JP7168221B2 - foaming inhibitor - Google Patents

Description

The present invention relates to foaming inhibitors used in part of the steelmaking process.

In the above technical field, Patent Literature 1 discloses a technology related to a foaming-suppressing molded body composed of a fiber aggregate to which combustible fibers are bound and particles containing a metal hydroxide dispersed in the fiber aggregate. ing.

Japanese Patent No. 6281800

However, with the evolution of steelmaking technology, a more effective foaming inhibitor has been desired, and the technology described in the above document has not been sufficiently effective in suppressing foaming. An object of the present invention is to provide a technique for solving the above problems.

In order to achieve the above object, the foaming inhibitor of the present invention is a foaming inhibitor obtained by mixing a fibrous organic material containing synthetic fibers and a powdery inorganic material and molding the mixture by non-melt compression while leaving the fiber form. .

In order to achieve the above object, the foaming inhibitor of the present invention is obtained by mixing a fibrous organic material containing synthetic fibers and a powdery inorganic material and molding the mixture by non-melt compression at 100° C. or less while leaving the fiber shape . It is a foaming inhibitor.

It is the figure which showed the model structure of the foaming inhibitor of 1st Embodiment. It is the figure which showed the model structure of the foaming inhibitor of 2nd Embodiment. 1 is a block diagram showing the configuration of a tile carpet pulverization and classification system used in a method for producing a foaming inhibitor; FIG. FIG. 2 is a block diagram for explaining the detailed configuration of a manufacturing system for a foaming inhibitor; FIG. 3 is an electrophotograph showing the microstructure of the foaming inhibitor produced in Example 1. FIG.

Exemplary embodiments of the invention are described in detail below. However, the configuration, numerical values, steps, flow of processing, etc. described in the following embodiments are merely examples, and are not meant to limit the technical scope of the present invention only to those descriptions. A detailed description will be given below.

[First embodiment]
FIG. 1 is a diagram showing a model structure of a foaming inhibitor 100 of this embodiment. As shown in FIG. 1, the foaming inhibitor 100 is formed by mixing a fibrous organic material 102 containing synthetic fibers 101 and a powdery inorganic material 103, and molding the synthetic fibers 101 by non-melt compression while leaving the fibrous form of the synthetic fibers 101. ing. This foaming inhibitor 100 is put in to suppress the slag foaming phenomenon.

The synthetic fibers 101 form voids 104 between the plurality of synthetic fibers 101 by entangling the plurality of synthetic fibers 101 with each other. That is, the foaming inhibitor 100 is a porous body having voids 104 formed between the synthetic fibers 101 .

Furthermore, particles of the powdery inorganic material 103 are physically adsorbed on the surface of the synthetic fiber 101 . That is, the foaming inhibitor 100 comprises a powdery inorganic material 103 dispersed in a fibrous organic material 102 containing synthetic fibers 101 .

The foaming inhibitor 100 is formed by mixing a fibrous organic material 102 containing synthetic fibers 101 and a powdery inorganic material 103 and molding the mixture by non-melt compression. Therefore, the foaming inhibitor 100 maintains the fibrous form of the synthetic fibers 101 without melting the fibrous organic material 102 containing the synthetic fibers 101 .

Since the foaming inhibitor 100 is a porous body having voids 104 formed between the synthetic fibers 101, it has a predetermined porosity and specific surface area. The porosity of the foaming inhibitor 100 is preferably 20 to 70% as measured by the open porosity measuring method specified in JIS K 2249, for example.

If the foaming inhibitor 100 has a porosity of 20% or more, slag enters the foaming inhibitor 100 from the voids 104 of the foaming inhibitor 100, and thermal decomposition and combustion reactions proceed, which is preferable. On the other hand, if the foaming inhibitor 100 has a porosity of 70% or less, it is preferable because the foaming inhibitor 100 has sufficient strength necessary for handling so that the foaming inhibitor 100 is not easily crushed during storage or transportation.

