JP2020040833A - Piling method of iron-making material - Google Patents

Abstract

To provide a piling method of iron-making material that makes it hard for landslide of the piled iron-making material to occur when piling the iron-making material at a raw material yard.SOLUTION: The method of piling iron-making material at a raw material yard includes a step to add diluted liquid with high polymer coagulant contained at 0.1 to 2 mass% as an active ingredient to at least one of iron-making materials before and after piling at the raw material yard.SELECTED DRAWING: None

Description

  The present invention relates to a method for stacking ironmaking raw materials.

  Iron ore raw materials such as iron ore and coal are piled up and stored in a storage area called a yard (hereinafter, referred to as “raw material yard”) in an ironworks. In the case of Japan, many of the steelmaking raw materials (especially iron ore and coal) are imported and are transported by ship from all over the world. They are piled up with raw materials from different production areas and taken out from the edge of the mountain for use. By doing so, the difference in properties depending on the place of production is reduced.

  The above-mentioned ironmaking raw materials are used, for example, in rainfall and dust prevention at mining sites, storage sites and storage sites inside and outside the mining sites, and sites transported from those sites to ships and the like (eg, belt conveyors and truck beds). Contains water due to water spraying. While this steelmaking raw material is being transported by ship such as a bulk carrier to an ironworks, the water in the steelmaking raw material separates from the steelmaking raw material and accumulates on the floor of the hold by the rocking and vibration of the ship. State. Therefore, in the process of unloading steelmaking raw materials from bulk cargo ships or barges with unloaders, etc., when steelmaking raw materials near the floor of the hold are grabbed by grab buckets etc., the steelmaking raw materials together with the water accumulated on the floor are taken out. There is. As a result, ironmaking raw materials having a high moisture content may be discharged. In addition, the above-mentioned landing may be performed during rainfall because the cost increases if the vessel stays for a long time. In that case, the amount of water in the steelmaking raw material to be unloaded may be higher.

  Since wet bulk materials such as steelmaking raw materials with a high water content are easy to flow, when unloading the wet bulk materials onto the belt conveyor, the wet bulk materials easily flow out of the belt conveyor and are easily unloaded. Is disclosed in Patent Document 1. In order to solve such an obstacle, in Patent Literature 1, a chemical containing a polymer flocculant as a main component is added as a chemical to a hydrated bulk material on a belt conveyor, and the obtained flocculant is conveyed by the belt conveyor. Transporting methods have been proposed.

International Publication No. WO 2014/058074

  In the method for unloading hydrated bulk material specifically disclosed in Patent Document 1 described above, a drug (a product containing a polymer flocculant) containing about 40% or more of a polymer flocculant as a main component is used as it is ( Undiluted solution), and used as a chemical solution to be added to hydrous bulk material. According to the method, the above chemical solution is added to the hydrated bulk material on the belt conveyor, and the hydrated bulk material and the chemical solution are mixed to generate aggregated particles. It is said that the supply of loose items to the yard can be done without any trouble.

  However, even if the unloading treatment of the hydrated bulk material is performed by the method disclosed in Patent Literature 1, in the ironmaking raw material transported by the belt conveyor and piled up in the raw material yard by the treatment, the ironmaking raw material It has been found that a phenomenon in which a mountain collapses (hereinafter referred to as “mountain collapse”) may occur due to fluidity caused by moisture. Conversely, when the water content in the steelmaking raw material is very small (for example, when the water content of the steelmaking raw material is less than 8% by mass), the collapse caused by the water content in the steelmaking raw material being too small. For ease, a mountain collapse may still occur.

  In view of the above, an object of the present invention is to provide a method of stacking steelmaking raw materials in which piled-up ironmaking raw materials are unlikely to collapse when piled up in a raw material yard.

  The present invention relates to a method of stacking steelmaking raw materials in a raw material yard, wherein at least one of the steelmaking raw materials before being piled up in the raw material yard and the ironmaking raw materials after being piled up is polymerized as an active ingredient. Provided is a method for stacking iron-making raw materials, the method including a step of adding a dilute solution having a coagulant content of 0.1 to 2% by mass.

  Advantageous Effects of Invention According to the present invention, it is possible to provide a method for stacking steelmaking raw materials in which piled-up ironmaking raw materials are unlikely to collapse when piled up in a raw material yard.

5 is a table showing, in comparison with photographs taken of the state of each sample used in Test Examples 1.1 and 1.2 after a test for confirming the easiness of collapse was performed. It is the chart which compared the photograph which image | photographed the state of the sample after performing the test which confirms the easiness of collapse about each sample used in Test Examples 2.1-2.3. It is the table | surface which compared and compared the photograph which image | photographed the state of the sample after performing the test which confirms the fragility easily about each sample used in Test Example 3.1 and 3.2. It is the table | surface which compared and compared the photograph which image | photographed the state of the sample after performing the test which confirms the easiness of collapse about each sample used in Test Examples 4.1-4.5. It is the chart which showed the state of the sample after performing the test which confirms the easiness of collapse about each sample used by Test Examples 5.1-5.7 by comparing the photograph taken from the upper surface side and the side surface side. . It is the chart which showed the state of the sample after performing the test which confirms easiness of collapse about each sample used in Test Examples 5.8 to 5.13 by comparing the photograph taken from the upper surface side and the side surface side. . It is the chart which showed the state of the sample after performing the test which confirms the easiness of collapse about each sample used by Test Examples 5.14-5.19 by comparing the photograph taken from the upper surface side and the side surface side. .

  Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

  The present inventors have studied a method for suppressing landslides that may occur due to the fact that a water-containing ironmaking raw material piled up in a raw material yard becomes more likely to flow due to moisture or the like in the raw material. In the study, assuming a raw material yard, the polymer coagulant used in the method specifically disclosed in Patent Document 1 was added to the steelmaking raw material before being piled up and the ironmaking raw material after being piled up. A method of adding a drug solution (stock solution) containing about 40% by mass as it was was tried.

  In an attempt to add the above-mentioned chemical solution to the steelmaking raw material after being piled up, since the steelmaking raw material is already piled up, after adding the above-mentioned chemical solution, the step of mixing them is omitted, so that a mountain collapse is likely to occur. The result was. Based on this result, the method of adding the chemical solution to the steelmaking raw material before being piled up was tested by changing the degree of mixing of the steelmaking raw material and the chemical solution by several degrees. It was found that it was likely to occur. These results and the observation of the iron-making raw material after the above-mentioned chemical solution was added.If the above-mentioned chemical solution was used as it was, the chemical solution did not wet the entire iron-making raw material, and the polymer flocculant in the chemical solution was iron-made. He concluded that the lack of raw material was the cause of the collapse.

  According to the method disclosed in Patent Document 1, when unloading a hydrated bulk material (iron-making raw material), a specific unloading obstacle such as a transport trouble such as easy outflow from a belt conveyor or easy dropping is solved. The configuration is adopted. Specifically, a method of spraying or spraying the above-mentioned chemical solution in a shower or a mist on a wet bulk material on a belt conveyor, a method of dropping and mixing a wet bulk material to which the above-mentioned chemical solution is added at a junction site of the belt conveyor, and the like. Is adopted. Therefore, it is difficult for a chemical solution (stock solution) containing about 40% by mass of the polymer flocculant to wet the whole of the hydrated bulk material (raw material for steelmaking), and for the polymer flocculant to hardly reach the entire hydrated bulk material. It is thought that it was not recognized in the technology.

