material for iron making. It is a grain processing method.

The present invention is also a treatment agent for hydrophobically treating a fuel containing iron coke and / or anthracite, wherein the treatment agent is composed of an aqueous emulsion of a hydrophobic substance, and the hydrophobic substance is carbon. It is also a powder coke for iron making and / or an anthracite treatment agent that is at least one compound selected from the group consisting of a compound having a paraffin chain of 5 or more, a compound having a naphthene ring, and silicone.
The present invention is described in detail below.

The granulation treatment method of the present invention is a process for granulating a sintered raw material for iron making, but the iron raw material sintered material to be granulated includes powdered iron ore, In addition, other iron ores, secondary materials and fuels will be included. Further, it may contain other components contained in a normal sintering raw material.
The iron ore is an iron ore mainly having a particle size of approximately 10 mm or less that cannot be used as a blast furnace raw material as it is, and the other iron ores are iron ores other than the iron ore, Any iron ore used as a raw material may be used.
The auxiliary material is sintered together with iron ore, fuel, and the like, and is limestone, dolomite, serpentine, silica stone, slag, dust, ore, and the like. Dust is a general term for fine particle waste generated at each step in the ironmaking process at steelworks. For example, dust is generated during sintering process, blast furnace dust generated during blast furnace process, and converter process. Examples include converter dust, converter graphite, pickling dust generated in cold rolling mills, coke digested sediment powder, rolled return water dust, lagoon dust, and the like. It may also contain dust generated in processes other than iron making. Specifically, dust generated in thermal power plants, such as fly ash and heavy oil ash, calami iron concentrate generated in copper making processes Or sludge such as copper slag, red mud discharged in the alumina production process, flue gas desulfurization gypsum, asbestos dust and the like.

In the granulation treatment method of the present invention, a fuel containing powdered coke and / or anthracite is subjected to a hydrophobic treatment with an aqueous emulsion of a hydrophobic substance, and the fuel after the hydrophobic treatment is used as a part of the remaining sintering raw material for iron making or The whole is granulated.
That is, the fuel used for the granulation treatment may be any fuel that includes at least the fuel subjected to the hydrophobic treatment (fuel after the hydrophobic treatment), and a new fuel may be added after the hydrophobic treatment. Especially, it is suitable that the fuel provided to the hydrophobic treatment is 50% by mass or more with respect to 100% by mass of the total amount of fuel used for the granulation treatment. More preferably, it is 80 mass% or more, More preferably, it is 100 mass%. In addition, examples of the fuel that may be newly added after the hydrophobic treatment include other fuel components described later in addition to coke breeze and anthracite.

The fuel to be subjected to the hydrophobic treatment may contain at least either powdered coke or anthracite, but as other fuel components, for example, combustible gas generated from inside and / or outside of the steelworks It may contain dust having a carbon content of 5% by mass or more, fine powder of coal or charcoal, and the like. With respect to dust having a combustible carbon content of 5% by mass or more, the carbon content varies. Therefore, when calculating the mass as fuel in the present invention, the combustible carbon equivalent mass is used. For the mass in terms of carbon that can be burned, for example, in the “quantification of carbon content in pseudo particles” method of the example described later, a desired dust is applied instead of the sifted portion of 1 mm or less of the pseudo particles. Can be measured.
The combustible carbon conversion referred to in the present invention means a carbon content obtained by subtracting a carbon content that cannot be used as a fuel such as carbon contained in limestone from the total carbon content. Therefore, when the mass with combustible carbon content of 5% by mass or more is treated with the hydrophobic substance of the present invention, when calculating the mass as fuel, the mass in terms of combustible carbon contained in the dust And the total mass of the hydrophobic substance used.

In the present invention, it is preferable to use a fuel containing 50% by mass or more of powdered coke and / or anthracite in a total amount of 100% by mass as the fuel to be subjected to the hydrophobic treatment. More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more. In addition, the mass ratio of "powder coke and / or anthracite" here means the mass ratio as the total mass when both the coke breeze and anthracite are included. Is included, the mass ratio as the quantity of the powder coke or anthracite alone is meant.

In the hydrophobic treatment step, the water-based emulsion used is an oil-in-water emulsion, and includes an emulsion in which a part of water is replaced with a water-soluble substance such as a water-soluble organic solvent. From the viewpoint of safety and performance, the water-soluble organic solvent is preferably reduced as much as possible, and most preferably not contained at all.
The aqueous emulsion of the hydrophobic substance (aqueous emulsion of hydrophobic substance and water) may be any emulsion obtained by emulsifying the hydrophobic substance. The production method is not particularly limited, and examples thereof include a method of mixing water, a hydrophobic substance, and, if necessary, other components with an appropriate shearing force. Preferably, water and a hydrophobic substance are mixed under an appropriate shear force in the presence of a surfactant.

As a mixing apparatus used in the above production method, an apparatus having blades rotating at high speed is preferably used. Homomixer, TK homomixer (model name; manufactured by Tokushu Kika Kogyo Co., Ltd., the shape of the stirring blade is a turbine type) , High-speed disperser, homodisper, TK lab disperser (model name: made by Tokushu Kika Kogyo Co., Ltd., the shape of the stirring blade is a turbine type) ), A line mixer having a stirring drive unit, BIO MIXER (model name; manufactured by Nippon Seiki Seisakusho Co., Ltd.) and the like are suitable.

In the above production method, the mixing of water and the hydrophobic substance can be performed in one stage or two or more stages, and in the case of performing in two or more stages, the same and / or different two or more kinds of mixing apparatuses are mixed. Can be used.
Examples of the device that applies the appropriate shearing force include the above-described device having a high-speed rotating blade, and the tip peripheral speed of the high-speed rotating blade is preferably 2 to 100 m / s. More preferably, it is 5-30 m / s.
The tip peripheral speed is expressed by the following formula:
Tip peripheral speed (m / s) = blade diameter (m) × π × stirring rotational speed (rpm) / 60
It can ask for.

The surfactant may be appropriately selected depending on the type of the hydrophobic substance to be dispersed, but as a suitable surfactant, a nonionic surfactant is preferably an essential component.
Examples of the nonionic surfactant include sorbitan ester compounds such as polyoxyalkylene sorbitan alkyl esters and sorbitan alkyl esters; sucrose fatty acid esters; polyoxyethylene alkyl ethers; polyoxyethylene alkylphenol ethers; polyoxyethylene alkyl esters. Polyglycerin alkyl ester; fatty acid ester; fatty acid soap; alkylamine ethylene oxide adduct; sterols such as cholesterol are suitable, and one or more of these can be used.
Among these, polyoxyethylene (ethylene oxide addition mole number 20 or more) alkyl (total carbon number 15 or more) ether and polyoxyethylene (ethylene oxide addition mole number 20 or more) sorbitan alkyl (total carbon number 15 or more) ester. It is preferable that it is an essential component. In such essential components, the number of moles of ethylene oxide added is suitably 20 or more, preferably 100 or less, more preferably 50 or less, and the total number of carbon atoms in the alkyl group is suitably 15 or more. However, it is preferably 40 or less, more preferably 30 or less. In addition, in the case of polyoxyethylene (ethylene oxide addition mole number 20 or more) sorbitan alkyl (total carbon number 15 or more) ester, a monoalkyl ester body is more preferable.

