KR19980067796A - Ceramic composition having electromagnetic wave absorptivity and manufacturing method thereof - Google Patents

Abstract

Disclosed are a ceramic composition having absorbing electromagnetic waves and a method of manufacturing the same. According to the composition and the preparation method according to the present invention, 70 to 90% by weight of titanium nitride, 5 to 15% by weight of iron oxide, 3 to 9% by weight of manganese (IV), and 2 to 6% by weight of copper (I) 20 to 40% by weight of water, 1.0 to 2.0% by weight of dispersant, 1.0 to 2.0% by weight of plasticizer, and 0.1 to 0.4% by weight of lubricant are added to the powder raw material consisting of the powder raw material. Wet grinding for ˜4 hours to prepare a powder having a particle size of 1 ~ 3㎛. And after spray-drying the powder into a granular powder, at a room temperature to a molded article having a density of 3.1 ~ 3.3g / cm ³ at a pressure of 1000 ~ 1200kg / cm ² . Subsequently, the molded body is placed in a sintering furnace and sintered for 15 hours, the temperature of the sintering furnace is slowly cooled to 200 ° C. or lower, and then the sintered body is naturally cooled and vibrated to prepare a ceramic composition having electromagnetic wave absorptivity. Thus, the composition can absorb the electromagnetic waves generated from the device by simply attaching to the inside or outside of the device emitting electromagnetic waves, and has a beautiful appearance with gloss of 14 gold, 18 gold, or 24 gold.

Description

Ceramic composition having electromagnetic wave absorptivity and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic composition having electromagnetic wave absorbency and a method of manufacturing the same, and more particularly, to absorb electromagnetic waves generated from various electric and electronic devices such as mobile phones, pagers, computers, wireless telephones, and televisions. The present invention relates to a ceramic composition having a gloss of 14-karat gold, 18-gold, or 24-gold, and a manufacturing method thereof.

Generally, fine ceramics or new ceramics are ceramics manufactured by using a molding method and a firing method that can highly control the chemical composition precisely formed using artificial raw materials or selected raw materials, unlike conventional ceramics such as conventional ceramics. Say. Fine ceramics have improved performance over traditional ceramics and can be used for many new applications because they have new features that have not existed so far.

Such fine ceramics can be broadly classified into oxide ceramics and non-oxide ceramics. The oxide ceramics include alumina (Al ₂ O ₃ ), ferrite (Fe ₂ O ₃ ), zirconia (ZrO ₂ ), titania (TiO ₂ ), and the like. Cargo-based ceramics include silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), and the like. The fine ceramics continue to find new functions in terms of thermal functions, mechanical functions, biological and chemical functions, electrical and electronic functions, and optical functions, and research is expected to continue in this respect in the future.

At present, numerous electric and electronic devices such as mobile phones, pagers, computers, cordless phones, televisions, etc. are used in daily life. Devices that use such electricity are essential to modern life, but most of them emit electromagnetic waves to the outside. It is already well known that electromagnetic waves generated and emitted from devices using electricity have various detrimental effects on the body of the person using the device. Accordingly, studies are underway to block electromagnetic waves harmful to the human body generated from the above devices, and a material capable of blocking electromagnetic waves by injecting conductive fibers into such matrix resins is disclosed in US Pat. al.) and also currently mount a ferrite core inside the device that emits electromagnetic waves or by modifying the design of the electrical circuitry embedded in the device to reduce the electromagnetic waves emitted and emitted from the devices. Also disclosed is a method.

However, the materials and methods are not able to adequately block the electromagnetic waves generated from the devices, and also to mount a ferrite core on the circuit substrate of devices generating electromagnetic waves or to change the design of the electrical circuit on the circuit board. Therefore, there is a problem such as a complicated manufacturing method and configuration.

Therefore, one object of the present invention is to easily attach to the inside or outside of the device that emits electromagnetic waves to absorb the electromagnetic waves generated from the device to significantly reduce the electromagnetic waves emitted to the outside, 14 k gold, 18 k gold depending on the polishing Or to provide a ceramic composition having electromagnetic wave absorptivity having a gloss of 24 gold.

In addition, another object of the present invention is to provide a method for producing a ceramic composition having electromagnetic wave absorptivity, which is particularly suitable for producing the ceramic composition having electromagnetic wave absorbency.

