A treated water production apparatus and a method for producing a cement-containing paste that has undergone carbon dioxide absorption treatment.

Abstract

This invention provides a treated water production device that efficiently dissolves carbon dioxide in the water necessary for the hydraulic action of fresh concrete, mortar, etc., so that the supplied carbon dioxide does not remain in the fresh concrete, etc., even when carbon dioxide is mixed with cement materials from an external source. It also provides a method for producing carbon dioxide-absorbing treated cement-containing mixtures that allows for the efficient addition of supplied carbon dioxide without any residue in the fresh concrete, etc., and without causing a deterioration in quality during the production of concrete, etc. [Solution] The treated water production apparatus degassed unwanted dissolved gases from the liquid, dissolved the necessary gases as replacement gases into the liquid, and produced a replacement gas solution. This replacement gas solution, which is the water required for the hydraulic treatment of fresh concrete, mortar, etc., is then mixed with dissolved carbon dioxide to produce hydraulic treated water.

Description

Technical Field

[0001] The present disclosure relates to a treated water production device that produces treated water such as carbonated water from recovered carbon dioxide gas, and a method for producing a carbon dioxide-absorbed cement-containing kneaded product that produces fresh concrete, mortar, etc. using the treated water produced by this treated water production device.

Background Art

[0002] At cement production sites, especially in the firing process of the cement production process, raw materials such as limestone, viscosity, and silica are fired at a high temperature of 1450°C or higher, generating combustion exhaust gas containing a large amount of carbon dioxide, which is exhausted into the atmosphere. On the other hand, the issue of climate change has become an urgent problem to be solved in recent years, and in order to avoid the emission of carbon dioxide gas, which is the main cause of this problem, the development of technologies for recovering carbon dioxide gas is required. Under such circumstances, as one means of recovering carbon dioxide gas, a technology for confining carbon dioxide gas in fresh concrete is disclosed in Patent Document 1.

[0003] Patent Document 1 is a method for producing carbon dioxide-immobilized re-alkalized concrete in which carbon dioxide-immobilized concrete containing carbon dioxide gas before placing is subjected to an alkalization treatment with an alkaline component released from a granular alkali supply material composed of water, cement, aggregate, and a cured product of a cement material, and cured after placing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, Patent Document 1 does not disclose at all how carbon dioxide is actually supplied to be incorporated into fresh concrete during the production of carbon dioxide-immobilized concrete. Furthermore, it does not mention the state in which the carbon dioxide is contained within the supplied paste-like fresh concrete. However, in the case of the technology described in Patent Document 1, if the carbon dioxide is not mixed into the paste-like fresh concrete without forming bubbles during supply, the following problems may occur.

[0006] In other words, according to Patent Document 1, when carbon dioxide is supplied to fresh concrete from a carbon dioxide source by a common method such as bubbling or aeration, there is a risk that the entire amount of supplied carbon dioxide may not react with the components of the fresh concrete as it is mixed into the paste-like fresh concrete, and may remain unreacted in the fresh concrete in the form of bubbles. If carbon dioxide remains in the form of bubbles in carbon dioxide-immobilized re-alkalized concrete, the strength of the concrete itself will decrease after the carbon dioxide-immobilized re-alkalized concrete hardens due to voids caused by the remaining carbon dioxide bubbles.

[0007] Furthermore, even if carbon dioxide is supplied from a carbon dioxide source to the fresh concrete, and a portion of the total supplied carbon dioxide is mixed with the paste-like fresh concrete, there is a risk that the remaining carbon dioxide that could not be mixed with the fresh concrete will simply be released into the atmosphere.

[0008] The present invention was made to solve the above problems, and aims to provide a treated water production device that can efficiently dissolve carbon dioxide in the water necessary for the hydraulic action of fresh concrete, etc., so that the supplied carbon dioxide does not remain in the fresh concrete, etc., even when carbon dioxide exhausted from the outside is mixed with cement material to produce fresh concrete, mortar, etc. Furthermore, the present invention aims to provide a method for producing carbon dioxide absorption treated cement-containing mixture that, when carbon dioxide exhausted from the outside is mixed with cement material to produce fresh concrete, mortar, etc., can be efficiently added without remaining in the fresh concrete, etc., and can produce concrete without causing a deterioration in quality. [Means for solving the problem]

[0009] (1) A treated water production apparatus in one aspect of the present invention, made to solve the above problems, is a type of dissolved gas replacement apparatus that degasssed unwanted dissolved gases from a liquid and dissolved the gas required as the replacement gas into the liquid to produce a replacement gas solution, comprising: a gas-liquid mixing container capable of containing the required gas and the liquid in its internal space; a gas storage section for storing the required gas under high pressure exceeding atmospheric pressure; and a gas introduction pipeline connecting the gas storage section and the gas-liquid mixing container, wherein the required A gas flow control valve for controlling the flow of gas, a liquid storage section for storing the liquid, a liquid introduction pipeline connecting the liquid storage section and the gas-liquid mixing container, a liquid flow control valve for controlling the flow of the liquid, a pump for dispensing the liquid, a nozzle capable of atomizing and discharging the liquid, a liquid temperature control means for adjusting the liquid to a set temperature within the gas-liquid mixing container, a gas exhaust means for drawing in gas present in the gas-liquid mixing container and exhausting it to the outside, and the gas exhaust means and the gas-liquid mixing container The gas-liquid mixing container is characterized by comprising an exhaust pipe communicating with the interior, a gas flow control valve for controlling the flow of the gas, and a control means, the nozzle being disposed in the interior space of the gas-liquid mixing container in communication with the liquid introduction pipe, the gas-liquid mixing container having a liquid circulation system that allows the gas-liquid mixture of the liquid contained in the interior space and the required gas to be circulated and flowed by the pump, the control means spraying the liquid, whose temperature has been controlled by the liquid temperature control means, from the nozzle while circulating it by the pump in the gas-liquid mixing container under vacuum pressure to a pressure lower than atmospheric pressure by the gas exhaust means, and supplying the required gas from the gas introduction pipe in a state in which it can come into contact with the sprayed mist-like liquid, and the dissolved gas replacement device being a treated water production device that produces treated water by dissolving the required gas, carbon dioxide, in at least one of the liquid, water, or an aqueous solution of a basic substance, as the replaced gas solution.

[0010] According to this embodiment, unwanted gases are efficiently removed from liquids such as water and aqueous solutions by a vacuum pump, and carbon dioxide, which is the necessary gas, can be efficiently supplied to the degassed liquid under high pressure. As a result, hydrohard treated water (treated water), such as carbonated water, can be produced in a shorter time and at a higher concentration as a displacement gas solution in which carbon dioxide and basic substances are dissolved in water, etc.

[0011] (2) In the above embodiment described in (1), it is preferable that the carbon dioxide gas is gaseous carbon dioxide originating from exhaust gas generated by an external facility.

[0012] According to this embodiment, for example, carbon dioxide emitted in large quantities from power plants, factories, waste disposal sites, etc., can be suppressed from being released into the atmosphere, and by being effectively used in the handling of materials as one of the materials for manufacturing concrete products commonly used in industry and manufacturing, it can contribute to achieving carbon neutrality, which is a pressing issue worldwide.

[0013] (2) In the embodiments described in (1) or (2) above, it is preferable that the invention includes a carbon dioxide recovery means for recovering and storing the carbon dioxide remaining in the gas-liquid mixing container after the production of the treated water.

[0014] According to this embodiment, the carbon dioxide recovered by the carbon dioxide recovery means can be reused in the production of treated water without being released into the atmosphere in order to protect the global environment.

[0015] (4) A method for producing a carbon dioxide absorption treated cement-containing mixture according to another aspect of the present invention, which was made to solve the above problems, is characterized in that it has a first cement-containing mixture production step, in which hydraulic treated water produced by mixing carbon dioxide and water as the water required for hydraulic treatment, is added to cement and aggregate and mixed together to produce a cement-containing mixture in a first state, and the cement-containing mixture in the first state is fresh concrete or mortar. Furthermore, in the above embodiment described in any one of (10)(4) to (6), it is preferable that the hydraulic treated water is the treated water produced by the treated water production apparatus described in any one of (1) to (3).

[0016] According to this embodiment, the cement-containing mixture in the first state can be used in concrete structures such as wave-dissipating blocks (tetrapods) as an example of the use of concrete after fresh concrete has hardened, and in applications such as mortar products, tile products, and unreinforced concrete that do not require greater strength as an example of mortar.

[0017] In the embodiments described in (5)(4) above, it is preferable to have a cement-containing mixture purification step in which a basic substance is added to the cement-containing mixture in the first state and mixed to produce a cement-containing mixture in a second state in which the cement-containing mixture in the first state is purified to an alkaline state.

[0018] According to this embodiment, when the cement-containing mixture in the second state is fresh concrete, it is a refined product of fresh concrete that has been purified to an alkaline pH of, for example, pH 11 or higher, which is sufficient to form a passive film on the surface of the reinforcing steel used in the construction of the concrete structure, thereby suppressing the occurrence of rust due to oxidation. Therefore, since the fresh concrete, which is the cement-containing mixture in the second state, can suppress rust formation for a long period of time, it can be used for concrete structures in combination with reinforcing steel, with the same handling as general fresh concrete that does not have carbon dioxide added during manufacturing.

[0019] In the embodiments described in (6)(4) or (5), it is preferable that in the first cement-containing compound manufacturing step, the cement, aggregate, and hydraulic water are mixed while the internal space of the mixing container for manufacturing the cement-containing compound in the first state is evacuated to a pressure lower than atmospheric pressure.

[0020] According to this embodiment, since the cement-containing mixture in the first state has had the bubbly gas removed, the formation of voids is suppressed within the hardened concrete made from this first state of cement-containing mixture (fresh concrete), thereby preventing a decrease in the strength of the concrete itself due to these voids.

[0021] (7) A second other embodiment of the present invention, made to solve the above problems, is characterized in that it has a second cement-containing compound manufacturing step, in which hydraulic water produced from carbon dioxide, water and a basic substance is used as the water required for hydraulics, and the hydraulic water is added to cement and aggregate and mixed to produce a cement-containing compound in a third state, and the cement-containing compound in the third state is fresh concrete or mortar. Furthermore, in the above embodiment described in any one of (10)(7) to (9), it is preferable that the hydraulic water is the treated water produced by the treated water production apparatus described in any one of (1) to (3).

[0022] According to this aspect, when the cement-containing kneaded material in the third state is fresh concrete, the fresh concrete is purified to a product state with alkalinity such that the pH value is, for example, pH 11 or higher, which can suppress the generation of rust due to oxidation with respect to the reinforcing bars used for the construction of the concreted structure. Therefore, the fresh concrete, which is the cement-containing kneaded material in the third state, can be handled in the same way as ordinary fresh concrete without adding carbon dioxide gas during production and can be used for concrete structures used in combination with reinforcing bars.

[0023] (8)(7) In the above aspect described in (8)(7), the hydraulic treatment water is hydraulic secondary treatment water obtained by dissolving carbon dioxide gas in hydraulic primary treatment water composed of the water and the basic substance to generate a pH of 11 or higher, and it is preferable that the hydraulic secondary treatment water is generated with a liquidity within the range of pH 6 to pH 8.

[0024] According to this aspect, by generating hydraulic primary treatment water TW2 having a strong alkalinity of pH 11 or higher, a larger amount of carbon dioxide gas can be dissolved (dissolved and fixed) within the pH value range of hydraulic secondary treatment water TW3 that can ensure good quality of fresh concrete and mortar in the product state when generating hydraulic secondary treatment water TW3.