As the surfactant, amphoteric surfactants, anionic surfactants, nonionic-anionic surfactants and cationic surfactants may be appropriately used. Examples of these surfactants include alkyl sulfate salts such as sodium alkyl sulfonate; alkyl benzene sulfonic acids and salts thereof such as sodium alkyl benzene sulfonate; alkyl (phenyl) ether sulfate salts such as sodium polyoxyethylene lauryl ether sulfate. Α-olefin sulfonates such as sodium tetradecenesulfonate; sulfosuccinates; ether sulfonates; ether carboxylic acids and salts thereof; betaines such as amidopropyl betaine laurate; quaternary ammonium such as dialkylammonium chloride Etc. are suitable.

Further, together with the surfactant or in place of the surfactant, as a dispersant, for example, polyvinyl alcohol, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl pyrrolidone, polyvinyl methyl ether, polyvinyl sulfone, maleic acid Copolymer, polyethylene oxide, polydiallylamine, polyethyleneimine, carboxymethylcellulose, methylcellulose, methylhydroxypropylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, soluble starch, dextrin, gum arabic, chitosan, agar, gelatin, soybean casein, polyvinylsulfonic acid , (Meth) acrylic acid ester copolymers, copolymers of (meth) acrylic acid and (meth) acrylic acid esters, etc. And it can also be.

As the usage-amount of the said surfactant, it is preferable to set it as 0.1 to 20 mass parts with respect to 100 mass parts of hydrophobic substances. If it exceeds 20 parts by mass, the effect of suppressing the adhesion of fine iron ore powder to the fuel may not be sufficient. On the other hand, if it is less than 0.1 parts by mass, emulsification may be difficult, and the stability of the obtained emulsion may not be sufficient, and the effect of suppressing the adhesion of iron ore fine powder to the fuel is sufficient. Sometimes it doesn't come out. More preferably, they are 0.5 mass part or more and 10 mass parts or less, More preferably, they are 1 mass part or more and 5 mass parts or less.

The hydrophobic substance used to obtain the water-based emulsion of the hydrophobic substance is preferably a substance having a strong hydrophobicity compared with pulverized coke and / or anthracite, but is more preferable than pulverized coke and / or anthracite. Even if it is a substance with low hydrophobicity, if it can contribute to granulation, it can be used conveniently.
In particular, the hydrophobic substance preferably contains at least one compound selected from the group consisting of a compound having a paraffin chain having 5 or more carbon atoms, a compound having a naphthene ring, and silicone. In particular, a form in which the hydrophobic substance is at least one compound selected from the group consisting of a compound having a paraffin chain having 5 or more carbon atoms, a compound having a naphthene ring, and silicone is a preferred form of the present invention. One. More preferably, it includes a compound having a paraffin chain having 5 or more carbon atoms.

As the compound having a paraffin chain having 5 or more carbon atoms, paraffins and isoparaffins are preferable. For example, n-decane, n-dodecane, isododecane, n-hexadecane, and the like and compounds having these structures are preferable. In addition, if it has a paraffin chain having 5 or more carbon atoms, other functional groups such as a vinyl group, a hydroxyl group, a carboxylate group, an ether group, an amide group, an imide group, a sulfonate group, an amino group, An aldehyde group, an isocyanate group, etc. may be included. For example, octadecene, octadecyl alcohol, octadecyl isocyanate, octadecyl aldehyde, octadecyl vinyl ether, octadecyl mercaptan and the like are suitable.
The compound having a paraffin chain having 5 or more carbon atoms is also a compound having a flash point of 50 ° C. or more from the viewpoint of safety and from the aspect of suppressing the interior of the powder coke and improving the ignitability and combustibility. It is preferable that The flash point is more preferably 60 ° C. or higher, and still more preferably 65 ° C. or higher. In addition, even if a flash point is less than the preferable range, if it can fully exhibit the effect of this invention, it can use suitably.

As the compound having a naphthene ring, cyclopentane, cyclohexane, cyclooctane and the like and compounds having these structures are preferable. From the viewpoint of safety, a compound having a flash point of 50 ° C. or higher is preferable. The flash point is more preferably 60 ° C. or higher, and still more preferably 65 ° C. or higher. In addition, even if a flash point is less than the preferable range, if it can fully exhibit the effect of this invention, it can use suitably.

The compound having a paraffin chain and the compound having a naphthene ring may be used alone, but it is economically preferable to use them as a mixture of several kinds. For example, paraffin oil, liquid paraffin, paraffin wax, asphalt, heavy oil, petroleum-based lubricating oil, for example, spindle oil, refrigerator oil, compressor oil, dynamo oil, turbine oil, machine oil, engine oil, cylinder oil, marine engine oil Gear oils, aviation lubricating oils; animal fats and oils, vegetable oils and the like are suitable. Moreover, the waste oil of the edible oil discharged | emitted by food industry, the restaurant industry, a general household, etc., and the recycle oil obtained by removing these impurities or refining these are preferable. Examples of the recycled oil include soybean oil-based, rapeseed oil-based, corn oil-based, palm oil-based, beef tallow recycled oil, and mixtures thereof. In addition, from the aspect of performance that suppresses the interior of powder coke and improves ignitability and flammability, liquid paraffin, crude oil particles with a flash point of 65 ° C or higher, petroleum oils, animal oils, vegetable oils, edible oils Waste oil and the above recycled oil are preferred, and liquid paraffin, edible oil waste oil and the above recycled oil are most preferred.

The silicone is not particularly limited as long as it is a compound having an organopolysiloxane structure, but a compound classified as silicone oil is preferable because of its high coke treatment efficiency. Silicone oil is a mixture of various molecular weights mainly composed of linear dimethylpolysiloxane having a relatively low degree of polymerization.

In the aqueous emulsion of the hydrophobic substance, the proportion of the hydrophobic substance and water used is 20% by mass to 80% by mass of the hydrophobic substance with respect to 100% by mass of the total amount of the hydrophobic substance and water. It is preferable that If it exceeds 80% by mass, emulsification may become difficult or the stability of the obtained emulsion may not be sufficient. On the other hand, if it is less than 20% by mass, the production efficiency of the emulsion may not be sufficient, or the effect of suppressing the adhesion of iron ore fine powder to the fuel may not be enhanced. More preferably, they are 30 mass% or more and 70 mass% or less, More preferably, they are 40 mass% or more and 60 mass% or less.
The aqueous emulsion of the hydrophobic substance used in the present invention is preferably produced by a method in which these are mixed under an appropriate shearing force so that the use ratio of the hydrophobic substance and water falls within the above range. It is. The aqueous emulsion of the hydrophobic substance may be used by concentrating or diluting it so as to obtain an appropriate hydrophobic substance concentration before mixing with powdered coke or anthracite.