  In addition, the method disclosed in Patent Document 1 described above requires equipment for adding the chemical solution (stock solution) in the form of a shower or a mist in the process of transporting a hydrated bulk material (iron-making raw material) on a belt conveyor. In order to sufficiently mix the chemical solution and the water-containing bulk material, it is necessary to provide a plurality of junctions of the belt conveyor with head portions. For this reason, the equipment becomes complicated, and where there is a restriction in the equipment design, it becomes difficult to sufficiently mix the chemical solution and the hydrated bulk material. Further, when it rains on the iron raw material piled up in the raw material yard, it is thought that the above-mentioned mountain collapse is more likely to occur.However, even if the chemical solution is further added to the iron raw material piled up in the raw material yard, However, mixing them results in landslides, and the method disclosed in Patent Document 1 cannot be used. Therefore, a simple and easy-to-use method is desired as a method for suppressing the landslide of piled iron-making raw materials.

  After the above examination, the present inventors have found that the concentration of the polymer flocculant is very low as a liquid (addition liquid) to be added to the steelmaking raw material so that the polymer flocculant can easily flow into the entire ironmaking raw material. It was examined whether the use of a liquid (dilute liquid of a polymer flocculant) could suppress mountain collapse. As a result, they have found that when the concentration of the polymer flocculant is in a specific low concentration range, the diluted solution can be easily used and the collapse of the mountain can be hardly generated, and the present invention has been accomplished.

  That is, the method for stacking iron-making raw materials according to one embodiment of the present invention (hereinafter, may be described as “the present method”) relates to a method for stacking iron-forming raw materials in a raw material yard. In the present method, the content of the polymer coagulant as an active ingredient is 0.1 to 2 mass in at least one of the iron making raw material before being piled up in the raw material yard and the iron making raw material after being piled up. % Of a dilute solution.

  When the diluted liquid is added to the iron-making raw material by the above process, the polymer flocculant in the diluted liquid spreads over the entire iron-making raw material, and the flocculating action of the polymer flocculant causes the iron-making raw material to agglomerate. By trapping water in the gaps, the fluidity of the iron-containing raw material in a water-containing state is reduced. Thereby, landslides due to fluidity due to moisture in the iron making raw material can be suppressed. In addition, when the water content in the steelmaking raw material is extremely small (for example, when the water content of the ironmaking raw material is less than 8% by mass), the ironmaking raw material can be appropriately moistened by the dilute liquid. In addition, landslides caused by too little moisture in the steelmaking raw material can be suppressed. Further, in the case of a steelmaking raw material having extremely low water content, a conventional chemical solution containing, for example, 10 to 50% by mass of a polymer coagulant hardly penetrates into the entire steelmaking raw material. The polymer flocculant can be energized throughout. Therefore, even when the ironmaking raw material is likely to flow due to rainfall or the like, it is possible to suppress mountain collapse due to the fluidity of the ironmaking raw material as described above.

  In the present method, since the dilute solution is used, the mixing of the ironmaking raw material and the dilute solution is not essential, but when the dilute solution is added to the ironmaking raw material before being piled up, it is preferable to mix them. . By mixing the iron-making raw material before being piled up and the dilute solution, the polymer coagulant can be more easily permeated throughout the iron-making raw material, and the collapse of the mountain can be made more difficult. Further, in the present method, since a dilute solution is used, it can be added to the ironmaking raw material after being piled up. Therefore, the present method can be said to be a useful and easy-to-use method.

  In the method for unloading hydrated bulk material disclosed in Patent Document 1 described above, when the hydrated bulk material is unloaded onto a belt conveyor, the processing is performed when the water content of the hydrated bulk material increases. Therefore, in the raw material yard, both the hydrated bulk material to which the chemical solution was not added because the moisture content did not increase at the time of unloading and the hydrated bulk material to which the chemical solution was added due to the increase in the moisture content at the time of unloading were transported together. And are piled up mixedly. In such a situation, when the rain falls on the hydrated roses piled up in the raw material yard, at least the portion of the hydrated roses to which the chemical solution has not been added in the hydrated roses is likely to flow, and the hills are easily collapsed. It is feared that it will become. Further, as described above, landslides may also occur when the water content in the iron-making raw material is too small. Regarding these circumstances, the present method allows the addition of a dilute solution to the ironmaking raw material regardless of whether the water content has increased. By doing so, it is possible to equalize the difference in the fluidity of the ironmaking raw materials piled up in the raw material yard, and it is possible to make the collapse more difficult.

  As described above, the present method preferably includes a step of adding a dilute liquid to the ironmaking raw material before being piled up in the raw material yard, and more preferably, mixing the ironmaking raw material with the dilute liquid, It is preferable to include a step of stacking the steelmaking raw materials to which the iron is added in the raw material yard. According to this method, the polymer flocculant is more easily permeated to the entire ironmaking raw material, and the collapse of the mountain is more easily suppressed. Further, the present method preferably includes a step of adding a dilute solution to the steelmaking raw material after being piled up in the raw material yard separately from or after these steps. In the process, the ironmaking raw material is piled up in the raw material yard and dried due to the water content thereof becoming too low, which may cause landslides or rainfall on the piled ironmaking raw material. Can be suppressed when the water content is increased to such an extent that water can easily flow.

  The objects to be treated by the present method are at least one of the steelmaking raw materials before being piled up in the raw material yard and the steelmaking raw materials after being piled up in the raw material yard. Both of them may be simply referred to as "iron making raw material" in this specification. In addition, the steelmaking raw material being piled up (for example, the steelmaking raw material while being dropped into the raw material yard) is included in the steelmaking raw material before being piled up because it is immediately before the piled state. . The raw material yard may be either outdoor or indoor, and outdoor is more preferable from the viewpoint of the effect of the present method. Examples of ironmaking raw materials include iron ore, coal, limestone, coke, and dust. Among these, iron ore and coal are preferred, and iron ore is more preferred.

  The steelmaking raw material to be treated by the present method usually contains water. The water content of the ironmaking raw material is not particularly limited, but is preferably 1 to 30% by mass, more preferably 1 to 25% by mass, and still more preferably 1 to 20% by mass. In the case where landslides due to fluidity due to moisture in the steelmaking raw material are suppressed, the ironmaking raw materials are liable to cause such landslides due to such fluidity. For example, the water content (moisture content) is 8 to 20% by mass. Ironmaking raw materials are more suitable as targets for treatment. In addition, in the case of suppressing landslides caused by too little water in the ironmaking raw material, such landslides are likely to occur, and for example, the water content (water content) is less than 8% by mass (1%). Mass% or more and less than 8 mass%) is more suitable as a treatment target. In the present specification, the water content of the iron making raw material is calculated by dividing the mass of the water in the iron making raw material by the total mass of the iron making raw material (the sum of the mass of the water and the solid content).

  As for the place and timing of adding the dilute solution to the ironmaking raw material, when adding the dilute solution to the piled ironmaking raw material, add the dilute liquid to the piled ironmaking raw material at the raw material yard. Can be. In addition, when adding a dilute solution to a raw material before being piled, the dilute solution is added when unloading the raw material from a ship such as a bulk carrier or when transferring the raw material to a raw material yard. Is preferred. Specifically, in a landing facility used for unloading ironmaking raw materials from a ship (for example, in a hopper in a grab bucket type unloader and a continuous unloader, etc.), a dilute liquid is applied to the ironmaking raw material in the landing equipment. More preferably, it is added. Further, it is more preferable to add a dilute liquid to the iron making raw material on a conveying means (for example, a belt conveyor) that conveys the iron making raw material discharged by the landing equipment to a raw material yard. With these methods, the outflow and fall of the iron making raw material from the conveying means can be suppressed, and the conveying of the iron making raw material can be further facilitated.