[0025] (9)(7) or (8) In the above aspect described in (9)(7) or (8), in the second cement-containing kneaded material production step, it is preferable that the internal space of the kneading container for producing the cement-containing kneaded material in the third state is evacuated to a pressure lower than atmospheric pressure, and the cement, the aggregate, and the hydraulic treatment water are kneaded.

[0026] According to this aspect, since the cement-containing kneaded material in the third state is in a state where gaseous gas has been degassed, the appearance of cavities inside the concrete hardened from fresh concrete and inside the mortar product can be suppressed, thereby suppressing a decrease in the strength resistance caused by these cavities with respect to the concrete and mortar products themselves.

[0027] (11) In the above aspect described in any one of (4) to (10), it is preferable that the basic substance is a salt containing a metal belonging to an alkali metal or an alkaline earth metal, or a basic amino acid. In particular, as an example of the preferable basic substance, there is a substance containing at least one of lithium oxide, calcium nitrite, potassium nitrite, or L-arginine.

[0028] According to this aspect, since the basic substance does not have a hydroxy group and can suppress the water content derived from the hydroxide to a small amount when the basic substance, carbon dioxide gas, and water are dissolved, after placing the fresh concrete in the product state, it is possible to suppress the water content in the concrete from becoming excessive due to the water content derived from the hydroxide. As a result, it is possible to prevent the occurrence of quality deterioration associated with excessive moisture in the concrete after placement. Also, in the case of mortar products, it is possible to suppress the water content from becoming excessive due to the water content derived from the hydroxide, and it is possible to prevent the occurrence of quality deterioration associated with excessive moisture.

[0029] (12) In the above aspect described in any one of (4) to (10), it is preferable that fine silica particles (SiO2) having a spherical shape with an average particle size of 0.2 to 10 μm are added as an admixture to the cement-containing kneaded material in the first state or the cement-containing kneaded material in the third state.

[0030] According to this embodiment, for example, when supplying fresh concrete to a ready-mix concrete transport truck or when pouring fresh concrete from a ready-mix concrete transport truck at a concrete placement site, it is possible to suppress the decrease in the fluidity of the fresh concrete in its product state due to deaeration, whether it be a cement-containing mixture in the first state or a cement-containing mixture in the third state. Therefore, fresh concrete in its product state, produced by the method for producing a carbon dioxide-absorbing treated cement-containing mixture according to the present invention, for example, by refining it to a state with a pH of 11 or higher, can be handled at the placement site without difficulty and does not impair the work efficiency of the workers, even when compared to general fresh concrete that does not have carbon dioxide added during production. Similarly, mortar products can be handled at the placement site without difficulty and do not impair the work efficiency of the workers, even when compared to general mortar products that do not have carbon dioxide added during production. [Effects of the Invention]

[0031] Therefore, the treated water production apparatus according to this disclosure has the excellent effect of degassing unwanted gases (gases before substitution) dissolved in the water when producing carbonated water or water with hardened water, and then dissolving carbon dioxide, which is the gas after substitution, as well as basic substances added as needed, in this water at a higher concentration and with greater efficiency.

[0032] Furthermore, the method for producing a carbon dioxide-absorbing cement-containing mixture according to this disclosure has the excellent effect of suppressing the residue of carbon dioxide in fresh concrete, mortar, etc., and producing concrete, mortar, etc., without causing a deterioration in quality due to the addition of carbon dioxide during the production of fresh concrete, mortar, etc. [Brief explanation of the drawing]

[0033] [Figure 1] This is an explanatory diagram showing an overview of the treated water production apparatus according to this embodiment. [Figure 2]This flowchart shows the necessary processes for the manufacturing method of carbon dioxide absorption treated cement-containing compound according to Embodiment 1. [Figure 3] Figure 2 is a schematic diagram illustrating the outline of the water hardening treatment process, as shown in the process diagram. [Figure 4] Figure 2 is a schematic explanatory diagram illustrating the outline of the carbonation treatment of fresh concrete, as shown in the process diagram. [Figure 5] Figure 2 is a schematic diagram illustrating the process up to the point of producing fresh concrete, as shown in the process diagram. [Figure 6] This is an explanatory diagram showing the process of placing fresh concrete, produced by the method for producing carbon dioxide-absorbing treated cement-containing mixture according to Embodiments 1 and 2, on site. [Figure 7] This is a flowchart illustrating the general cement manufacturing process, showing each step of the process. [Figure 8] This is an explanatory diagram showing an overview of the equipment responsible for the raw material process, as shown in the process diagram in Figure 7. [Figure 9] This is an explanatory diagram showing an overview of the equipment responsible for the firing process, as shown in the process diagram in Figure 7. [Figure 10] This is an explanatory diagram showing an overview of the equipment responsible for the finishing process, as shown in the process diagram in Figure 7. [Figure 11] This flowchart shows the necessary processes for the manufacturing method of carbon dioxide absorption treated cement-containing compound according to Embodiment 2. [Figure 12] This is a schematic explanatory diagram showing the outline of the hydraulic water hardening treatment process, which is one of the process diagrams shown in Figure 11. [Figure 13] Figure 11 is a schematic diagram illustrating the process up to the point of producing fresh concrete. [Figure 14] This is a process diagram for manufacturing tiles using the method for producing a carbon dioxide absorption treated lime-containing kneaded material according to the reference form. [Modes for carrying out the invention]

[0034] Hereinafter, embodiments of the treated water production apparatus of the present invention and embodiments 1 and 2 of the method for producing a carbon dioxide absorption treated cement-containing kneaded product will be described in detail with reference to the drawings.

[0035] The treated water production apparatus according to the present invention degasseds unwanted dissolved gases from a liquid and generates a substituted gas solution in which carbon dioxide, a necessary gas, is dissolved in the liquid as the substituted gas. The apparatus produces either treated water (carbonated water) obtained by dissolving carbon dioxide, a necessary gas, in water, or treated water (hydraulic treated water) obtained by dissolving carbon dioxide, a necessary gas, in an aqueous solution of a basic substance. The liquid is water, etc. Furthermore, the method for producing a carbon dioxide absorption treated cement-containing mixture according to the present invention is a method for producing fresh concrete, mortar, etc., by mixing cement and aggregate with treated water produced by the treated water production apparatus according to the present invention as the water required for hydraulic hardening of concrete, mortar, etc.

[0036] Carbon dioxide is a gas that originates from large quantities of exhaust gas generated at various facilities, mainly located in external factories, such as power plants, industrial gas manufacturing plants, oil refineries, steel mills and smelters, cement manufacturing plants, chemical manufacturing plants, and waste treatment plants. The exhaust gas can be pure carbon dioxide or a mixed gas containing carbon dioxide. However, in the case of a mixed gas, the treated water production apparatus and the method for producing carbon dioxide-absorbing cement-containing kneaded material according to the present invention are used to supply the necessary gas, which is pre-treated to remove components other than carbon dioxide from the mixed gas, so that it is substantially the same as pure carbon dioxide.

[0037] In addition to exhaust gas from factory equipment, the carbon dioxide gas may also be industrial-grade carbon dioxide gas filled in reusable cylinders.

[0038] The method for producing carbon dioxide-absorbing treated cement-containing mixed products according to the present invention is a technology that contributes to carbon neutrality or carbon negativity by using carbon dioxide exhausted from the equipment in the production of fresh concrete and mortar, in order to suppress atmospheric emission of carbon dioxide.

[0039] First, we will briefly explain the general cement manufacturing process using Figures 7 to 10. Figure 7 is a flowchart showing the general cement manufacturing process for each stage. Figure 8 is an explanatory diagram showing the equipment responsible for the raw material stage in the process diagram shown in Figure 7, Figure 9 shows an explanatory diagram showing the equipment responsible for the firing stage, and Figure 10 shows an explanatory diagram showing the equipment responsible for the finishing stage.

[0040] As shown in Figure 7, a typical cement manufacturing process is broadly divided into three stages: the raw material stage S111, the firing stage S112, and the finishing stage S113, and is carried out in the order from the raw material stage S111 to the finishing stage S113.

[0041] <Raw material process> As shown in Figures 7 and 8, the raw material process S111 is carried out in the first manufacturing plant 500A, which is equipped with a crusher 510, a dryer 520, a mixer 530, etc. The raw materials for cement are limestone (CaCO3) K1, clay K2, silica K3, and iron oxide K4. In the raw material process S111, these raw materials are each fed separately into the crusher 510 via a collection and conveying path 501. In the crusher 510, the limestone K1, clay K2, silica K3, and iron oxide K4 are each crushed separately. After crushing, the limestone K1, clay K2, silica K3, and iron oxide K4 are each transported separately to the dryer 520 via a post-crushing conveying path 502, where they are heated.

[0042] As a result, limestone K1, clay K2, silica K3, and iron oxide K4 become dry cement raw materials with their moisture content removed. Next, these cement raw materials are transported to the mixer 530 via the post-drying transport path 503, where the powdered limestone K1, clay K2, silica K3, and iron oxide K4 are mixed together. At this time, the dry cement raw materials have been finely ground by the crusher 510 and dehydrated by the dryer 520, so they are formed into a homogeneous, fine powder mixture. The cement raw material powder discharged from the mixer 530 is sent to the next step, the firing step S112, via the post-powder transport path 504.

[0043] <Firing Process> As shown in Figures 7 and 9, the firing process S112 is carried out in the second manufacturing plant 500B, which is equipped with a preheater 540, a firing furnace 550, a cooler 560, etc. In the firing process S112, the cement raw material powder sent from the post-powder transport path 504 is preheated in the preheater 540 in order to improve the efficiency of the firing work in the firing furnace 550 and to improve the firing quality. After preheating, the cement raw material powder is transported to the firing furnace 550 via the post-preheat transport path 505 and heated to a maximum of 1450°C in the firing furnace 550.

[0044] As a result, the cement raw material powder is converted into clinker, which is formed into lumps of about 10 to 50 mm in diameter by the reaction that occurs in the firing furnace 550. After being rapidly cooled with cold air by the cooler 560, it is transported out through the clinker transport path 506. The clinker sent to the clinker transport path 506 is temporarily stored in a clinker storage facility (not shown) and cooled to a predetermined temperature in the facility before being sent from the clinker transport path 506 to the next finishing process S113.

[0045] <Finishing Process> As shown in Figures 7 and 10, the finishing process S113 is carried out in the third manufacturing plant 500C, which is equipped with a coarse crusher 570 and a finishing crusher 580, etc. In the finishing process S113, the clinker produced in the firing process S112 is fed into the coarse crusher 570 through the clinker transport path 507a, and gypsum is fed into the gypsum transport path 507b. Gypsum is added during the production of fresh concrete to adjust the hardening rate of the cement.

[0046] Clinker and gypsum are first coarsely ground in a coarse grinder 570, and then further ground in a finish grinder 580 to produce fine powder with even finer particle sizes, which is then used to make cement. The cement is discharged from the third manufacturing plant 500C through a cement transport path 509. In the case of mixed cements such as blast furnace cement or fly ash cement, blast furnace slag or fly ash is added as one of the admixtures in addition to clinker and gypsum.

[0047] Next, an overview of the treated water production apparatus according to this embodiment will be described using Figure 1. Figure 1 is an explanatory diagram showing an overview of the treated water production apparatus according to this embodiment. Note that in Figure 1, in order to make the diagram easier to read, illustrations of non-essential parts such as electrical wiring have been omitted. Furthermore, as will be described later, the treated water production apparatus according to this embodiment is used to produce treated water used in the method for producing carbon dioxide absorption treated cement-containing kneaded material according to Embodiments 1 and 2.

