Hydration-resistant reactive aqueous suspension composition and powder molded body manufactured using same

Abstract

The present invention relates to a hydration-resistant reactive aqueous suspension composition and a powder molded body manufactured using same, and provides a suspension composition comprising: an aqueous solvent; a hydration-resistant reactive agent; and at least one raw material powder among a hydration-reactive metal, a metal compound, and a non-metal powder.

Description

Water-resistant reactive water-based suspension composition and powder molded body prepared using the same

[0001] The present invention relates to a composition capable of forming a stable aqueous suspension by minimizing the hydration reaction when preparing a powder suspension that undergoes a hydration reaction upon contact with water or moisture, and to a powder molded body prepared from said composition.

[0002] Molding methods for ceramic powder materials can be broadly classified into dry molding and wet molding methods. Dry ceramic molding methods, such as powder press molding, are widely used in ceramic manufacturing processes due to their excellent economic efficiency and mass production capabilities, as well as the advantages of being able to easily produce large molded bodies and control quality. Additionally, wet molding methods, such as slip casting or tape casting, are highly advantageous for manufacturing molded bodies of complex shapes or very thin plate-like bodies.

[0003] In manufacturing such a molded body, a common prerequisite step is the process of preparing a suspension of raw material powder. For example, in dry molding, a molded body is manufactured by press molding using granules prepared by spray drying or the like, while in wet molding, the molded body is manufactured by pouring the suspension directly into a porous mold or by applying it thinly onto a polymer film.

[0004] However, some ceramic raw material powders (MgO, CaO, BaO, AlN, etc.) have a problem in that they change into hydroxides with completely different crystal structures and chemical formulas due to hydration reactions when in contact with water or moisture. For example, magnesium oxide has a problem in that a hydration reaction of MgO + H2O = Mg(OH)2 occurs when it comes into contact with moisture or water, which makes it impossible to use water, which is the most commonly used solvent for preparing suspensions in the conventional ceramic spray drying process. To overcome this problem, existing technology adopts a method using non-aqueous suspensions that use alcohol-based solvents instead of water as the solvent for preparing suspensions.

[0005] However, in processes using non-aqueous suspensions containing organic solvents, explosion-proof spray dryers are used to prevent the explosion of flammable organic solvent suspensions for safety during granule manufacturing; these explosion-proof spray dryers are more expensive than those used in water-based spray drying processes. Furthermore, the cost of high-purity organic solvents, which are consumed in large quantities during mass production, is significantly higher than that of distilled water used in water-based processes. Moreover, since most organic solvents are hazardous to varying degrees depending on the type, water-based processes are generally more desirable than non-aqueous ones whenever possible. Additionally, in the manufacture of ceramic powder bodies by slip casting, which is widely used in wet molding processes, production is very difficult using suspensions composed of organic solvents. Moreover, process control is extremely challenging, as workers are exposed to organic solvents for extended periods during drying, and the molded bodies have weak strength and are prone to cracking.

[0006] Accordingly, the present invention has developed a stable aqueous suspension composition applicable to the process and a process for manufacturing a powder molded body using the same by suppressing the hydration reaction during the preparation of an aqueous suspension of ceramic raw material powder having hydration reactivity.

[0007] The objective of the present invention is to provide a composition capable of forming a stable aqueous suspension by minimizing the hydration reaction when preparing a powder suspension that undergoes a hydration reaction upon contact with water or moisture, and a powder molded body prepared from said composition.

[0008] To achieve the above-mentioned purpose, the present invention provides a suspension composition comprising: an aqueous solvent; a hydration-resistant reactive agent; and one or more raw material powders selected from hydration-reactive metals, metal compounds, and non-metal powders.

[0009] In the present invention, the water-resistant reactive agent may be one or more of citric acid, tartaric acid, aminopolycarboxylate, polyphosphate, and eco-friendly chelating agent.