  As a method of adding the dilute solution to the ironmaking raw material, a method of spraying the dilute liquid on the ironmaking raw material in the form of a shower, a method of spraying in a mist form, and a method of flowing the tap water from a faucet into a straight rod shape are preferable. , These methods may be combined. Among these, in an actual site, a method in which a dilute solution is flowed and added to a steelmaking raw material on a belt conveyor in the form of a straight rod is more preferable, and a method in which the dilute liquid is flowed down in a straight rod shape is more preferable. By such a method of flowing in the form of a straight rod, the polymer flocculant in the dilute solution can be easily supplied to the entire ironmaking raw material, and the dilute solution can be added with simple equipment.

  The dilute solution added to the ironmaking raw material contains 0.1 to 2% by mass of a polymer flocculant as an active ingredient based on the total mass of the dilute solution. When the content of the polymer flocculant in the dilute solution is 0.1% by mass or more and 2% by mass or less, an effect of making the collapse hard to occur can be obtained. From the viewpoint that the effect can be more easily obtained, the content of the polymer flocculant in the diluted liquid is preferably 0.2% by mass or more. In addition, from the viewpoint of more easily obtaining the effect of making the landslide hard to occur and the viewpoint of easily manufacturing the diluted liquid, the content of the polymer flocculant in the diluted liquid is preferably 1.8% by mass or less, The content is more preferably 0.6% by mass or less, and further preferably 1% by mass or less.

  The polymer flocculant refers to a polymer compound that functions as a flocculant, and a water-soluble polymer (including a copolymer) having the function is suitably used. As the polymer flocculant, a nonionic polymer flocculant, an anionic polymer flocculant, a cationic polymer flocculant, and an amphoteric polymer flocculant can be used. One of these may be used alone, or two or more thereof may be used in combination. Among these, a nonionic polymer flocculant and an anionic polymer flocculant are preferable, and an anionic polymer flocculant is more preferable.

  Suitable polymer flocculants include, for example, poly (meth) acrylic acid-based flocculant which is a polymer of (meth) acrylic acid-based monomer, and poly (meth) which is a polymer of (meth) acrylic acid ester-based monomer Acrylate ester-based coagulant, poly (meth) acrylamide-based coagulant which is a polymer of (meth) acrylamide, polyalkylaminoalkyl (meth) acrylate quaternary salt which is a polymer of alkylaminoalkyl (meth) acrylate-based monomer A coagulant and a polyvinylamidine coagulant. Further, as a preferable polymer flocculant, one selected from the group consisting of (meth) acrylic acid-based monomer, (meth) acrylate-based monomer, (meth) acrylamide, and alkylaminoalkyl (meth) acrylate-based monomer Copolymeric coagulants containing structural units derived from one or more types of monomers can be mentioned.

  In the present specification, the term “(meth) acryl” means that both words of acryl and methacryl are included. Further, in the present specification, the “structural unit” means a monomer unit constituting a polymer flocculant (polymer compound). The "structural unit derived from a monomer" includes, for example, a structural unit in which a polymerizable double bond (C = C) in a monomer is cleaved to form a single bond (-CC-).

  Examples of the (meth) acrylic acid-based monomer include (meth) acrylic acid and, for example, (meth) acrylic acid such as sodium (meth) acrylate, potassium (meth) acrylate, and lithium (meth) acrylate. Examples thereof include, but are not limited to, metal salts; ammonium (meth) acrylate; and amine salts of (meth) acrylic acid. Hereinafter, "(meth) acrylic acid (salt)" may be described, including such (meth) acrylic acid and salts thereof. Examples of the (meth) acrylate-based monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid. Examples include, but are not limited to, 2-ethylhexyl.

  More preferable examples of the copolymer coagulant include (meth) acrylic acid (salt) / (meth) acrylamide copolymer and (meth) acrylamide / (meth) acrylic acid (salt) / 2-acrylamide -2-methylpropanesulfonic acid (salt) copolymer, alkylaminoalkyl (meth) acrylate quaternary salt / (meth) acrylamide copolymer, and (meth) acrylamide / (meth) acrylic acid / alkylaminoalkyl (meth) And a) a coagulant such as acrylate quaternary salt copolymer.

  The above-mentioned copolymer coagulant may contain a structural unit derived from a monomer other than the above-mentioned monomer (other monomer). Other monomers include, for example, unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, and salts thereof; carboxylic anhydrides such as maleic anhydride and itaconic anhydride; styrene and α-methylstyrene; Aromatic vinyl compounds; unsaturated sulfonic acids such as vinylsulfonic acid and styrenesulfonic acid, and salts thereof; vinyl acetate; acrylonitrile; methacrylonitrile.

  The weight average molecular weight (Mw) of the polymer flocculant is preferably from 5,000,000 to 30,000,000, more preferably from 10,000,000 to 25,000,000. This weight average molecular weight can be measured by gel permeation chromatography (GPC).

  Polymer flocculants include poly (meth) acrylic acid-based flocculants, poly (meth) acrylic acid ester-based flocculants, poly (meth) acrylamide-based flocculants, and sodium (meth) acrylate / (meth) acrylamide copolymers It is preferable to include one or more selected from the group consisting of system coagulants. Among these, the dilute liquid is a polymer coagulant such as sodium (meth) acrylate / (meth) acrylamide copolymer (the above-mentioned sodium (meth) acrylate / (meth) acrylamide copolymer coagulant) and acrylic More preferably, it contains at least one member selected from the group consisting of a polymer of an acid or a salt thereof (the above-mentioned poly (meth) acrylic acid-based coagulant) and an acrylamide polymer, and a sodium acrylate-acrylamide copolymer. More preferably, it is contained.

  Examples of the form of the dilute liquid when added to the raw material for iron making include emulsions such as water-in-oil (W / O) emulsions and oil-in-water (O / W) emulsions; dispersions such as aqueous dispersions; A solution such as an aqueous solution can be used. Among these, from the viewpoint that the polymer flocculant in the dilute solution is more easily perceived by the entire ironmaking raw material, the dilute liquid is a liquid in the form of an oil-in-water emulsion or an aqueous solution when added to the ironmaking raw material. It is preferred that

  As the diluted liquid, for example, a dispersion liquid (dispersed liquid diluted liquid) containing a specific amount of the polymer flocculant and a dispersion medium from the time of manufacturing the polymer flocculant can be used. As the diluted liquid, for example, a dispersion liquid (for example, a commercially available liquid polymer flocculant product) containing a polymer flocculant (for example, 10 to 50% by mass) and a dispersion medium is used. A dilute solution obtained by diluting with a specific amount of a liquid medium can also be used. Further, as the dilute solution, for example, a solution in which a specific amount of a commercially available powdery polymer flocculant is dissolved in a solvent (a dilute solution in a solution) can be used. The dilute liquid contains a polymer coagulant and at least one liquid component such as the above-described dispersion medium, solvent, and liquid medium that can be used for dilution, and contains unavoidable impurities (for example, constituting the polymer coagulant). Monomer remaining).