The present invention to achieve the above object of the present invention;

70-90 wt% titanium nitride (TiN), 5-15 wt% iron oxide (Fe ₂ O ₃ ), 3-9 wt% manganese oxide (IV) (MnO ₂ ), and copper oxide (I) (Cu ₂ O) Electromagnetic wave, comprising 20 to 40% by weight of water, 1.0 to 2.0% by weight of dispersant, 1.0 to 2.0% by weight of plasticizer, and 0.1 to 0.4% by weight of lubricant in powder raw material composed of 2 to 6% by weight. Provided is a ceramic composition having absorbency.

Preferably, the content of the titanium nitride is 75 to 85% by weight, more preferably, the content of the titanium nitride is 80% by weight.

Hexamethanol or polyethylene is used as the dispersant, polyvinyl alcohol is used as the plasticizer, and zinc acid is used as the lubricant.

In addition, the present invention in order to achieve the other object of the present invention;

70-90 wt% titanium nitride (TiN), 5-15 wt% iron oxide (Fe ₂ O ₃ ), 3-9 wt% manganese oxide (IV) (MnO ₂ ), and copper oxide (I) (Cu ₂ O) To the powder raw material consisting of 2 to 6% by weight, 20 to 40% by weight of water, 1.0 to 2.0% by weight of dispersant, 1.0 to 2.0% by weight of plasticizer and 0.1 to 0.4% by weight of lubricant are uniformly kneaded. step ;

Grinding the kneaded raw material to form powder;

Spray drying the pulverized powder to form granular powder;

Molding the granular powder to form a molded body;

Sintering the molded body to form a sintered body;

Cooling the sintered body; And

It provides a method for producing a ceramic composition having an electromagnetic wave absorbency comprising the step of polishing the sintered body.

The step of pulverizing the kneaded raw material to form a powder is a step of forming a powder having a particle size of 1 ~ 3㎛ by wet grinding for 2 to 4 hours using a ball mill and granulated by spray drying the pulverized powder Forming the powder, the inlet temperature of the spray dryer is maintained at 550 ~ 600 ℃, the outlet temperature of the spray dryer is maintained at 100 ~ 150 ℃ so that the water content of the granular powder is 0.1 to the granular powder This step is to be 0.4% by weight.

Forming the molded body by molding the granular powder is a step of forming a molded body having a density of 3.1 to 3.3 g / cm ³ at a pressure of 1000 ~ 1200kg / cm ² at room temperature using a mold press, the sintered body The step of forming is a step of sintering at a temperature of 1200 to 1400 ° C. for 10 to 20 hours under a nitrogen atmosphere.

The cooling of the sintered body may include: slowly cooling the sintered body loaded in the sintering furnace for 40 to 60 hours after closing the sintering furnace and removing the sintered body loaded in the sintering furnace at a temperature of 200 ° C. or lower, thereby sintering the sintered body. It further comprises the step of cooling.

Preferably, the step of polishing the sintered body is a step of vibrating polishing the sintered body for 2 to 5 hours.

When the titanium nitride content is 70 to 90% by weight, the absorption rate of the electric field generated from the devices that emit electromagnetic waves was 60.3% to 66.8%. In this case, especially when the titanium nitride content is 80% by weight and the iron oxide content is 10% by weight, the absorption rate of the electric field was the highest as 66.8% when measured using the Holaday HI-4000 RF Hazard Measurement System. In addition, when the content of the titanium nitride is less than 60% by weight, a sintered compact having a low value of 40% or less of an electric field absorption rate generated from devices emitting electromagnetic waves is obtained. In addition, when the content of titanium nitride is more than 95% by weight, it is difficult to control the pulverization and particle size of the raw material powder, the sintered body produced therefrom showed a low value of the absorption rate of the electric field also 40% or less.

Therefore, the ceramic composition having the electromagnetic wave absorbing property according to the present invention is produced from the devices by simply attaching the inside or outside of the device for emitting electromagnetic waves such as a mobile phone, a pager, a computer, a cordless phone, a television, various electric and electronic devices, and the like. By absorbing electromagnetic fields, it is possible to significantly reduce electromagnetic waves generated and emitted from the devices. In addition, since the ceramic composition has a beautiful appearance having a gloss of 14 gold, 18 gold, or 24 gold depending on the vibration polishing time, it can be used for jewelry and the like.

Hereinafter, a ceramic composition having electromagnetic absorptivity and a method of manufacturing the same according to the present invention will be described in detail.