The content of the powdery inorganic substance 103 is preferably 30 to 90% by weight, more preferably 50 to 70% by weight, based on the total weight of the foaming inhibitor 100. If the content of the powdery inorganic material 103 is 90% by weight or less with respect to the total weight of the foaming inhibitor 100, the specific gravity of the foaming inhibitor 100 can be adjusted to 1.5 to 2.5, and the occurrence of It is preferable because it can pierce the slag that is forming. On the other hand, if the content of the powdery inorganic material 103 is 30% by weight or more with respect to the total weight of the foaming inhibitor 100, black smoke generated by combustion decomposition of the fibrous organic material can be suppressed, which is preferable. .

Since the foaming inhibitor 100 contains the powdery inorganic substance 103, it has a specific gravity of 1.5 to 2.5. Therefore, when the foaming inhibitor 100 is added to the slag, it does not float on the surface of the slag, but quickly starts to settle. The foaming inhibitor 100 that has started settling separates into a fibrous organic material 102 and a powdery inorganic material 103 at a certain depth in the slag. The separated fibrous organic material 102 is combusted within the slag.

On the other hand, the separated synthetic fibers 101 and the powdery inorganic substance 103 adhering to the synthetic fibers 101 suppress the generation of air bubbles in the slag due to carbon monoxide. When the synthetic fibers 101 are thrown into a converter or a slag pot, they are explosively gasified by combustion and decomposition, and the adhering powdery inorganic substances 103 diffuse widely in the slag. Thereby, the foaming suppressing agent 100 exhibits an excellent foaming suppressing effect.

The form of the foaming inhibitor 100 is not particularly limited, but may be, for example, a columnar pellet, a polygonal cylinder, or a polygonal body having a through hole in the axial direction.

As described above, according to the foaming inhibitor of the present embodiment, the antifoaming component diffuses over a wide range, and slag overflow can be sufficiently suppressed.

[Second embodiment]
Compared to the above embodiment, the foaming inhibitor according to the present embodiment uses industrial waste as a raw material as a fibrous organic material containing synthetic fibers, and uses an anhydride such as a metal oxide or a metal carbonate as a powdery inorganic material. It is different in that it uses Since other configurations and processes are the same as those of the above-described embodiment, detailed description thereof will be omitted.

FIG. 2 is a diagram showing a model structure of the foaming inhibitor 200 of this embodiment. The foaming inhibitor 200 of this embodiment is formed by mixing a fibrous organic material 202 containing a synthetic fiber 201 derived from a tile carpet with a powdered inorganic anhydride 203 and molding the mixture by non-melt compression while leaving the fiber form. The foaming inhibitor 200 of this embodiment will be described below.

<Raw material for fibrous organic material>
The fibrous organic material 202 contained in the foaming inhibitor 200 is not particularly limited as long as it is an organic material containing the synthetic fiber 201. For example, interior products, clothing products, medical hygiene products, and automobiles products for civil engineering or pulverized waste materials for civil engineering and construction products.

Examples of interior products include, but are not limited to, tile carpets, roll carpets, rugs, and curtains.

Clothing products are not particularly limited, but examples include clothing products made from materials such as elastomer, nylon, polyester, rayon, lyocell, spandex, and acrylic fibers.

Examples of medical sanitary products include, but are not limited to, gauze, absorbent cotton, bandages, absorbable sutures, non-absorbable sutures, medical coverings (drapes), medical gowns (surgical gowns/ isolation gowns/patient clothes), non-woven fabric products, medical sheets, plaster casts, medical splints, medical supporters, wet tissues, adult disposable diapers, incontinence-related cloth products, sterilized packaging materials, and the like.

Examples of automotive products include, but are not limited to, floor mats, seat upholstery fabrics, seat vinyl leather, seat covers, seat sponges, airbags, and the like.

Products for civil engineering and construction are not particularly limited, but examples thereof include slope protection sheets, building heat insulating materials, building wallpaper, FRP nonwoven fabrics, air conditioning filters, and liquid filters.

<Synthetic fiber>
The synthetic fiber 201 is not particularly limited as long as it can adsorb the powdered inorganic anhydride 203 and can be completely burned. For example, fibers manufactured from the following synthetic resins can be mentioned.