  As a more preferable diluent, a dispersion (for example, a commercially available liquid polymer flocculant product) containing a polymer flocculant (for example, 10 to 50% by mass) and a dispersion medium is used. A diluted liquid obtained by diluting with water in an amount of 0.1 to 2% by mass and stirring the mixture is mentioned. Examples of the dispersion medium in the dispersion before dilution of the diluted liquid include water (including, for example, aqueous solutions containing salts such as alkali metal salts and ammonium salts), hydrorefined light distillate (petroleum), and the like. be able to.

  As a more preferred specific example of the above-mentioned diluted liquid, a water-in-oil (W / O) emulsion containing a polymer flocculant and a hydrorefined light distillate (petroleum) as a dispersion medium is used. And a diluted liquid obtained by diluting and stirring with water in such an amount that the concentration of the polymer coagulant becomes 0.1 to 2% by mass. The diluted liquid is diluted with a larger amount of water than the dispersion medium, so that the continuous phase is converted from oil to water, and the polymer flocculant is dissolved in the continuous phase (water). A dilute liquid in the form of a drop (O / W) emulsion can be used.

  Further, as a more preferable specific example of the above-mentioned diluted liquid, an aqueous dispersion liquid containing a polymer flocculant and a sulfate aqueous solution (for example, an ammonium sulfate aqueous solution and a magnesium sulfate aqueous solution) as a dispersion medium (for example, (Suspension) is diluted with water in such an amount that the concentration of the polymer coagulant becomes 0.1 to 2% by mass, and a dilute liquid obtained by stirring the suspension is also included. In this dilute liquid, the polymer flocculant was dissolved in the water (aqueous solution) by being diluted with a larger amount of water than the dispersion medium and increasing the content of water in the aqueous solution as a continuous phase. An aqueous dilute solution can be used. Further, as a preferred specific example of the dilute solution, an aqueous dilute solution in which 0.1 to 2% by mass of a powdery polymer coagulant is dissolved in water can also be mentioned.

  The liquid component in the dilute liquid may contain other liquid components other than the above-mentioned water and hydrorefined light distillate oil (petroleum). Other liquid components include, for example, water-soluble organic solvents such as alcohols, polyhydric alcohols, polyglycols, and glycol ethers, and one or more of them can be used. As described above, the dilute liquid preferably contains water as a liquid component. The content of water in the dilute solution is preferably 90 to 99.9% by mass, more preferably 95% by mass or more, and preferably 98% by mass or more based on the total mass of the dilute solution. Is more preferred.

  When the above-mentioned preferred dilute solution is added to the iron-making raw material, the polymer flocculant, which is a kind of water-soluble polymer in the dilute solution, is dissolved in free water in the iron-making raw material. Then, an adhesive crosslinking action based on the adsorption of the polymer flocculant occurs in the raw material particles in the iron making raw material, and the raw material particles are aggregated and coarsened by the action, and most of the free water is present in the gaps between the coarse particles. Is thought to be captured. As a result, the iron-making raw material has a reduced fluidity, is apparently modified to an aggregated or nodular appearance, has an appearance having fewer raw material particles and free water portions, and is unlikely to collapse. The gap is very small, and the preferred polymer flocculant has a property of hardly penetrating rainwater, spring water, etc., so that after the addition of the dilute solution and after the pile, the steelmaking raw material is mixed with water due to rainfall or the like. Even if they meet, they do not mix, and it is easy to keep the shape as it is.

  As the amount of the dilute liquid added to the iron making raw material, it is preferable to add the dilute liquid to the iron making raw material in an amount of 0.0001 to 0.05% by mass as a polymer coagulant with respect to the total mass of the iron making raw material. . The addition ratio of the polymer coagulant to the total mass of the ironmaking raw material is more preferably 0.0005 to 0.02% by mass, and still more preferably 0.001 to 0.01% by mass. The “total mass of the iron making raw material” is the total mass of the iron making raw material to which the dilute liquid is added, and is the sum of the mass of the solid content of the iron making raw material and the mass of the water in the iron making raw material. Further, the addition ratio of the polymer coagulant to the total mass of the ironmaking raw material is calculated by dividing the addition mass of the polymer coagulant (active ingredient) in the dilute liquid by the total mass of the ironmaking raw material.

  Further, it is preferable to control the amount of the diluted liquid to be added to the iron making raw material to an amount such that the water content of the iron manufacturing raw material after the addition of the diluted liquid is 8 to 25% by mass. By adding the dilute solution to the ironmaking raw material, the water content of the ironmaking raw material after the dilute liquid is added is adjusted to 8 to 25% by mass, so that the appropriate amount of water in the ironmaking raw material after the dilute liquid is added and after piled up By using the polymer coagulant, mountain collapse can be made more difficult to occur. From this viewpoint, it is more preferable to control the amount of the diluted liquid to be added to the iron making raw material to an amount such that the water content of the iron manufacturing raw material after the addition of the diluted liquid is 10 to 20% by mass.

  The method for stacking iron raw materials according to one embodiment of the present invention described above is characterized in that a polymer as an active ingredient is added to at least one of the iron raw materials before being piled in the raw material yard and the iron raw materials after being piled. A step of adding a dilute solution having a coagulant content of 0.1 to 2% by mass. By this process, the dilute solution wets the entire ironmaking raw material, and the polymer flocculant in the dilute solution spreads over the entire ironmaking raw material. Mountain collapse caused by too little water in the lands can be suppressed. Therefore, the present method is more suitable as a method for suppressing a landslide of a steelmaking raw material in a raw material yard. The ironmaking raw material after the addition of the dilute solution and after the pile can be used in the same manner as in the past, and the components such as the polymer flocculant in the dilute solution added to the ironmaking material are burned off during the ironmaking process. Is done.

As described above, the method for stacking iron-making raw materials according to one embodiment of the present invention can employ the following configuration.
[1] A method of stacking ironmaking raw materials in a raw material yard, wherein polymer aggregation as an active ingredient is added to at least one of the steelmaking raw materials before being piled in the raw material yard and the ironmaking raw materials after being piled up. A method of stacking raw materials for ironmaking, comprising a step of adding a dilute solution having a content of an agent of 0.1 to 2% by mass.
[2] The above-mentioned [1] including a step of adding the dilute solution to the ironmaking raw material before being piled up in the raw material yard, and a step of stacking the ironmaking raw material to which the dilute liquid has been added in the raw material yard. ] The pile method of the iron-making raw material as described in the above.
[3] The method for stacking iron-making raw materials according to the above [1] or [2], comprising a step of adding the dilute liquid to the iron-making raw materials after being stacked in the raw material yard.
[4] The pile of the ironmaking raw material according to any one of the above [1] to [3], wherein the diluted liquid is a liquid in the form of an oil-in-water emulsion or an aqueous solution when added to the ironmaking raw material. Method.
[5] The dilute liquid contains at least one selected from the group consisting of sodium acrylate / acrylamide copolymer, acrylic acid or a salt thereof, and acrylamide polymer as the polymer flocculant. The method for stacking iron-making raw materials according to any one of [1] to [4].
[6] The above-mentioned [1] to [5], wherein the diluted liquid is added to the ironmaking raw material in an amount of 0.0001 to 0.05% by mass as the polymer coagulant based on the total mass of the ironmaking raw material. 5. The method of stacking raw materials for iron according to any one of the above.
[7] The above-mentioned [1] to [6], wherein the amount of the dilute solution added to the ironmaking raw material is controlled so that the water content of the ironmaking raw material after the dilute liquid is added becomes 8 to 25% by mass. ] The pile method of the iron-making raw material as described in any of [1].