[0048] As shown in Figure 1, the treated water production apparatus 1 comprises a gas-liquid mixing container 2, a liquid supply unit 3 (liquid storage unit), a gas supply unit 4 (gas storage unit), a solution recovery unit 5, a control unit 6 (control means), and a carbon dioxide recovery means 60 (see Figures 3 and 12). The control unit 6 is electrically connected to the delivery pump 21 (pump), vacuum pump 22 (gas exhaust means), three-way switching valve 24 (liquid flow control valve), temperature controller 25 (liquid temperature control means), control unit 31c of the flow control valve 31 (gas flow control valve), pressure regulating valve 32, on-off valves 33a to 33d, on-off valve 33X (gas flow control valve), thermometer 41, dissolved gas concentration meter 42, liquid level gauge 43, and compound gauge 44, etc., and controls the operation of various devices such as valve operation and pump on / off.

[0049] Liquid L (water) can be contained within the liquid supply unit 3 by an on-off valve 33a on the liquid containment pipe 13 connected to the liquid supply unit 3, and is stored within the liquid supply unit 3. The necessary gas G (carbon dioxide) is stored in the gas supply unit 4 under high pressure exceeding atmospheric pressure. The gas-liquid mixing container 2 is a container having an internal space 2S that can contain the liquid L supplied from the liquid containment pipe 13 and the necessary gas G supplied from the gas supply unit 4 in a liquid-tight and airtight manner. The liquid supply unit 3 is connected in series with the gas-liquid mixing container 2 via a liquid supply pipe 11 (liquid introduction pipeline, liquid introduction flow path), a three-way switching valve 24, a delivery pump 21, and an on-off valve 33b. The liquid supply pipe 11 is connected in communication with a nozzle 23 located in the internal space 2S of the gas-liquid mixing container 2.

[0050] The delivery pump 21 delivers liquid L from the liquid storage pipe 13 into the internal space 2S of the gas-liquid mixing container 2. The nozzle 23 atomizes the liquid L delivered by the delivery pump 21 and sprays it into the internal space 2S. Specifically, the nozzle 23 is either a multi-port nozzle with a first port connectable to the liquid supply pipe 11 and a second port connectable to the gas supply pipe 14, or a single-port nozzle connectable to the liquid supply pipe 11.

[0051] The multi-port nozzle 23 is a so-called two-fluid nozzle that mixes liquid L with the required gas G and sprays the liquid L at a higher pressure, for example, in a fine mist of several micrometers. In the multi-port nozzle 23, increasing the flow rate ratio of the required gas G to be discharged (gas-water volume ratio) relative to liquid L results in finer particles of the sprayed liquid L. The single-port nozzle 23 is a so-called single-fluid nozzle that can spray liquid L at a higher pressure in a fine mist of several micrometers, such as a fan spray nozzle that performs a fan-shaped liquid film jet. The structure of the multi-port nozzle 23 and the single-port nozzle 23 are not particularly limited.

[0052] The gas-liquid mixing container 2 has liquid circulation systems F and F2 that allow the liquid L contained in the internal space 2S to be circulated and flowed by the delivery pump 21. In this embodiment, a three-way switching valve 24 that controls the flow of liquid L is disposed between the liquid supply section 3 and the delivery pump 21 of the liquid supply pipe 11. In addition, separate from the liquid supply pipe 11, a liquid circulation pipe 12 is connected in parallel with the delivery pump 21 via an on-off valve 33c between the internal space 2S of the gas-liquid mixing container 2 and the three-way switching valve 24.

[0053] In other words, in the treated water production apparatus 1, the control unit 6, as shown in Figure 1, selectively switches between the first flow paths F1 and F for liquid L and the second flow paths F2 and F for liquid L or a gas-liquid mixture LG containing liquid L and the necessary gas G, using a three-way switching valve 24. The first flow paths F1 and F are flow paths that supply liquid L from the liquid supply unit 3 to the internal space 2S of the gas-liquid mixing container 2 via the liquid supply pipe 11, the three-way switching valve 24, and the discharge pump 21. The second flow paths F2 and F are flow paths that circulate and supply the liquid L or gas-liquid mixture LG contained in the internal space 2S of the gas-liquid mixing container 2 to the internal space 2S of the gas-liquid mixing container 2 via the liquid circulation pipe 12 and the liquid supply pipe 11.

[0054] The temperature controller 25 is installed in the gas-liquid mixing container 2. The temperature controller 25 heats or cools the liquid L, the gas-liquid mixture LG containing the liquid L (hereinafter, the liquid L and the gas-liquid mixture LG may be collectively referred to as "target liquid LG"), or the required gas G contained in the internal space 2S of the gas-liquid mixing container 2, to adjust it to the desired set temperature T.

[0055] A thermometer 41, a dissolved gas concentration meter 42, a liquid level gauge 43, and a compound gauge 44 are installed in the gas-liquid mixing container 2. The thermometer 41 measures the temperature of the target liquid LG inside the gas-liquid mixing container 2 using its sensor unit 41s. The dissolved gas concentration meter 42 is, for example, a dissolved carbon dioxide concentration meter, a dissolved nitrogen concentration meter, or a dissolved oxygen concentration meter, and measures the concentration of indicator gases dissolved in the target liquid LG, i.e., the amount of carbon dioxide, nitrogen, oxygen, etc., using its sensor unit 42s. The liquid level gauge 43 detects the liquid level of the target liquid LG using its sensor unit 43s in order to determine the amount of liquid LG stored. The compound gauge 44 measures the vacuum level and pressure of the atmosphere in the internal space 2S. The measurement control unit 44c of the compound gauge 44 is electrically connected to the control unit 6.

[0056] The gas-liquid mixing container 2 is connected to the internal space 2S by a venting pipe 17 equipped with an on-off valve 33d, and a pressure regulating valve 32 is also provided. The pressure regulating valve 32 adjusts the atmospheric pressure to an acceptable range to prevent excessive pressure rise in the internal space 2S. The venting pipe 17 is a pipe for exhausting the gas that makes up the atmosphere in the internal space 2S to the outside. The control unit 6 controls the valve operation of the on-off valve 33b and the pressure regulating valve 32 in the internal space 2S based on the vacuum level and pressure of the atmosphere measured by the compound gauge 44.

[0057] A carbon dioxide recovery means 60 is connected to the gas-liquid mixing container 2 via a piping route including an on-off valve 62 and a recovery pipe 63. The carbon dioxide recovery means 60 is responsible for recovering the necessary gas G (carbon dioxide) remaining in the gas-liquid mixing container 2 through the recovery pipe 63 after the treatment process to generate the treated water TW, which is the replacement gas solution SQ, is completed, and storing it in the carbon dioxide recovery storage unit 61.

[0058] The vacuum pump 22 is connected in series with the gas-liquid mixing container 2 via a suction pipe 15 (exhaust pipe), an on-off valve 33X, and a mist filter 26, and is in communication with the internal space 2S. The vacuum pump 22 is configured to suck in the gas that makes up the atmosphere inside the gas-liquid mixing container 2 and exhaust it to the outside. The on-off valve 33X controls the flow of the gas that makes up the atmosphere inside the gas-liquid mixing container 2. The mist filter 26 removes moisture (target liquid LG) present with the exhausted gas. The mist filter 26 and the gas-liquid mixing container 2 are also connected to a return pipe 16 that is piped in parallel with the suction pipe 15.

[0059] As a result, when the on-off valve 33X is in the open position, the gas forming the atmosphere inside the gas-liquid mixing container 2 is drawn in from the internal space 2S through the suction pipe 15 by the vacuum pump 22, and after moisture is removed by the mist filter 26, it flows out to the outside. When the on-off valve 33X is in the closed position, the gas forming the atmosphere inside the gas-liquid mixing container 2 is drawn in from the internal space 2S through the suction pipe 15, and after moisture is removed by the mist filter 26, it is returned to the internal space 2S again through the return pipe 16.

[0060] The gas supply unit 4 is connected in series with the gas-liquid mixing container 2 via a gas supply pipe 14 (gas introduction pipeline / gas introduction flow path) and a flow control valve 31, and communicates with the internal space 2S. The flow control valve 31 controls the flow of the required gas G to the internal space 2S of the gas-liquid mixing container 2.

[0061] As shown in Figure 1, in the treated water production apparatus 1, the nozzle 23 is a double-port nozzle 23. The gas supply pipe 14 is connected to the liquid supply pipe 11 and communicates with the double-port nozzle 23. As a result, the required gas G is supplied to the internal space 2S of the gas-liquid mixing container 2 through the double-port nozzle 23 in a state mixed with the target liquid LG (liquid L, or gas-liquid mixture LG).

[0062] In the treated water production apparatus 1, the control unit 6 uses a vacuum pump 22 to create a vacuum in the gas-liquid mixing container 2, which is under a pressure lower than atmospheric pressure. The control unit 6 then uses a discharge pump 21 to spray a liquid L or gas-liquid mixture LG, whose temperature has been adjusted to a set temperature T by a temperature controller 25, from a nozzle 23 while circulating it. At the same time, the control unit 6 supplies the necessary gas G from a gas supply pipe 14 in a state that allows it to come into contact with the sprayed mist-like liquid L. As a result, a replacement gas solution SQ, described later, is generated in the internal space 2S of the gas-liquid mixing container 2.

[0063] The solution recovery unit 5 is connected to the internal space 2S of the gas-liquid mixing container 2 by an outlet pipe 18 equipped with an on-off valve 33e, and is also connected to a discharge pipe 19 equipped with an on-off valve 33f. The solution recovery unit 5 is a container that temporarily contains and stores the substituted gaseous solution SQ generated in the internal space 2S. The inside of the solution recovery unit 5 is always configured to be approximately the same pressure as the external pressure (e.g., atmospheric pressure). The substituted gaseous solution SQ is discharged from the solution recovery unit 5 through the discharge pipe 19 to the outside of the treated water production device 1 and used for the purpose of adding water necessary for the hydraulic hardening of concrete, mortar, etc., as will be described later.

[0064] Next, the functions of the treated water production apparatus 1 according to this embodiment will be described. The treated water production apparatus 1 according to this embodiment is an apparatus that performs a dissolved gas replacement treatment process to produce a replaced gas solution SQ by degassing unwanted dissolved gases from liquid L and dissolving the necessary gas G as the replacement gas in liquid L. The dissolved gas replacement treatment process consists of four steps: a liquid heating process in the container, a degassing process for unwanted gases, a liquid cooling and heating process after degassing, and a gas-liquid mixing process. The necessary gas G is carbon dioxide (gas carbon dioxide). The liquid is water or the hydraulic primary treated water TW2 (hydraulic treated water according to the present invention), which will be described later. The replaced gas solution SQ is, as described later, carbonated water TW1, hydraulic primary treated water TW2, or hydraulic secondary treated water TW3 (hydraulic treated water according to the present invention), which is the treated water TW required in the method for producing a carbon dioxide absorption treated cement-containing kneaded product according to Embodiments 1 and 2.

[0065] First, a liquid heating process inside the container is performed. The liquid heating process inside the container includes opening the liquid supply pipe 11, supplying the liquid L from the liquid supply unit 3 into the internal space 2S of the gas-liquid mixing container 2, closing the liquid supply pipe 11 once, and then heating all the liquid L contained in the internal space 2S to a set temperature T1 higher than the normal temperature.