The amount of the hydrophobic substance used is preferably 0.05 to 0.5 parts by mass with respect to 100 parts by mass of the total amount of fuel. When it is less than 0.05 parts by mass, it is difficult to obtain the effect of selectively reducing the granulation property of the fuel and improving the ignitability and combustibility of the fuel, and when it exceeds 0.5 parts by mass. Therefore, the amount of oil and fat discharged into the exhaust gas becomes excessive, increasing the concern of causing equipment troubles in the electric dust collector for exhaust gas treatment. More preferably, it is 0.1-0.4 mass part.
Here, the “total amount of fuel” means the total mass of the fuel used in the present invention. That is, it means the total mass (dry basis mass) of the fuel used from the hydrophobic treatment step through the granulation treatment step, specifically, the mass of the fuel added simultaneously with the hydrophobic substance, and the hydrophobicity This is the dry basis mass, which is the sum of the mass of fuel added (added) before the substance is added and the mass of fuel added after the hydrophobic substance is added.

A processing agent for treating iron powdered coke and / or anthracite, which is composed of an aqueous emulsion of such a hydrophobic substance (iron powdered coke and / or anthracite treatment agent; hereinafter, “iron powdered coke” Also referred to as a “treatment agent”) is also one aspect of the present invention.
The iron coke treating agent for iron making is used for hydrophobic treatment of powder coke, anthracite, etc., which are fuels used when sintering a sintering raw material for iron making. By performing the treatment, it becomes possible to suppress the ore fine powder and the like from adhering to the surface of the powder coke and anthracite during the granulation treatment of the sintered raw material, so that the combustion efficiency of the fuel is improved and the desired state It becomes possible to perform sintering. That is, it becomes easy to control the heat balance during sintering, the heat excess and the heat shortage during local sintering in the sintered layer are suppressed, the productivity is improved, and the obtained sinter strength is improved. It will be.

The iron coke treating agent for iron making is preferably an aqueous emulsion of a hydrophobic substance obtained by the above production method. Such a powdery coke treatment agent for iron making is preferably diluted with water and used, but can be used as it is or after being concentrated. The hydrophobic substance constituting the aqueous emulsion of the hydrophobic substance is at least one compound selected from the group consisting of a compound having a paraffin chain having 5 or more carbon atoms, a compound having a naphthene ring, and silicone. Is appropriate.

The iron coke treatment agent for iron making is also preferably one containing a surfactant, and the preferred surfactant is as described above. In addition, the ratio of the hydrophobic substance and water and the ratio of the hydrophobic substance and the surfactant in the processing agent for the iron coke for iron making are as described above.
It is preferable that the total amount of the hydrophobic substance, water, and surfactant in the iron-making powder coke treatment agent is 50% by mass or more with respect to 100% by mass of the iron-making powder coke treatment agent. More preferably, it is 90 mass% or more, More preferably, it is 100 mass%.
In addition, the said powdery coke processing agent for iron manufacture may also contain the other raw material used by a normal iron manufacturing process.

In the hydrophobic treatment step, the fuel containing powdered coke and / or anthracite is subjected to a hydrophobic treatment with an aqueous emulsion of the hydrophobic substance (the powdery coke treatment agent for iron making). Hydrophobic treatment as used herein means bringing part or all of the fuel containing powdered coke and / or anthracite into contact with a hydrophobic substance, so that the hydrophobic substance in the emulsion adheres to the surface of the fuel. It is suitable to process. For example, it is more preferable that the aqueous emulsion of the hydrophobic substance be added to a fuel containing powdered coke and / or anthracite and mixed with stirring and then dried. Thereby, the hydrophobic substance in the emulsion can be uniformly and thinly adhered to the surface of the fuel containing powdered coke and / or anthracite. By the above procedure, a part or all of the fuel containing powdered coke and / or anthracite is subjected to hydrophobic treatment.
The timing of hydrophobizing the fuel with an aqueous emulsion of a hydrophobic substance is not limited as long as it is before the start of granulation. The method of adding on a belt conveyor etc. is preferable.

In a suitable process (addition / drying process) of the hydrophobic treatment, examples of the stirring method (mixing method) include an Eirich mixer, a Redige mixer, a pug mill, a rod mill, a ball mill, a roller mill, a drum mixer, and a pan pelletizer. The method of mixing with is preferable.
As a drying method, a method of drying with a general-purpose industrial dryer such as a belt dryer, a rotary dryer, a fluidized bed dryer, a microwave dryer or the like is preferable. In particular, a method using a fluidized bed dryer or a rotary dryer is most preferable in terms of high running cost and high drying capacity.
It is preferable to dry the fuel after the addition of the aqueous emulsion of the hydrophobic substance and before mixing with a part or all of the remaining sintering raw material for iron making.

In the hydrophobic treatment step, in order to sufficiently adhere the hydrophobic substance to the surface of the fuel containing powdered coke and / or anthracite coal, the water content is set to 4% by mass or less in 100% by mass of the fuel after the hydrophobic treatment. It is preferable to do. If the water content exceeds 4% by mass, the adhesion of the hydrophobic substance to the surface of the fuel will be weakened, so that the effect of preventing the adhesion of fine ore powder will not be sufficiently exhibited in the subsequent granulation treatment with the sintering raw material. There is. Thus, the embodiment in which the hydrophobic treatment is performed so that the water content is 4% by mass or less in 100% by mass of the fuel after the hydrophobic treatment is also one of the preferred embodiments of the present invention. More preferably, the moisture content is 2% by mass or less.
In addition, when the said hydrophobic treatment process is the suitable form (addition and drying process process) mentioned above, it is dried so that a water | moisture content may be 4 mass% or less in 100 mass% of fuel after drying. preferable.

Next, in the granulation method of the present invention, the fuel after the hydrophobic treatment is granulated together with a part or all of the remaining sintered raw material for iron making.
Here, the timing of mixing the hydrophobic-treated fuel with a part or all of the remaining iron-making sintering raw material may be before the granulation process is started, and ends after the start of the granulation process. It may be between. Mixing the fuel and a part or all of the remaining sintered raw material for iron making can be performed by adding the fuel to a part or all of the remaining sintered raw material for iron making. Further, the fuel may be mixed once in the iron-making sintered raw material, or may be mixed in a plurality of times.