  Hereinafter, the effects related to the method of stacking iron-making raw materials according to one embodiment of the present invention will be described more specifically with reference to test examples at the laboratory level.

<Test Example 1>
In Test Example 1, iron ore having a particle size of 5 mm or less and having a water content of 7.7% by mass was used as a raw material for ironmaking by screening.

(Test Example 1.1)
In Test Example 1.1, as a blank test, the above-mentioned calajas iron ore was used as a sample without using a liquid to be added to iron ore (hereinafter sometimes referred to as “addition liquid”), and a test described later was performed. Was done.

(Test Example 1.2)
In Test Example 1.2, after the additive liquid was added to the above-mentioned carajas iron ore in the container, the container was capped, and the container was stirred up and down 5 times, and the iron ore and the additive liquid were mixed to obtain Using the obtained mixture as a sample, a test described later was performed. The additive liquid includes an anionic W / O emulsion containing a sodium acrylate / acrylamide copolymer as a polymer coagulant (trade name “NS Dry-322L”, manufactured by Nippon Steel & Sumitomo Metal Corporation; sodium acrylate / acrylamide) A pale yellowish white to light brown emulsion containing a copolymer and a hydrorefined light distillate (petroleum) as components) with water in an amount such that the content of the copolymer becomes 0.4% by mass. A diluted liquid (white emulsion) obtained by diluting (100-fold dilution) and stirring was used. The diluted liquid was diluted with a larger amount of water than the dispersion medium (oil), so that the continuous phase was changed from oil to water, and the copolymer was dissolved in the continuous phase (water). It is an oil-in-water (O / W) emulsion-type diluted liquid. The addition ratio of the additive liquid (dilute liquid) to the total mass of the iron ore was 2.0% by mass. Therefore, the addition ratio of the iron ore as the copolymer with respect to the total mass of the iron ore was set to 0.008% by mass.

(Test for confirming easiness of collapse)
As described below, a test for confirming the easiness of collapse and the easiness of crushing of each sample in a simulated piled state (referred to as a “collapse easiness confirmation test” in this specification) was performed. A test tank was prepared, which was a rectangular parallelepiped tank having an inner size of 200 mm in width (depth), 400 mm in length, and 100 mm in height, and one side of which was open and fixed with silica sand for slip prevention on the bottom surface. After placing a plastic cylinder (hereinafter, referred to as “cylindrical mold M”) having an inner diameter of 100 mm and a height of 105 mm near the center of the bottom surface of the test tank, The sample in each test example was completely filled. Next, the cylindrical mold M was pulled out upward, and the sample remaining on the bottom surface of the test tank at that time was evaluated for the degree of collapse from the cylindrical sample that was filled in the cylindrical mold M. Specifically, the maximum length in the radial direction of the sample remaining in the test tank after the cylindrical mold M was pulled out (x value; the length in the horizontal direction in the test tank) and the maximum height of the remaining sample ( y value; height in the vertical direction of the test tank). Then, based on the measured x value and y value, the difficulty of collapse and the ease of collapse (hereinafter, simply referred to as “easiness of collapse”) were evaluated. The smaller the x value of the remaining sample is closer to the inner diameter (100 mm) of the original cylindrical mold M, and the larger the y value of the remaining sample is closer to the height (105 mm) of the original cylindrical mold M, This indicates that the sample had a shape close to the original columnar shape in the cylindrical mold M, and that the sample did not easily collapse.

(Evaluation of ease of collapse)
Based on the x value and the y value obtained as a result of the above-described collapsibility test, the collapsibility was evaluated according to the following evaluation criteria. A to D indicate that it was difficult to collapse, and A and B were permissible levels that were difficult to collapse, and C and D were levels that were not permissible.
A: The difference between the x value and its original value (inner diameter 100 mm) and the difference between the y value and its original value (height 105 mm) were all less than 5 mm.
B: The difference between the x value and its original value and the difference between the y value and its original value are all less than 15 mm, and the difference between the x value and its original value, and the y value. At least one of the differences from the original value was 5 mm or more and less than 15 mm.
C: The difference between the x value and its original value, and the difference between the y value and its original value are all less than 30 mm, and the difference between the x value and its original value, and the y value. At least one of the differences from the original value was 15 mm or more and less than 30 mm.
D: At least one of the difference between the x value and its original value and the difference between the y value and its original value was 30 mm or more.

  Table 1 shows the test conditions and test results of Test Examples 1.1 and 1.2. In each of Test Examples 1.1 and 1.2, a photograph of the state of the sample remaining in the test tank by the above-described collapsibility test is shown in FIG. 1 in the form of a comparison table. . In Test Example 1.1, as shown in FIG. 1, the x value was set to 150 mm or more because the sample was largely disintegrated and reached the inner wall in the length direction of the test tank by the above-described test.

  In Test Example 1.1 (blank test), the sample remaining after pulling out the cylindrical mold M was significantly collapsed, whereas in Test Example 1.2, the sample remaining after pulling out the cylindrical mold M was significantly collapsed. However, the x and y values were high, and the original shape was generally maintained. In Test Example 1, since a steelmaking raw material having a low water content of 7.7% by mass was used, the sample collapsed in Test Example 1.1 is considered to be caused by too little water in the steelmaking raw material. . In addition, the collapse was suppressed in Test Example 1.2 because the addition of the dilute liquid to the extremely low water content of the ironmaking raw material greatly affected the ironmaking raw material in an appropriately wet state. Conceivable.

<Test Example 2>
In Test Example 2, water was added to the same calajas iron ore (water content: 7.7% by mass) as the iron making raw material used in Test Example 1 above, and the water content was adjusted to 15% by mass. .

(Test Example 2.1)
In Test Example 2.1, as a blank test, the above-mentioned Karajas iron ore having a water content of 15% by mass was used as a sample without using an additive liquid, and the above-described collapsibility test was performed. And y value were measured to evaluate the easiness of collapse.

(Test Example 2.2)
In Test Example 2.2, as compared with Test Example 1.2, the calajas iron ore having a water content of 7.7% by mass used in Test Example 1.2 was used at a water content of 15% by mass. A sample was obtained by the same procedure and method as in Test Example 1.2, except that a change was made to a certain calajas iron ore. The sample was subjected to the above-described collapsibility test, the x value and the y value were measured, and the collapsibility was evaluated.

(Test Example 2.3)
In Test Example 2.3, as compared with Test Example 1.2, as in Test Example 2.2, the above-mentioned carajas iron ore having a water content of 15% by mass was used, and the used additive liquid was used. A sample was obtained by the same procedure and method as in Test Example 1.2 except for the change. The sample was subjected to the above-described collapsibility test, the x value and the y value were measured, and the collapsibility was evaluated. The undiluted solution in Test Example 2.3 used was the same anionic W / O emulsion (trade name “NS Dry-322L”, manufactured by Nippon Steel & Sumikin Environment Co., Ltd.) as used in Test Example 2.2. Used in The addition ratio of the additive liquid (stock solution) to the total mass of the iron ore was 0.02% by mass. Therefore, the addition ratio of the iron ore as the copolymer with respect to the total mass of the iron ore was set to 0.008% by mass.

  Table 2 shows the test conditions and test results of Test Examples 2.1 to 2.3. In each of Test Examples 2.1 to 2.3, a photograph of the state of the sample remaining in the test tank in the above-described collapse easiness confirmation test is shown in FIG. 2 in the form of a comparison table. .