[0066] In the unnecessary gas degassing process, the gas supply pipe 14 is closed, and the gas existing in the internal space 2S of the gas-liquid mixing container 2 is sucked by the vacuum pump 22 in a vacuum state lower than the atmospheric pressure. While sucking, the liquid heated to the set temperature T1 is made to flow with circulation through the nozzle 23 into a fine and diffused state and sprayed into the internal space 2S, so that the unnecessary gas degassed from the liquid L is exhausted outside the gas-liquid mixing container 2.

[0067] After the unnecessary gas degassing process, in the post-degassing liquid cooling and heating process, the post-degassing liquid L, which is in a state where unnecessary gas has been degassed, is cooled to a set temperature T2 (T2 < T1) lower than the set temperature T1.

[0068] After the unnecessary gas degassing process, in the gas-liquid mixing process, the post-degassing liquid L is sprayed into the internal space 2S in a state of being made fine and diffused through the nozzle 23 with circulation with respect to the gas-liquid mixing container 2. At the same time, the necessary gas G supplied from the gas supply unit 4 is brought into contact with and mixed with the post-degassing liquid L sprayed from the nozzle 23 under high pressure by opening the gas supply pipe 14. [[ID=1,4]]

[0069] Specifically described is as follows. In implementing the dissolved gas replacement treatment process, in the treated water production apparatus 1, the on-off valves 33c, 33d, 33e, the on-off valve 33X, and the flow control valve 31 are pre-closed, and the on-off valve 33b is open. In the three-way switching valve 24, the first flow paths F1 and F of the liquid L are open. <s

[0070] In the process of heating the liquid inside the container, a predetermined amount of liquid L is first supplied from the liquid supply unit 3 through the first flow path F1, F (liquid supply pipe 11) to the internal space 2S of the gas-liquid mixing container 2 by suction using the delivery pump 21. In the liquid supply unit 3, the on-off valve 33a is normally closed, but to prevent the inside of the liquid supply unit 3 from becoming a vacuum, the on-off valve 33a is opened when liquid L is supplied to the liquid supply unit 3 through the liquid containment pipe 13, and closed after the liquid L has been supplied.

[0071] Once the supply of liquid L is complete, the operation of the delivery pump 21 is stopped. Next, the entire supplied amount of liquid L is heated to a set temperature T1, which is higher than room temperature, by the temperature controller 25. The temperature of liquid L can be determined from the measurement value of the thermometer 41 detected by the sensor unit 41s, and the temperature controller 25 adjusts the temperature by heating the liquid L until it reaches the set temperature T1 based on the measurement value of the thermometer 41.

[0072] Next, once the entire volume of liquid L has been heated to the set temperature T in the internal space 2S of the gas-liquid mixing container 2, the unwanted gas degassing process is performed. During the unwanted gas degassing process, the control unit 6 closes valve 33b and opens valves 33c, 33d and 33X, and simultaneously switches the flow path opened by the three-way switching valve 24 from the first flow paths F1, F to the second flow paths F2, F. The control unit 6 also restarts the delivery pump 21 and the vacuum pump 22.

[0073] As a result, liquid L is not supplied from the liquid supply unit 3 to the gas-liquid mixing container 2, and only the entire amount of liquid L contained in the internal space 2S is circulated repeatedly through the second flow paths F2, F, including the liquid circulation pipe 12, by the delivery pump 21 within the internal space 2S of the gas-liquid mixing container 2. That is, within the internal space 2S of the gas-liquid mixing container 2, the heated liquid L is atomized through the nozzle 23 under flow accompanied by circulation within the gas-liquid mixing container 2 via the second flow paths F2, F, and sprayed in a diffused state. Through the atomization of liquid L, any unwanted dissolved gases are degassed from the liquid L.

[0074] The removed unwanted gas is released into the atmosphere of the internal space 2S. During the unwanted gas degassing process, the gas-liquid mixing container 2 is evacuated by the vacuum pump 22, so the gas that makes up the atmosphere of the internal space 2S is sucked in by the vacuum pump 22 and exhausted to the outside of the gas-liquid mixing container 2 through the suction pipe 15.

[0075] The gas that makes up the atmosphere in the internal space 2S is originally, for example, air or gases other than the required gas G. By releasing the degassed unwanted gas into the internal space 2S, it becomes a state containing unwanted gas. In the unwanted gas degassing process, after closing the on-off valve 33b, the vacuum pump 22 sucks out the atmosphere gas containing unwanted gas from the internal space 2S and exhausts it to the outside of the gas-liquid mixing container 2, creating a vacuum state inside the gas-liquid mixing container 2 at a pressure lower than atmospheric pressure.

[0076] Let me explain in detail. In a sealed, negative-pressure internal space 2S, the liquid L contained in the internal space 2S is sprayed from the nozzle 23 as a fine mist of several μm in size into the gas-liquid mixing container 2, and is stored at the bottom of the internal space 2S. The liquid L accumulated at the bottom of the internal space 2S is sent by the discharge pump 21 through the second flow paths F2, F towards the nozzle 23. The liquid L, diffused into fine particles from the nozzle 23, is sprayed back into the internal space 2S.

[0077] In this way, only the liquid L contained in the internal space 2S is repeatedly circulated through the second flow paths F2 and F, including the liquid circulation pipe 12, by the delivery pump 21 within the internal space 2S of the gas-liquid mixing container 2. Although particulate liquid L floating in the internal space 2S may also be sucked into the suction pipe 15 by the vacuum pump 22, the sucked-in particulate liquid L (mist) is collected by the mist filter 26 and returned to the internal space 2S through the return pipe 16.

[0078] When liquid L is sprayed from nozzle 23 in a finely diffused state, each time liquid L is sprayed, unwanted gases dissolved in liquid L are gradually degassed from the liquid L and released into the negative-pressure internal space 2S. Since liquid L has been heated to the set temperature T1 in the container liquid heating process beforehand, unwanted gases dissolved in liquid L are easily degassed. Furthermore, during the unwanted gas degassing process, if the liquid L contained in the internal space 2S is kept at the set temperature T1 by the temperature controller 25, or if necessary, the cooled liquid L is reheated to the set temperature T1, the degassing of unwanted gases dissolved in liquid L is accelerated. As a result, unwanted gases are degassed in a shorter time.

[0079] When removing unwanted gases, the on-off valve 33d is open, so the unwanted gases are removed from the liquid L in an amount equal to the total volume of liquid L sprayed into the closed internal space 2S and released into the internal space 2S, and then exhausted to the outside through the discharge pipe 17. The state of unwanted gas removal can be determined based on the measured value of the dissolved gas concentration meter 42 detected by the sensor unit 42s, with respect to the concentration of an indicator gas (e.g., oxygen or nitrogen) dissolved in the liquid L contained in the internal space 2S, and based on a judgment that takes into account the rate of change per unit time.

[0080] Furthermore, the vacuum state inside the gas-liquid mixing container 2 can be determined by a compound gauge 44 based on measured values ​​of the vacuum degree and pressure in the internal space 2S, taking into account the rate of change per unit time. The vacuum degree in the internal space 2S is, for example, in the vacuum classification defined by JIS (Japanese Industrial Standards), at least medium vacuum (100 to 0.1 Pa) and high vacuum (10 ‐1 ~10 ‐5 It is preferable that the vacuum state corresponds to Pa.

[0081] Thus, the dissolved unwanted gas is removed from the liquid L, the operation of the vacuum pump 22 is stopped, and the unwanted gas removal process is completed.

[0082] Next, after degassing the unnecessary gas, the post-degassing liquid cooling and heating process is carried out. The control unit 6 adjusts the temperature regulator 25 to a set temperature T2 (T2 < T1) around room temperature by lowering it from the set temperature T1. As a result, the post-degassing liquid L, which is in a state where unnecessary gas has been degassed, is cooled to the set temperature T2.

[0083] Next, the gas-liquid mixing process is carried out. After the unnecessary gas degassing process, the control unit 6 closes the on-off valve 33d and the on-off valve 33X while keeping the delivery pump 21 operating, and at the same time opens the flow control valve 31. As a result, the necessary gas G stored at high pressure in the gas supply unit 4 continues to be supplied through the gas supply pipe 14 and is accommodated in the internal space 2S of the gas-liquid mixing vessel 2 which is in a vacuum state under airtight conditions while remaining in a high-pressure state. When accommodating the necessary gas G in the internal space 2S, the supply amount of the necessary gas G is appropriately adjusted by the control unit 6 controlling the valve opening degree of the flow control valve 31 under the pressure management by the pressure gauge 44 so that the pressure in the internal space 2S remains within the allowable range.

[0084] The necessary gas G (carbon dioxide gas) is discharged by merging with the liquid L delivered through the second flow paths F2 and F at the nozzle 23 in the internal space 2S. As a result, the necessary gas G (carbon dioxide gas) in a high-pressure state comes into contact with and mixes with the particulate liquid L (water or primary treated water for water hardness), dissolves in the liquid L, and becomes a gas-liquid mixture LG (carbonated water or secondary treated water for water hardness). The gas-liquid mixture LG is stored at the bottom of the internal space 2S.

[0085] Before being stored at the bottom of the internal space 2S, since the gas-liquid mixture LG is generally at the set temperature T1, the temperature regulator 25 cools the gas-liquid mixture LG to a set temperature T2 around room temperature lower than the set temperature T1. The temperature of the gas-liquid mixture LG can be obtained from the measured value of the thermometer 41 detected by the sensor unit 41s, and the temperature regulator 25 adjusts the temperature of the gas-liquid mixture LG based on the measured value of the thermometer 41.

[0086] The gas-liquid mixture LG accumulated at the bottom of the internal space 2S is temperature-controlled to the set temperature T2 by the temperature controller 25 and sent again to the nozzle 23 in the internal space 2S via the second flow paths F2 and F by the delivery pump 21. From the nozzle 23, it is sprayed into the internal space 2S in a diffused, fine-particle state. In addition, the necessary gas G is continuously discharged from the gas supply unit 4 at high pressure and supplied to the internal space 2S in a mixed state with the sprayed gas-liquid mixture LG. As a result, the internal space 2S is gradually pressurized to a pressure within the allowable range.

[0087] In this way, the gas-liquid mixture LG contained in the internal space 2S is repeatedly circulated through the second flow paths F2 and F, including the liquid circulation pipe 12, by the delivery pump 21, while the necessary gas G is continuously supplied to the particulate gas-liquid mixture LG. When the gas-liquid mixture LG is sprayed from the nozzle 23 in a diffused, particulate state, each time the gas-liquid mixture LG is sprayed, the sprayed particulate gas-liquid mixture LG is pressurized with the necessary gas G, and the necessary gas G gradually dissolves into the gas-liquid mixture LG.

[0088] In other words, in the internal space 2S, the gas-liquid mixture LG is at a temperature close to room temperature. This gas-liquid mixture LG is atomized into fine particles and sprayed into the internal space 2S by the supply of the required gas G. Therefore, when the required gas G, supplied under high pressure, comes into contact with the fine-particle gas-liquid mixture LG, the dissolution of the required gas G into the gas-liquid mixture LG is promoted, and the required gas G dissolves into the gas-liquid mixture LG in a shorter time.

[0089] In this case, when the required gas G under high pressure is dissolved in a particulate gas-liquid mixture LG cooled to room temperature, the dissolved state of the required gas G in the gas-liquid mixture LG becomes more stable over a long period of time compared to when the required gas G is not supplied under high pressure and the gas-liquid mixture LG is not cooled from the set temperature T.

