Method for manufacturing a cured body, cured body, treatment agent, and method for using the treatment agent.

Abstract

To provide a method of producing a hardened body, capable of easily providing a novel concrete substitute material that does not use cement, a hardened body, a treatment agent, and a method of using the treatment agent.SOLUTION: The method of producing a hardened body, includes (a) a step of mixing a plurality of objects including an amorphous silicon oxide compound, an alkali metal compound or an alkali earth metal compound, and water, and a step (b) of subjecting the mixture obtained by the step (a) to heat treatment to obtain a hardened body constituted of the plurality of objects bonded with each other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a method for manufacturing a cured body, a cured body, a treatment agent, and a method for using the treatment agent.

Background Art

[0002] Concrete is the most widely used construction material in the world. The main material of concrete is cement, but the estimated years of extractable limestone, which is the main raw material of cement, is several decades to about a hundred and several decades in our country. The same is true in other countries that produce a large amount of concrete, such as China and India, so there is also a limit to coping by import. Therefore, the development of concrete alternative building materials that do not use cement, as described in Patent Document 1, has become an urgent issue.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a method for manufacturing a cured body, a cured body, a treatment agent, and a method for using the treatment agent that simply provide a novel concrete alternative material that does not use cement.

Means for Solving the Problems

[0005] The requirements for concrete substitutes include the availability of virtually unlimited raw materials and the ability to be reused. The inventors conceived the idea that the most abundant materials on Earth are sand and gravel, which are mainly composed of silicon, and that if construction materials could be manufactured directly from these, they would be promising concrete substitutes. As a result of diligent research to solve the above problems, they discovered that a hardened body can be obtained without using cement by bonding amorphous silicon oxide materials together using alkali metal compounds or alkaline earth metal compounds.

[0006] The present invention includes the following embodiments. [1] A method for producing a cured body, (a) A step of mixing a plurality of objects containing amorphous silicon oxide, an alkali metal compound or alkaline earth metal compound, and water. (b) A step of obtaining a hardened body in which the materials are bonded together by heat treatment of the mixture obtained in step (a), Methods that include... [2] The method according to [1], wherein the object comprises one or more selected from the group consisting of glass, sand, gravel, diatomaceous earth, glass fiber, and silica gel. [3] The method according to [1] or [2], wherein the object comprises 10% by weight or more of amorphous silicon oxide. [4] The alkali metal compound or alkaline earth metal compound comprises one or more selected from the group consisting of hydroxides, carbonates, bicarbonates, and halides of alkali metals or alkaline earth metals, according to any one of [1] to [3]. [5] The alkali metal compound or alkaline earth metal compound comprises one or more selected from the group consisting of NaOH, NaHCO3, Na2CO3, KOH, KHCO3, K2CO3, Ca(OH)2, Ca(HCO3)2, and CaCO3, according to any one of [1] to [4]. [6] The alkali metal compound or alkaline earth metal compound exhibits acidity or basicity when dissolved in water, according to any one of [1] to [5]. [7] The method according to any one of [1] to [6], wherein in step (a), the amount of the alkali metal compound or alkaline earth metal compound is 0.01 parts by weight or more and 50 parts by weight or less per 100 parts by weight of the object. [8] The method according to any one of [1] to [7], wherein in at least one of step (a) and step (b), the object is at least partially gelled. [9] The method according to any one of [1] to [8], wherein in step (b), the amorphous silicon oxide is at least partially crystallized.

[10] The method according to any one of [1] to [9], wherein the temperature of the heat treatment is 20°C to 500°C.

[11] The heat treatment is carried out in a sealed reaction vessel, according to any one of [1] to

[10] .

[12] The method according to any one of [1] to

[11] , wherein the porosity of the hardened body is 10% to 90%.

[13] A hardened body in which silicon oxide-containing granules are integrated together, containing an alkali metal or alkaline earth metal, and having a porosity of 10% to 90%.

[14] A treatment agent for bonding together multiple objects containing amorphous silicon oxide by treating them, the treatment agent comprising an alkali metal compound or an alkaline earth metal compound and water.