  In Test Example 2.1 (blank test), the sample remaining after the cylindrical mold M was pulled out was crushed and the y value was reduced, and the x value was increased by flowing in the horizontal direction. It was confirmed that the stone (water content: 15% by mass) was easily broken by the fluidity caused by the moisture. On the other hand, in Test Example 2.2, the sample remaining after the cylindrical mold M was pulled out was not largely collapsed, the x value and the y value were high, and the original shape was generally maintained. From this, it was confirmed that the collapse of the sample could be suppressed by adding a dilute solution containing 0.4% by mass of the polymer flocculant to iron ore having a water content of 15% by mass. This result indicates that the addition of the dilute solution caused the polymer coagulant in the dilute solution to permeate the entire iron ore. It is considered that a large amount of water was captured in the gaps of the iron ore, and the fluidity of the iron ore was reduced.

  Further, in Test Example 2.3, although the collapse of the sample was able to be suppressed more than in Test Example 2.1, the x value was larger and the y value was smaller than the result of Test Example 2.2. It was confirmed that collapse occurred, and further, outflow of water (free water) from the lower portion of the sample remaining in the test tank was also observed. These results indicate that the chemical solution (stock solution) containing 40% by mass of the polymer flocculant used in Test Example 2.3 was less likely to wet the entire iron ore, and the polymer flocculant in the chemical solution was less than the entire iron ore. It is thought that it was due to the fact that he did not keep up.

<Test Example 3>
In Test Example 3, water was added to ultrafine iron ore having a water content of 9.6% by mass, and the ultrafine iron ore whose water content was adjusted to 20% by mass was used as an ironmaking raw material.

(Test Example 3.1)
In Test Example 3.1, as a blank test, the above-described ultrafine iron ore having a water content of 20% by mass was used as a sample without using an additive liquid, and the above-described collapsibility test was performed. The value and y value were measured to evaluate the easiness of collapse.

(Test Example 3.2)
In Test Example 3.2, in comparison with Test Example 1.2, the calajas iron ore having the water content of 7.7% by mass used in Test Example 1.2 was used at the water content of 20% by mass. A sample was obtained by the same procedure and method as in Test Example 1.2, except that the sample was changed to a certain ultrafine iron ore. The sample was subjected to the above-described collapsibility test, the x value and the y value were measured, and the collapsibility was evaluated.

  Table 3 shows the test conditions and test results of Test Examples 3.1 and 3.2. Further, in each of Test Examples 3.1 and 3.2, a photograph of the state of the sample remaining in the test tank by the above-described collapse easiness confirmation test is shown in FIG. 3 in the form of a comparison table. .

  From the results of Test Example 3, the fluidity of the sample was reduced by adding a dilute solution containing 0.4% by mass of a polymer flocculant to iron ore that had a high water content of 20% by mass and thus was easily flowable. Thus, it was confirmed that the collapse of the sample could be suppressed.

<Test Example 4>
In Test Example 4, as in Test Example 2, water was added to the same calajas iron ore (water content: 7.7% by mass) as the iron-making raw material used in Test Example 1 to adjust the water content to 15% by mass. Was used as a raw material for steelmaking.

(Test Example 4.1)
In Test Example 4.1, as a blank test, a test described later was performed using a calajas iron ore having a water content of 15% by mass as a sample without using an additive liquid.

(Test Example 4.2)
A plastic container was charged with 500 g of the above-mentioned carajas iron ore having a water content of 15% by mass. After the additive liquid was added to the iron ore in the container, the container was capped, and the container was stirred up and down 5 times vertically to mix the iron ore and the additive liquid. Using the obtained mixture as a sample, a test described below was performed. As an additive liquid, the same anionic W / O emulsion (trade name “NS Dry-322L”, manufactured by Nippon Steel & Sumikin Environment Co., Ltd.) as used in Test Example 2.3 was used as a stock solution. The addition ratio of the additive liquid (stock solution) to the total mass of the iron ore was 0.02% by mass. Therefore, the addition ratio of the iron ore as the copolymer with respect to the total mass of the iron ore was set to 0.008% by mass.

(Test Example 4.3)
In Test Example 4.3, a sample was obtained by the same procedure and method as in Test Example 4.2 except that the used additive liquid and the amount thereof were changed as compared with Test Example 4.2. The test described below was performed on the sample. As in the test examples 1.2, 2.2, and 3.2, the additive liquid contains an anionic W / O emulsion containing a sodium acrylate-acrylamide copolymer as a polymer coagulant (trade name) "NS Dry-322L", manufactured by Nippon Steel & Sumitomo Metal Environment Co., Ltd.) was diluted (100-fold dilution) with water in an amount such that the content of the above copolymer was 0.4% by mass, and stirred to obtain O. A / W emulsion dilute solution (see Test Example 1.2 above) was used. The addition ratio of the additive liquid (dilute liquid) to the total mass of iron ore was 2.0% by mass. Therefore, the addition ratio as the above-mentioned copolymer with respect to the total mass of iron ore was set to 0.008 mass%.

(Test Example 4.4)
In Test Example 4.4, a sample was obtained in the same procedure and method as in Test Example 4.2, except that the used additive liquid and the amount thereof were changed as compared with Test Example 4.2. The test described below was performed on the sample. The additive liquid includes an aqueous dispersion containing a sodium acrylate / acrylamide copolymer as a polymer coagulant (trade name “NS Dry-709L”, manufactured by Nippon Steel & Sumitomo Metal Corporation; sodium acrylate / acrylamide copolymer; A white to pale brown emulsion containing ammonium sulfate as a component) is diluted (20-fold dilution) with water in such an amount that the content of the above-mentioned copolymer becomes 1% by mass, and stirred to obtain a dilute solution ( Transparent liquid) was used. This dilute solution is diluted with a larger amount of water than the dispersion medium (aqueous ammonium sulfate solution), and the content of water in the aqueous solution which is a continuous phase increases, so that the polymer flocculant is contained in the water (aqueous solution). It is a dissolved, aqueous dilute solution. The addition ratio of the additive liquid (dilute liquid) to the total mass of the iron ore was 0.8% by mass. Therefore, the addition ratio as the above-mentioned copolymer with respect to the total mass of iron ore was set to 0.008 mass%.

(Test Example 4.5)
In Test Example 4.5, a sample was obtained in the same procedure and method as in Test Example 4.2, except that the used additive liquid and the amount thereof were changed as compared with Test Example 4.2. The test described below was performed on the sample. The same additive liquid as the diluted liquid used in Test Example 4.4 was used. The addition ratio of the additive solution (dilute solution) to the total mass of the iron ore was 0.4% by mass. Therefore, the addition ratio of the polymer coagulant (sodium acrylate / acrylamide copolymer) to the total mass of the iron ore was 0.004 mass%.

(Test for confirming easiness of collapse)
After placing a plastic cylinder (hereinafter, referred to as a “cylindrical mold m”) having an inner diameter of 60 mm and a height of 100 mm near the center of the bottom surface of the test tank, The sample in each test example was completely filled. Next, the cylindrical mold m was pulled out upward, and the sample remaining on the bottom surface of the test tank at that time was evaluated for the degree of collapse from the sample which had been filled into the cylindrical mold m and had a cylindrical shape. Specifically, the maximum length in the radial direction of the sample remaining in the test tank after the cylindrical mold m was pulled out (x value; the length in the horizontal direction in the test tank) and the maximum height of the remaining sample ( y value; height in the vertical direction of the test tank). The smaller the x value of the remaining sample is closer to the inner diameter (60 mm) of the original cylindrical mold m and the larger the y value of the remaining sample is closer to the height (100 mm) of the original cylindrical mold m, This indicates that the sample had a shape close to the original columnar shape in the cylindrical mold m, indicating that the sample hardly collapsed.

