KR20200035596A - Method for manufacturing ceramic support body - Google Patents

Abstract

The present invention relates to a ceramic support and a method for manufacturing the same. More specifically, the present invention relates to a method for manufacturing a ceramic support which removes carbon dioxide rapidly generated in a heat treatment step to increase an oxidation reaction rate, thereby reducing a process time and lowering the possibility of deformation of a structure.

Description

Manufacturing method of ceramic support {METHOD FOR MANUFACTURING CERAMIC SUPPORT BODY}

The present invention relates to a method for manufacturing a ceramic support.

Currently, the water shortage phenomenon is intensifying in the world, and the importance of water treatment technology is increasing due to the serious water shortage phenomenon.

Among the water treatment technologies, the ceramic support for water treatment is actively used in fields where conventional paper filters or filters made of various polymers cannot be used because of excellent heat resistance and chemical properties.

In addition, it can be used as a variety of membranes when adjusting the pore amount or pore size of the ceramic support or coating a material having other fine pores.

A ceramic support used in a conventional water treatment or automobile exhaust gas treatment apparatus is provided with a honeycomb-type integral structure. In the honeycomb form, an extrusion molding method is used.

Ceramic molding methods include compression, extrusion, injection, injection molding, and tape casting. However, the production yield is not good because the green sheet produced through extrusion molding has a high defect rate such as warping or cracking during drying and heat treatment. Due to the high hardness and shear stress of the material itself, contamination and replacement costs are incurred due to wear of the mechanical device.

In addition, during the heat treatment process, a large amount of carbon dioxide gas due to rapid oxidation at high temperature affects the structure of the ceramic support, and lowers the oxidation reaction rate, thereby increasing the process time required to manufacture the ceramic support.

Korean Patent Publication No. 2014-0028705

An object of the present invention is to provide a method for manufacturing the ceramic support.

An exemplary embodiment of the present invention includes the steps of disposing a carbon dioxide remover inside or in an exhaust line of a kiln where reaction of the kiln occurs; And it provides a method of manufacturing a ceramic support comprising the step of heat-treating a laminate including an upper plate, an intermediate plate and a lower plate in the firing furnace.

According to the present invention, by removing carbon dioxide gas generated in a large amount due to rapid oxidation at a high temperature during the heat treatment process, it prevents affecting the structure of the ceramic support, and increases the oxidation reaction rate to increase the oxidation reaction rate. It has the advantage of reducing time and reducing the amount of carbon dioxide emitted to the atmosphere.

1 is a schematic layout view of Example 1 and Comparative Example 1.
2 is a schematic layout view of Example 2 and Comparative Example 2.

In the present invention, two or more elements are sequentially provided, for example, the term “A and B sequentially provided”, wherein the elements A and B are arranged in the above order, and are different between A and B. When elements are interposed, it is also included, for example, when A and B and C are arranged in the above order.

In the present invention, when a part is said to “include” a certain component, it means that the component may further include other components, not to exclude other components, unless otherwise stated.

Hereinafter, preferred embodiments of the present invention will be described. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

In one embodiment of the present invention, the step of laminating a stack containing a carbon component containing an upper plate, an intermediate plate and a lower plate inside the kiln; Disposing a carbon dioxide removing agent in the interior of the reaction of the kiln or in the exhaust line of the kiln; And it provides a method of manufacturing a ceramic support comprising the step of heat-treating the laminate including the upper plate, the intermediate plate and the lower plate in the firing furnace. By disposing the carbon dioxide remover inside the firing furnace or in the exhaust line of the firing furnace before the heat treatment step, carbon dioxide generated in the heat treatment process can be removed to improve the oxidation reaction rate to shorten the ceramic support manufacturing time. In addition, by reducing the influence of the structure of the laminate from carbon dioxide, the defect rate of the ceramic support can be reduced, and the amount of carbon dioxide discharged to the atmosphere can be continuously reduced.

Examples of the carbon component include carbon black, graphite, and polymer materials including polyethylene, PE, but are not limited thereto.

