KR100895867B1 - Method for preparing of porous sintered bodies - Google Patents

Abstract

A method for manufacturing porous sintered-composite is provided as a material for toxic gas absorbents, carriers and fillers for a filter due to high surface strength and appearance better than activated charcoal. A method for manufacturing porous sintered-composite comprises the following steps of: mixing 20-90wt% of clay mineral having a sheet-like structure and 10-80wt% of carbon materials to prepare a mixture; adding water and binder compositions to the mixture to prepare composite; and molding and drying composite and sintering the composite at a low temperature to oxidize surface of the composite. The binder compositions contains 0.01-30wt% of sodium compound, 0.001-20wt% of vanadium, 0.1-89wt% of water, 0.1-20wt% of organic acid, 10-50wt% of ammonia or caustic soda and 0.1-70wt% of nano colloidal silica.

Description

Method for preparing porous composite sintered body {Method for preparing of porous sintered bodies}

The present invention relates to a method for producing a porous composite sintered body, and in particular, a clay mineral and a carbon material of the plate-like structure is mixed, the binder composition and water is mixed and kneaded, and then the dough is molded, dried and calcined. It relates to a method for producing a porous composite sintered body.

Clay minerals have a lower surface area during drying and firing during firing alone, and have a lower surface physicochemical adsorption compared to activated carbon. On the other hand, activated carbon has a well-developed surface area, which has been used in various applications as an adsorbent, but has a disadvantage in that it is difficult to form and calcinate in a specific form and is only involved in physical adsorption in the adsorption action. In addition, certain chemicals tend to have poor adsorption properties.
Currently, the illite series sintered body is not commercialized as an adsorbent, and many adsorbents that have been tried also exhibit very small surface area and adsorption performance in surface area, which is a measure of activity.
Activated carbon is a standardized product, which has granular activated carbon and compressed activated carbon, but shows a simple appearance according to the shape of chips or compression molding. In addition, carbon is deposited on the surface and dust is generated, and it is used in an isolation frame to avoid direct contact with the human body.
As a conventional technique for improving the disadvantages, a composite material is used for activated carbon and various organic and inorganic materials. Looking at the prior art, Korean Patent Laid-Open Publication No. 1998-066406 discloses a filter in which an activated carbon and an artificial enzyme catalyst are applied and impregnated on a polyurethane foam, and Korean Patent Laid-Open Publication No. 1999-0068341 and Korean Patent Publication No. 2003-00552257 No. discloses a method of utilizing activated carbon and activated carbon fibers alone. In addition, Korean Laid-Open Patent Publication No. 2000-0075343 discloses a method for producing activated carbon by sintering a mixture of a thermosetting resin powder such as a phenol resin and a precursor powder of a metal such as copper, silver, and cadmium to activate carbonization and water vapor. .

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In order to solve the problems of the prior art as described above, the present invention can be molded and fired in various forms without deterioration of the surface area, has a high surface area, excellent physical and chemical adsorption performance, and can impart additional adhesive materials. An object of the present invention is to provide a method for producing a porous composite sintered body.

In addition, the present invention can be utilized as a variety of harmful gas adsorbent material or carrier, and the appearance is beautiful unlike activated carbon, the object is to provide a method for producing a porous composite sintered body that can be used as a variety of filter fillers with good surface strength. It is done.
In addition, it is an object of the present invention to provide a method for preserving the activity of clay minerals and activated carbon by firing in the low-temperature firing region 200 ~ 500 ℃.

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In order to achieve the above object, the present invention

a) mixing the clay mineral and carbon material of the plate-like structure;

b) mixing and kneading the binder composition and water in the mixture; And

c) molding and drying the dough to oxidize the surface by low temperature baking at a temperature of 200 to 500 ° C;

It provides a method for producing a porous composite sintered body comprising a.

The clay mineral of the plate-like structure of step a) is preferably 20 to 90% by weight, the carbon material is mixed in 10 to 80% by weight.
The binder composition of step b) preferably comprises sodium compound, vanadium compound, water, organic acid, ammonia or caustic soda and nano colloidal silica.

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In addition, in step b), the surface activated carbon oxidation promoter may be further mixed.

Firing of step c) is preferably carried out for 1 to 5 minutes at 200 to 500 ℃ low temperature baking zone.

In another aspect, the present invention provides a porous composite sintered body, characterized in that composed of a clay mineral shell layer and a composite layer of clay mineral and carbon material from the outside.

The porous composite sintered body of the present invention can be molded and fired in various forms without deteriorating the surface area, has a high surface area, has excellent physicochemical adsorption performance, and can give an additional adhesive material. Also, it can be used as various kinds of harmful gas adsorbent materials or carriers, and its appearance is beautiful unlike activated carbon, and its surface strength is good, so it can be used as a variety of filter fillers. Adsorption to harmful gas substances that cannot be removed or adsorbed is possible.