[0010] In the present invention, the water-resistant reactive agent dissolves in a solvent to form a liquid carrier and may be included in a range of 0.01 to 5 weight percent relative to the weight of the raw material powder.

[0011] In the present invention, the metal is one or more of Mg, Si, B, Al, and Ca; the metal compound is one or more of metal oxide, metal nitride, metal carbide, metal boride, metal silicide, metal hydroxide, and metal carbonate; and the nonmetal may be one or more of carbon, phosphorus, and sulfur.

[0012] In the present invention, the raw material powder has an average particle size of 30 μm or less and may be included in a range of 1 to 60 volume% relative to the total volume of the composition.

[0013] The composition according to the present invention further comprises a dispersant or a surfactant, and the dispersant or surfactant may be included in a range of 0.01 to 10 weight percent relative to the weight of the raw material powder.

[0014] The amount of hydroxide formed by the hydration reaction in the suspension of the present invention can be suppressed to 20 weight% or less.

[0015] In addition, the present invention provides granules formed from the above-described suspension composition.

[0016] In the present invention, the granules are spherical, and the average particle size of the granules may be 0.1 to 500 μm.

[0017] In addition, the present invention provides a molded body formed from the granules described above.

[0018] In addition, the present invention provides a method for preparing a suspension composition comprising the step of mixing a solvent, a water-resistant reactive agent, and a raw material powder.

[0019] In the present invention, mixing may be one or more of ball milling, bead milling, attrition milling, planetary milling, high-energy milling, and ultrasonic treatment.

[0020] In addition, the present invention provides a method for manufacturing granules comprising the step of granulating a suspension composition.

[0021] In the present invention, granulation may be one or more of spray drying, freeze drying, drying, crushing, and sieving.

[0022] In addition, the present invention provides a method for manufacturing a molded body comprising the step of molding granules.

[0023] In addition, the present invention provides a method for manufacturing a sintered body comprising the step of manufacturing granules in their original granular form or in the form of a dry-molded powder body and sintering them to produce a dense ceramic sintered body.

[0024] In addition, the present invention provides a method for manufacturing a powder molded body comprising the step of wet molding using a suspension composition.

[0025] In the present invention, wet molding may be one or more of slip casting, pressure casting, solid casting, and tape casting.

[0026] By preparing a stable aqueous suspension having hydration reaction resistance according to the present invention, there is an advantage in that hydration-reactive ceramic powder molded bodies can be mass-produced in an environmentally friendly and low-cost economical manner.

[0027] Figure 1 shows the degree to which magnesium oxide is converted into hydroxide over time in a hydration reaction, where A (●) is 36℃, B (△) is 46℃, and C (○) is 56℃.

[0028] Figure 2(a) shows a scanning electron microscope (SEM) image of MgO granules prepared by the method of Example-1, (b) shows a scanning electron microscope image of the granules of Example-1 sintered at 1350°C for 2 hours, (c) shows an MgO crucible molded body produced by slip casting using the suspension prepared by the method of Example-1, and (d) shows the X-ray diffraction analysis pattern of the MgO granules prepared by Example-1.

[0029] Figure 3 (a) shows a scanning electron microscope image of AlN granules prepared by the method of Example-2, and (b) shows the X-ray diffraction analysis pattern of the Example-2 granules.

[0030] The present invention will be described in detail below.

[0031] The present invention relates to a water-resistant reactive water-based suspension composition. The suspension composition according to the present invention essentially comprises a solvent (water), a water-resistant reactive agent (citric acid, etc.), and a raw material powder (MgO, AlN, etc.). Preferably, it may additionally comprise a dispersant (surfactant), and optionally, it may additionally comprise a sintering aid (TiO2, etc., 0.01 to 1 wt%) and / or a sintering additive (La2O3, V2O5, etc., 0.01 to 1 wt%).