Resins from which the synthetic fibers 201 can be manufactured include acrylic resins, nylon resins, polyester resins, polyethylene resins, polypropylene resins, polyurethane resins, polyester resins, polyester urethane resins, alkyd resins, butyral resins, acetal resins, polyamide resins, and styrene resins. - acrylic resin, styrene resin, nitrocellulose, benzyl cellulose, cellulose (tri)acetate, casein, shellac, gilsonite, gelatin, styrene-maleic anhydride resin, polybutadiene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinylidene fluoride Resin, polyvinyl acetate resin, ethylene vinyl acetate resin, vinyl chloride/vinyl acetate copolymer resin, vinyl chloride/vinyl acetate/maleic acid copolymer resin, fluorine resin, silicon resin, epoxy resin, phenoxy resin, phenol resin, Maleic acid resin, urea resin, melamine resin, benzoguanamine resin, ketone resin, petroleum resin, rosin, rosin ester, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, hydroxyethylmethylcellulose, hydroxypropyl Examples include methylcellulose, carboxymethylcellulose, carboxymethylethylcellulose, carboxymethylnitrocellulose, ethylene/vinyl alcohol resins, and the like.

The fiber length of the synthetic fiber 201 is preferably 0.5 mm or more and 2.5 mm or less. When the fiber length of the synthetic fiber 201 is 0.5 mm or more, the fibers are entangled with each other, which is preferable for maintaining the strength of the molded article. On the other hand, if the fiber length of the synthetic fiber 201 is 2.5 mm or less, the synthetic fiber 201 can easily diffuse, which is preferable.

The fiber form of the synthetic fiber 201 is not particularly limited as long as it has a form capable of adsorbing the powdered inorganic anhydride. For example, it may be linear or bent. Moreover, the synthetic fiber 201 may be twisted in the fiber length direction. The cross-sectional shape of the synthetic fiber 201 may be circular, elliptical, triangular, quadrangular, or other polygonal shapes.

<Powder inorganic anhydride>
The powdery inorganic anhydride 203 is not particularly limited as long as it can react with the slag and make the specific gravity of the foaming inhibitor 200 1.5 to 2.5. Since the specific gravity of the fibrous organic material 202 containing the synthetic fibers 201 is less than 1.5, the specific gravity of the powdery inorganic anhydride 203 is preferably 2.0-8.0. If the specific gravity of the powdery inorganic anhydride 203 is 2.0 or more, the specific gravity of the foaming inhibitor 200 can be adjusted to 1.5 or more, which is preferable. If the specific gravity of the powdery inorganic anhydride 203 is 8.0 or less, the specific gravity of the foaming inhibitor 200 can be made 2.5 or less, which is preferable.

Molecules constituting the powdery inorganic anhydride 203 do not contain hydroxyl groups in the molecules and do not contain water of crystallization. does not generate

Thus, since the foaming inhibitor 200 of the present embodiment does not generate water, the temperature inside the slag does not decrease, and the efficiency of the foaming suppressing effect does not decrease.

The particle size of the powdery inorganic anhydride 203 is preferably 10 μm or more and 500 μm or less. If the particle size of the powdery inorganic anhydride is 10 μm or more, the particles of the powdery inorganic anhydride do not adhere to each other, which is preferable. On the other hand, if the particle size of the powdery inorganic anhydride is 500 μm or less, the surface area of the powdery inorganic anhydride that reacts with the slag increases, which is preferable because the reactivity improves. Further, if the particle size of the powdery inorganic anhydride 203 is 10 μm or more, the powdery inorganic anhydride 203 is easily dispersed in the gaps between the synthetic fibers 201, which is preferable. On the other hand, if the particle size of the powdery inorganic anhydride 203 is 500 μm or less, the reactivity between the slag and the powdery inorganic anhydride 203 is improved, which is preferable.