[15] A method of using a treatment agent comprising an alkali metal compound or an alkaline earth metal compound and water, (a) A step of mixing a plurality of objects containing amorphous silicon oxide with the treatment agent, (b) A step of bonding the objects together by heat treatment of the mixture obtained in step (a), Method of using the treatment agent, including the treatment agent. [Effects of the Invention]

[0007] According to embodiments of the present invention, a method for producing a hardened body, a hardened body, a treatment agent, and a method for using the treatment agent can be provided to easily provide a novel concrete substitute material that does not use cement. [Brief explanation of the drawing]

[0008] [Figure 1] A photograph of the prepared hardened body is shown. [Modes for carrying out the invention]

[0009] The following describes a method for manufacturing the cured body of the embodiment, the cured body, the treatment agent, and a method for using the treatment agent. Note that the following embodiments represent one aspect of the present invention and are not limiting, and can be modified as needed within the scope of the technical concept of the present invention.

[0010] <Method for manufacturing a hardened body> According to one embodiment of the present invention, a method for manufacturing a cured body, (a) A step of mixing a plurality of objects containing amorphous silicon oxide, an alkali metal compound or alkaline earth metal compound, and water. (b) A step of obtaining a hardened body in which the materials are bonded together by heat treatment of the mixture obtained in step (a), A method is provided that includes this.

[0011] Although the present invention is not limited by theory, in the above method, one possible mechanism by which multiple objects containing amorphous silicon oxide bond with each other to form a hardened body in the presence of an alkali metal compound or alkaline earth metal compound is, for example, the alkali-aggregate reaction described below.

[0012] Alkali-aggregate reaction is a reaction in which silica minerals such as sand and gravel in concrete gel when they react with alkaline components. This alkali-silica gel then absorbs water and generates expansion pressure, and is known to be one of the causes of deterioration such as cracking in concrete structures. This reaction can be represented by the following chemical equation, for example. (Stage 1: Alkali silica gel formation reaction) nSiO2 + 2NaOH → Na2O·nSiO2 + H2O (Second stage: Water absorption reaction of alkali silicate gel) Na2O·nSiO2 + mH2O → Na2O·nSiO2·mH2O

[0013] In the above method, it is presumed that an amorphous silicon oxide reacts with an alkali metal compound or an alkaline earth metal compound to form an alkali silicate gel, and a cured body is formed by heating the alkali silicate gels while they are bonded to each other. A mechanism is conceivable in which the alkali silicate gel is at least partially crystallized by the heat treatment, thereby forming a cured body having excellent strength.

[0014] In this specification, "silicon oxide" means any compound containing a Si - O bond, and may contain any element other than silicon and oxygen. In this specification, "silicon dioxide" means a silicon oxide composed only of silicon and oxygen.

[0015] In the above method, the amorphous silicon oxide is not particularly limited as long as it is an amorphous compound containing silicon and oxygen, and may be, for example, an inorganic compound such as amorphous silicon oxide (e.g., silicon dioxide SiO2), soda - lime glass, quartz glass, silicate glass, borosilicate glass, etc. Preferably, the amorphous silicon oxide is amorphous silicon oxide.

[0016] In the above method, the object containing amorphous silicon oxide is not particularly limited as long as it contains amorphous silicon oxide in at least part, and may be a natural mineral, an artificial object, a biologically derived material, etc. Examples of natural minerals include silica sand, silica stone, diatomaceous earth, and opal. Examples of artificial objects include general glass, silica gel, fumed silica, glass beads, glass fiber, and glass wool. Examples of biologically derived materials include diatom shells, radiolarian skeletons, plant combustion ash, and plant silicate bodies contained in plants (so-called plant opal). Preferably, the "object containing amorphous silicon oxide" includes one or more selected from the group consisting of glass, sand, gravel, diatomaceous earth, glass fiber, and silica gel. The sand may be regolith, which is sand and gravel from extraterrestrial celestial bodies (such as the Moon), or imitation sand that mimics it. The object may also contain crystalline materials (such as crystalline silicon oxide) in addition to amorphous silicon oxide.

[0017] In the above method, the material containing amorphous silicon oxide may be granular. This is preferable because it increases the surface area and allows the reaction to proceed efficiently. The size of the material (e.g., maximum diameter) is not particularly limited, but for example, it may be 1 μm or more, 10 μm or more, 100 μm or more, or 1 mm or more, and 10 cm or less, 5 cm or less, 3 cm or less, 2 cm or less, or 1 cm or less. Preferably, the above method yields a hardened body in which the granules are bonded together and integrated.