[0032] The solvent is intended to form a liquid vehicle and may be an aqueous solvent. The aqueous solvent may include one or more selected from various solvents, such as water (distilled water, etc.). The solvent content is the remainder remaining after subtracting the total content of the remaining components, and may be, for example, 20 to 80 weight%, 30 to 70 weight%, or 40 to 60 weight% based on the total weight of the composition.

[0033] The raw material powder may be in the form of a powder as a main component of the suspension composition. The raw material powder may be one type (alone) or two or more types (combination) of metal, metal compound, and non-metal powder. The metal may be various metals (e.g., Fe, B, Al, Si, Mg, Co, Ni, Cu, Pd, Ag, In, Sn, Sb, Pt, Au, Ti, W, Ir, Mo, Nd, Ta, Ti, La, Ce, V, Cr, Zr, Pb, Bi, Li, Be, Na, Ca, Sr, Ba, Sc, Mn, Zn, Ga, Ge, Y, Nb, Ru, Rh, Sm, Gd), preferably Mg, Si, B, Al, Ca, etc. The metal compound may be a ceramic powder such as, for example, metal oxide, metal nitride, metal carbide, metal boride, metal silicide, metal hydroxide, metal carbonate, etc. Nonmetals can be, for example, carbon, phosphorus, sulfur, etc.

[0034] In particular, the raw material powder may be a hydration-reactive raw material powder that undergoes a hydration reaction upon contact with water or moisture, and specifically, may be a hydration-reactive metal oxide such as MgO or a hydration-reactive metal nitride such as AlN. The raw material powder may consist of fine particles and may have an average particle size of, for example, 30 μm or less, 0.01 to 20 μm, 0.1 to 10 μm, or 0.5 to 5 μm. The content of the raw material powder in the suspension may be, for example, 1 to 60 volume%, 5 to 50 volume%, or 10 to 40 volume% relative to the total volume of the composition; and based on the total weight of the composition, it may be 20 to 80 weight%, 30 to 70 weight%, or 40 to 60 weight%.

[0035] A hydration-resistant reactive agent (chelating agent) is intended to suppress hydration reactions that occur during processes such as grinding and mixing for the preparation of an aqueous suspension (slurry), and a hydration-resistant reactive suspension can be provided by using a hydration-resistant reactive agent. The hydration-resistant reactive agent may be used only for raw powders (such as MgO and AlN) that undergo hydration reactions, and may not be used for raw powders (such as SiC and BN) that do not undergo hydration reactions.

[0036] The hydration-resistant reactive agent is a chelating agent soluble in the above solvent, and may be, for example, one (alone) or two or more (combination) of citric acid, tartaric acid, aminopolycarboxylates, polyphosphates, and environmentally friendly chelating agents. As aminopolycarboxylates, for example, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), nitrilotriacetic acid (NTA), etc. may be used. As polyphosphates, for example, 1-hydroxyethylidene-1,1-diylbisphosphonic acid (HEDP), aminotrimethylethanolisphosphonic acid (ATMP), diethylenetriaminepentamethylenepentakisphosphonic acid (DTPMPA), etc. may be used. Examples of eco-friendly chelating agents that can be used include aspartic acid-N,N-diacetic acid (ASDA), glutamic acid-N,N-diacetic acid (GLDA), methylglycindiacetic acid (MGDA), ethylenediamine-N,N-disuccinic acid (EDDS), iminodisuccinic acid (IDS), etc.

[0037] The hydration-resistant reactive agent can dissolve in an aqueous solvent to form a liquid carrier. The content of the hydration-resistant reactive agent may be, for example, 0.01 to 5 wt%, 0.1 to 3 wt%, or 0.3 to 1 wt% relative to the weight of the raw powder; and based on the total weight of the composition, it may be 0.01 to 3 wt%, 0.05 to 2 wt%, or 0.1 to 0.5 wt%. The amount of hydroxide formed by the hydration reaction in the suspension may be suppressed by the hydration-resistant reactive agent to 20 wt%, 15 wt%, 10 wt%, 5 wt%, or 3 wt% or less (0 wt% or more).