The amount of the fuel used varies depending on the properties of the raw materials and the like, but is preferably 1% by mass or more and preferably 10% by mass or less with respect to 100% by mass of the iron-making sintered raw material. If the amount is less than 1% by mass, it may be difficult to maintain the ignition of the sintering raw material layer. If the amount exceeds 10% by mass, the sintering bed will have an excessive amount of heat during sintering, resulting in an increase in melt. Therefore, the air permeability may not be good. Moreover, there is a possibility that the cost of fuel may be increased. More preferably, it is 2% by mass or more and 6% by mass or less.
Here, the “amount of fuel used” means the total amount of all the fuels used in the granulation treatment method of the present invention. As described above, the mass of the fuel added simultaneously with the hydrophobic substance, This is the dry standard mass of all of the mass of fuel blended (added) before the addition of the hydrophobic substance and the mass of fuel added after the addition of the hydrophobic substance. The mass of the fuel that has been subjected to the hydrophobic treatment with the hydrophobic substance includes the mass of the hydrophobic substance.

The granulation treatment step is preferably performed in the presence of a polymer compound having at least one group selected from the group consisting of a carboxyl group, a sulfonic acid group, and salts thereof. In addition, the salt of a carboxyl group or a sulfonic acid group is a group having a structure in which a hydrogen atom in a carboxyl group or a sulfonic acid group is replaced with a metal atom or the like, and means a group in a salt form.
The amount of the polymer compound used may be appropriately set according to the granulating property of the sintering raw material, the type of the polymer compound, the type of equipment used, etc. The polymer compound is preferably 0.001 part by mass or more, and more preferably 2 parts by mass or less. If the amount is less than 0.001 part by mass, the granulation property may not be further improved. If the amount exceeds 2 parts by mass, the amount of the polymer compound added to the sintered raw material for iron making becomes too large, and iron making is performed. The sintering raw material may be agglomerated and may be difficult to sinter. More preferably, it is 0.003 parts by mass or more and 1 part by mass or less.

In the granulation step, a granulating agent other than the polymer compound may be used in combination with the polymer compound or in place of the polymer compound. The granulating agent means a compound or the like used for improving the granulation property when granulating a sintered raw material for iron making.
As a granulating agent other than the polymer compound, for example, one or more kinds of quicklime, bentonite, lignin sulfite (pulp waste liquid), starch, sugar, molasses, water glass, cement, gelatin, corn starch and the like are used. be able to. The amount of the granulating agent other than the above polymer compound is preferably 0.05 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the iron-making sintered raw material. Is preferred.

It does not specifically limit as a form using the said high molecular compound and / or other granulation processing agent, In the case of a granulation process, you may add to the sintering raw material for iron making once, and divide into multiple times. May be added.
The granulation process is also preferably performed using the same apparatus as the mixing method in the above-described hydrophobic process of fuel.

In the method for granulating a sintered raw material for iron making according to the present invention, there is a problem when the sintered raw material for iron making is sufficiently granulated using the above polymer compound and / or other granulating agent. Sintering can be performed without the influence of ore fine powder adhesion to the obtained coke particles and anthracite. That is, for example, it is possible to sufficiently maintain the ignition of the sintered raw material layer. For example, as the granulation property, the GI index of a granulated product (pseudoparticle) having a particle size of 0.25 mm or less is 80% or more. Is preferable because productivity of the sintering machine is improved. More preferably, the GI index is 85 or more, and still more preferably 90 or more.
The GI index is one of the evaluation methods disclosed in Steel Manufacturing Research No. 288 (1976), page 9, and indicates the ratio of fine powder particles adhering around the core particles. The GI index was measured by drying the pseudo particles obtained by granulation operation at 80 ° C. for 1 hour and then classifying them using a sieve to obtain the particle size (pseudo particle size). No. (1976), page 9, and can be calculated by the following formula.
GI index = {(ratio of raw material of 0.25 mm or less before granulation−ratio of raw material of 0.25 mm or less after granulation) / (ratio of raw material of 0.25 mm or less before granulation)} × 100

Moreover, as the pseudo particles which are the granulated product obtained in the present invention, the carbon content (powder coke content) of the pseudo particles of 1 mm or less is 3% by mass or more in the total amount of the pseudo particles of 100% by mass. It is preferable that the content is 3.5% by mass or more.
The carbon content of the pseudo particles having a size of 1 mm or less is preferably measured by the following method. First, the sifted portion of 1 mm or less of the pseudo particles is mixed, and the whole amount is pulverized by a pulverizer such as a mill. About 1 g of pseudo particles after pulverization are collected in a container, and the mass is accurately measured (assumed to be Ag). Add 10 g of distilled water to lightly adjust, and add 1.2 g to 1.3 g of phosphoric acid to remove carbon contained in limestone out of the system as carbon dioxide. After being shaken by hand, it is sufficiently dried in a vacuum dryer set at 135 ° C. The contents are removed from the container, transferred to a mortar, crushed, and dried in an oven at 130 ° C. The mass of this dried product is measured (referred to as Bg). The amount of C (carbon) in the dried product is determined by elemental analysis (C%). The amount of carbon (powder coke amount) contained in pseudo particles of 1 mm or less is calculated as follows.
The amount of powder coke contained in pseudo particles of 1 mm or less (%) = B (g) × C (%) / A (g)
The carbon content referred to in the present invention is a carbon content obtained by subtracting carbon that cannot be used (burned) as fuel such as carbon contained in limestone from the total carbon content.

The granulated product obtained by the granulation treatment method for the iron-making sintered raw material of the present invention can be sintered by a sintering machine to form a sintered ore. A sintered ore produced from such a granulated product obtained by the method for granulating a sintering raw material for iron making according to the present invention is one of the preferred embodiments of the present invention.
The above-mentioned sintered ore improves the granulation property of the granulated product obtained by the method for granulating a sintered raw material for iron making according to the present invention, that is, maintains the ignition of the sintered raw material layer at the same time. Thus, it is useful to be produced from a granulated product capable of realizing sufficient productivity of sintered ore.

The productivity of sintered ore production in the present invention can be measured by the product yield and production rate of the sintered ore. For example, the product yield can be measured by sintering after sintering in the sintering pot test. It can be evaluated by measuring the proportion of particles having a particle size of 5 mm or more when 50 kg of ore (sinter cake) is dropped 5 times onto a steel plate from a height of 2 m. The productivity can be calculated by the following formula.
Production rate (t / day / m ² ) = total mass of particles having a particle size of 5 mm or more after evaluation of product yield (t) / sintering time (day) / surface area of sintering machine (pan) (m ² )

Below, the high molecular compound which has at least 1 type of group selected from the group which consists of a carboxyl group in this invention, a sulfonic acid group, and these salts is further demonstrated.
Examples of the polymer compound include a polymer compound having a carboxyl group and / or a salt thereof, (2) a polymer compound having a sulfonic acid group and / or a salt thereof, a carboxyl group and / or a salt thereof, and a sulfonic acid group. And / or any one or more of the polymer compounds having a salt thereof. As such a polymer compound, at least one monomer selected from the group consisting of a monomer having a carboxyl group, a monomer having a sulfonic acid group, and a monomer having a salt thereof is essential. What can be obtained by superposing | polymerizing with the monomer component made into is preferable. These monomers can be used alone or in combination of two or more.