Example 1

Powder consisting of 80 wt% titanium nitride (TiN), 10 wt% iron oxide (Fe ₂ O ₃ ), 6 wt% manganese oxide (IV) (MnO ₂ ), and 4 wt% copper (I) (Cu ₂ O) To the raw material, 30% by weight of water is added to the powder raw material, 1.5% by weight of hexamethanol or polyethylene is added to the powder raw material as a dispersant, and 1.5% by weight of polyvinyl alcohol is added to the powder raw material as a plasticizer. Thereafter, 0.2 wt% of zinc acid was added to the powder raw material as a lubricant to knead uniformly.

Preferably, the titanium nitride, iron oxide, manganese oxide (IV) and copper oxide (I) are powders produced by Kyocera Co., Ltd., and the dispersant and plasticizer are products produced by Sanop Co., Ltd., Japan. to be.

Subsequently, the kneaded raw material is wet milled using a ball mill for 2 to 4 hours, preferably 3 hours, and then spray-dried to granule having a particle size of 1 to 3 μm. Mold powder was prepared. At this time, the inlet temperature of the spray dryer (spray-drier) during the preparation of the granular powder is maintained to be 550 ~ 600 ℃, preferably, 580 ℃, the outlet temperature of the spray dryer is 110 ~ 130 ℃, Preferably, it is maintained at 120 ° C so that the water content in the powder is 0.1 to 0.4% by weight, preferably about 0.3% by weight.

And, by molding in a mold presses the granular powder to the 1000 ~ 1200kg / cm ^2, preferably at a pressure of about 1200kg / cm ² at room temperature, made into a shaped body having a density of about 3.1 ~ 3.3g / cm ^3.

Subsequently, the molded body was placed in a firing furnace and sintered at a temperature of 1400 to 1600 ° C, preferably 1500 ° C for 10 to 20 hours, preferably 15 hours.

Thereafter, the firing furnace was sealed and gradually cooled for 50 hours. When the temperature of the firing furnace reached about 200 ° C., the sintered compact was taken out of the firing furnace, and then the sintered compact was naturally cooled to produce a sintered compact having a predetermined shape. It was. Subsequently, the sintered compact was vibrated for 2 to 5 hours, preferably 3 hours to prepare a ceramic composition having a beautiful gold luster. In this case, the appearance of the ceramic composition may be adjusted to have a gloss of 14 gold, 18 gold, or 24 gold according to the vibration polishing time.

Absorption rates of the electric field of the ceramic composition according to the present embodiment are shown in Tables 1 and 2 below. The measured values of the electric field shown in Table 1 are measured at an interval of 5 cm from the cell phone using the Holaday HI-4000 RF Hazard Measurement System for the electric field emitted from the LG freeway cell phone.

TABLE 1

As shown in Table 1, the measured values of the electric field emitted from the LG phone after attaching the ceramic composition according to the present embodiment to the LG phone are 9.8 V / m, respectively, and the LG phone before the ceramic composition is attached. 65.5% reduction compared to 28.4 V / m, the measured value of the electric field emitted from.

In addition, the measured value of the electric field shown in Table 2 is a value measured at an interval of 2 cm from the Motorola mobile phone using the Holaday HI-4000 RF Hazard Measurement System for the electric field emitted from the Motorola mobile phone.

TABLE 2

As shown in Table 2, the measured value of the electric field emitted from the Motorola mobile phone after attaching the ceramic composition according to the present embodiment to the Motorola mobile phone is 10.4 V / m, and the Motorola mobile phone before the ceramic composition is attached. 66.8% reduction compared to the measured value of 31.3 V / m of the electric field emitted from.

Therefore, it can be seen from the results of Table 1 and Table 2 that the ceramic composition according to the present embodiment can significantly reduce the electric field emitted from the mobile phone, thereby absorbing the electromagnetic waves generated from the mobile phones to block the electromagnetic waves emitted to the outside. have.

Example 2

Powder composed of 70% by weight of titanium nitride (TiN), 15% by weight of iron oxide (Fe ₂ O ₃ ), 9% by weight of manganese oxide (IV) (MnO ₂ ), and 6% by weight of copper (I) (Cu ₂ O) To the raw material, 40% by weight of water is added to the powder raw material, hexamethanol or polyethylene is added as a dispersant to 2.0% by weight of the powder raw material, and 1.5% by weight of polyvinyl alcohol is added to the powder raw material as a plasticizer. Thereafter, 0.3 wt% of zinc acid was added to the powder raw material as a lubricant to knead uniformly.

In this embodiment, the raw materials used the same product as in the case of the first embodiment of the present invention described above.