[0038] A dispersant or surfactant is used to smoothly disperse raw powder particles within a solvent or liquid carrier, and commercially available water-based dispersants, such as BYK-194N and APCA, may be used. The content of the dispersant or surfactant may be, for example, 0.01 to 10 weight%, 0.1 to 8 weight%, or 1 to 5 weight% relative to the weight of the raw powder; and based on the total weight of the composition, it may be 0.01 to 5 weight%, 0.1 to 4 weight%, or 0.5 to 3 weight%.

[0039] In addition, the present invention provides water-resistant reactive granules formed from the suspension composition described above. The granules may preferably be spherical. The relative bulk density of the granules may be, for example, 25% or more (80% or less). The average particle size of the granules may be, for example, 0.1 to 500 μm, 1 to 300 μm, 3 to 200 μm, or 5 to 150 μm.

[0040] In addition, the present invention provides a molded body formed from granules. The powder molded body may be formed through dry molding (press molding, CIP molding, etc.) or wet molding (slip casting, tape casting, etc.).

[0041] In addition, the present invention provides a method for preparing a suspension composition comprising the step of mixing a solvent, a hydration-resistant reactive agent, and a raw material powder. For example, a water-based suspension (slurry) composition can be prepared by adding a raw material powder to a liquid carrier in which a hydration-resistant reactive agent is dissolved in an aqueous solvent, and then mixing or milling. Specifically, the method for preparing a suspension composition may include the step of preparing a liquid carrier by adding and dissolving a hydration-resistant reactive agent, i.e., a chelating agent, in an aqueous solvent; the step of preparing a composition by adding a desired amount of hydration-resistant reactive raw material powder to the prepared liquid carrier; and the step of preparing a suspension by uniformly mixing the prepared composition. Various mixing methods for preparing the suspension may be used, such as ball milling, bead milling, attrition milling, planetary milling, high-energy milling, and ultrasonication.

[0042] In addition, the present invention provides a method for manufacturing granules comprising the step of granulating a suspension composition. Specifically, granules can be manufactured using various granulation methods including spray drying, freeze drying, drying, crushing, and sieving. For example, raw material powder can be introduced into a liquid carrier in which a water-resistant reactive agent is dissolved in a solvent, and a suspension can be formed by mixing or milling, and then spherical granules can be formed by atomizing and drying the suspension; that is, granules can be manufactured by applying a process of atomizing and drying the prepared suspension.

[0043] In addition, the present invention provides a method for manufacturing a molded body comprising the step of molding granules. Molding may be dry molding (press molding, CIP molding, etc.) or wet molding (slip casting, tape casting, etc.). For example, in dry molding, a molded body may be manufactured by press molding using granules prepared by methods such as spray drying a suspension of raw material powder, and in wet molding, the molded body may be manufactured by pouring the suspension directly into a porous mold or by thinly coating it onto a polymer film. In this way, a powder molded body may be manufactured by applying a wet molding process such as slip casting, or the granules may be dry-molded into a powder molded body, or used as a molded body in their granular state.

[0044] In addition, the present invention provides a method for manufacturing a sintered body comprising the step of manufacturing granules in their original granular form or in the form of a dry-molded powder body and sintering them to produce a dense ceramic sintered body.

[0045] In addition, the present invention provides a method for manufacturing a powder molded body comprising the step of wet molding using a suspension composition. Wet molding may be one or more of slip casting, pressure casting, solid casting, and tape casting.

[0046] In the case of MgO and AlN, which undergo a phase change into a hydroxide through a hydration reaction when in contact with water or moisture, the hydration reaction occurs rapidly during the grinding-mixing process (e.g., ball milling) for preparing an aqueous suspension (slurry), causing the amount of hydroxide in the slurry to increase rapidly and the viscosity of the suspension to increase significantly, making it impossible to produce a stable MgO suspension.