(Evaluation of ease of collapse)
Based on the x value and the y value obtained as a result of the above-described collapsibility test, the collapsibility was evaluated according to the following evaluation criteria.
A: The difference between the x value and its original value (inner diameter 60 mm) and the difference between the y value and its original value (height 100 mm) were all less than 5% of the original value.
B: The difference between the x value and its original value and the difference between the y value and its original value are both less than 10% of the original value, and the difference between the x value and its original value. At least one of the difference and the difference between the y value and the original value was 5% or more and less than 10% of the original value.
C: The difference between the x value and its original value, and the difference between the y value and its original value are both less than 25% of the original value, and the difference between the x value and its original value. At least one of the difference and the difference between the y value and the original value was 10% or more and less than 25% of the original value.
D: At least one of the difference between the x value and its original value and the difference between the y value and its original value was 25% or more of the original value.

(Apparent moisture condition of sample)
A part of the sample after conducting the test for confirming the easiness of collapse in each of Test Examples 4.1 to 4.5 was sampled, the state of the sample was visually checked, and the appearance of the sample was evaluated according to the following evaluation criteria. The condition of water (free water) was evaluated.
A: Almost no water was found on the surface of the sample, and the sample had a granular or nodular appearance.
B: Moisture appeared on a part of the surface of the sample, but it had an appearance of aggregate or aggregate.
C: Moisture appeared on most of the surface of the sample, and had a muddy appearance that was easy to flow.

  Table 4 shows the test conditions and test results of Test Examples 4.1 to 4.5. In each of Test Examples 4.1 to 4.5, a photograph of the state of the sample (state 1 in FIG. 4) remaining in the test tank and the apparent moisture content were obtained by the above-described collapse easiness confirmation test. FIG. 4 shows a photograph of the state (state 2 in FIG. 4) of the sample whose condition was evaluated in the form of a comparison table.

  In Test Example 4.2, although the collapse of the sample was suppressed more than in Test Example 4.1 (blank test), the x value was larger and the y value was lower than the results of Test Examples 4.3 to 4.5. The result was small, and it was confirmed that the sample collapsed. In addition, the iron-making raw material (sample) after adding the stock solution in Test Example 4.2 was apparently (on the surface), most of which appeared to have moisture, and had a mud-like appearance that was easy to flow. Therefore, it is presumed that the polymer flocculant in the chemical solution (stock solution) did not permeate the entire iron ore.

  In Test Examples 4.3 to 4.5, by adding a diluted solution of a dispersion containing 0.4% by mass or 1% by mass of a polymer coagulant to a steelmaking raw material having a water content of 15% by mass, It was confirmed that the collapse of the steelmaking raw material (sample) after the addition of the dilute solution could be suppressed. In addition, in the iron making raw materials (samples) after adding the dilute solution in Test Examples 4.3 to 4.5 (especially in Test Examples 4.3 and 4.4), much water was apparently observed (on the surface). There was no aggregated or nodular appearance. This is considered to be because the polymer flocculant in the dilute solution spread over the entire iron ore, and the moisture was sufficiently captured in the gaps between the iron-making raw materials that were flocculated by the flocculating action of the polymer flocculant.

<Test Example 5>
In Test Example 5, the iron ore having a particle size of 5 mm or less and having a water content of 4.1% by mass was added with water by sieving to adjust the water content to 15% by mass. Stone was used as a steelmaking raw material. From the ironmaking raw material, the following samples were prepared, and the prepared samples were subjected to a test for confirming the likelihood of collapse of the same method as described in Test Example 4. The results are shown in Table 5 below (Tables 5-1 to 5-3). Further, in Test Example 5, FIG. 5 (FIGS. 5A to 5C) in which photographs of the state of the sample remaining in the test tank taken from the upper surface side and the side surface by the collapsibility confirmation test are shown in the form of a comparison table. Show.

  The iron making raw material used in Test Example 5 was a calajas iron ore whose water content was adjusted to 15% by mass, like the iron making raw material used in Test Examples 2 and 4, but was used in Test Examples 2 and 4. Compared to the iron-making raw material, there were many finer particles, so that it was easier to flow (see Test Example 5.1). Therefore, in the test for confirming the easiness of collapse in Test Example 5, the evaluation was performed based on the results of the test for confirming the susceptibility of the steelmaking raw material itself used in Test Example 5 (the results of the blank test in Test Example 5.1).

(Test Example 5.1)
In Test Example 5.1, as a blank test, the above-mentioned Karajas iron ore having a water content of 15% by mass was used as a sample without using an additive liquid.

(Test Example 5.2)
In a plastic container, 500 g of the above-mentioned iron-making raw material was put. After the additive liquid was added to the iron making raw material in the container, the container was capped, and the container was stirred up and down 5 times to mix the iron making raw material and the additive liquid to obtain a sample. The additive liquid includes an aqueous dispersion containing a sodium acrylate / acrylamide copolymer as a polymer coagulant (trade name “NS Dry-709L”, manufactured by Nippon Steel & Sumitomo Metal Corporation; sodium acrylate / acrylamide copolymer; A white to pale brown emulsion containing ammonium sulfate as a component) is diluted (20-fold dilution) with water in such an amount that the content of the copolymer becomes 1% by mass, and the aqueous solution obtained by stirring is diluted. A dilute liquid (clear liquid) was used (see Test Example 4.4 above). The addition ratio of the additive solution (dilute solution) to the total mass of the ironmaking raw material was 0.10% by mass. Therefore, the addition ratio of the polymer coagulant (the above copolymer) to the total mass of the ironmaking raw material was set to 0.001 mass%.

(Test Examples 5.3 to 5.7)
In Test Examples 5.3 to 5.5, compared with Test Example 5.2, the addition ratio of the additive liquid (dilute liquid) to the total mass of the ironmaking raw material (the accompanying polymer coagulant relative to the total mass of the ironmaking raw material) A sample was obtained in the same manner as in Test Example 5.2 except that (addition ratio as the above-mentioned copolymer) was changed as shown in Table 5-1. In Test Examples 5.6 and 5.7, the aqueous dispersion was diluted with water in such amounts that the copolymer content was 0.50% by mass and 0.25% by mass, respectively (40 times each). And an aqueous diluted solution (transparent liquid) obtained by stirring as an additive solution, and the addition ratio of the additive solution (dilute solution) to the total mass of the steelmaking raw material (according to this, A sample was obtained in the same manner as in Test Example 5.2 except that the addition ratio of the polymer flocculant (the above copolymer) was as shown in Table 5-1.

(Test Examples 5.8 to 5.10)
In Test Examples 5.8 to 5.10, an aqueous dispersion containing sodium acrylate / acrylamide copolymer as a polymer coagulant used in Test Example 5.2 (trade name “NS Dry-709L”) was used as an additive liquid. , Nippon Steel & Sumikin Environment Co., Ltd.) was used as a stock solution. Then, the additive liquid (stock solution) was added in an amount of 0.02% by mass with respect to the total mass of the ironmaking raw material. Therefore, the addition ratio of the polymer coagulant (the above copolymer) to the total mass of the ironmaking raw material was set to 0.004% by mass. In addition, the number of times of overturning and stirring after adding the additive liquid (stock solution) to the steelmaking raw material in the container was 5 times in Test Example 5.8, 50 times in Test Example 5.9, and 100 times in Test Example 5.10. And Except for these, a sample was obtained in the same manner as in Test Example 5.2.