Preferred forms of the polymer compound include (1) a monomer having a carboxyl group and / or a salt thereof, and (2) a sulfonic acid with respect to 100 mol% of all monomer components. It is formed by polymerizing a monomer component containing 10 mol% or more of at least one of a monomer having a group and / or a monomer having a salt thereof. When the content of the monomer (1) and / or (2) is less than 10 mol%, the granulation effect may not be sufficiently obtained in the granulation treatment step. More preferably, it is 30 mol% or more, More preferably, it is 50 mol% or more.
A particularly preferred form of the polymer compound is obtained by polymerizing a monomer component that essentially comprises a monomer having a carboxyl group and / or a monomer having a salt thereof. That is, the polymer compound is obtained by polymerizing a monomer component containing 10 mol% or more of a monomer having a carboxyl group and / or a salt thereof with respect to 100 mol% of all monomer components. It is particularly preferable that More preferably, it is 30 mol% or more, More preferably, it is 50 mol% or more.

Examples of the monomer (1) having a carboxyl group and a salt thereof include (meth) acrylic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, crotonic acid, acrylamide glycolic acid and the like. A monomer having a carboxyl group or a salt thereof is preferred. Among these, (meth) acrylic acid and / or a salt thereof is more preferable. That is, the polymer compound having a carboxyl group and / or a salt thereof in the present invention is preferably formed by polymerizing a monomer component mainly composed of (meth) acrylic acid and / or a salt thereof. More preferred is acrylic acid and / or a salt thereof. Moreover, as a salt, alkali metal salts, such as sodium and potassium; Alkaline earth metal salts, such as calcium and magnesium; Ammonium salt; Organic amici salts, such as monoethanolamine and triethanolamine, are suitable. Among these, alkali metal salts such as sodium and potassium, and ammonium salts are preferable, and sodium salts are more preferable.

Examples of the monomer (2) having a sulfonic acid group or a salt thereof include vinyl sulfonic acid, styrene sulfonic acid, sulfoethyl (meth) acrylate, and 2-acrylamido-2-methylpropane sulfonic acid. A monomer having a sulfonic acid group or a salt thereof is preferred.

In addition to the monomer having a carboxyl group, the monomer having a sulfonic acid group, and the monomer having a salt thereof, the above monomer component includes other copolymerizable with these monomers. One type or two or more types of polymerizable monomers may be included.
Examples of the other copolymerizable monomers include 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxypropyl acid phosphate, 2- (meth) acryloyloxy-3-chloropropyl acid phosphate, 2 -Monomers having an acidic phosphate group such as (meth) acryloyloxyethylphenyl phosphate; monomers having an acid group such as a vinyl acid monomer such as vinylphenol, and salts thereof are preferred.

Examples of the other copolymerizable monomers also include polyalkylene glycol (meth) acrylates such as polyethylene glycol monomethacrylate, methoxypolyethylene glycol monomethacrylate, and methoxypolyethyleneglycol monoacrylate; Polyalkylene glycol monoalkenyl ether monomer formed by adding ethylene oxide to methyl-3-buten-1-ol; polyethylene glycol monoethenyl ether monomer formed by adding ethylene oxide to allyl alcohol; A monomer having a polyalkylene glycol chain such as maleic acid polyethylene glycol half ester to which polyethylene glycol has been added is preferred. Among these monomers having a polyalkylene glycol chain, a monomer having a polyalkylene glycol chain having a chain length of 5 mol or more and 100 mol or less in terms of ethylene oxide is easy to obtain, It is preferable from the viewpoints of improvement in polymerizability and polymerization. More preferably, it is a monomer having a polyalkylene glycol chain having a chain length of 10 mol or more and 100 mol or less in terms of ethylene oxide.

As said other copolymerizable monomer, the following compound can be used besides the thing mentioned above.
Methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylic acid (N, N-dimethylaminoethyl), (meth) acrylic acid (N, N-diethylaminoethyl) C1-C18 (meth) acrylic acid alkyl esters such as aminoethyl (meth) acrylate; (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (Meth) acrylamide and its derivatives such as (meth) acrylamide; vinyl acetate; (meth) acrylonitrile; base-containing monomers such as N-vinyl-2-pyrrolidone, vinylpyridine and vinylimidazole; N-methylol (meth) acrylamide , N-butoxymethyl (meth) acrylamide and other cross-linkability (Meth) acrylamide monomers; hydrolyzable groups such as vinyltrimethoxysilane, vinyltriethoxysilane, γ- (meth) acryloylpropyltrimethoxysilane, vinyltris (2-methoxyethoxy) silane, allyltriethoxysilane A silane monomer in which is directly bonded to a silicon atom; a monomer having an epoxy group such as glycidyl (meth) acrylate, glycidyl ether (meth) acrylate; 2-isopropenyl-2-oxazoline, 2-vinyl-2 -Monomers having an oxazoline group such as oxazoline; monomers having an aziridin group such as 2-aziridinylethyl (meth) acrylate and (meth) acryloylaziridine; vinyl fluoride, vinylidene fluoride, vinyl chloride, chloride A monomer having a halogen group such as vinylidene; E) Esters of acrylic acid and polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, 1,3-butylene glycol, neopentyl glycol, 1,6-hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol Polyfunctional (meth) acrylic acid ester having a plurality of unsaturated groups in the molecule such as fluoride; polyfunctional (meth) acrylamide having a plurality of unsaturated groups in the molecule such as methylenebis (meth) acrylamide; diallyl phthalate, diallyl maleate Polyfunctional allyl compounds having a plurality of unsaturated groups in the molecule, such as diallyl fumarate; allyl (meth) acrylate; divinylbenzene.

When (co) polymerizing the monomer, a chain transfer agent may be used for the purpose of adjusting the molecular weight. Examples of the chain transfer agent include compounds having a mercapto group such as mercaptoethanol, mercaptopropionic acid, t-dodecyl mercaptan; carbon tetrachloride; isopropyl alcohol; toluene; hypophosphorous acid, sodium hypophosphite, sodium bisulfite, etc. A compound having a high chain transfer coefficient is preferred. These may be used alone or in combination of two or more. The amount of the chain transfer agent used is preferably 0.005 to 0.15 mole per mole of monomer.

As a method for (co) polymerizing the above monomers, conventional polymerization methods such as oil-in-water emulsion polymerization method, water-in-oil emulsion polymerization method, suspension polymerization method, dispersion polymerization method, precipitation polymerization method, solution A polymerization method, an aqueous solution polymerization method, a bulk polymerization method, or the like can be employed. Among these, the aqueous solution polymerization method is preferable from the viewpoint of reduction in polymerization cost (production cost) and safety.