Whether the oxidation reaction rate is improved can be determined by comparing the mass before and after heat treatment for the same time. That is, it is assumed that only the carbon component is oxidized and blown away by heat treatment, and the oxidation rate is improved as the mass reduction ratio according to heat treatment increases.

In one embodiment of the present invention, a material capable of removing the carbon dioxide may be disposed inside the kiln. Through this, it is possible to remove carbon dioxide at the same time as the reaction.

In one embodiment of the present invention, the material capable of removing the carbon dioxide may be disposed in the exhaust line of the kiln. Through this, a material capable of removing carbon dioxide during the reaction may be additionally disposed, or a concentration device or a heating system may be provided on the exhaust line side.

In an exemplary embodiment of the present invention, the material capable of removing the carbon dioxide is disposed in the barry line of the kiln, and may be an independent heating system. The heating system can be a commonly used system.

In another exemplary embodiment of the present invention, a carbon dioxide concentration device may be introduced into the exhaust line of the kiln. The concentration device may be a commonly used device.

In the present invention, the carbon dioxide removing agent means a material that selectively reacts with carbon dioxide or a material capable of adsorbing carbon dioxide.

In the present invention, materials that selectively react with carbon dioxide include CaO, Ca (OH) ₂ , MgO, and Mg (OH) ₂ , and preferably, CaO and Ca (OH) ₂ can be used, but are not limited thereto. It does not work.

In addition, in the present invention, a material capable of adsorbing carbon dioxide is a porous material, and is typically a zeolite, but is not limited thereto.

In one embodiment of the present invention, the carbon dioxide remover is disposed inside the reaction of the kiln, and the carbon dioxide remover may be CaO, Ca (OH) ₂ , MgO, or Mg (OH) ₂ . The materials are materials capable of removing carbon dioxide at a temperature of 500 ° C or higher.

In one embodiment of the present invention, the carbon dioxide remover is disposed in the exhaust line of the kiln, and the carbon dioxide remover may be zeolite. The zeolite is a material capable of adsorbing carbon dioxide at less than 100 ° C.

In the present invention, the heat treatment means treating a temperature higher than room temperature.

In one embodiment of the present invention, the heat treatment temperature may be 500 ℃ to 1700 ℃, preferably 1000 ℃ to 1700 ℃. In addition, the heat treatment time may be 3 hours or more and less than 6 hours, preferably 4 hours or more and less than 5 hours.

The heat treatment step is heat-treated at a temperature of 500 ° C or higher, while the carbon component can be quickly removed, sintering of the laminate composed of the upper plate, the middle plate, and the lower plate starts, and the heat treatment is performed at a temperature of 1700 ° C or less to cause excessive sintering. It is possible to prevent the internal pores of the upper and lower plates from disappearing.

In one embodiment of the present invention, the heat treatment step includes removing the carbon component; And sintering the laminate. The temperature in the step of removing the carbon component may be 500 ° C or higher and 700 ° C or lower, preferably 500 ° C or higher and 600 ° C or lower.

In one embodiment of the present invention, the temperature of the exhaust line of the kiln may be less than 100 ° C, preferably 99 ° C or less, and more preferably 95 ° C or less.

In the present invention, sintering means a phenomenon in which particles are brought into close contact with each other and hardened when heat-treated at a constant temperature.

In one embodiment of the present invention, the upper plate and the lower plate may be provided by stacking 2 to 7 sheets of green sheets having a thickness of 80 μm to 2 mm produced by tape casting.

In one embodiment of the present invention, the upper plate and the lower plate are, but are not limited to, alumina powder, TiO ₂ , SiC, and MgAl ₂ O ₄ . It may be manufactured, the upper plate may be that the ceramic powder particle size becomes smaller as it goes to the upper portion, and the ceramic powder particle size becomes smaller as the lower plate goes to the lower portion.

In one embodiment of the present invention, the upper plate and the lower plate are alumina powder, TiO ₂ , SiC, and MgAl ₂ O ₄ . It may be prepared by a ceramic slurry containing a pore-forming agent containing any one or more of, but is not limited thereto.