[0018] In the above method, the content of amorphous silicon oxide in the substance is not particularly limited, but may be, for example, 1% or more by weight, 5% or more by weight, 10% or more by weight, 15% or more by weight, 20% or more by weight, 25% or more by weight, 30% or more by weight, 35% or more by weight, 40% or more by weight, 45% or more by weight, 50% or more by weight, 55% or more by weight, 60% or more by weight, 65% or more by weight, 70% or more by weight, 75% or more by weight, 80% or more by weight, 85% or more by weight, 90% or more by weight, 95% or more by weight, or 99% or more by weight. From the viewpoint of reaction efficiency, it is preferable that the substance contains 10% or more by weight of amorphous silicon oxide.

[0019] In the above method, the alkali metal compound or alkaline earth metal compound is not particularly limited, but may be, for example, a compound of lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), or a combination thereof. Preferably, the alkali metal compound or alkaline earth metal compound is a compound of sodium, potassium, or calcium.

[0020] Furthermore, the alkali metal compound or alkaline earth metal compound may be, for example, hydroxides, oxides, carbonates, bicarbonates, halides, sulfates, nitrates, silicates, phosphates, aluminates, borates, organic acid salts of alkali metals or alkaline earth metals, or combinations thereof. Preferably, the alkali metal compound or alkaline earth metal compound contains one or more selected from the group consisting of hydroxides, carbonates, bicarbonates, and halides of alkali metals or alkaline earth metals. More preferably, the alkali metal compound or alkaline earth metal compound contains one or more selected from the group consisting of NaOH, NaHCO3, Na2CO3, KOH, KHCO3, K2CO3, Ca(OH)2, Ca(HCO3)2, and CaCO3.

[0021] In the above method, it is preferable that the alkali metal compound or alkaline earth metal compound exhibits acidity or alkalinity when dissolved in water, from the viewpoint of promoting the chemical reaction.

[0022] In the above method, the amount of alkali metal compound or alkaline earth metal compound relative to the amorphous silicon oxide-containing material is not particularly limited, but for example, per 100 parts by weight, it may be 0.01 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, or 5 parts by weight or more, and may be 100 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, 30 parts by weight or less, or 20 parts by weight or less. Preferably, the amount of alkali metal compound or alkaline earth metal compound is 0.01 parts by weight or more and 50 parts by weight or less per 100 parts by weight of material. The inventors have found that adding more alkali metal compound or alkaline earth metal compound tends to increase the porosity and degree of hardening of the resulting hardened material.

[0023] In the above method, the amount of the substance containing amorphous silicon oxide relative to water is not particularly limited, but for example, per 100 parts by weight of water, it may be 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, 5 parts by weight or more, and may be 100 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, 30 parts by weight or less, or 20 parts by weight or less.

[0024] In the above method, the amount of alkali metal compound or alkaline earth metal compound relative to water is not particularly limited, but for example, per 100 parts by weight of water, it may be 0.001 parts by weight or more, 0.005 parts by weight or more, 0.01 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.2 parts by weight or more, 0.3 parts by weight or more, 0.4 parts by weight or more, 0.5 parts by weight or more, 0.6 parts by weight or more, and may be 10 parts by weight or less, 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, 5 parts by weight or less, 4 parts by weight or less, or 3 parts by weight or less.

[0025] In the above method, reinforcing materials, adhesives, and other optional additives may be used as the materials mixed in step (a). Adding reinforcing materials is preferable from the viewpoint of increasing the strength of the cured body. Reinforcing materials are not particularly limited, but examples include fibrous materials, glass fibers, plastics, and fiber-reinforced plastics. Adding adhesives is preferable from the viewpoint of strengthening the bonds between the silica particles constituting the cured body. Adhesives are not particularly limited, but examples include epoxy adhesives, urethane adhesives, acrylic adhesives, and silicone adhesives.

[0026] In the above method, the materials mixed in step (a) are not limited to the above example, and any other object may be mixed in as well. For example, a crystalline object (e.g., sand, gravel, etc.) may be mixed with the above object, an alkali metal compound or alkaline earth metal compound, and water.