[0090] The dissolved state of the required gas G can be monitored and determined based on the measured value of the dissolved gas concentration meter 42 detected by the sensor unit 42s, taking into account the rate of change per unit time, relative to the concentration of an indicator gas dissolved in the gas-liquid mixture LG accumulated at the bottom of the internal space 2S. In this embodiment, since the required gas G is carbon dioxide, the dissolved state of carbon dioxide is determined based on the measured value of the dissolved carbon dioxide concentration by the dissolved gas concentration meter 42. The circulation operation of the delivery pump 21 and the supply of the required gas G are continued until the desired dissolved carbon dioxide concentration is reached in the gas-liquid mixture LG.

[0091] When the desired dissolved carbon dioxide concentration is reached in the gas-liquid mixture LG, i.e., the replaced gaseous solution SQ, which is generated in the internal space 2S, the flow control valve 31 is closed to stop the supply of the necessary gas G from the gas supply unit 4, and the venting pipe 17 is opened to reduce the pressure of the internal space 2S to atmospheric pressure. In the case that, under the high-pressure conditions of the internal space 2S, if the dissolution of the necessary gas G in the gas-liquid mixture LG exceeds saturation, and the necessary gas G continues to be supplied to the internal space 2S, the excess necessary gas G that has become supersaturated is recovered from the gas-liquid mixing container 2 and stored in the carbon dioxide recovery storage unit 61 of the carbon dioxide recovery means 60.

[0092] Thus, during the gas-liquid mixing process, the substituted gaseous solution SQ is generated at room temperature in the internal space 2S. After the opening of the on-off valve 33e, the substituted gaseous solution SQ is transferred to the solution recovery section 5 through the outlet pipe 18 with the on-off valve 33d open, and then flows out from the solution recovery section 5 through the discharge pipe 19 with the opening of the on-off valve 33f, and as described below, it can be used as treated water necessary for the hydraulic hardening of concrete, mortar, etc. in the method for producing carbon dioxide-absorbing treated cement-containing kneaded material according to Embodiments 1 and 2.

[0093] (Embodiment 1) Next, the method for producing a carbon dioxide absorption treated cement-containing mixture according to Embodiment 1 will be explained with reference to Figures 2 to 5.

[0094] The method for producing a carbon dioxide absorption treated cement-containing mixture according to Embodiment 1 comprises a first cement-containing mixture production step and, if necessary, a cement-containing mixture purification step. In the first cement-containing mixture production step, as the water required for the hydraulic hardening of the concrete, in Embodiment 1, hydraulic treated water (carbonated water) in which carbon dioxide gas is dissolved in water is used to produce fresh concrete in a first state (cement-containing mixture in a first state) by adding the hydraulic treated water (carbonated water) together with cement and aggregate and mixing them. The hydraulic treated water (carbonated water) is treated water in the form of a displacement gas solution SQ produced by the treated water production device 1. In the first cement-containing mixture production step, the internal space of the mixing container for producing the fresh concrete in a first state is evacuated to a pressure lower than atmospheric pressure, and the cement, aggregate and hydraulic treated water (carbonated water) are mixed.

[0095] Furthermore, the cement-containing mixture refining process involves adding a basic substance to the fresh concrete in the first state and mixing it to produce fresh concrete in the second state (a cement-containing mixture in the second state) which is purified to an alkaline state. The basic substance is a salt containing a metal belonging to the alkali metal or alkaline earth metal group, or a basic amino acid.

[0096] Let me explain in detail. Figure 2 is a flowchart showing the necessary processes for the manufacturing method of carbon dioxide absorption treated cement-containing mixture according to Embodiment 1. Figure 3 is a schematic explanatory diagram showing the outline of the hydraulic water generation process among the processes shown in Figure 2. Figure 4 is a schematic explanatory diagram showing the outline of the carbonation process of fresh concrete among the processes shown in Figure 2. Figure 5 is a schematic explanatory diagram showing the outline of the process up to the point of producing fresh concrete among the processes shown in Figure 2.

[0097] In the method for producing a carbon dioxide-absorbing treated cement-containing mixture according to Embodiment 1, the replaced gaseous solution SQ is carbonated water, which is hydraulically treated water TW1 (treated water TW). As shown in Figure 2, the first cement-containing mixture production process involves cement input S1, material mixing treatment S2, water addition with carbonated water S4, mixing treatment S5, carbonation treatment of fresh concrete S6, alkalization treatment of fresh concrete S7, and completion of fresh concrete production S8, all of which are performed in a batching plant (first mixing equipment section 101A and second mixing equipment section 101B shown in Figures 4 and 5) installed in a ready-mix concrete plant. The hydraulically treated water TW1 generation treatment S3 is performed by a treated water production device 1 (see Figure 1) located in the treated water generation equipment section 101, which generates the replaced gaseous solution SQ (treated water TW) as the hydraulically treated water TW1 (carbonated water) to be used.

[0098] <Production process S3 for water hardening treatment TW1> In the method for producing a carbon dioxide-absorbing cement-containing mixture according to Embodiment 1, in the hydraulic water production process S3 of hydraulic water TW1, as shown in Figure 3, water (liquid L) is supplied to the treated water production device 1 through the liquid supply pipe 11, and carbon dioxide (required gas G) is supplied through the gas supply pipe 14. The water (liquid L) is tap water or industrial water, etc. When water (liquid L) and carbon dioxide (required gas G) are added to the treated water production device 1, the following reaction occurs: (chemical 1) H2O + CO2 → H2CO3 ... Chemical reaction equation (1) In the treated water production apparatus 1, the displacement gas solution SQ becomes hydrohard treated water TW1 (treated water TW) (carbonated water) in which carbon dioxide is dissolved in water, particularly in a supersaturated state exceeding the saturation concentration of carbon dioxide.

[0099] As shown in Figure 3, in the treated water production apparatus 1, if carbon dioxide (required gas G) that did not contribute to the generation of the hydraulically treated water TW1 remains in the internal space 2S of the gas-liquid mixing container 2, the unused carbon dioxide that did not contribute to the generation is returned to the carbon dioxide recovery and storage unit 61 and recovered. The carbon dioxide recovered in the carbon dioxide recovery and storage unit 61 is purified to its original high-concentration state and reused.

[0100] <Cement input S1 and material mixing process S2> On the other hand, in the method for producing a carbon dioxide-absorbing treated cement-containing mixture according to Embodiment 1, the first cement-containing mixture production step is carried out in the first mixing equipment section 101A of the batching plant, as shown in Figure 4. Specifically, in the initial cement input S1, as an example, in addition to the cement M1 produced in the cement production process, coarse aggregate M2, fine aggregate M3, admixture M4, and admixture M5 are used. The admixture M5 is fine silica particles (SiO2) that form a spherical shape with an average particle size of 0.2 to 10 μm. All of the coarse aggregate M2, fine aggregate M3, admixture M4, and admixture M5 are fed into the mixing kneader 120 via the collection and conveying path 111. In the next material mixing process S2, the coarse aggregate M2, fine aggregate M3, admixture M4, and admixture M5 are stirred in the mixing kneader 120 so that they are mixed in a homogeneous state.

[0101] Incidentally, as shown in Figures 7 and 9, exhaust gas is generated from the second manufacturing plant 500B during the firing process, which is the main step in the cement manufacturing process at the cement manufacturing plant. In particular, the carbon dioxide contained in the exhaust from the preheater 540 and the firing furnace 550 can be used in the hydraulic water treatment water TW1 generation process S3, and thus serves as a supply source for the treated water production device 1.

[0102] Carbon dioxide, or CO2 gas, is supplied to the treated water production device 1 via a piping system connecting the treated water production device 1 and the calcination furnace 550 (not shown), and can be effectively utilized as carbon dioxide (required gas G) consumed in the production process S3 of the hydraulically treated water TW1.

[0103] In other words, as shown in Figures 7 and 9, when the second manufacturing plant 500B performs the calcination process S112, the limestone K1 (CaCO3) contained in the cement raw material powder is heated to 1450°C or higher in the calcination furnace 550, resulting in the following reaction: (Case 2) CaCO3 → CaO + CO2 ... Chemical reaction equation (2) Limestone (CaCO3) K1 separates into calcium oxide (CaO) and carbon dioxide (CO2) gases. In the first mixing equipment section 101A, the calcium oxide (CaO) becomes one of the components of the clinker and is sent from the clinker transport path 506 to the next finishing process S113.

[0104] <Hydration S4 and kneading treatment S5 using water hardened water TW1> In the next step, water addition S4 with hydraulic treated water TW1, the hydraulic treated water TW1 (treated water TW) (carbonated water) generated in the hydraulic treated water TW1 generation process S3 is poured into the mixing kneader 120 of the first mixing equipment section 101A via the collective conveying path 111, as shown in Figure 4. The mixture of cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, and admixture M5, along with the hydraulic treated water TW1 (treated water TW), is mixed in the mixing kneader 120 (mixing process S5). In the mixing process S5, the mixture obtained by mixing cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, admixture M5, and hydraulic treated water TW1 (treated water TW) (carbonated water) is produced as neutralized fresh concrete (fresh concrete in the first state according to the present invention) (neutralization process S6 for fresh concrete).

[0105] In other words, this carbonated fresh concrete is produced through the following reaction: (3) CaO + H2CO3 → CaCO3 + H2O ...Chemical reaction equation (3)

[0106] Incidentally, in the first mixing equipment section 101A where the mixing process S5 is carried out, an on-off valve 131a is piped to the collective conveying path 111, and an on-off valve 131b is piped to the post-mixing conveying path 112, so that the vacuum level inside the mixing kneader 120 can be maintained. In addition, a vacuum exhaust pipe 113, which is in communication with the inside of the mixing kneader 120, is connected to a vacuum valve 131c, a leak valve 132, and a vacuum pump 133 with a gas ballast valve. The gas ballast valve is also present in the vacuum pump 173a with a gas ballast valve, which will be described later, and is provided to increase the water vapor resistance of the vacuum pump 133 when it sucks in and exhausts humid gases or water vapor with the vacuum pump 133.

[0107] When performing the mixing process S5, the internal space of the mixing machine 120 is evacuated to a pressure lower than atmospheric pressure, and the carbonated fresh concrete is produced. This will be explained in detail. During the material mixing process S2, the on-off valves 131a and 131b are closed, while the vacuum valve 131c is opened, and the vacuum pump 133 sucks out the atmosphere inside the mixing machine 120, thereby degassing the inside of the mixing machine 120 to a near-vacuum state. As a result, when mixing the mixture (carbonated fresh concrete) made of cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, admixture M5, and hydraulic water TW1 (treated water TW), any air or other mixed gases that are present as bubbles in the mixture are degassed from the mixture. Therefore, it is possible to prevent bubbles caused by mixed gases from remaining in the produced carbonated fresh concrete.

[0108] Furthermore, in order to avoid impairing the freeze-thaw resistance of the hardened concrete, it is important to maintain an optimal level of air bubbles in the neutralized fresh concrete and the alkaline fresh concrete (described later) by adjusting the vacuum level during suction using vacuum pumps 133 and 173a, the vacuuming time, and the vacuuming speed.

[0109] When the mixing process S5 is completed and the inside of the mixing kneader 120 is returned from a negative pressure state to an atmospheric pressure state, the suction by the vacuum pump 133 is stopped, and the leak valve 132 is gradually opened while the vacuum valve 131c remains open, thereby returning the inside of the mixing kneader 34 to atmospheric pressure.