The powdery inorganic anhydride 203 is a metal oxide or metal carbonate. Examples of metal oxides include, but are not limited to, aluminum oxide, calcium oxide, magnesium oxide, crystalline silica, amorphous silica, germanium oxide, tin oxide, lead oxide, gallium oxide, indium oxide, Titanium oxide, zirconium oxide, hafnium oxide, iron oxide, sodium oxide, potassium oxide and the like can be mentioned. In addition, if the powdery inorganic anhydride 203 is mainly composed of metal oxides or metal carbonates, metal nitrides such as aluminum nitride, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, It may also include metal carbides such as silicon carbide, metal silicate salts such as calcium silicate, hydrated metal compounds, and combinations thereof.

The metal carbonate is not particularly limited, but examples include ammonium carbonate, potassium carbonate, calcium carbonate, aluminum carbonate, sodium carbonate, barium carbonate, magnesium carbonate, lithium carbonate, copper carbonate, iron carbonate, silver carbonate, Calcium carbonate, magnesium carbonate and the like can be mentioned. These metal carbonates release carbon dioxide and become metal oxides in the hot metal in the converter. Metal oxides are preferable because they have the function of reducing the basicity of slag and improving the fluidity of slag.

Among these gold oxides and metal carbonates, the powdery inorganic anhydride 203 is preferably calcium carbonate, aluminum oxide, silica or a mixture thereof from the viewpoint of reactivity with hot metal and cost.

<Non-melt compression>
The foaming inhibitor 200 is manufactured by kneading a fibrous organic material 202 containing synthetic fibers 201, a powdery inorganic anhydride 203, and water, followed by non-melt compression. Non-melt compression is performed at a temperature at which the fibrous organic material 202 does not melt. The temperature at which the non-melt compression is performed is preferably 50-100°C. The pressure for non-melt compression can be set so that the water content in the mixture of the fibrous organic material 202 containing the synthetic fiber 201, the powdery inorganic anhydride 203, and water is 1.0 to 3.0% by weight. It should be set within a possible range.

Non-melt compression is not particularly limited as long as it is a method capable of compressing and molding a mixture of fibrous organic material 202 containing synthetic fiber 201, powdery inorganic anhydride 203, and water. , for example, extrusion molding, pressure molding, and the like. The non-melt compression method can be appropriately adopted according to the materials of the fibrous organic material 202 including the synthetic fiber 201, the powdery inorganic anhydride 203, and the form of the foaming inhibitor 200 as a product. For example, extrusion molding is molding performed by applying pressure to a raw material and extruding it from a die (die). Since the extrusion molding can make the cross-sectional area of the foaming inhibitor 200 constant, it is suitable for manufacturing the foaming inhibitor 200 in the shape of a rod or a pipe. In addition, in extrusion molding, it is necessary to keep the raw material extrusion speed constant so that the foaming inhibitor 200 does not bend or break during extrusion molding. In order to improve the productivity of the foaming inhibitor by non-melt compression, it is necessary to increase the extrusion speed.

Thus, the foaming inhibitor of the present embodiment is formed by mixing the fibrous organic material including synthetic fibers and the powdery inorganic anhydride, and molding the mixture by non-melt compression. Therefore, the foaming inhibitor of the present embodiment is molded while leaving the fiber form of the fibrous organic material including synthetic fibers as it is. Therefore, in the foaming inhibitor of the present embodiment, the antifoaming component diffuses over a wide range, so that the generation of air bubbles can be suppressed and the overflow of slag can be effectively suppressed.

[Third Embodiment]
Compared to the above embodiment, the foaming inhibitor according to the present embodiment uses a fibrous organic material derived from a tile carpet as the fibrous organic material and calcium carbonate as the powdery inorganic anhydride in combination. different in Since other configurations are the same as those of the above embodiment, detailed description thereof will be omitted.

<Raw material for fibrous organic material>
The foaming inhibitor of the present embodiment uses tile carpet waste as a raw material for the fibrous organic material. In urban areas where office buildings are lined up, large quantities of tile carpets are consumed, and the used tile carpets are discarded as waste materials. Since the foaming inhibitor of the present embodiment is made by reusing waste tile carpets, it is of great technical significance from the viewpoint of effective utilization of resources.