[0027] In at least one of steps (a) and (b) of the above method, the substance preferably gels at least partially. For example, as described above, alkali silica gel can be produced by the reaction of silicon oxide with an alkaline component.

[0028] In the above method, the temperature of the heat treatment in step (b) may be, for example, 20°C or higher, 50°C or higher, 60°C or higher, 70°C or higher, 80°C or higher, 90°C or higher, 100°C or higher, 110°C or higher, 120°C or higher, 130°C or higher, 140°C or higher, 150°C or higher, 160°C or higher, 170°C or higher, 180°C or higher, 190°C or higher, or 200°C or higher, and may be 1000°C or lower, 900°C or lower, 800°C or lower, 700°C or lower, 600°C or lower, 500°C or lower, 450°C or lower, 400°C or lower, 350°C or lower, 300°C or lower, 290°C or lower, 280°C or lower, 270°C or lower, 260°C or lower, 250°C or lower, or 240°C or lower. Preferably, the heat treatment temperature is between 20°C and 500°C. The optimal temperature may vary depending on the type of alkali metal compound or alkaline earth metal compound. The inventors have found that the porosity and degree of hardening of the hardened body tend to increase with higher heating temperatures. Although the present invention is not limited by theory, it is conceivable that when the treatment temperature is low, the reaction occurs only in certain areas, such as the surface of the object containing amorphous silicon oxide, and raw materials with almost zero porosity remain, resulting in a smaller overall porosity. However, because bonding between the materials is less likely to occur, the strength of the hardened body may not develop easily.

[0029] In the above method, the holding time of the heating temperature in step (b) may be, for example, 0 hours or more, 1 hour or more, 2 hours or more, or 3 hours or more, and may be 72 hours or less, 60 hours or less, 48 ​​hours or less, 36 hours or less, 24 hours or less, 18 hours or less, 12 hours or less, 10 hours or less, 8 hours or less, 6 hours or less, or 4 hours or less. Here, a holding time of 0 hours means that after raising the temperature to the target heating temperature, the temperature is immediately lowered without holding that heating temperature. The inventors have found that by increasing the holding time of the heating temperature, high results tend to be obtained even with heat treatment at relatively low heating temperatures.

[0030] In the above method, the equipment such as reaction vessels used in steps (a) and (b) are not particularly limited. Preferably, the heat treatment in step (b) is carried out in a sealed reaction vessel. If the heating temperature is above the melting point of water, the reaction vessel may be filled with steam. However, the reaction vessel is not limited to a sealed vessel, and an open vessel may be used.

[0031] In the above method, the pressure in steps (a) and (b) is not particularly limited. The pressure may be, for example, 0.1 MPa or more, 0.2 MPa or more, 0.3 MPa or more, 0.4 MPa or more, 0.5 MPa or more, or 1 MPa or more, for example, 60 MPa or less, 30 MPa or less, 20 MPa or less, or 10 MPa or less. The pressure may be applied by any method. For example, the above pressure may be the atmospheric pressure inside the reaction vessel, or it may be applied by applying external press pressure or by using both atmospheric pressure and press pressure of the same or different magnitudes simultaneously.

[0032] In the above method, the strength of the resulting cured body may be improved by any method. For example, the above method may include steps such as pressing the cured body, further heat treatment of the cured body, and blowing carbon dioxide gas onto the cured body.

[0033] In the above method, preferably, in step (b), the amorphous silicon oxide crystallizes at least partially. In this specification, "crystallize" means that at least a portion of the amorphous structure, in which atoms are irregularly arranged, changes into a crystalline structure, in which atoms are regularly arranged, and preferably involves a change in the diffraction pattern, such as the X-ray diffraction pattern or the electron diffraction pattern (for example, the appearance of diffraction peaks that were not present or a decrease in the linewidth of diffraction peaks). However, the present invention is not limited to the above example, and crystallization of the amorphous silicon oxide does not necessarily occur.

[0034] <Cured body> According to one embodiment of the present invention, a hardened body is provided in which granular bodies containing silicon oxide are integrated together, and which contains an alkali metal or alkaline earth metal, and has a porosity of 10% to 90%.