[0110] Furthermore, when cement is added S1 and the material mixing process S2 is performed, the on-off valve 131b is closed and the on-off valve 131a is opened. Also, when the mixing process S5 is completed and the next fresh concrete carbonation process S6 is performed, the on-off valve 131b is opened. In addition, if the mixed gas is not to be degassed from the mixture, the vacuum valve 131c is kept closed.

[0111] <Alkalinization treatment of fresh concrete S7> As shown in Figure 5, in the carbonation treatment S6 of fresh concrete, the carbonated fresh concrete that has completed the mixing treatment S5 is sent to the second mixing equipment section 101B of the batching plant. In the second mixing equipment section 101B, the post-mixing transport path 141, the basic agent transport path 142, and the post-mixing transport path 143 are each connected to the inside of the mixing machine 150. The post-mixing transport path 143, which has an on / off valve 171c piped to it, is installed toward the ready-mix concrete supply area 160. An on / off valve 171a is piped to the post-mixing transport path 141, and an on / off valve 171b is piped to the basic agent transport path 142, so that the vacuum level inside the mixing machine 150 can be maintained. In addition, a vacuum exhaust pipe 144, which is connected to the inside of the mixing machine 150, is connected to a vacuum valve 171d, a leak valve 172a, and a vacuum pump 173a with a gas ballast valve.

[0112] On the other hand, as shown in Figure 5, ready-mix concrete transport vehicles 161, such as ready-mix concrete mixer trucks and ready-mix concrete truck agitators, are stationed at the ready-mix concrete supply area 160 of the second mixing equipment section 101B. The ready-mix concrete transport vehicle 161 is equipped with a vacuum exhaust pipe 145 that connects to an on-board vacuum pump 173b with a gas ballast valve, and is configured to communicate with the inside of the drum section 162. A vacuum valve 171e and a leak valve 172b are piped to the vacuum exhaust pipe 145, respectively, so that the atmosphere inside the drum section 162 can be exhausted to the outside by the on-board vacuum pump 173b. The ready-mix concrete transport vehicle 161 is also equipped with a chute 163 having an on / off valve 164.

[0113] In the method for producing a carbon dioxide-absorbing treated cement-containing mixture according to Embodiment 1, in the cement-containing mixture purification step, which corresponds to the alkalization treatment S7 of fresh concrete, neutralized fresh concrete is introduced into the mixing and mixing machine 150 through the post-mixing transport path 141, and a basic agent is introduced into the basic agent transport path 142. The basic agent is a basic substance such as lithium oxide or potassium nitrite as an example of a salt containing a metal belonging to alkali metals, calcium nitrite as an example of a salt containing a metal belonging to alkaline earth metals, or L-arginine as an example of a basic amino acid.

[0114] In the mixing and kneading machine 150, a basic agent is added to the neutralized fresh concrete, and the mixture is stirred and kneaded until both are homogeneous, thereby producing alkaline fresh concrete (fresh concrete in the second state) which is purified from the neutralized fresh concrete to an alkaline state (completion of fresh concrete production S8). Alkaline fresh concrete is a product of fresh concrete that has been purified to an alkaline pH value such as pH 11 or higher, which is sufficient to suppress the occurrence of rust due to oxidation on the reinforcing steel used in the construction of the concrete structure.

[0115] When performing the alkalizing treatment S7 of fresh concrete, the on / off valves 171a, 171b, and 171c are closed, while the vacuum valve 171d is opened. The vacuum pump 173a then sucks out the atmosphere inside the mixing machine 150, thereby vacuum-degassing the inside of the mixing machine 150. This removes any air or other gases that may be mixed in as bubbles within the mixture while the neutralized fresh concrete and basic agent are being stirred. Therefore, it is possible to prevent bubbles caused by mixed gases from remaining in the manufactured alkalized fresh concrete.

[0116] When returning the inside of the mixing and kneading machine 150 from a negative pressure state to an atmospheric pressure state after completing the alkalizing treatment S7 of the fresh concrete, the suction by the vacuum pump 173a is stopped, and the leak valve 172a is gradually opened while the vacuum valve 171d remains open, thereby returning the inside of the mixing and kneading machine 150 to atmospheric pressure.

[0117] Furthermore, when the de-aerated, alkalized fresh concrete is fed from the mixing and kneading machine 150 through the post-mixing transport path 143 into the drum section 162 of the ready-mix concrete transport vehicle 161 waiting at the ready-mix concrete supply area 160, the inside of the drum section 162 of the ready-mix concrete transport vehicle 161 is evacuated to a pressure lower than atmospheric pressure, and the alkalized fresh concrete discharged from the post-mixing transport path 143, that is, fresh concrete in a product state refined to an alkalinity of, for example, pH 11 or higher, is supplied to the ready-mix concrete transport vehicle 161.

[0118] Specifically, by closing the on-off valves 164 and 171c while opening the vacuum valve 171e, the on-board vacuum pump 173b sucks the atmosphere inside the drum section 162 of the ready-mix concrete transport vehicle 161, thereby creating a vacuum and degassing the inside of the drum section 162. This degasses any air or other gases that may be mixed in as bubbles in the fresh concrete during agitation. Therefore, it is possible to prevent bubbles caused by mixed gases from remaining in the fresh concrete. If degassing is not performed inside the fresh concrete, the vacuum valve 171e is kept closed.

[0119] It is preferable to continue using the on-board vacuum pump 173b to continuously suction the inside of the drum 162 by rotating the drum 162, even while the fresh concrete in its finished state is being agitated by the rotation of the drum 162 until it is discharged from the chute 163. This is because it can further reduce the residual amount of mixed gases in the fresh concrete in its finished state. Furthermore, the quality of the fresh concrete in its finished state can be maintained from the ready-mix concrete supply plant 160 to the concrete pouring site.

[0120] When the ready-mix concrete transport vehicle 161 arrives at the site where the fresh concrete is to be poured, and it is necessary to return the inside of the drum section 162 of the ready-mix concrete transport vehicle 161 from a negative pressure state to an atmospheric pressure state, the suction by the on-board vacuum pump 173b is stopped, and the leak valve 172b is gradually opened while the vacuum valve 171e remains open, thereby returning the inside of the drum section 162 of the ready-mix concrete transport vehicle 161 to atmospheric pressure.

[0121] <Concrete pouring> Figure 6 is an explanatory diagram showing the process of placing fresh concrete, manufactured using the method for producing carbon dioxide-absorbing treated cement-containing mixed material according to Embodiments 1 and 2, at a construction site. At the construction site, as shown in Figure 6, the fresh concrete FC in its finished state is poured out from a cylindrical flexible guide 170 attached to the chute 163 of a ready-mix concrete transport vehicle 161. At this time, when the fresh concrete FC in its finished state is poured out by the ready-mix concrete transport vehicle 161 with the tip opening of the cylindrical flexible guide 170 embedded in the poured fresh concrete FC, it is possible to prevent the incorporation of outside air (air) from the surrounding area into the fresh concrete FC in its finished state during placement.

[0122] (Embodiment 2) Next, the method for producing a carbon dioxide-absorbing treated cement-containing mixture according to Embodiment 2 will be explained with reference to Figures 11 to 13. In the method for producing a carbon dioxide-absorbing treated cement-containing mixture according to Embodiment 1, neutralized fresh concrete was produced using hydraulic treated water TW1 (carbonated water) in which carbon dioxide gas was dissolved in the treated water production device 1, and then purified to alkalize fresh concrete. In contrast, Embodiment 2 differs from Embodiment 1 in that it produces alkalize fresh concrete using hydraulic secondary treated water in which carbon dioxide gas is dissolved in hydraulic primary treated water generated in the treated water production device 1. Therefore, in Embodiment 2, the explanation will focus on the parts that differ from Embodiment 1, and the explanation of parts common to Embodiment 1 will be simplified or omitted using the same reference numerals.

[0123] The method for producing a carbon dioxide absorption treated cement-containing mixture according to Embodiment 2 includes a second cement-containing mixture production step in which, as the water required for the hydraulic hardening of concrete, hydraulic treated water is produced from carbon dioxide, water, and a basic substance, and the hydraulic treated water is added and mixed together with cement and aggregate to produce fresh concrete in a third state, wherein the hydraulic treated water is treated water produced by the treated water production device 1.

[0124] Hydraulic treated water is produced by generating a pH of 11 or higher from primary hydraulic treated water, which consists of water and a basic substance, and then dissolving carbon dioxide in the primary hydraulic treated water to produce secondary hydraulic treated water, which is produced with a pH in the range of 6 to 8. In the second cement-containing mixture production process, the cement, aggregate, and hydraulic treated water are mixed in a state where the internal space of the mixing container for producing fresh concrete in the third state is evacuated to a pressure lower than atmospheric pressure.

[0125] Let me explain in detail. Figure 11 is a flowchart showing the necessary processes for the manufacturing method of carbon dioxide absorption treated cement-containing compound according to Embodiment 2.

[0126] The second cement-containing mixed product manufacturing process, as shown in Figure 11, involves cement input S21, material mixing treatment S22, water addition with hydraulic secondary treated water TW3 S24, mixing treatment S25, and completion of fresh concrete production S26, all of which are carried out in a batching plant (mixing equipment section 201A) installed in the ready-mix concrete plant. The hydraulic secondary treated water TW3 generation treatment S23 involves generating a substituted gaseous solution SQ (treated water TW) as hydraulic secondary treated water TW3 (hydraulic treated water according to the present invention) using the treated water production device 1 in the treated water generation equipment section 201.

[0127] <Cement input S21 and material mixing process S22> The cement input S21 and material mixing process S22 are carried out in the same manner as the cement input S1 and material mixing process S2 in the first cement-containing compound manufacturing process according to Embodiment 1.

[0128] Figure 12 is a schematic explanatory diagram showing the outline of the hydraulic treatment water generation process among the process diagrams shown in Figure 11, and Figure 13 is a schematic explanatory diagram showing the outline of the process up to the point of producing fresh concrete among the process diagrams shown in Figure 11.

[0129] <Production process S23 for water hardening secondary treatment water TW3> In the process S23 for generating the hardened secondary treated water TW3, the hardened secondary treated water TW3, which is the treated water TW (displaced gaseous solution SQ), is generated in the second stage after the hardened primary treated water TW2 is generated in the first stage, as shown in Figure 12.

[0130] The first-stage treated water TW2 is prepared by dissolving a basic agent in water in the first-stage treated water production device 1A(1). The water (liquid L) is supplied to the first-stage treated water production device 1A(1) for dissolution acceleration treatment via the liquid supply pipe 211A(11), and the basic agent is supplied via the basic agent transport path 214A (a pipeline substantially the same as the gas supply pipe 14). In the method for producing a carbon dioxide absorption treated cement-containing compound according to Embodiment 2, the liquid is water such as tap water or industrial water. The basic agent is a basic substance that includes a salt containing a metal belonging to an alkali metal or alkaline earth metal, or a basic amino acid.

[0131] Specifically, basic substances include basic substances such as lithium oxide and potassium nitrite as examples of salts containing metals belonging to the alkali metals, calcium nitrite as an example of a salt containing metals belonging to the alkaline earth metals, and L-arginine as an example of a basic amino acid. In this embodiment 2, calcium nitrite is used. The basic substance may also be an amine, such as methylamine.

[0132] The first-stage treated water TW2 is a calcium nitrite aqueous solution with a pH of 11 or higher, produced by the dissolution of calcium nitrite in water by the first-stage treated water production device 1A(1). The first-stage treated water TW2 is sent to the second-stage treated water production device 1B(1) through the alkaline aqueous solution piping 19 (discharge pipe 19), and supplied to the second-stage treated water production device 1B(1) through the liquid supply pipe 211B(11) which is connected to the alkaline aqueous solution piping 19 (discharge pipe 19). Carbon dioxide (the necessary gas G) is supplied to this second-stage treated water production device 1B(1) through the gas supply pipe 214B(14).