The upper plate may have a smaller content of the pore-forming agent as it goes upwards, and the lower plate may have a smaller content of the pore-forming agent as it goes downwards.

Preferably, the pore-forming agent may include 2 wt% to 30 wt%, and in the firing step, the carbon powder is oxidized to form pores on the upper plate and the lower plate. The upper plate and the lower plate may have a porosity of 28% to 100%. In addition, the difference in porosity may be 5% to 50%.

The porosity gradient may be that the porosity decreases as the upper plate goes upward, and the porosity decreases as the lower plate moves downward.

Preferably, the ceramic powder may be provided with a particle size of 1.4 μm to 20 μm to form pores on the upper plate and the lower plate.

In the present invention, the upper portion of the upper plate means the opposite side of the surface opposite to the upper plate and the intermediate plate, and the lower portion of the lower plate means the opposite side of the surface opposite to the lower plate and the intermediate plate.

In one embodiment of the present invention, the thickness of the upper and lower plates is 1 mm to 3 mm. More preferably, it is 1 mm to 2 mm.

In one embodiment of the present invention, the channel (channel) formed intermediate plate may be formed by a method of making a flat sheet through tape casting and cutting a channel portion. The intermediate plate may be located between the upper plate and the lower plate, and may serve to maintain a gap between the upper plate and the lower plate.

In one embodiment of the present invention, the flat sheet may be manufactured by tape casting a material that is not removed when heat-treated. For example, alumina, zirconia, silica, or the like may be used as a material that is not removed during the heat treatment.

In one embodiment of the present invention, the thickness of the channel of the intermediate plate may be 1 mm to 3 mm, preferably 1 mm to 2 mm. That is, a channel at regular intervals can be formed. Having a channel at regular intervals imparts a binding force to an upper plate or a lower plate, and functions to improve the strength of the ceramic support, but it means that the number of barrier ribs capable of lowering the transmittance is adjustable. It means that it is prevented from being excessively degraded, and it can have a desired level of uniform transmittance.

In an exemplary embodiment of the present invention, before the step of heat-treating the laminate including the upper plate, the intermediate plate, and the lower plate in the firing furnace, the method may further include applying pressure to the laminate composed of the upper plate, the intermediate plate, and the lower plate. have. Through this, it is possible to increase the bonding strength of the ceramic support. For example, when using a uniaxial pressure press (press), it can be pressurized at a condition of 0.5MPa to 2MPa at 40 ° C to 60 ° C. More preferably, it can be uniaxially pressurized under conditions of 1 Mpa to 2 Mpa at 50 ° C to 60 ° C.

In another exemplary embodiment of the present invention, a separation layer may be stacked on the outermost layer in addition to the upper plate and the lower plate, and heat-treated at the same time. This can simplify the process. The separation layer may be the same material as the upper and lower plates.

In one embodiment of the present invention, the lower plate; Midplate; And a ceramic plate having a top plate sequentially provided with a support manufactured by the above-described manufacturing method. The thickness of the ceramic support is 3 mm to 9 mm, preferably 4 mm to 6 mm.

Hereinafter, examples will be described in detail to specifically describe the present invention. However, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention is not interpreted to be limited to the embodiments described below. The embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

<Example 1>

In the reactor, 3.5 g of carbon dioxide (CO ^- ₂ ) remover CaO was placed together with 9.88 g of graphite, and heat treated at 500 ° C for 4 hours. After the heat treatment, the mass of the remaining graphite was measured, and the value was 7.06 g (carbon reduction rate 28.5%).

<Example 2>

In the reactor, 3.15 g of the carbon dioxide (CO ^- ₂ ) remover, CaO, is placed together with a flat green sheet containing 1.23 g of graphite and 2.257 g of organic binder. The total mass of the flat green sheet was 14.59 g. Thereafter, heat treatment was performed at 500 ° C for 1 hour. After heat treatment, the mass of the remaining flat green sheet was measured, and its value was 12.23 g. Materials other than the organic binder and graphite are not removed by heat treatment, and the weight change of graphite is measured on the assumption that all of the organic binder is removed before reaching a temperature of 400 ° C. Through this, it was confirmed that the weight of graphite was decreased by 0.103 g (carbon reduction rate 8.3%).