[0035] The above-mentioned hardened body may contain amorphous silicon oxide, or crystalline silicon oxide, and may contain both amorphous silicon oxide that has not crystallized and crystalline silicon oxide in which the amorphous silicon oxide has crystallized.

[0036] In the above-described hardened body, alkali metals or alkaline earth metals may be included in the hardened body in any form. For example, alkali metals or alkaline earth metals may be included in the hardened body as monatomic ions, polyatomic ions, compounds, or in a form bonded to the surface or internal structure of the silicon oxide.

[0037] In the hardened body described above, the content of alkali metals or alkaline earth metals relative to silicon oxide may be, for example, 0.001 parts by weight or more, 0.01 parts by weight or more, 0.1 parts by weight or more, or 1 part by weight or more, per 100 parts by weight of silicon oxide, or 100 parts by weight or less, 50 parts by weight or less, 20 parts by weight or less, or 10 parts by weight or less.

[0038] In the above-mentioned cured body, the porosity is calculated as the "open porosity" as defined in JIS R1634:1998. The porosity of the cured body may be, for example, 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, or 60% or more, and may be 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, or 65% or less. The inventors have found that in the cured body obtained by the above method, the degree of curing tends to increase as the porosity increases.

[0039] The hardened material described above can be used in a variety of applications, including construction materials such as building materials and structural materials, and as a raw material for industrial products and crafts (e.g., containers, molds, tableware, decorative items, etc.). In particular, when used as a construction material, it is useful as a concrete substitute that can be manufactured without using cement.

[0040] According to the above embodiment, a novel concrete substitute material that does not use cement is provided by a simple method of mixing amorphous silicon oxide with an alkali metal compound or alkaline earth metal compound and water and heating it. The oxygen and silicon that constitute silicon oxide have Clarke numbers of 1 and 2, respectively, which indicate their abundance near the Earth's surface, and can be said to be the most abundant resources on Earth. As described above, by manufacturing the above hardened body that can be used for applications such as construction materials using silicon oxide as a raw material, it is possible to obtain a concrete substitute material while avoiding resource depletion. Furthermore, since the above hardened body can be manufactured from lunar sand and other materials, it is useful in space development as it allows for the manufacture of construction materials from sand and gravel that can be easily obtained on extraterrestrial celestial bodies.

[0041] Since the above method does not use cement, it not only suppresses the generation of carbon dioxide during cement production, but the resulting hardened material has advantages over concrete made with cement, such as smaller volume change due to wetting and a shorter time required for strength development. Furthermore, if the above hardened material is produced via alkali-aggregate reaction, further alkali-aggregate reaction may be suppressed, thus suppressing deterioration due to alkali-aggregate reaction.

[0042] <Treatment agent> According to one embodiment of the present invention, a treatment agent is provided for bonding multiple objects containing amorphous silicon oxide together by treating them, the treatment agent comprising an alkali metal compound or an alkaline earth metal compound and water.

[0043] The above-mentioned treatment agent can be produced by mixing an alkali metal compound or an alkaline earth metal compound with water.

[0044] <How to use the treatment agent> According to one embodiment of the present invention, a method for using a treatment agent comprising an alkali metal compound or an alkaline earth metal compound and water, (a) A step of mixing a plurality of objects containing amorphous silicon oxide with a treatment agent, (b) A step in which the mixture obtained in step (a) is subjected to a heat treatment to bond the materials together, A method for using the treatment agent is provided, including the use of the treatment agent.

[0045] The purpose of using the above-mentioned treatment agent is not particularly limited. For example, in addition to manufacturing hardened materials, the treatment agent can also be used for joining and integrating multiple materials, and for repairing damage and cracks in structures and buildings such as buildings and roads (e.g., on-site repair work).

[0046] In the above-mentioned treatment agent and its usage method, the type and amount of amorphous silicon oxide-containing material, alkali metal compound or alkaline earth metal compound, and the conditions for each treatment are as described in the above-mentioned method for producing the hardened body. [Examples]

[0047] Examples of the present invention will be described below. These examples are not intended to limit the present invention.