[0133] The second-stage treated water production apparatus 1B(1) performs a dissolved gas displacement treatment in which carbon dioxide is dissolved in the primary treated water TW2 (calcium nitrite aqueous solution).

[0134] In other words, in the dissolved gas displacement treatment, when the primary treated water TW2 (calcium nitrite aqueous solution) and carbon dioxide are administered to the second-stage treated water production device 1B(1), secondary treated water TW3 is generated.

[0135] At this time, when carrying out the dissolved gas replacement treatment, it is important that carbon dioxide is not added in an amount that is relatively excessive to the primary treated water hardened water TW2 (calcium nitrite aqueous solution). The reason for this will be explained with the following chemical reaction equation, using the case where calcium nitrite is used as a basic substance in the production of the primary treated water hardened water TW2.

[0136] If the excess carbon dioxide is completely dissolved in the hardened primary treated water TW2 (calcium nitrite aqueous solution), as shown in the chemical reaction equations (4) to (7) below, the calcium nitrite aqueous solution, which has a pH of 11 or higher, will be converted into calcium carbonate (CaCO3) and dinitrogen trioxide (N2O3), which exhibits a deep blue color. However, as the reaction proceeds, the nitrite (HNO2) hydrolyzed based on dinitrogen trioxide will be further hydrolyzed into nitric acid (HNO3), which exhibits a stronger acidity, and hydrogen gas (H2).

[0137] (C4) CaN2O4 + H2O + CO2 → CaCO3 + H2O + N2O3 ... Chemical reaction equation (4) (C5) N2O3 → NO2 + NO ···Chemical reaction equation (5) (6) NO2 + NO + H2O → 2HNO2 ... Chemical reaction equation (6) (7) 2HNO2 + 2H2O → 2HNO3 + 2H2 ... Chemical reaction equation (7)

[0138] Therefore, in the dissolved gas replacement treatment, the concentration of the carbon dioxide gas introduced is adjusted relative to the concentration of the supplied primary hard water treatment water TW2 (calcium nitrite aqueous solution) within the second-stage treated water production device 1B(1) to produce secondary hard water treatment water TW3 with a pH of 6-8. The secondary hard water treatment water TW3 is a mixed solution of calcium nitrite and nitric acid produced from the primary hard water treatment water TW2 (calcium nitrite aqueous solution) and carbon dioxide gas. The hydrogen gas generated in the dissolved gas replacement treatment is exhausted from the second-stage treated water production device 1B(1).

[0139] Furthermore, since carbon dioxide dissolves with very high solubility in the primary hydrohard treated water TW2 (calcium nitrite aqueous solution), it is preferable to control the pH value of the generated secondary hydrohard treated water TW3 so that its pH does not fall below 6 during the dissolved gas replacement treatment. Also, as shown in Figure 12, in the second-stage treated water production apparatus 1B(1), if carbon dioxide (required gas G) that did not contribute to the generation of the secondary hydrohard treated water TW3 remains in the internal space 2S of the gas-liquid mixing container 2, the unused carbon dioxide that did not contribute to the generation is returned to the carbon dioxide recovery storage unit 61 and recovered. The carbon dioxide recovered in the carbon dioxide recovery storage unit 61 is purified to its original high-concentration state and reused.

[0140] <Hydration S24 and kneading treatment S25 using water hardened secondary treatment water TW3> In the next step, water addition S24 with hydraulic secondary treated water TW3, the hydraulic secondary treated water TW3 (treated water TW) generated in the water generation process S23 is injected into the mixing kneader 150 of the mixing equipment section 201A via the collection and conveying path 141, and the mixture of cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, and admixture M5 is mixed with the hydraulic secondary treated water TW3 (treated water TW) in the mixing kneader 150 (mixing process S25).

[0141] <Fresh Concrete Treatment S26> As a result, as shown in Figure 13, in the mixing equipment section 201A, cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, admixture M5, and hydraulic secondary treatment water TW3 (treated water TW) are mixed until they reach a product state, and these mixtures are produced as fresh concrete (the third state of fresh concrete according to the present invention) that has been refined to an alkaline state such as having a pH of 11 or higher (completion of fresh concrete production S26).

[0142] Furthermore, when concrete is formed from fresh concrete in its finished state along with reinforcing steel, a preferred configuration for protecting the reinforcing steel from rust is that the fresh concrete in its finished state, even when using TW3, a water-hardening secondary treatment water adjusted to pH 6-8, is strongly alkaline, for example, with a pH of 11 or higher.

[0143] In other words, as mentioned above, in mixing treatment S25, the hydraulic secondary treatment water TW3 is mixed with a mixture of cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, and admixture M5. Therefore, even if the hydraulic secondary treatment water TW3 is adjusted to a pH range of 6 to 8, in mixing treatment S25, the fresh concrete in its finished state, along with the hydraulic secondary treatment water TW3, contains components such as calcium oxide contained in cement M1, resulting in a strong alkalinity of pH 11 or higher, similar to conventional fresh concrete. Consequently, the fresh concrete in its finished state has a rust-preventive effect on reinforcing steel.

[0144] On the other hand, in the production process S23 for the hydraulic secondary treatment water TW3, if carbon dioxide is added to the hydraulic primary treatment water TW2 (calcium nitrite aqueous solution) in excess, and the carbon dioxide is dissolved in excess, the hydraulic secondary treatment water TW3 becomes an acidic aqueous solution with a pH of 6 or lower, then the fresh concrete in the product state using this hydraulic secondary treatment water TW3 is mainly suitable for unreinforced concrete. This is because the reinforcing steel becomes more susceptible to corrosion due to the hydraulic secondary treatment water TW3.

[0145] In the second cement-containing compound manufacturing process, when performing the mixing process S25, the internal space of the mixing machine 150, which manufactures fresh concrete in its finished state, is evacuated to a pressure lower than atmospheric pressure, and cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, admixture M5, and hydraulic secondary treatment water TW3 (treated water TW) are mixed together.

[0146] Specifically, while the mixing process S25 is being performed, the mixing equipment section 201A closes the on-off valves 171a and 171c while opening the vacuum valve 171d, and the vacuum pump 173a sucks out the atmosphere inside the mixing machine 150, thereby vacuum-degassing the inside of the mixing machine 150. As a result, when the cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, admixture M5, and hydraulic secondary treatment water TW3 (treated water TW) are being stirred, any air or other mixed gases that are present in the mixture as bubbles are degassed from the mixture. Therefore, it is possible to prevent bubbles caused by mixed gases from remaining in the fresh concrete in its manufactured state.

[0147] Furthermore, when the degassed, freshly manufactured concrete is fed from the mixing and kneading machine 150 through the post-mixing transport path 143 into the drum section 162 of the ready-mix concrete transport vehicle 161 waiting at the ready-mix concrete supply area 160, the drum section 162 of the ready-mix concrete transport vehicle 161 is evacuated to a pressure lower than atmospheric pressure, and the fresh concrete discharged from the post-mixing transport path 143 is supplied to the ready-mix concrete transport vehicle 161 in a product state, that is, fresh concrete in a product state that has been refined to be alkaline to a degree such as pH 11 or higher.

[0148] <Concrete pouring> Furthermore, at the concrete placement site, as shown in Figure 6, the fresh concrete FC in its finished state is poured out from a cylindrical flexible guide 170 attached to the chute 163 of the ready-mix concrete transport vehicle 161. At this time, when the fresh concrete FC in its finished state is poured out by the ready-mix concrete transport vehicle 161 with the tip opening of the cylindrical flexible guide 170 embedded in the fresh concrete FC being poured out, it is possible to prevent outside air (air) from being mixed into the fresh concrete FC in its finished state during placement.

[0149] Next, the operation and effects of the treated water production apparatus and the method for producing carbon dioxide-absorbing treated cement-containing kneaded product according to this embodiment will be described.

[0150] The treated water production apparatus 1 according to this embodiment is a treated water production apparatus that degasssed unwanted dissolved gases from liquid L and dissolved carbon dioxide, which is the gas G required as the replacement gas, into liquid L to produce a replacement gas solution SG, and comprises a gas-liquid mixing container 2 capable of containing the required gas G and liquid L in its internal space 2S, a gas supply unit 4 for storing the required gas G under high pressure exceeding atmospheric pressure, a gas supply pipe 14 communicating the gas supply unit 4 and the inside of the gas-liquid mixing container 2, a flow control valve 31 for controlling the flow of the required gas G, and a liquid supply unit 3 for storing liquid L. The gas-liquid mixing container 2 is equipped with a liquid supply pipe 11 that communicates the liquid supply unit 3 and the inside of the gas-liquid mixing container 2, a three-way switching valve 24 that controls the flow of liquid L, a delivery pump 21 that delivers liquid L, nozzles 23A, 23B (23) that can atomize and discharge liquid L, a temperature controller 25 that can adjust the liquid L to a set temperature T inside the gas-liquid mixing container 2, a vacuum pump 22 that can suck up gas present inside the gas-liquid mixing container 2 and exhaust it to the outside, a suction pipe 15 that communicates the vacuum pump 22 and the inside of the gas-liquid mixing container 2, an on-off valve 33X that controls the flow of gas, and a control unit 6. The nozzles 23 are arranged in the internal space 2S of the gas-liquid mixing container 2 in communication with the liquid supply pipe 11, and the gas-liquid mixing container 2 has liquid circulation systems F, F2 that can circulate and flow the gas-liquid mixture LG of liquid L and the required gas G contained in the internal space 2S by the delivery pump 21. The control unit 6 is characterized in that, using a vacuum pump 22, it sprays liquid L, whose temperature has been controlled by a temperature controller 25, from a nozzle 23 with circulation using a delivery pump 21 in a gas-liquid mixing container 2 under vacuum pressure lower than atmospheric pressure, and also supplies the necessary gas G from a liquid supply pipe 11 in a state that can come into contact with the sprayed mist-like target liquid LG (liquid L, or gas-liquid mixture LG containing liquid L). The necessary gas G is carbon dioxide, and the replacement gas solution SQ is carbonated water, which is water that is liquid L, in which carbon dioxide is dissolved, or hydraulically treated water, which is water that is liquid L, in which carbon dioxide and a basic substance are dissolved. The treated water production device is a treated water production device 1 that produces treated water TW, which is either hydraulically treated water TW1 (carbonated water) or hydraulically treated secondary water TW3.

[0151] Due to this feature, unwanted gases are efficiently removed from the liquid L (water) such as water or aqueous solutions by the vacuum pump 22, and the necessary gas G, carbon dioxide, can be efficiently supplied to the degassed liquid L (water, etc.) under high pressure. As a result, hydrohard treated water TW1 (carbonated water) or hydrohard secondary treated water TW3 (treated water TW), which is a displacement gas solution SG in which carbon dioxide or basic substances are dissolved in water, can be produced in a shorter time and at a higher concentration.

[0152] Therefore, the treated water production apparatus 1 according to this embodiment has the excellent effect of being able to degas unwanted gases (gases before substitution) dissolved in the liquid L (water, etc.) when producing carbonated water or hydraulically treated water, which are the gases after substitution SG, and to dissolve carbon dioxide, which is the gas G required after substitution, as well as basic substances added as needed, in this liquid L (water, etc.) at a higher concentration and more efficiently.