<Synthetic fiber>
The foaming inhibitor of the present embodiment is made from tile carpet waste as a raw material. The pile portion of the tile carpet is synthetic fiber. Synthetic fibers are not particularly limited as long as they are synthetic fibers made from petroleum-based synthetic resins, but include acrylic, nylon, polyester, polyethylene, polyethylene terephthalate (PET), and polypropylene. can be done.

<Calcium carbonate>
Calcium carbonate contained in the foaming inhibitor of the present embodiment is an inorganic material with high versatility, is easy to handle, and is inexpensive, so it can be most preferably used. Calcium carbonate may be heavy calcium carbonate obtained by pulverizing and classifying limestone, or light calcium carbonate obtained by depositing fine crystals in a liquid through a chemical reaction.

The particle size of calcium carbonate is preferably 10 μm or more and 200 μm or less. If the particle size of calcium carbonate is 10 μm or more, the particles of calcium carbonate do not adhere to each other, which is preferable. On the other hand, if the particle size of calcium carbonate is 200 μm or less, the surface area of calcium carbonate that reacts with the slag increases and the reactivity improves, which is preferable.

Calcium carbonate contained in the foaming inhibitor of the present embodiment is thermally decomposed into calcium oxide and carbon dioxide in the slag. Carbon dioxide generated from calcium carbonate destroys bubbles generated in the slag. Furthermore, the thermal decomposition of calcium carbonate is an endothermic reaction. Therefore, calcium carbonate exerts a foaming suppressing effect by taking away the heat generated in the slag.

[Fourth Embodiment]
This embodiment is a method for producing the foaming inhibitor of the first to third embodiments. The foaming inhibitor is molded by mixing the fibrous organic material and the powdery inorganic anhydride, followed by non-melt compression. Hereinafter, the method for producing the foaming inhibitor of the present embodiment will be described separately for the step of producing a fibrous organic material and the step of mixing the fibrous organic material and the powdery inorganic anhydride and then performing non-melt compression. do.

<Step of producing fibrous organic material>
FIG. 3 is a block diagram showing the configuration of a tile carpet pulverization and classification system 300 used in the method for producing a foaming inhibitor of the present embodiment. The fibrous organic material containing synthetic fibers contained in the foaming inhibitors of the first to third embodiments is produced, for example, by pulverizing waste materials of tile carpets, which are interior products.

As shown in FIG. 3, the tile carpet pulverization and classification system 300 used in the method for producing the foaming inhibitor of the present embodiment pulverizes and classifies the tile carpet to produce fibrous fibers containing synthetic fibers contained in the foaming inhibitor. A system for manufacturing organic materials.

As shown in FIG. 3 , a tile carpet pulverization and classification system 300 includes a coarse pulverizer 301 , a fine pulverizer 302 and a classifier 303 .

The coarse pulverizer 301 crushes the tile carpet 350 including the synthetic fiber portion 351 covering the front surface and the resin plate-like portion 352 supporting the synthetic fiber portion 351 on the back surface into the tile carpet pieces 311 of the first size. Smash.

The fine pulverizer 302 pulverizes the first size tile carpet pieces 311 pulverized by the coarse pulverizer 301 into powder 321 of a second size smaller than the first size.

The classifier 303 places the powder 321 of the second size on the mesh member 331 and applies vibration to separate the powder 332 derived from the synthetic fiber part and the powder 333 derived from the plate-shaped part. The classifier 303 sucks powder 332 derived from the synthetic fiber part. In this way, the powder 332 derived from the synthetic fiber portion obtained by the classifier 303 can be used as a fibrous organic material containing synthetic fibers. In addition, in the method for producing a foaming inhibitor of the present embodiment, a tile carpet pulverization and classification system equipped with one classifier is adopted. A tile carpet pulverization and classification system may be employed.

Thus, the tile carpet pulverization and classification system 300 used in the method for producing a foaming inhibitor of the present embodiment efficiently and highly accurately produces a fibrous organic material containing synthetic fibers contained in the foaming inhibitor. be able to. The manufactured powder 342 derived from the synthetic fiber portion is transferred to the fiber storage tank 401 with a screw feeder of the foaming inhibitor manufacturing system 400 .