[0048] [Example 1] 2.0 g of blasting glass beads #120 (product name: blasting glass beads, manufactured by Migyoya, hereinafter referred to as "glass beads") containing amorphous silicon dioxide and a predetermined amount (0.10 g, 0.20 g, 0.30 g, or 0.40 g) of calcium hydroxide were mixed in a cylindrical container made of copper foil. This copper foil container was placed in a reaction vessel, 15 g of water was added, and the reaction vessel was sealed. Then, the reaction vessel was placed upright in an oil bath, and while monitoring the oil temperature with a thermocouple placed in the silicone oil, it was heated to a predetermined processing temperature (100°C, 140°C, 200°C, or 240°C) using an immersion heater, held for 3 hours, and then returned to room temperature. As a result, a hardened body was obtained in which the raw material glass beads bonded together, as shown in Figure 1. The obtained hardened body was removed from the container, dried, and the porosity was measured according to the calculation method of "open porosity" as defined in JIS R1634:1998. Furthermore, the "degree of hardening" of the obtained hardened material was evaluated on a five-point scale: A (does not break even when pressed firmly with a finger), B+ (does not break even when pressed firmly, but some damage to the surface or corners), B (breaks when pressed firmly with a finger), C (breaks when pressed lightly with a finger), and D (does not harden). Table 1 shows the experimental conditions and the measurement results of porosity and degree of hardening for Example 1. Overall, both porosity and degree of hardening tended to increase with increasing amounts of calcium hydroxide and processing temperature.

[0049] [Table 1]

[0050] [Example 2] A cured body was obtained in the same manner as in Example 1, except that the processing temperature was set to 240°C and the holding time after heating was changed from 3 hours to 1.5 hours. Table 2 shows the experimental conditions for Example 2 and the measurement results of porosity and degree of curing.

[0051] [Table 2]

[0052] [Example 3] A cured body was obtained in the same manner as in Example 1, except that potassium carbonate was used instead of calcium hydroxide and the processing temperature was set to 180°C, 200°C, or 240°C. Table 3 shows the experimental conditions and the measurement results of porosity and degree of hardening for Example 3. Note that under the conditions of 0.10 g or 0.20 g of potassium carbonate, a processing temperature of 180°C, and a heating time of 3 hours, the raw material did not harden and no cured body was obtained.

[0053] [Table 3]

[0054] [Example 4] A cured body was obtained in the same manner as in Example 3, except that the processing temperature was set to 180°C or 240°C and the holding time after heating was set to 1.5 hours or 24 hours. Table 4 shows the experimental conditions for Example 4 and the measurement results of porosity and degree of curing. Under the conditions in Example 3 under which a cured body was not obtained, a sufficiently cured body was obtained when the holding time after heating was changed from 3 hours to 24 hours.

[0055] [Table 4]

[0056] [Example 5] A cured body was obtained in the same manner as in Example 1, except that potassium hydroxide was used instead of calcium hydroxide and the treatment temperature was set to 120°C, 140°C, 200°C, or 240°C. Table 5 shows the experimental conditions and the measurement results of porosity and degree of curing for Example 5.

[0057] [Table 5]

[0058] [Example 6] A cured body was obtained in the same manner as in Example 1, except that the amount of glass beads was 4.0 g, the amount of calcium hydroxide was 0.80 g or 0.85 g, the amount of water was 75 g, the processing temperature was 100°C, 120°C, 140°C, 160°C, 180°C, 200°C, or 240°C, the heating time was 1.5 hours, 3 hours, 6 hours, or 9 hours, and a band heater was used instead of an oil bath for the heat treatment. The heat treatment was performed by wrapping a band heater around the container holding the sample. The temperature inside the reaction vessel was measured by inserting a thermocouple from the top into a cylindrical part extending inward from the lid of the reaction vessel. The thermocouple and the band heater were connected to a temperature control device, and the heating of the band heater was adjusted to reach the target temperature while monitoring the temperature inside the container. Table 6 shows the experimental conditions and the measurement results of porosity and degree of hardening for Example 6. In this scaled-up example, a cured body similar to that of Example 1 was obtained.

[0059] [Table 6]

[0060] [Example 7] A cured body was obtained in the same manner as in Example 6, except that 0.80 g of potassium carbonate was used instead of calcium hydroxide, the processing temperature was set to 200°C or 240°C, and the heating time was 3 hours. Table 7 shows the experimental conditions and the measurement results of porosity and degree of curing for Example 7.