Hereinafter, the present invention will be described in detail.

The porous composite sintered body of the present invention comprises the steps of mixing the clay mineral and carbon material of the plate-like structure, kneading by mixing the binder composition and water in the mixture and forming the dough, drying and low temperature at a temperature of 200 ~ 500 ℃ By sintering and oxidizing the surface, the adsorbability and reactivity of the existing clay minerals can be preserved and the carbon material can be added to impart the adsorption and porosity of the carbon material itself.
In the porous composite sintered body of the present invention prepared by the above steps, only the carbon material in the mixture of clay mineral and carbon material is oxidized on the surface of the fired body by oxidizing only the surface of the fired body, Blocking to form a thin clay mineral porous surface layer, the interior has a shape that is maintained / revolved clay mineral and carbon material.

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The clay mineral of the plate-like structure may be used, such as illite, sericite, mormoriolite, bontonite, biotite and the like. The content is preferably included in 20 to 90% by weight relative to the sum of the clay mineral and the carbon material content of the plate-like structure, it is more preferable in the adsorbent and reactivity preservation of clay minerals within the content range.

The carbon material may be a powdered activated carbon, granular activated carbon, lignite, a combustion material having a cenosphere structure, and the like, and the average particle diameter is preferably 5 mm or less. The content of the carbon material is preferably contained in 10 to 80% by weight based on the sum of the content of the clay mineral and the carbon material of the plate-like structure, and in the content range it is better in the adsorption and porosity of the carbon material itself.

In addition, the binder composition mixed with the clay mineral and the carbon material of the plate-like structure is 0.01 to 30% by weight sodium compound, 0.001 to 20% by weight vanadium compound, 0.1 to 89% by weight water, 0.1 to 20% by weight organic acid, ammonia or caustic soda 10 to 50% by weight and nano-colloidal silica 0.1 to 70% by weight.
The sodium compound is sodium nitrate (NaNO ₃ ); Sodium nitrite (NaNO ₂ ); Sodium sulfate (Na ₂ SO ₄ ); Sodium oxide such as Na ₂ O and Na ₂ O ₂ ; Organic acid salts such as sodium gluconate, sodium citrate and sodium oxalate; Sodium chloride; Sodium carbonate; Sodium bicarbonate or the like can be used. As the vanadium compound, V ₂ O ₅ , V ₂ O ₄ , V ₂ O ₃ , V ₂ O ₂ , ammonium vanadate, seadium chloride, or the like may be used. The organic acid may be citric acid, oxalic acid, gluconic acid and the like. The nano colloidal silica preferably has an average particle diameter of 5 to 25 nm, a solid content of 30 to 50% by weight, and a surface area of 100 to 350 m 2 / g. In addition, the binder composition may be further used boron compounds such as boric acid (Boric acid), ammonium borate, sodium borate compounds.
The binder composition is preferably included so that the total of the alkali metal salt and the transition metal salt is 5 ppm.
In addition, the mixture of the binder composition and water may further include a surface activated carbon oxidation promoter to promote oxidation of the surface activated carbon.
The surface activated carbon oxidation promoter may be a transition metal, an alkali metal, an alkaline earth metal, a rare metal, an organic-inorganic compound thereof, or the like, and the content thereof may be included so that the sum of the concentrations of the oxidation promoter is 5 ppm or more.
The mixed mixture as described above is kneaded and molded using a molding mold to undergo a drying process or to fire an undried molding. The firing is carried out for a certain time under a certain temperature condition in a specific oxidizing atmosphere, in particular in a non-combustible gas atmosphere containing nitrogen to prevent the propagation of the flame, the firing process is stopped at the same time as the surface combustion starts.
The firing may be performed at 200 to 500 ° C. for 1 to 5 minutes depending on the content and composition of the binder, and particularly, the firing process may be performed at a low temperature of about 250 to 500 ° C. At this time, the fired body is burned only by the carbon material by the strong catalytic oxidation on the surface, and the clay mineral forms a strong shell by the remaining binder.
In order to promote the precipitation of the clay mineral layer from the calcined body as described above, the combustion catalyst aqueous solution may be additionally sprayed or immersed and refired, and recuring treatment may be performed by raising the firing temperature. In addition, the surface area of the fired body can be controlled by the pore-forming properties of the binder used and the type and amount of the carbon material filled.
1 is a view showing a method for manufacturing a porous composite sintered body according to the present invention.
As shown in FIG. 1, the unburned composite layer of clay mineral (porous illite) and carbon material (porous activated carbon) immediately before molding is surface-oxidized by low temperature baking to activate activated carbon and oxidize the precipitate. . Subsequently, when the firing is stopped and cooled, oxidation stops and pores are formed on the surface due to oxidation of activated carbon, and an activated carbon / illite unburned composite layer is formed therein. You get
The porous composite sintered body of the present invention prepared as described above is composed of a light yellow clay mineral shell layer on the surface and a composite layer of clay mineral and carbon material therein, and has overall porosity.
It is preferable that the clay mineral and carbon material of the said plate-shaped structure have a weight ratio of 0.1-4.
The clay mineral shell layer preferably has a thickness of 1 to 2 mm, and the composite layer of clay mineral and carbon material therein exhibits a solid unburned black color.
It is preferable that the compressive strength of the porous composite sintered body in which the firing is completed is 10 to 50 N (1 to 5 Kgf).
The porous composite sintered body as described above may be fired in various forms, and thus may be used as a filter material, an adsorption material, a carrier, a support for chemical substance adhesion, and the like. Specifically, it can be used as various air purifier filter material, automotive filter material, home appliance filter material, air conditioner filter material, gas mask material, air purifier material, clean room material and the like. In addition, it can be molded and fired into desired objects and shapes as interior materials, and can be utilized as building materials and functional interior materials.
Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