[0047] Figure 1 shows the results of investigating the degree of hydration reaction over time after dispersing 1.5 g of MgO powder in 9 ml of water in a Teflon container. As can be seen here, it is evident that the hydration reaction occurs very rapidly even in a static state.

[0048] To explain the reason using the case of MgO powder particles in an aqueous solution as an example, MgO + H2O = MgOH + (surface) + OH - Due to the (aqueous) reaction, MgOH on the surface of the MgO powder + is formed, and at the same time, in the aqueous solution, OH - As the concentration increases, the pH of the aqueous solution rises to approximately 10–12. Simultaneously with this process, OH in the aqueous solution - ions on the surface of MgO particles MgOH + This is because Mg(OH)2 is formed on the surface as it combines with ions.

[0049] For this reason, methods have been developed to prepare magnesium oxide aqueous suspensions by adding a small amount of anti-hydration agents, such as lignin sulfonate, to inhibit the hydration reaction. Furthermore, according to recent research, if a small amount of chelating agents, such as citric acid, is added at 0.2 wt.% or more to a static suspension containing MgO, the citric acid dissociates in the aqueous solution to form citrate ions (Cit n- It is adsorbed onto the surface of MgO particles while forming n=3, 2, or 1), and nMgOH + (surface) + Cit n- (aqueous) = [nMgOH + ·Cit n- By the ] reaction, stable [nMgOH with hydration resistance + ·Citn- It has been reported that the formation of a layer can significantly inhibit the hydration reaction of MgO.

[0050] However, these methods used simple mixing methods such as pump recirculation, turbine agitation, or simple stirring to prepare magnesium oxide suspensions. However, in a process that includes continuously ball-milling the suspension to reduce the size of powder particles (i.e., a grind-mixing process) as in the present invention, the Mg(OH)2 layer on the surface of the powder particles is continuously destroyed due to impact by the balls, compressive or shear stress, or wear, and as new MgO surfaces are continuously exposed, the hydration reaction may not only continue but also accelerate during the ball-milling process. As a result, the proportion of MgO in the aqueous solution continues to decrease, and the viscosity of the aqueous solution continues to increase due to the formation of Mg(OH)2, eventually reaching a high viscosity stage where it is impossible to drop the suspension.

[0051] To address this problem, a method of ball-milling at a low temperature of about 5°C or lower has been proposed; however, this method has the inconvenience of requiring ball-milling to be performed inside a separate refrigerated space, and furthermore, it does not completely suppress the hydration reaction. Therefore, there is a need to develop a more improved grinding-mixing (ball-milling) method that suppresses the hydration reaction. To this end, it is necessary to devise a method that can passivate the powder particle surfaces that are continuously newly exposed during the grinding-mixing (ball-milling) process in real time.

[0052] To this end, the present invention increases the concentration of the chelating agent in the suspension so that even in grinding and mixing processes where new MgO surfaces are continuously exposed for a long time, such as in a ball-milling process, the mechanism of passivation by excess chelate ions in the aqueous solution, i.e., the hydration reaction inhibition mechanism, operates continuously, thereby forming a protective film layer on the surface in real time and significantly suppressing the generation of hydroxides in the suspension, thereby suppressing the increase in viscosity of the suspension and making it possible to produce a stable suspension that can be droplet-forming.

[0053] Chelating agents that can be used for this purpose include, in addition to citric acid and tartaric acid, traditional chelating agents such as aminopolycarboxylates (EDTA, DTPA, NTA) and polyphosphates (HEDP, ATMP, DTPMPA), and eco-friendly chelating agents (ASDA, GLDA, MGDA, EDDS, IDS).