<Process of non-melting compression>
FIG. 4 is a block diagram for explaining the detailed configuration of the foaming inhibitor manufacturing system 400. As shown in FIG. The fiber storage tank 401 stores fibrous organic materials including synthetic fibers transferred from the tile carpet crushing and classifying system. The inorganic storage tank 402 stores powdered inorganic anhydride.

A fibrous organic material stored in a fiber storage tank 401 with a screw feeder is fed into a mixing mixer 405 with a weighing machine by a bucket-type transfer conveyor 403 . The powdery inorganic anhydride stored in the inorganic material storage tank 402 equipped with a screw feeder is fed into a mixing mixer 405 equipped with a weighing machine by a bucket-type transfer conveyor 404 . The weighing mixer 405 measures the weight of the fed fibrous organic material by the bucket-type transfer conveyor 403 . The weighing mixer 405 measures the weight of the powdered inorganic anhydride fed by the bucket-type conveyer 404 .

In this manner, the mixing mixer 405 with a weighing machine adjusts the weight ratio of the fibrous organic material including the synthetic fiber constituting the foaming inhibitor and the powdery inorganic anhydride. A pre-melt-compressed mixture is produced by a weighing mixing mixer 405 . The produced mixture is stored in a mixture storage tank 406 with a screw feeder.

The mixture stored in mixture storage tank 406 is divided into approximately two halves. The halved mixture is conveyed to granulator 408 by bucket conveyor 407 . Another halved mixture is conveyed to granulator 410 by bucket conveyor 409 .

The granulator 408 granulates the mixture of the fibrous organic material containing synthetic fibers conveyed from the bucket-type conveyer 407 and the powdered inorganic anhydride to produce a granular foaming inhibitor. Granulation may be carried out by adding water to a mixture of a fibrous organic material containing synthetic fibers and a powdery inorganic anhydride. Addition of water to the mixture facilitates granulation, which is preferable. When water is added to the mixture, the proportion of water is preferably 5 to 20% with respect to the total weight of the mixture and water.

The temperature at which the mixture of the fibrous organic material including synthetic fibers and the powdery inorganic anhydride is non-melt-compressed is preferably 100° C. or less. A temperature of 100° C. or less during non-melt compression is preferable because the fibrous organic material including synthetic fibers does not melt.

The granulator 410 performs non-melt compression, similar to the granulator 408, to produce the foaming inhibitor in granular form. The foaming inhibitor having a predetermined size and shape produced by the granulators 408 and 410 is transported by the belt-type product transport conveyor and sieved by the sieve 412 . The form of the foaming inhibitor is homogenized by the sieving machine 412 and shipped as a product.

Although the form of the foaming inhibitor produced in this way is not particularly limited, it may be in the form of pellets with a diameter of 5 to 20 mm, for example. If the foaming inhibitor is in the form of pellets, it is preferable because it is excellent in handleability, easy to pack into a bag, and excellent in handleability during use.

As described above, according to the present embodiment, the foaming inhibitor can be produced more efficiently and with high accuracy.

[Other embodiments]
Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. Compositions in any combination of separate features included in each embodiment are also included in the scope of the present invention.

<Example>
Examples of the present invention will be described below. However, the present invention is not limited to this example. The following foaming inhibitors of Examples 1-5 and Comparative Examples 1-2 were produced, and the foaming inhibitory effects of the foaming inhibitors were evaluated by observing the degree of swelling of the slag during dephosphorization and refining in the refining process.

<Production of foaming inhibitor>
(Example 1)
A discarded tile carpet was used as a raw material for the fibrous organic material. After coarsely pulverizing the tile carpet waste material (collected by Refineverse Co., Ltd.), it was finely pulverized to produce a fibrous organic material. Calcium carbonate was used as the powdery inorganic anhydride. 100 kg of fibrous organic material, 100 kg of powdery inorganic anhydride calcium carbonate, and 20 kg of water were mixed using a mixing mixer with a weighing machine, and then sufficiently stirred. A sufficiently stirred mixture of the fibrous organic material and calcium carbonate was extruded by non-melt compression through a die with a diameter of 10 mm (mm) using a granulator to obtain the foaming inhibitor of Example 1.