Subsequently, the kneaded raw material was wet pulverized for 2 to 4 hours, preferably 3 hours using a ball mill, and then spray dried to prepare granular powder having a particle size of about 1 to 3 μm. At this time, the inlet temperature of the spray dryer is maintained at 550 ~ 600 ℃, preferably, 580 ℃ during the preparation of the granular powder, the outlet temperature of the spray dryer is 110 ~ 130 ℃, preferably, 120 It is maintained at 占 폚 so that the water content in the powder is 0.1 to 0.4% by weight, preferably about 0.3% by weight.

And, by molding in a mold presses the granular powder to the 1000 ~ 1200kg / cm ^2, preferably at a pressure of about 1200kg / cm ² at room temperature, made into a shaped body having a density of about 3.1 ~ 3.3g / cm ^3.

Subsequently, the molded body was placed in a firing furnace and sintered at a temperature of 1400 to 1600 ° C, preferably 1500 ° C for 10 to 20 hours, preferably 15 hours in a nitrogen (N ₂ ) atmosphere.

Thereafter, the firing furnace was sealed and gradually cooled for 50 hours. When the temperature of the firing furnace reached about 200 ° C., the sintered compact was taken out of the firing furnace, and then the sintered compact was naturally cooled to produce a sintered compact having a predetermined shape. It was. Subsequently, the sintered compact was vibrated for 2 to 5 hours, preferably 3 hours to prepare a ceramic composition having a beautiful gold luster. In this case, the appearance of the ceramic composition may be adjusted to have a gloss of 14 gold, 18 gold, or 24 gold according to the vibration polishing time.

Absorption rates of the electric field of the ceramic composition according to the present embodiment are shown in Tables 3 and 4 below.

TABLE 3

The measured values shown in Table 3 are measured at an interval of 5 cm from the LG mobile phone using the Holaday HI-4000 RF Hazard Measurement System.

As shown in Table 3, the measured values of the electric field emitted from the LG phone after attaching the ceramic composition according to the present embodiment to the LG phone are 10.7 V / m, respectively, from the LG phone before the ceramic composition is attached. It is 62.2% lower than the 28.3 V / m measured for the electric field emitted.

In addition, the measured values shown in Table 4 are measured at intervals of 2 cm from the Motorola mobile phone using the electric field Holaday HI-4000 RF Hazard Measurement System emitted from the Motorola mobile phone.

TABLE 4

As shown in Table 4, the measured value of the electric field emitted from the Motorola mobile phone after the ceramic composition according to the present embodiment is attached to the Motorola mobile phone is 11.8 V / m, and the Motorola mobile phone before the ceramic composition is attached. 62.5% reduction compared to the measured value of 31.5 V / m of the electric field emitted from.

Therefore, it can be seen from the results of Tables 3 and 4 that the ceramic composition according to the present embodiment can significantly reduce the electric field emitted from the mobile phone to absorb the electromagnetic waves generated from the mobile phones to block the electromagnetic waves emitted to the outside. have.

Example 3

90% by weight titanium nitride (TiN), 5% by weight iron (Fe ₂ O ₃ ), ₃ % by weight manganese (IV) (MnO ₂ ), and 2% by weight copper (I) (Cu ₂ O) To the raw material, 35% by weight of water is added to the powder raw material, hexamethanol or polyethylene is added as dispersant to 1.5% by weight with respect to the powder raw material, and 1.5% by weight of polyvinyl alcohol is added to the powder raw material as a plasticizer. Thereafter, 0.2 wt% of zinc acid was added to the powder raw material as a lubricant to knead uniformly.

In the present embodiment, the raw materials used were the same products as in the first embodiment of the present invention described above, and the grinding process, the molding process, the sintering process, the cooling process, and the polishing process of the raw material powder were performed in Example 1 Same as the case.

Absorption rates of the electric field of the ceramic composition according to the present embodiment are shown in Tables 5 and 6 below. The measured values shown in Table 5 are measured at 5 cm intervals from the LG cell phone using the Holaday HI-4000 RF Hazard Measurement System.

TABLE 5

As shown in Table 5, the measured values of the electric field emitted from the LG phone after attaching the ceramic composition according to the present embodiment to the LG phone are 9.9V / m, respectively, and the LG phone before the ceramic composition is attached. The reduction of 64.8% compared to 28.1 V / m, the measured value of the electric field emitted from.

In addition, the measured values shown in Table 6 are measured at intervals of 2 cm from the Motorola mobile phone using the electric field Holaday HI-4000 RF Hazard Measurement System emitted from the Motorola mobile phone.