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EXAMPLE

Example  One

6 g of sodium nitrate (Na ₂ NO ₃ ) was mixed with 5 g of vanadium pentoxide (V ₂ O ₅ ), and 360 g of distilled water was added thereto. 160 g of nitric acid (68% liquid) was added thereto, followed by heating. At this time, 96 g of hydrogen peroxide (35% liquid) was added as a melting accelerator to completely dissolve the hydrogen peroxide. The hydrogen peroxide was evaporated by heating. Then, 25 g of citric acid was added to the reaction, dissolved and cooled, and then neutralized by adding 360 g of caustic soda (25% liquid). Boric acid was added thereto and the pH was terminated. A binder aqueous solution was prepared by adding a nano colloidal silica (solid content 30%) solution to 30% of the total weight to the reaction.

Then 75 g of illite polarized to 325 mesh and 25 g of activated carbon were mixed in a homogeneous mixer. The binder solution prepared above was added thereto, followed by injection molding, and dried at room temperature for 2 hours. The dried molded body was calcined for 3 minutes in the air at a temperature of 350 ℃ in the kiln, and cooled at room temperature.
Before and after the firing of the prepared porous composite sintered body, the cross-sectional photograph after the firing is shown in Figures 2 to 4. 2 is a picture before firing, the surface is black, but after firing, Figure 3 shows that activated carbon is oxidized to light yellow. In addition, the light yellow shell layer and the black elite and activated carbon composite layer structure were confirmed from FIG.

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Example  2

75 g of illite polarized to 325 mesh and 25 g of activated carbon were mixed in a homogeneous mixer. The binder aqueous solution prepared in Example 1 was added thereto, followed by injection molding, and dried at room temperature for 2 hours. The dried molded body was calcined for 3 minutes in an incombustible gas atmosphere containing nitrogen at a temperature of 350 ℃ in a kiln, and cooled at room temperature.

Example 3
50 g of illite polarized to 325 mesh and 50 g of activated carbon were mixed in a homogeneous mixer. The binder aqueous solution prepared in Example 1 was added thereto, followed by injection molding, and dried at room temperature for 2 hours. The dried molded body was calcined for 3 minutes in the air at a temperature of 350 ℃ in the kiln, and cooled at room temperature.

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Example  4

50 g of illite polarized to 325 mesh and 50 g of activated carbon were mixed in a homogeneous mixer. The binder aqueous solution prepared in Example 1 was added thereto, followed by injection molding, and dried at room temperature for 2 hours. The dried molded body was calcined for 3 minutes in an incombustible gas atmosphere containing nitrogen at a temperature of 350 ℃ in a kiln, and cooled at room temperature.

Example  5

70 g of illite polarized to 325 mesh and 30 g of activated carbon were mixed in a homogeneous mixer. The binder aqueous solution prepared in Example 1 was added thereto, followed by injection molding, and dried at room temperature for 2 hours. The dried compact was calcined for 3 minutes in an incombustible gas atmosphere containing nitrogen at a temperature of 350 ℃ in a kiln, and cooled at room temperature.

Example  6

30 g of illite polarized to 325 mesh and 70 g of activated carbon were mixed in a homogeneous mixer. The binder aqueous solution prepared in Example 1 was added thereto, followed by injection molding, and dried at room temperature for 2 hours. The dried molded body was calcined for 3 minutes in an incombustible gas atmosphere containing nitrogen at a temperature of 350 ℃ in a kiln, and cooled at room temperature.