The polymerization initiator used for the polymerization may be a compound that decomposes by heat or a redox reaction to generate radical molecules. Moreover, when performing superposition | polymerization by aqueous solution polymerization method, it is preferable to use the polymerization initiator provided with water solubility. Examples of the polymerization initiator include persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; 2,2′-azobis- (2-amidinopropane) dihydrochloride, 4,4′-azobis- (4-cyano Water-soluble azo compounds such as pentanoic acid; thermal decomposable initiators such as hydrogen peroxide; hydrogen peroxide and ascorbic acid, t-butyl hydroperoxide and Rongalite, potassium persulfate and metal salts, ammonium persulfate and sodium bisulfite A redox polymerization initiator comprising a combination of the above is preferred. These may be used alone or in combination of two or more. What is necessary is just to set suitably as the usage-amount of a polymerization initiator according to a monomer composition, polymerization conditions, etc. FIG.

The polymerization conditions such as the reaction temperature and reaction time in the above polymerization may be appropriately set according to the composition of the monomer, the type of the polymerization initiator, etc. The reaction temperature is 0 to 150 ° C. Is preferable, and it is more preferable to set it as 40-105 degreeC. The reaction time is preferably about 3 to 15 hours. As a method for supplying the monomer to the reaction system when the polymerization is performed by an aqueous solution polymerization method, a batch addition method, a divided addition method, a component dropping method, a power feed method, or a multistage dropping method can be used. The polymerization may be performed under normal pressure, reduced pressure, or increased pressure.

In the production of the polymer compound, the concentration of the non-volatile component containing the polymer compound contained in the polymer compound aqueous solution obtained when the aqueous solution polymerization method is adopted is preferably 70% by mass or less. When it exceeds 70 mass%, there exists a possibility that a viscosity may become high too much.

As the polymer compound having a sulfonic acid group and / or a salt thereof, β-naphthalene sulfonate formalin condensate, melamine sulfonate formalin condensate, aromatic amino sulfonic acid polymer and the like can be suitably used.

The polymer compound having at least one group selected from the group consisting of carboxyl groups, sulfonic acid groups and salts thereof in the present invention preferably has a weight average molecular weight of 1,000 to 1,000,000. If the weight average molecular weight is less than 1000, the action as a dispersant may not be sufficiently improved and the granulation property may not be improved. If it exceeds 1,000,000, the viscosity of the polymer compound becomes too high. There is a possibility that it may be difficult to add so that the action as a dispersant is sufficiently exhibited. More preferably, it is 3000 or more and 100,000 or less.
In the present specification, the weight average molecular weight is a value measured under the following measurement conditions.

(Weight average molecular weight measurement conditions)
Column: Aqueous GPC column “GF-7MHQ” (trade name, manufactured by Showa Denko KK) One carrier liquid: 34.5 g of disodium hydrogen phosphate dodecahydrate and 46.2 g of sodium dihydrogen phosphate dihydrate Ultrapure water is added to make the total amount 5000 g.
Aqueous solution flow rate: 0.5 ml / min
Pump: “L-7110” (trade name, manufactured by Hitachi, Ltd.)
Detector: Ultraviolet (UV) detector “L-7400” (trade name, manufactured by Hitachi, Ltd.), wavelength 214 nm
Molecular weight standard sample: sodium polyacrylate (sodium polyacrylate having a weight average molecular weight of 1300 to 1360000 available from Soka Kagaku)
The analysis sample is prepared by diluting with the carrier liquid so that the polymer compound is 0.1% by mass in solid content.

However, for polymer compounds that cannot be measured under the above measurement conditions, the following measurement conditions are applied.
Model: Waters LCM1
Carrier solution: 115.6 g of sodium acetate trihydrate dissolved in a mixture of 10999 g of water and 6001 g of acetonitrile, and further adjusted to pH 6.0 with 30% aqueous sodium hydroxide solution Flow rate: 0.8 ml / min
Column: Water-based GPC column “TSKgel GuardColumnSWXL + G4000SWXL + G3000SWXL + G2000SWXL” (manufactured by Tosoh Corporation)
Column temperature: 35 ° C
Detector: Waters 410 Differential refraction detector Molecular weight standard sample: Polyethylene glycol The analytical sample is prepared by diluting with the carrier solution so that the polymer compound is 0.1% in solid content.

The polymer compound preferably has a dispersity of 12 or less. If the dispersity exceeds 12, the action of dispersing the fine iron ore becomes small, and therefore, the action of making pseudo particles may not be sufficiently improved. More preferably, it is 10 or less.
The dispersity is a ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn), and represents the molecular weight distribution. The number average molecular weight is measured by the same method as the weight average molecular weight.
These polymer compounds may be added in a solid form, but are preferably added in the form of an aqueous solution having a solid content concentration of 0.1 to 70% by mass.

The method for granulating a sintered raw material for iron making according to the present invention has the above-described configuration, and is used for granulating a sintered raw material such as fine iron ore in the production of sintered ore used as a raw material for charging a blast furnace in the iron making process. It is effective, and at the same time it can improve the granulation of the sintering raw material for iron making, and at the same time, improve the ignitability and combustibility of fuel such as coke breeze and anthracite, and realize sufficient sinter productivity. .

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by mass” and “%” means “% by mass”.

In the examples and comparative examples, the GI index, product yield, production rate, and carbon content (powder coke content) of the pseudo particles were measured by the following methods.
(GI index of pseudo particles)
The pseudo particles obtained by the granulation operation were dried at 80 ° C. for 1 hour and classified using a sieve to obtain the particle size (pseudo particle size). The GI index of the granulated pseudo particles is one of the evaluation methods disclosed in Koji Research No. 288, page 9, and indicates the ratio of fine particles adhering around the core particles. The GI index was measured according to the method described in Steel Manufacturing Research No. 288 (1976), page 9.
In each of the following Examples and Comparative Examples, the GI index of pseudo particles having a particle size after granulation of 0.25 mm or less was determined. Moreover, the GI index (pseudo graining index) of pseudo particles of 0.25 mm or less was calculated by the following formula.
GI index = {(ratio of raw material of 0.25 mm or less before granulation−ratio of raw material of 0.25 mm or less after granulation) / (ratio of raw material of 0.25 mm or less before granulation)} × 100

(Product yield, production rate)
In the product yield, in the sintering pot test, 50 kg of sintered ore after sintering (sinter cake) was dropped 5 times on a steel plate from a height of 2 m. The ratio was evaluated by measuring. The production rate was calculated by the following formula.
Production rate (t / day / m ² ) = total mass of particles having a particle size of 5 mm or more after evaluation of product yield (t) / sintering time (day) / surface area of sintering machine (pan) (m ² )