TABLE 6

As shown in Table 6, the measured value of the electric field emitted from the Motorola mobile phone after the ceramic composition according to the present embodiment is attached to the Motorola mobile phone is 11.1 V / m, and the Motorola mobile phone before the ceramic composition is attached. It is 64.9% lower than the measured value of the electric field emitted from the 31.6V / m.

Therefore, it can be seen from the results of Table 5 and Table 6 that the ceramic composition according to the present embodiment can significantly reduce the electric field emitted from the mobile phone to absorb the electromagnetic waves generated from the mobile phones to block the electromagnetic waves emitted to the outside. have.

Example 4

85% by weight titanium nitride (TiN), 10% by weight iron (Fe ₂ O ₃ ), ₃ % by weight manganese (IV) (MnO ₂ ), and 2% by weight copper (I) (Cu ₂ O) To the raw material, 40% by weight of water is added to the powder raw material, 1.5% by weight of hexamethanol or polyethylene is added to the powder raw material as a dispersant, and 1.5% by weight of polyvinyl alcohol is added to the powder raw material as a plasticizer. Thereafter, 0.2 wt% of zinc acid was added to the powder raw material as a lubricant to knead uniformly.

In the present embodiment, the raw materials used were the same products as in the first embodiment of the present invention described above, and the grinding process, the molding process, the sintering process, the cooling process, and the polishing process of the raw material powder were performed in Example 1 Same as the case.

Absorption rates of the electric field of the ceramic composition according to the present embodiment are shown in Tables 7 and 8 below. The measured values shown in Table 7 are measured at 5 cm intervals from the LG cell phone using the Holaday HI-4000 RF Hazard Measurement System.

TABLE 7

As shown in Table 7, the measured values of the electric field emitted from the LG phone after attaching the ceramic composition according to the present embodiment to the LG phone are 10.3 V / m, respectively, and the LG phone before the ceramic composition is attached. 63.6% reduction compared to 28.3 V / m, the measured value of the electric field emitted from.

In addition, the measured values shown in Table 8 are measured at a distance of 2 cm from the Motorola mobile phone using the electric field Holaday HI-4000 RF Hazard Measurement System emitted from the Motorola mobile phone.

TABLE 8

As shown in Table 8, the measured value of the electric field emitted from the Motorola mobile phone after the ceramic composition according to the present embodiment is attached to the Motorola mobile phone is 11.4 V / m, and the Motorola mobile phone before the ceramic composition is attached. It is 63.5% lower than the measured value of 31.2 V / m.

Therefore, it can be seen from the results of Tables 7 and 8 that the ceramic composition according to the present embodiment can significantly reduce the electric field emitted from the mobile phone, thereby absorbing electromagnetic waves generated from the mobile phones to block the electromagnetic waves emitted to the outside. have.

Example 5

A powder consisting of 75% by weight of titanium nitride (TiN), 15% by weight of iron oxide (Fe ₂ O ₃ ), 6% by weight of manganese oxide (IV) (MnO ₂ ), and 4% by weight of copper oxide (I) (Cu ₂ O) To the raw material, 40% by weight of water is added to the powder raw material, 1.5% by weight of hexamethanol or polyethylene is added to the powder raw material as a dispersant, and 1.5% by weight of polyvinyl alcohol is added to the powder raw material as a plasticizer. Thereafter, 0.2 wt% of zinc acid was added to the powder raw material as a lubricant to knead uniformly.

In the present embodiment, the raw materials used were the same products as in the first embodiment of the present invention described above, and the grinding process, the molding process, the sintering process, the cooling process, and the polishing process of the raw material powder were performed in Example 1 Same as the case.

Absorption rates of the electric field of the ceramic composition according to the present embodiment are shown in Tables 9 and 10 below. The measured values shown in Table 9 are measured at 5 cm intervals from the LG cell phone using the Holaday HI-4000 RF Hazard Measurement System.

TABLE 9

As shown in Table 9, the measured values of the electric field emitted from the LG mobile phone after attaching the ceramic composition according to the present embodiment to the LG mobile phone are 11.2 V / m, respectively, and the LG mobile phone before the ceramic composition is attached. 60.3% reduction compared to 28.2 V / m, which is a measure of the electric field emitted from.

In addition, the measured values shown in Table 10 are measured at a distance of 2 cm from the Motorola mobile phone using the electric field Holaday HI-4000 RF Hazard Measurement System emitted from the Motorola mobile phone.