[0054] [Example-1]

[0055] The process for preparing an MgO aqueous suspension composition having water-resistant reactivity and spherical granules using the same is as follows. For the preparation of the composition, distilled water produced by reverse osmosis, raw powders of MgO (ZH-V2, 98%, 0.8 μm, Jiangsu Zehui Magnesium New Material Technology Co., Ltd.), TiO2 (Extra Pure, Kosundo Chemicals Co., Ltd., Japan), La2O3 (Extra Pure, Duksan Pure Chemicals, Korea), and V2O5 (Extra Pure, Kosundo Chemicals Co., Ltd., Japan) were used, and BYK-194N (BYK-Chemie GmbH) and APCA were used as dispersants to control the viscosity and dispersibility of the suspension. APCA is a solution prepared by mixing a commercial aqueous dispersant (SN-Dispersant 5468, Sannopco Korea Co., Ltd.) and ammonia water (30%, Samjeon Chemical Co., Ltd.) in a weight ratio of 3:5. And citric acid (CH2COOH-C(OH)COOH-CH2COOH, C6H8O7, Duksan Pure Chemicals, Korea) was used as a chelating agent.

[0056] At this time, the overall composition of the prepared composition is as shown in Table 1. Accordingly, a polyethylene container with a volume of 500 ml was first filled approximately halfway with ZrO2 balls with a diameter of 10 mm, and the raw materials were added in the proportions shown in the composition table of Example-1 in Table 1. At this time, distilled water, citric acid, and a dispersant were added in that order, and then ball milling was performed for about 1 minute to ensure uniform mixing. In addition to the prepared liquid carrier, TiO2, La2O3, V2O5, and MgO powders were added according to the example as presented in Table 1, and then ball milling was performed for 23.5 hours at a rotation speed of 180 rpm. If viscosity adjustment was required for the ball-milled suspension, 0 to 0.6% of the second dispersant APCA was added, and ball milling was performed for an additional 20 minutes. Table 1 is the composition table of the water-resistant reactive suspension (unit weight%).

[0057] Material Example-1 Material Example-2 Remarks Distilled water 50.78 Distilled water 48.41 Citric acid 0.24 Citric acid 0.25 0.5 wt.% relative to powder Dispersant 0.91 Dispersant 0.89 BYK-194NT iO2 0.14 Sintering aid La2O 3 0.12 Sintering additive V2O 5 0.02 Sintering additive MgO 47.79 AlN 50.45 Raw material powder

[0058] The ball-milled suspension (slurry) was sprayed and dried using a laboratory spray dryer with hot air at approximately 150°C to produce spherical granules with a diameter of approximately 5 to 40 μm. Figure 2(a) is a scanning electron microscope image of magnesium oxide granules prepared by the method of Example-1, and Figure 2(b) is a scanning electron microscope image of the prepared magnesium oxide granules after sintering at 1350°C for 2 hours. As can be seen here, it can be confirmed that spherical magnesium oxide granules and dense magnesium oxide sintered granules were successfully produced. In addition, Figure 2(c) shows an MgO crucible powder molded body made by pouring the MgO aqueous suspension prepared by the above method into a plaster mold (by slip casting) and holding it for 30 minutes, then draining the remaining suspension, drying it at room temperature for 1 day, and then demolding it. It can be seen that wet molding was successfully performed using the water-resistant reactive aqueous suspension prepared in the present invention.

[0059] Meanwhile, FIG. 2(d) is an X-ray diffraction analysis graph of the MgO raw material powder and the granules prepared in Example-1. As a result of analyzing the diffraction patterns obtained for each using the Rietveld method, it was confirmed that the increase in the content of the Mg(OH)2 phase due to the hydration reaction was only 2.9% even after ball-milling for a long time (24 hours) at room temperature, indicating that the hydration reaction was significantly suppressed during the ball-milling process. Therefore, it was possible to prepare a stable MgO aqueous suspension with significantly suppressed hydration reaction at room temperature using the same method as in Example-1 of the present invention. Furthermore, it was confirmed that even when the hydration-reactive raw material powder is subjected to a grinding-mixing process such as ball-milling for a long time, a stable suspension with a viscosity range that allows for droplet formation can be prepared.