The sintered raw materials and pellet raw materials used in the examples and comparative examples described below were all in an absolutely dry state.
(Quantification of carbon content in pseudo particles)
The sifted portion of 1 mm or less of the pseudo particles after the GI index measurement is mixed, and the whole amount is pulverized by a pulverizer such as a mill. At this time, the average particle size after pulverization is set to 50 μm or less. If there are many sieving parts and it cannot be pulverized at once, pulverize in two or more times and mix so as to be uniform after pulverization.
About 1 g of pseudo particles after pulverization are collected in a commercially available PP (polypropylene) container having a capacity of 120 ml, and the mass is accurately measured (assumed to be Ag). Add 10 g of distilled water and let it blend lightly. In order to remove carbon contained in limestone out of the system as carbon dioxide, 1.2 g to 1.3 g of phosphoric acid was added, and the container was shaken by hand while firing was observed, and then heated to 135 ° C. Dry sufficiently with the set vacuum dryer. The contents are removed from the PP container, transferred to a mortar, crushed, and dried in an oven at 130 ° C. At this time, when the content does not become powder, it is pulverized and dried again after drying in an oven at 130 ° C. The mass of the content after drying (referred to as composition 1) is measured (referred to as Bg). The amount of C in the composition 1 is determined by elemental analysis (C%). The amount of carbon contained in pseudo particles of 1 mm or less is calculated as follows.
The amount of powder coke contained in pseudo particles of 1 mm or less (%) = B (g) × C (%) / A (g)

Example 1
As an aqueous emulsion of the hydrophobic substance in the present invention, 50 parts by mass of liquid paraffin (manufactured by Wako Pure Chemical Industries, Ltd.), 48.5 parts by mass of distilled water, and polyoxyethylene (methylene oxide addition mole number 20) stearyl ether as a surfactant 1.5 parts by mass were charged into a container. With a high-speed stirrer having a blade diameter of 0.1 m (TK AUTO HOMO MIXER DL-SL, manufactured by Tokushu Kika Kogyo Co., Ltd. (currently Primix)), the stirring speed was increased to 4000 rpm over 10 minutes, and the rotation was continued. The aqueous emulsion (powder coke treatment agent 1) of a hydrophobic substance was manufactured by continuing stirring for 10 minutes by the number. 40 parts of the emulsion and 500 parts of distilled water were added to 10000 parts of powdered coke having a particle size distribution shown in Table 1, and stirred for 10 minutes with a mixer. Further, the treated powder coke was dried with hot air at 105 ° C. for 20 minutes using a rotary dryer (the powder coke treated with the powder coke treating agent 1 is treated powder coke 1).
Next, a sintering raw material (raw material for iron making) having the composition shown in Table 2 was prepared. Here, the treated powder coke 1 was used as the powder coke.

70000 parts of the above-mentioned sintered raw material is put into a drum mixer, and 5250 parts of an aqueous sodium polyacrylate solution having a weight average molecular weight of 6000 adjusted to a non-volatile content of 0.4% in advance as a dispersant in the composition (sintered raw material) Was sprayed (added) over 1.5 minutes using a spray bottle. The ratio of sodium polyacrylate to the sintering raw material was 0.03%. After spraying, the composition (final composition for granulation treatment) to which the dispersant was added was further stirred at the same rotational speed for 3 minutes to perform granulation treatment (pseudo granulation).
Moreover, about 1 kg was sampled uniformly from the obtained pseudo particles, and the contained moisture was measured, and the pseudo particles were dried and classified using a sieve to obtain the GI index of the pseudo particles. Furthermore, a portion of 1 mm or less of the pseudo particles after the GI index measurement was remixed, and the whole amount was pulverized using a hammer mill so that the average particle diameter was 50 μm or less. The amount of powder coke contained in the pseudo particles of 1 mm or less was measured for the pseudo particles after pulverization by the above method. These results are summarized in Table 3.

Example 2
As an aqueous emulsion of the hydrophobic substance in the present invention, 50 parts by mass of liquid paraffin (manufactured by Wako Pure Chemical Industries, Ltd.), 48.5 parts by mass of distilled water, and polyoxyethylene (methylene oxide addition mole number 20) stearyl ether as a surfactant 1.5 parts by mass were charged into a container. With a high-speed stirrer having a blade diameter of 0.1 m (TK AUTO HOMO MIXER DL-SL, manufactured by Tokushu Kika Kogyo Co., Ltd. (currently Primix)), the stirring speed was increased to 4000 rpm over 10 minutes, and the rotation was continued. An aqueous emulsion (powder coke treatment agent 2) was produced by continuing stirring for another 10 minutes. 80 parts of the emulsion and 500 parts of distilled water were added to 10000 parts of powdered coke having a particle size distribution shown in Table 1, and stirred for 10 minutes with a mixer. Further, the treated coke breeze was dried with hot air at 105 ° C. for 20 minutes using a rotary dryer. (The powder coke treated with the powder coke treating agent 2 is treated powder coke 2).
Next, a sintering raw material (raw material for iron making) having the composition shown in Table 2 was prepared. Here, the processed coke 2 was used as the powder coke.
In the same manner as in Example 1, the GI index, the amount of powder coke contained in pseudo particles of 1 mm or less, and productivity were measured. The results are shown in Table 3.

Example 3
Using the treated powder coke 1 used in Example 1, a sintered raw material (raw material for iron making) having the composition shown in Table 2 was prepared.
70000 parts of the sintered raw material and 840 parts of quicklime were put into a drum mixer, and 5600 parts of water was sprayed (added) to the composition (sintered raw material) using a spray bottle over about 1.5 minutes. After spraying, the composition (final composition for granulation treatment) to which the dispersant was added was further stirred at the same rotational speed for 3 minutes to perform granulation treatment (pseudo granulation).
In the same manner as in Example 1, the GI index, the amount of powder coke contained in the pseudo particles of 1 mm or less, and the production rate were measured. The results are shown in Table 3.

Example 4
In the method for producing the treated powder coke 1 described in Example 1, instead of using 100 parts of liquid paraffin as a hydrophobic substance, 100 parts of mixed vegetable oil B standard (manufactured by Haruo), which is a recycled oil, is used. Treated powder coke 3 was obtained by the same method as the method for producing treated powder coke 1. Next, a sintering raw material (raw material for iron making) having the composition shown in Table 2 was prepared. Here, the treated powder coke 3 was used as the powder coke.
In Example 1, sodium acrylate having a weight average molecular weight of 33,000 previously adjusted to a non-volatile content of 0.27% was replaced with 5250 parts of a sodium acrylate aqueous solution having a weight average molecular weight of 6000 previously adjusted to a non-volatile content of 0.4%. Using 5250 parts of an aqueous solution of methyl acrylate copolymer (composition ratio of sodium acrylate of 78.7 mol%) and using the treated powder coke 3 instead of the treated powder coke 1, as in Example 1, Evaluation was made on the amount of coke coke contained in quasi-particles having a GI index of 1 mm or less and the production rate. The results are shown in Table 3. The addition amount of the copolymer with respect to the sintering raw material was 0.02%.