<Comparative Example 1>

Without CaO as a carbon dioxide (CO ^- ₂ ) remover in the reactor, only 9.8g of graphite was placed and heat treated under the same conditions as in Example 1. After the heat treatment, the mass of the remaining graphite was measured, and the value was 7.51 g.

<Comparative Example 2>

A flat green sheet containing 0.52 g of graphite and 0.944 g of organic binder was placed in the reactor without CaO as a carbon dioxide (CO ^- ₂ ) remover. The total mass of the flat green sheet was 6.1 g. Thereafter, heat treatment was performed under the same conditions as in Example 2. After heat treatment, the mass of the remaining flat green sheet was measured, and its value was 5.12 g. As in Example 2, the material except the organic binder and graphite is not removed by heat treatment, and the organic binder is measured for weight change of graphite on the premise that it is all removed before reaching a temperature of 400 ° C. Through this, it was confirmed that the weight of graphite was reduced by 0.036 g (carbon reduction rate 7%).

The approximate arrangement of Example 1 and Comparative Example 1 can be confirmed through FIG. 1, and the approximate arrangement of Example 2 and Comparative Example 2 can be confirmed through FIG. 2.

In addition, the results are summarized in Tables 1 and 2 below. When the graphite (graphite) is arranged, it is summarized in Table 1, and when a flat green sheet is disposed, it is summarized in Table 2.

CaO placement Graphite mass (g) before heat treatment Graphite mass (g) after heat treatment Carbon reduction rate (%) Example 1 O 9.88 7.06 28.5 Comparative Example 1 X 9.8 7.51 23.4

Through Table 1, it was confirmed that the proportion of carbon removed in the same time in Example 1, in which the ratio of graphite mass reduction was high, was higher than that in Comparative Example 1.

CaO placement Graphite mass (g) before heat treatment Graphite mass (g) after heat treatment Carbon reduction rate (%) Example 2 O 1.23 1.13 8.3 Comparative Example 2 X 0.52 0.48 7

Through Table 2, it was confirmed that the proportion of carbon removed in the same time in Example 1 in which the ratio of graphite mass reduction was high was higher than in Comparative Example 1.

1: firing furnace
2: CaO
3. Graphite
4. Flat type green sheet

Claims (8)

Placing a laminate including a top plate, an intermediate plate and a bottom plate containing a carbon component inside the kiln;
Disposing a carbon dioxide removing agent in the interior of the reaction of the kiln or in the exhaust line of the kiln; And
A method of manufacturing a ceramic support comprising the step of heat-treating a laminate including the upper plate, the intermediate plate and the lower plate in the firing furnace. According to claim 1,
The carbon dioxide removing agent is disposed inside the reaction of the kiln, and the carbon dioxide removing agent is CaO, Ca (OH) ₂ , MgO, or Mg (OH) ₂ . According to claim 1,
The carbon dioxide removing agent is disposed in the exhaust line of the kiln, and the carbon dioxide removing agent is a zeolite. According to claim 1,
The heat treatment temperature is 500 to 1700 ℃ method of manufacturing a ceramic support. According to claim 1,
The heat treatment step includes removing the carbon component; And sintering the laminate. According to claim 1,
Method of manufacturing a ceramic support that the temperature of the exhaust line of the kiln is less than 100 ℃. According to claim 1,
A method of manufacturing a ceramic support, wherein a carbon dioxide remover is disposed in the exhaust line of the kiln and an independent heating system is used. The method according to any one of claims 1 to 7,
The method of manufacturing a ceramic support further comprising the step of applying pressure to the laminate composed of the upper plate, the intermediate plate and the lower plate before the step of heat-treating the laminate comprising the upper plate, the intermediate plate and the lower plate in the kiln.

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