Comparative example  One

The aqueous binder solution prepared in Example 1 was added to 100 g of illite polarized into 325 mesh, followed by injection molding, and dried at room temperature for 2 hours. The dried molded body was calcined for 3 minutes in the air at a temperature of 350 ℃ in the kiln, and cooled at room temperature.
The strength of the fired body was measured using the sintered bodies prepared in Examples 1 to 4 and Comparative Example 1, and the results are shown in Table 1 below.

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division Plastic Strength (N, Newton) Example 1 75:25 (Waiting) 19.7 Example 2 75:25 (N ₂ firing) 14.6 Example 3 50:50 (atmosphere) 37.8 Example 4 50:50 (N ₂ firing) 34.5 Comparative Example 1 Illite 100 80.4

As shown in Table 1, the porous composite sinters of Examples 1 to 4 prepared according to the present invention showed a strength of 10 to 50 N in the fired body, even when using the same sample, incombustible gas atmosphere containing nitrogen. In the case of Examples 2 and 4 fired at, it was confirmed that the plastic strength was somewhat lower than that of Examples 1 and 3 fired in the air.

In addition, the specific surface area, the total pore volume, and the adsorption average pore area were measured using the porous composite sintered bodies prepared in Examples 3, 5, and 6, and the results are shown in Table 2 below.

division Specific surface area (㎡ / g) Total Pore Volume (Single Pt.) Adsorption Average Pore Area BET Langmuir Example 3 (50:50, N ₂ firing) 244.4751 320.4071 0.172710 28.0905 Example 5 (70:30, Atmospheric firing) 177.2034 244.1420 0.145498 32.8432 Example 6 (30:70, N ₂ firing) 451.6932 612.7895 0.192945 25.0120

As shown in Table 2, the porous composite sintered body prepared according to the present invention showed a higher specific surface area and total pore volume as the amount of activated carbon increased, and the average pore area of adsorption was slightly higher as the amount of illite increased. Could confirm.
This result was predicted to be the result of the porosity of activated carbon was given to the elite and activated carbon composite sintered body while maintaining the adsorption of the elite.

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1 is a view showing a method for manufacturing a porous composite sintered body according to an embodiment of the present invention.

Figure 2 is a photo before firing of the porous composite sintered body prepared according to an embodiment of the present invention.

Figure 3 is a photograph after firing of the porous composite sintered body prepared according to an embodiment of the present invention.

Figure 4 is a photograph of the cross section after the plastic completion of the porous composite sintered body prepared according to an embodiment of the present invention.

Claims (9)

a) mixing the clay mineral and carbon material of the plate-like structure; b) mixing and kneading the binder composition and water in the mixture; And c) molding and drying the dough to oxidize the surface by low temperature baking at a temperature of 200 to 500 ° C; Method for producing a porous composite sintered body comprising a. The method of claim 1, The clay mineral of the plate-like structure in step a) is 20 to 90% by weight, carbon material is a method for producing a porous composite sintered body, characterized in that mixed in 10 to 80% by weight. The method of claim 1, In step a), the clay mineral of the plate-like structure is at least one selected from the group consisting of elite, sericite, molmorite, bontonite, and biotite, and the carbonaceous material is powdered activated carbon, granular activated carbon, lignite and xenosphere ( cenosphere) method for producing a porous composite sintered body, characterized in that any one or more selected from the group consisting of a combustion material. The method of claim 1, The binder composition in step b) is 0.01-30% by weight sodium compound, 0.001-20% by weight vanadium compound, 0.1-89% by weight water, 0.1-20% by weight organic acid, 10-50% by weight ammonia or caustic soda and nano colo Method for producing a porous composite sintered body comprising 0.1 to 70% by weight of silica this month. The method of claim 1, The method of producing a porous composite sintered body, characterized in that further mixing at least one surface activated carbon oxidation promoter selected from the group consisting of transition metals, alkali metals, alkaline earth metals, rare metals and combinations thereof. The method of claim 1, Firing in step c) is a method for producing a porous composite sintered body, characterized in that carried out for 1 to 5 minutes at 250 to 500 ℃. A porous composite sintered body prepared by the method of any one of claims 1 to 6, characterized in that composed of a clay mineral shell layer and a composite layer of clay mineral and carbon material from the outside. The method of claim 7, wherein The porous composite sintered body is a porous composite sintered body, characterized in that applied to the support for the filter material, the adsorption material, the carrier or chemicals. The method of claim 8, The filter material is at least one formulation selected from the group consisting of air purifier filter material, automotive filter material, household appliance filter material, air conditioner filter material, gas mask material, air purifier material and clean room material. Porous composite sintered body.

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