TABLE 10

As shown in Table 10, the measured value of the electric field emitted from the Motorola mobile phone after attaching the ceramic composition according to the present embodiment to the Motorola mobile phone is 12.2V / m, and the Motorola mobile phone before the ceramic composition is attached. It was 61.3% lower than the measured value of 31.5 V / m.

Therefore, it can be seen from the results of Table 9 and Table 10 that the ceramic composition according to the present embodiment can significantly reduce the electric field emitted from the mobile phone, thereby absorbing the electromagnetic waves generated from the mobile phones to block the electromagnetic waves emitted to the outside. have.

Therefore, the ceramic composition having the electromagnetic wave absorbing property according to the present invention is generated from the devices by simply attaching to the inside or outside of the device for emitting electromagnetic waves, such as mobile phones, pagers, computers, cordless phones, televisions, various electrical and electronic devices, etc. By absorbing the electric field it is possible to significantly reduce the electromagnetic waves generated and emitted from the devices. In addition, since the ceramic composition has a beautiful appearance with gloss of 14 gold, 18 gold, or 24 gold depending on the vibration polishing time, it can be used for jewelry and the like.

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited thereto, and it is possible for a person skilled in the art to modify or improve the present invention within a conventional range.

Claims (11)

70-90 wt% titanium nitride (TiN), 5-15 wt% iron oxide (Fe ₂ O ₃ ), 3-9 wt% manganese oxide (IV) (MnO ₂ ), and copper oxide (I) (Cu ₂ O) Electromagnetic wave, comprising 20 to 40% by weight of water, 1.0 to 2.0% by weight of dispersant, 1.0 to 2.0% by weight of plasticizer, and 0.1 to 0.4% by weight of lubricant in powder raw material composed of 2 to 6% by weight. Ceramic composition having absorbency. The ceramic composition according to claim 1, wherein the content of the titanium nitride is 75 to 85% by weight. The ceramic composition according to claim 1, wherein the content of the titanium nitride is 80% by weight. The ceramic composition according to claim 1, wherein the dispersant is hexamethanol or polyethylene. The ceramic composition according to claim 1, wherein the plasticizer is polyvinyl alcohol, and the lubricant is zinc acid. 70-90 wt% titanium nitride (TiN), 5-15 wt% iron oxide (Fe ₂ O ₃ ), 3-9 wt% manganese oxide (IV) (MnO ₂ ), and copper oxide (I) (Cu ₂ O) To the powder raw material consisting of 2 to 6% by weight, 20 to 40% by weight of water, 1.0 to 2.0% by weight of dispersant, 1.0 to 2.0% by weight of plasticizer and 0.1 to 0.4% by weight of lubricant are uniformly kneaded. step ; Grinding the kneaded raw material to form powder; Spray drying the pulverized powder to form granular powder; Molding the granular powder to form a molded body; Sintering the molded body to form a sintered body; Cooling the sintered body; And A method of manufacturing a ceramic composition having electromagnetic wave absorbency, comprising the step of polishing the sintered body. The method of claim 6, wherein the step of pulverizing the kneaded raw material to form a powder by wet milling for 2 to 4 hours using a ball mill to form a powder having a particle size of 1 ~ 3㎛, Spray drying the powder to form the granular powder, the inlet temperature of the spray dryer is maintained at 550 ~ 600 ℃, the outlet temperature of the spray dryer is maintained at 100 ~ 150 ℃ to maintain the water content in the granular powder Method for producing a ceramic composition having an electromagnetic wave absorbency, characterized in that the step of 0.1 to 0.4% by weight relative to the granular powder. According to claim 6, Forming the molded body by molding the granular powder is to form a molded body having a density of 3.1 ~ 3.3g / cm ³ under a pressure of 1000 ~ 1200kg / cm ² at room temperature using a mold press A method for producing a ceramic composition having electromagnetic wave absorbency, characterized in that the step. The method of claim 6, wherein the forming of the sintered compact is a step of sintering at a temperature of 1200 to 1400 ° C. for 10 to 20 hours under a nitrogen atmosphere. The method of claim 9, wherein the cooling of the sintered compact comprises: slowly cooling the sintered compact loaded in the firing furnace for 40 to 60 hours after closing the firing furnace and the sintered compact loaded in the firing furnace at a temperature of 200 ° C. or less. The method of manufacturing a ceramic composition having electromagnetic wave absorbency, further comprising the step of naturally cooling the sintered compact by taking out. 7. The method of claim 6, wherein the polishing of the sintered compact comprises vibration-polishing the sintered compact for 2 to 5 hours.