(Test Examples 5.11 to 5.13)
In Test Examples 5.11 to 5.13, an aqueous dispersion containing sodium acrylate / acrylamide copolymer as a polymer coagulant (trade name “NS Dry-709L”, manufactured by Nippon Steel & Sumikin Environment Co., Ltd.) A white to light brown emulsion containing a sodium acrylate / acrylamide copolymer and ammonium sulfate as components) (diluted 100-fold) with water in such an amount that the content of the copolymer becomes 0.2% by mass. Then, an aqueous dilute solution (transparent liquid) obtained by stirring was used (see Test Example 4.4 above). This additive liquid (dilute liquid) was added in an amount of 2.0% by mass based on the total mass of the ironmaking raw material. Therefore, the addition ratio of the polymer coagulant (the above copolymer) to the total mass of the ironmaking raw material was set to 0.004% by mass. In addition, the number of times of overturning and stirring after adding the additive liquid (dilute liquid) to the steelmaking raw material in the container was 5 in Test Example 5.11, 25 in Test Example 5.12, and 50 in Test Example 5.13. Times. Except for these, a sample was obtained in the same manner as in Test Example 5.2.

(Test Examples 5.14 to 5.16)
In Test Examples 5.14 to 5.16, as in the case of Test Example 2.3, an anionic W / O emulsion containing sodium acrylate / acrylamide copolymer as a polymer coagulant (trade name: NS Dry-322L "(manufactured by Nippon Steel & Sumikin Environment Co., Ltd.). Then, the additive liquid (stock solution) was added in an amount of 0.02% by mass with respect to the total mass of the ironmaking raw material. Therefore, the addition ratio of the polymer coagulant (the copolymer) to the total mass of the ironmaking raw material was set to 0.008% by mass. In addition, the number of times of overturning and stirring after adding the additive liquid (stock solution) to the steelmaking raw material in the container was 5 times in Test Example 5.14, 50 times in Test Example 5.15, and 100 times in Test Example 5.16. And Except for these, a sample was obtained in the same manner as in Test Example 5.2.

(Test Examples 5.17 to 5.19)
In Test Examples 5.17 to 5.19, an anionic W / O emulsion containing a sodium acrylate-acrylamide copolymer as a polymer coagulant (trade name “NS Dry-322L”, Nippon Steel) A pale yellowish white to light brown emulsion containing a sodium acrylate / acrylamide copolymer and a hydrorefined light distillate (petroleum) as components). A diluted liquid (white emulsion) in the form of an oil-in-water (O / W) emulsion obtained by diluting with water in an amount of 0.2% by mass (diluted 200 times) and stirring was used (the above test). See Example 1.2). This additive liquid (dilute liquid) was added in an amount of 4.0% by mass based on the total mass of the ironmaking raw material. Therefore, the addition ratio as the above-mentioned copolymer with respect to the total mass of the ironmaking raw material was set to 0.008% by mass. Further, the number of times of overturning and stirring after adding the additive liquid (dilute liquid) to the iron making raw material in the container was 5 in Test Example 5.17, 25 in Test Example 5.18, and 50 in Test Example 5.19. Times. Except for these, a sample was obtained in the same manner as in Test Example 5.2.

  From the results of Test Examples 5.2 to 5.7, the polymer coagulant was added in an amount of 0.25 to 1.00% by mass based on the extremely fluid ironmaking raw material shown in the results of Test Example 5.1. It was confirmed that the addition of the dilute solution contained could sufficiently lower the fluidity of the iron making raw material and suppress the collapse of the iron making raw material (see FIG. 5A).

  In Test Examples 5.8 to 5.10, when a stock solution of an aqueous dispersion containing 20% by mass of a polymer flocculant was used, the number of stirring times between the solution and the ironmaking raw material was increased to 50 times and 100 times, and this was sufficient. , The fluidity of the steelmaking raw material could not be sufficiently reduced, and the collapse of the steelmaking raw material could not be effectively suppressed. From these results, it is considered that the above-mentioned stock solution was such that the polymer flocculant in the stock solution was hard to reach the whole iron-making raw material. On the other hand, in Test Examples 5.11 to 5.13, an iron-made raw material was added by adding an aqueous dilute solution containing 0.2% by mass of a polymer flocculant to a highly fluid iron-made raw material. It was confirmed that even when the number of times of stirring of the raw material and the dilute solution was small, the fluidity of the iron manufacturing raw material could be sufficiently reduced and the collapse of the iron manufacturing raw material could be suppressed (see FIG. 5B). From these results, it is considered that the diluted liquid was such that the polymer flocculant in the diluted liquid was easy to reach the entire iron-making raw material.

Further, in Test Examples 5.14 to 5.16, when a stock solution of a W / O emulsion containing 40% by mass of the polymer flocculant was used, the number of times of stirring the raw material and the ironmaking raw material was increased to 50 times and 100 times. However, even if they were mixed sufficiently, the fluidity of the steelmaking raw material could not be sufficiently reduced, and the collapse of the steelmaking raw material could not be effectively suppressed. From these results, it is considered that the above-mentioned stock solution was such that the polymer flocculant in the stock solution was hard to reach the whole iron-making raw material. On the other hand, in Test Examples 5.17 to 5.19, an O / W emulsion dilute liquid containing 0.2% by mass of a polymer coagulant was added to a highly fluid ironmaking raw material. Thus, it was confirmed that even when the number of times of stirring of the ironmaking raw material and the dilute solution was small, the fluidity of the ironmaking raw material could be sufficiently reduced and the collapse of the ironmaking raw material could be suppressed (see FIG. 5C). From these results, it is considered that the diluted liquid was such that the polymer flocculant in the diluted liquid was easy to reach the entire iron-making raw material.

Claims (7)

A method of stacking steelmaking raw materials in a raw material yard,
A dilute solution in which at least one of the steelmaking raw material before being piled up in the raw material yard and the ironmaking raw material after being piled up has a polymer coagulant content of 0.1 to 2% by mass as an active ingredient; A method for stacking raw materials for ironmaking, comprising the step of adding iron. Adding the dilute solution to the iron raw material before being piled up in the raw material yard;
Stacking the steelmaking raw material to which the dilute liquid has been added in the raw material yard,
The method according to claim 1, comprising:   3. The method according to claim 1, further comprising a step of adding the dilute liquid to the ironmaking raw material after being piled up in the raw material yard. 4.   4. The method according to claim 1, wherein the diluted liquid is an oil-in-water emulsion or an aqueous solution when added to the iron-making raw material. 5.   The dilute solution contains, as the polymer flocculant, at least one selected from the group consisting of sodium acrylate / acrylamide copolymer, acrylic acid or a salt thereof, and acrylamide polymer. 5. The method for pile-up of steelmaking raw materials according to any one of 4.   6. The method according to claim 1, wherein the dilute liquid is added to the ironmaking raw material in an amount of 0.0001 to 0.05% by mass based on the total mass of the ironmaking raw material as the polymer coagulant. 7. The method of stacking the raw materials for iron described. The amount of the dilute solution added to the ironmaking raw material is controlled to an amount such that the water content of the ironmaking raw material after the dilute liquid is added becomes 8 to 25% by mass. 5. The method of stacking raw materials for iron according to 4.