[0060] [Example-2]

[0061] The process for preparing an AlN aqueous suspension composition having water-resistant reactivity and spherical granules using the same is as follows. For the preparation of the composition, distilled water produced by reverse osmosis, aluminum nitride (AlN) (AlN020AF, 2 μm, Thrutek Applied Materials Co., Ltd, Taiwan; 99.9% High Purity Chemical, Japan) as a raw material powder, and BYK-194N (BYK-Chemie GmbH) and APCA were used as dispersants to control the viscosity and dispersibility of the suspension. APCA is a solution prepared by mixing a commercial aqueous dispersant (SN-Dispersant 5468, Sannopco Korea Co., Ltd.) and ammonia water (30%, Samjeon Chemical Co., Ltd.) in a weight ratio of 3:5. Citric acid (CH2COOH-C(OH)COOH-CH2COOH, C6H8O7, Duksan Pure Chemicals, Korea) was used as a chelating agent.

[0062] At this time, the overall composition of the prepared composition is as shown in Table 1. Accordingly, a polyethylene container with a volume of 250 ml was first filled about halfway with ZrO2 balls with a diameter of 10 mm, and the raw materials were added in the ratios shown in the composition table of Example-2 in Table 1. At this time, distilled water, citric acid, and a dispersant were added in that order, and then ball milling was performed for about 1 minute to ensure they were uniformly mixed. After adding aluminum nitride powder to the prepared liquid carrier according to the example as presented in Table 1, ball milling was performed for 45 minutes at a rotation speed of 180 rpm. If viscosity adjustment was required for the ball-milled suspension, 0 to 0.6% of the second dispersant APCA was added, and ball milling was performed for an additional 15 minutes.

[0063] The ball-milled suspension was used to produce spherical granules with a diameter of approximately 5 to 40 μm using a laboratory spray dryer in the same manner as in Example 1. Figures 3 (a) and 3 (b) show scanning electron microscope images and X-ray diffraction analysis results of the aluminum nitride granules prepared by the method of Example 2, respectively. As can be seen here, spherical aluminum nitride granules with a size of 10 to 40 μm were produced, and notably, as can be seen in the X-ray diffraction pattern, no Al(OH)3 hydroxide phase was detected within the granules. This confirms that a hydration-resistant aluminum nitride suspension was successfully prepared.

Claims

1. Aqueous solvents; Hydrogen-resistant reactive formulations; and A suspension composition comprising one or more raw material powders selected from hydration-reactive metals, metal compounds, and non-metal powders.

2. In Paragraph 1, A suspension composition in which the hydration-resistant reactive agent is one or more of citric acid, tartaric acid, aminopolycarboxylate, polyphosphate, and an eco-friendly chelating agent.

3. In Paragraph 1, A suspension composition comprising a water-resistant reactive agent that dissolves in a solvent to form a liquid carrier and is included in a range of 0.01 to 5 weight percent relative to the weight of the raw material powder.

4. In Paragraph 1, The metal is one or more of Mg, Si, B, Al, and Ca; The metal compound is one or more of metal oxides, metal nitrides, metal carbides, metal borides, metal silicides, metal hydroxides, and metal carbonates; A suspension composition in which the nonmetal is one or more of carbon, phosphorus, and sulfur.

5. In Paragraph 1, A suspension composition comprising a raw material powder having an average particle size of 30 μm or less and included in a range of 1 to 60 volume% relative to the total volume of the composition.

6. In Paragraph 1, A suspension composition further comprising a dispersant or a surfactant, wherein the dispersant or surfactant is included in a range of 0.01 to 10 weight percent relative to the weight of the raw material powder.

7. In Paragraph 1, A suspension composition in which the amount of hydroxide formed by a hydration reaction within the suspension is suppressed to 20 weight% or less.

8. Granules formed from the suspension composition according to paragraph 1.

9. In Paragraph 8, Granules are spherical, and the average particle size of the granules is 0.1 to 500 μm.

10. A molded body formed from granules according to paragraph 8.

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