An electron microscope was used to confirm whether the foaming inhibitor produced in Example 1 contained fiber morphology. The cross-sectional structure of the foaming inhibitor produced in Example 1 is shown in FIG. 5 is an electrophotograph showing the microstructure of the foaming inhibitor produced in Example 1. FIG.

(Examples 2-5)
A foaming inhibitor was produced in the same manner as in Example 1, except that the raw material of the fibrous organic material, the powdery inorganic anhydride, and the extrusion molding conditions were changed.

(Comparative Examples 1 and 2)
A foaming inhibitor of Comparative Example 1 was produced by extruding by non-melt compression using only the fibrous organic material. Further, a foaming inhibitor of Comparative Example 2 was produced by extruding only the powdery inorganic anhydride by non-melt compression. Table 1 shows the composition of the foaming inhibitors produced in Examples 1 to 5 and Comparative Examples 1 and 2, the diameter of the die used in producing the foaming inhibitors, and the presence or absence of fiber morphology.

(Evaluation of foaming inhibitor)
The foaming inhibitors produced in Examples 1-5 and Comparative Examples 1-2 were evaluated. The foaming inhibitor was evaluated by measuring the degree of foaming during dephosphorization refining in the refining process.

Specifically, the foaming inhibitor was evaluated by the following procedures. The foaming inhibitors produced in Examples 1 to 5 and Comparative Examples 1 to 2 were added to the hot metal in the converter from the top of the converter into the converter at a rate of about 15 to 20 kg/ton (foaming inhibitor/hot metal). I put it in.

About 60 seconds after the foaming inhibitor was introduced into the converter, the degree of swelling of the slag in the converter was visually evaluated. The composition of the hot metal in the converter is C: 4.5% or more, Si: 0.35 to 0.4%, P: 0.11 to 0.13%. there were.

The degree of expansion of the overflowing slag by visual observation was evaluated as follows.

"High slag swelling": When a large amount of slag swells from the top of the converter and the operation of the refining process has to be interrupted. "Medium slag swelling": Slag swells from the top of the converter. "No swelling of slag": When no swelling of slag is observed from the top of the converter, the slag The foaming suppressing effect of the foaming agent was evaluated based on the degree of swelling. Table 2 shows the results. In addition, the evaluation criteria of the foaming suppression effect are as follows.

◎: Excellent foaming suppression effect (no slag swelling)
○: Effective in suppressing foaming (during swelling of slag)
×: Insufficient foaming suppression effect (large swelling of slag)

As is clear from FIG. 5, it was found that the foaming inhibitor produced in Example 1 was molded while maintaining the fiber form as it was. Further, as is clear from the comparison between Examples 1 to 5 and Comparative Examples 1 and 2, a fibrous organic material containing synthetic fibers and a powdery inorganic anhydride are mixed and the fiber form is formed by non-melt compression. By molding while leaving the slag, it is possible to provide a foaming inhibitor capable of suppressing the amount of slag overflowing.

Claims (5)

A foaming inhibitor obtained by mixing a fibrous organic material containing synthetic fibers and a powdery inorganic material and molding the mixture by non-melt compression at a temperature of 100° C. or less while leaving the fibrous form. 2. The foaming inhibitor according to claim 1, wherein the synthetic fiber contains at least one of acrylic, nylon, polyester, polyethylene, polyethylene terephthalate and polypropylene. 2. The foaming inhibitor according to claim 1, wherein the fibrous organic material is a pulverized interior product, clothing product, medical hygiene product, automobile product, or civil engineering and construction product. The foaming inhibitor according to any one of claims 1 to 3, wherein the powdery inorganic substance is at least one of metal oxide and metal carbonate. 5. The foaming inhibitor according to claim 4, wherein said powdery inorganic substance is at least one substance selected from calcium carbonate, aluminum oxide and silica.

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