[0061] [Table 7]

[0062] [Example 8] A cured body was obtained in the same manner as in Example 1, except that the amount of glass beads was 4.0 g, sodium hydroxide was used instead of calcium hydroxide, the amount of water was 75 g, the processing temperature was 243°C, and the heating time was 8 hours. Table 8 shows the experimental conditions and the measurement results of the degree of curing for Example 8. Note that the measurement of porosity was omitted in Example 8.

[0063] [Table 8]

[0064] [Example 9] A hardened body was obtained in the same manner as in Example 1, except that 2.0 g of lunar simulated sand (FJS-1; composition SiO2:TiO2:Al2O3:Cr2O3:Fe2O3:FeO:MnO:MgO:CaO:Na2O:K2O=45.3:2.0:17.7:0.0:4.0:8.9:0.2:3.3:12.1:3.9:1.2) was used instead of glass beads, 0.20 g of calcium hydroxide was used, and the processing temperature was set to 110°C. Table 9 shows the experimental conditions and measurement results of porosity and degree of hardening for Example 9. It was confirmed that a hardened body could be formed even when lunar simulated sand was used.

[0065] [Table 9]

Claims

1. A method for manufacturing a hardened body, (a) A step of mixing a plurality of objects containing amorphous silicon oxide, an alkali metal compound or alkaline earth metal compound, and water. (b) A step of obtaining a hardened body in which the materials are bonded together by heat treatment of the mixture obtained in step (a), Includes, In step (a) above, the amount of the substance is 0.1 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of water. The temperature of the heat treatment in step (b) is 100°C or higher and 250°C or lower. The porosity of the hardened body is 40% or more and 65% or less. method.

2. The object comprises one or more materials selected from the group consisting of glass, sand, gravel, diatomaceous earth, glass fiber, and silica gel. The method according to claim 1.

3. The aforementioned object contains 10% by weight or more of amorphous silicon oxide. The method according to claim 1 or 2.

4. The alkali metal compound or alkaline earth metal compound comprises one or more selected from the group consisting of hydroxides, carbonates, bicarbonates, and halides of alkali metals or alkaline earth metals. The method according to any one of claims 1 to 3.

5. The alkali metal compound is one or more selected from the group consisting of alkali metal carbonates, bicarbonates, and halides. The method according to claim 4.

6. The alkali metal compound or alkaline earth metal compound is NaOH, NaHCO ３ , Na ２ CO ３ , KOH, KHCO ３ , K ２ CO ３ , Ca(OH) ２ , Ca(HCO ３ )([[]] ２ [[]]) ２ , and CaCO ３ including one or more selected from the group consisting of: The method according to any one of claims 1 to 4.

7. The alkali metal compound or alkaline earth metal compound exhibits acidity or alkalinity when dissolved in water. The method according to any one of claims 1 to 6.

8. In step (a) above, the amount of the alkali metal compound or alkaline earth metal compound is 0.01 parts by weight or more and 50 parts by weight or less per 100 parts by weight of the object. The method according to any one of claims 1 to 7.

9. In step (a) above, the amount of the alkali metal compound or alkaline earth metal compound is 5 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the substance. The method according to claim 8.

10. In at least one of steps (a) and (b), the object gels at least partially. The method according to any one of claims 1 to 9.

11. In step (b) above, the amorphous silicon oxide crystallizes at least partially. The method according to any one of claims 1 to 10.

12. The aforementioned heat treatment is carried out in a sealed reaction vessel. The method according to any one of claims 1 to 11.

13. A hardened body in which granular particles containing silicon oxide are integrated together, Containing alkali metals or alkaline earth metals, A hardened body with a void ratio of 40% to 65%.

14. A treatment agent for bonding multiple objects containing amorphous silicon oxide together by treating them, It contains an alkali metal compound or an alkaline earth metal compound and water. The alkali metal compound is one or more selected from the group consisting of alkali metal carbonates, bicarbonates, and halides. Treatment agent.

15. A method for using a treatment agent containing an alkali metal compound or an alkaline earth metal compound and water, (a) a step of mixing a plurality of objects containing amorphous silicon oxide with the treatment agent, and (b) a step of bonding the objects together by heat treatment of the mixture obtained in step (a), Includes, In step (a) above, the amount of the substance is 0.1 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of water. Instructions for using the treatment agent.

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