Example 5
In the manufacturing method of the processing powder coke 1 described in Example 1, the processing powder coke 4 is obtained by the same method as the manufacturing method of the processing powder coke 1 except that the drying processing time in the rotary dryer is changed from 20 minutes to 10 minutes. It was. Next, a sintering raw material (raw material for iron making) having the composition shown in Table 2 was prepared. Here, the treated coke 4 was used as the powder coke.
In the same manner as in Example 1, the GI index, the amount of powder coke contained in the pseudo particles of 1 mm or less, and the production rate were measured. The results are shown in Table 3.

Example 6
In the method for producing the treated powder coke 1 described in Example 1, the treated powder coke 5 is obtained in the same manner as the method for producing the treated powder coke 1 except that the drying time in the rotary dryer is changed from 20 minutes to 6 minutes. It was. Next, a sintering raw material (raw material for iron making) having the composition shown in Table 2 was prepared. Here, the treated powder coke 5 was used as the powder coke.
In the same manner as in Example 1, the GI index, the amount of powder coke contained in the pseudo particles of 1 mm or less, and the production rate were measured. The results are shown in Table 3.

Example 7
In the method for producing the treated powder coke 1 described in Example 1, the treated powder coke 6 is obtained in the same manner as the method for producing the treated powder coke 1 except that the drying time in the rotary dryer is changed from 20 minutes to 3 minutes. It was. Next, a sintering raw material (raw material for iron making) having the composition shown in Table 2 was prepared. Here, the treated coke 6 was used as the powder coke.
In the same manner as in Example 1, the GI index, the amount of powder coke contained in the pseudo particles of 1 mm or less, and the production rate were measured. The results are shown in Table 3.

Comparative Example 1
Sintered raw materials (raw materials for iron making) having the composition shown in Table 2 were prepared. Here, the powder coke used was untreated (that is, powder coke not subjected to hydrophobic treatment).
In the same manner as in Example 1, the GI index, the amount of powder coke contained in pseudo particles of 1 mm or less, and productivity were measured. The results are shown in Table 3.

Comparative Example 2
Processed coke 7 was obtained by adding 20 parts of liquid paraffin (manufactured by Wako Pure Chemical Industries, Ltd.) to 10000 parts of powder coke having a particle size distribution shown in Table 1, and stirring for 10 minutes with a mixer. Next, a sintering raw material (raw material for iron making) having the composition shown in Table 2 was prepared. Here, the treated coke 7 was used as the powder coke.
In the same manner as in Example 1, the GI index, the amount of powder coke contained in the pseudo particles of 1 mm or less, and the production rate were measured. The results are shown in Table 3.

Comparative Example 3
Sintered raw materials (raw materials for iron making) having the composition shown in Table 2 were prepared. Here, the treated coke 7 was used as the powder coke.
In the same manner as in Example 3, 70000 parts of the above-mentioned sintered raw material and 840 parts of quicklime are put into a drum mixer, and 5600 parts of water are sprayed on the composition (sintered raw material) for about 1.5 minutes using a sprayer. Sprayed (added). After spraying, the composition (final composition for granulation treatment) to which the dispersant was added was further stirred at the same rotational speed for 3 minutes to perform granulation treatment (pseudo granulation). In the same manner as in Example 1, the GI index, the amount of powder coke contained in the pseudo particles of 1 mm or less, and the production rate were measured. The results are shown in Table 3.

Reference example 1
In the method for producing the treated powder coke 1 described in Example 1, the treated powder coke 8 is obtained in the same manner as the method for producing the treated powder coke 1 except that the drying time in the rotary dryer is changed from 20 minutes to 2 minutes. It was. Next, a sintering raw material (raw material for iron making) having the composition shown in Table 2 was prepared. Here, the processed coke 8 was used as the powder coke.
In the same manner as in Example 1, the GI index, the amount of powder coke contained in the pseudo particles of 1 mm or less, and the production rate were measured. The results are shown in Table 3.

From Table 3, the following was confirmed.
When Example 1, 2, 5-7 which performed the granulation process using sodium polyacrylate as a granulation processing agent is compared with Comparative Example 1, it granulates using the powder coke which is not hydrophobically processed. In Comparative Example 1 where the treatment was performed, the GI index was “92.5%” and the production rate was “26.9 t / day / m ² ”, whereas in Examples 1, 2, and 5-7, It can be seen that the GI index was “93.1%” and the production rate was “29.5 to 31.9 t / day / m ² ”, indicating that both the GI index and the production rate were extremely high.

Moreover, even if it is an example using sodium polyacrylate as a granulation processing agent similarly to Example 1, 2, 5-7, and using the same hydrophobic substance, in comparative example 2 which has not emulsified the hydrophobic substance, Since the GI index is “92.1%” and the production rate is “27.6 t / day / m ² ”, the hydrophobic treatment of the fuel using the aqueous emulsion of the hydrophobic substance as in the present invention is performed. Further, it is understood that the effect of remarkably improving the granulation property and productivity can be obtained.
Similarly, the same can be said from the results of Example 3 and Comparative Example 3 in which granulation treatment was performed using quick lime as a granulation treatment agent.
Further, comparison between Example 4 and Comparative Examples 1 to 3 using a copolymer of sodium polyacrylate and methyl acrylate as a granulating agent reveals that productivity was significantly improved in Example 4. .

Further, Example 1 (0.2% by mass), Example 5 (1.0% by mass), and Example 6 (2.1% by mass) were carried out by changing the water content after the hydrophobic treatment (after the drying treatment). From the results of Example 7 (3.8% by mass) and Reference Example 1 (5.2% by mass), the effect of reducing the water content is more remarkable in terms of granulation and productivity. I understand.

Claims (3)

A method of granulating a sintered raw material for iron making in the presence of powdered coke and / or anthracite,
The method for granulating the sintered raw material for iron making includes the step of subjecting a fuel containing powdered coke and / or anthracite to a hydrophobic treatment with an aqueous emulsion of a hydrophobic substance, and then subjecting the fuel after the hydrophobic treatment to the remaining sintered raw material for iron making look containing a granulation process to step together with a part or the whole of,
The method for granulating a sintered raw material for iron making , wherein the hydrophobic treatment is performed such that the water content is 4% by mass or less in 100% by mass of the fuel after the hydrophobic treatment . The method for granulating a sintered raw material for iron making according to claim 1, wherein the amount of the hydrophobic substance used is 0.05 to 0.5 parts by mass with respect to 100 parts by mass of the total amount of fuel. The hydrophobic substance is at least one compound selected from the group consisting of a compound having a paraffin chain having 5 or more carbon atoms, a compound having a naphthene ring, and silicone. Granulation method of sintering raw material for iron making.