[0153] Furthermore, the treated water production apparatus 1 according to this embodiment is characterized in that the carbon dioxide gas is derived from exhaust gas generated by external equipment.

[0154] This characteristic helps to suppress the release of large amounts of carbon dioxide from power plants, factories, waste disposal sites, etc., into the atmosphere. By being effectively used as one of the materials for manufacturing concrete products commonly used in industry and manufacturing, it can contribute to achieving carbon neutrality and carbon negativity, which are urgent global issues.

[0155] Furthermore, the treated water production apparatus 1 according to this embodiment is characterized by having a carbon dioxide recovery means 60 that recovers and stores the carbon dioxide remaining in the gas-liquid mixing container 2 after the treated water TW has been generated.

[0156] This feature allows the carbon dioxide recovered in the carbon dioxide recovery and storage unit 61 to be reused in the production of treated water TW without being released into the atmosphere, thus protecting the global environment.

[0157] Furthermore, the method for producing a carbon dioxide absorption treated cement-containing mixture according to this embodiment is characterized in that, as the water added for the hydraulic hardening of concrete, hydraulic treated water TW1 (treated water TW) (carbonated water) in which carbon dioxide gas is dissolved in water is used, and a first cement-containing mixture production step is made by mixing cement M1, coarse aggregate M2, fine aggregate M3, admixture M4 and admixture M5 with hydraulic treated water TW1 (treated water TW) to produce neutralized fresh concrete, and the hydraulic treated water TW1 is the treated water TW produced by the treated water production device 1 described above.

[0158] Due to these characteristics, neutralized fresh concrete can be used in concrete structures such as wave-dissipating blocks (tetrapods) as an example of the applications of hardened concrete, and in mortar products as an example of mortar, which is a cement-containing mixture in its first state, as well as in applications of unreinforced concrete that do not require greater strength, such as tile products.

[0159] Therefore, the method for producing carbon dioxide-absorbing treated cement-containing mixed materials according to Embodiments 1 and 2 has the excellent effect of suppressing the residue of carbon dioxide in fresh concrete, mortar, etc., and producing concrete, mortar, etc., without causing a deterioration in quality due to the addition of carbon dioxide during the production of fresh concrete, mortar, etc.

[0160] Furthermore, the method for producing a carbon dioxide-absorbing treated cement-containing mixture according to this embodiment is characterized by having a cement-containing mixture purification step, in which a basic material is added to neutralized fresh concrete and mixed to produce alkaline fresh concrete, which is obtained by purifying neutralized fresh concrete into alkaline fresh concrete.

[0161] Due to this characteristic, alkalized fresh concrete forms a passive film on the surface of the reinforcing steel used in the construction of the concrete structure, suppressing rust formation due to oxidation. For example, it is refined to a pH of 11 or higher. Therefore, because alkalized fresh concrete can suppress rust formation for a long period of time, it can be used in concrete structures in combination with reinforcing steel, with the same handling as general fresh concrete that does not have carbon dioxide added during manufacturing.

[0162] Furthermore, in the method for producing a carbon dioxide absorption treated cement-containing mixture according to this embodiment, the first cement-containing mixture production step is characterized in that, while the internal space of the mixing kneader 120 for producing neutralized fresh concrete is evacuated to a pressure lower than atmospheric pressure, cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, admixture M5, and hydraulically treated water TW1 (treated water TW) are mixed.

[0163] Due to this characteristic, neutralized fresh concrete has had its bubbly gases removed, and as this neutralized fresh concrete hardens, the formation of voids within the concrete is suppressed. This prevents a decrease in the strength of the concrete itself due to these voids. Examples of applications for concrete hardened from neutralized fresh concrete include concrete structures such as wave-dissipating blocks (tetrapods), mortar products made from cement-containing mixtures in the third state, and tile products, which do not require high strength and do not use reinforcing steel. In these products, since there is no reinforcing steel to increase the product strength, the certain strength inherent in the product itself is prevented from being reduced due to the aforementioned voids.

[0164] Furthermore, the method for producing a carbon dioxide absorption treated cement-containing mixture according to this embodiment is characterized in that, as the water required for the hydraulic hardening of concrete, hydraulic secondary treated water TW3 (treated water TW) produced from carbon dioxide, water, and a basic substance is used, and a second cement-containing mixture production step is made to produce fresh concrete in a product state by adding and mixing cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, and admixture M5 together with hydraulic secondary treated water TW3 (treated water TW), and the hydraulic secondary treated water TW3 is the treated water TW produced by the treated water production device 1 described above.

[0165] Due to this characteristic, the fresh concrete in its finished state is refined to an alkaline pH of, for example, pH 11 or higher, which can suppress the occurrence of rust due to oxidation in the reinforcing steel used in the construction of the concrete structure. Therefore, the fresh concrete in its finished state can be used in concrete structures in combination with reinforcing steel, with the same handling as general fresh concrete that does not have carbon dioxide added during manufacturing.

[0166] Furthermore, in the method for producing a carbon dioxide absorption treated cement-containing compound according to this embodiment, the hydraulic secondary treated water TW3 (treated water TW) in the second cement-containing compound production step is characterized in that hydraulic primary treated water TW2, which consists of water and calcium nitrite (a basic substance), is produced to a pH of 11 or higher, and carbon dioxide is dissolved in the hydraulic primary treated water TW2 to produce hydraulic secondary treated water TW3, and that the hydraulic secondary treated water TW3 is produced with a pH in the range of pH 6 to pH 8.

[0167] This characteristic allows for the generation of primarily treated water TW2, which exhibits a strong alkalinity of pH 11 or higher. This enables the generation of primarily treated water TW3, which allows for the dissolution (dissolution and fixation) of a larger amount of carbon dioxide within the pH range of the primarily treated water TW3, ensuring good quality of the finished product, such as fresh concrete or mortar.

[0168] Furthermore, in the method for producing a carbon dioxide-absorbing treated cement-containing mixture according to this embodiment, the second cement-containing mixture production step is characterized in that, in a state where the internal space of a mixing kneader 150 that produces fresh concrete in its finished state is evacuated to a pressure lower than atmospheric pressure, cement M1, coarse aggregate M2, fine aggregate M3, admixture M4, admixture M5, and hydraulic secondary treatment water TW3 (treated water TW) are mixed.

[0169] Due to this characteristic, fresh concrete in its finished state has had its aerated gas bubbles removed, which suppresses the formation of voids within the hardened concrete. As a result, the reduction in strength caused by these voids is prevented. Furthermore, in mortar products, the water content is prevented from becoming excessive due to hydroxide-derived moisture, thus preventing quality degradation associated with excessive moisture.

[0170] Furthermore, the method for producing a carbon dioxide absorption treated cement-containing compound according to Embodiments 1 and 2 is characterized in that the basic substance contains at least one of the following: lithium oxide, calcium nitrite, potassium nitrite, or L-arginine.

[0171] Due to this characteristic, the basic substance does not contain a hydroxyl group, and when the basic substance dissolves with carbon dioxide and water, the amount of water derived from hydroxides can be kept to a minimum. Therefore, after placing fresh concrete in its finished state, it is possible to suppress the excessive water content in the concrete caused by water derived from hydroxides. In other words, it is possible to prevent quality deterioration due to excessive water content in the concrete after placement.

[0172] Furthermore, the method for producing a carbon dioxide-absorbing treated cement-containing mixture according to this embodiment is characterized in that the neutralized fresh concrete and the fresh concrete in its product state contain fine silica particles (SiO2) with an average particle size of 0.2 to 10 μm and a spherical shape as the admixture M5.

[0173] This feature makes it possible to suppress the decrease in the fluidity of the fresh concrete in its finished state due to deaeration, for example, when supplying fresh concrete to a concrete transport truck 161 or when pouring fresh concrete from the concrete transport truck 161 at the pouring site. Therefore, the fresh concrete produced by the method for producing carbon dioxide-absorbing treated cement-containing mixed material according to this embodiment can be handled without difficulty at the site and does not impair the work efficiency of the workers, even when compared to general fresh concrete without added carbon dioxide. Similarly, the mortar product can be handled without difficulty at the pouring site and does not impair the work efficiency of the workers, even when compared to general mortar product without added carbon dioxide during manufacturing.

[0174] Although the present invention has been described above in reference to embodiments, the present invention is not limited to the above embodiments and can be modified and applied as appropriate without departing from the spirit of the invention.

[0175] (1) For example, in Embodiments 1 and 2, a vacuum pump 133 with a gas ballast valve was used to suction the internal space of the mixing machine 120 when producing fresh concrete in the first state and when producing fresh concrete in the third state. However, a vacuum dry pump with water vapor resistance may also be used to suction the internal space of the mixing machine 120.

[0176] (2) In embodiments 1 and 2, the internal space of the mixing and kneading machines 120 and 150 was degassed by vacuuming with vacuum pumps 133 and 173a equipped with gas ballast valves. However, if the fresh concrete in its product state can be degassed to a state sufficient for placement by the on-board vacuum pump 173b within the drum section 162 of the ready-mix concrete transport vehicle 161, the degassing treatment within the mixing and kneading machines 120 and 150 may be omitted.

[0177] (3) Alternatively, the fresh concrete in its finished state that has been poured out from the ready-mix concrete transport vehicle 161 may be degassed in a vacuum degassing tank installed at the pouring site.

[0178] (4) Furthermore, regarding the hydraulic water used in the method for producing a carbon dioxide-absorbing cement-containing compound according to the present invention, the hydraulic water TW1 (carbonated water) according to Embodiment 1 and the hydraulic secondary water TW3 (a mixed solution of calcium nitrite and nitrate as mentioned in the example) according to Embodiment 2 were used as the hydraulic water TW produced by the hydraulic water production apparatus 1 according to the embodiment.

[0179] However, the hydraulic water used in the method for producing a carbon dioxide-absorbing cement-containing compound according to the present invention is not limited to the hydraulic water TW produced by the hydraulic water production apparatus 1 according to the embodiment, but can be any hydraulic water obtained by dissolving carbon dioxide in at least one of water or an aqueous solution of a basic substance. Furthermore, the hydraulic water production apparatus for producing the hydraulic water is not limited to the hydraulic water production apparatus according to the present invention, but can be appropriately modified as long as it is an apparatus capable of producing hydraulic water obtained by dissolving carbon dioxide in at least one of water or an aqueous solution of a basic substance.

[0180] (5) In Embodiments 1 and 2, treated water TW, produced by adding carbon dioxide as one of the raw materials using the treated water production device 1, was used as the water required for hydraulic cement to produce fresh concrete and mortar, which are cement-containing mixtures. However, the treated water produced by the treated water production device according to the present invention can be used not only for cement-containing mixtures, but also, for example, for the production of tiles corresponding to Class III of JIS A 5209. Figure 14 is a process diagram when producing tiles using the method for producing carbon dioxide-absorbing treated lime-containing mixture according to the reference embodiment.

[0181] Specifically, in the method for producing a carbon dioxide-absorbing treated lime-containing kneaded material, as illustrated in Figure 14, raw materials mainly consisting of lime and clay are placed into a ball meal in a coarsely crushed state (S31). Next, treated water TW produced by the treated water production apparatus 1 according to the embodiment is added to the ball meal (S32). Next, in the ball meal, a slurry is produced by kneading the finely crushed raw materials and treated water TW while stirring the raw materials such as lime and clay with the treated water TW (S33). Next, the granular clay obtained by drying this slurry is molded into the shape of a desired tile product (S34), and then the tile material, which has glaze attached to the surface of the clay (S35), is fired (S36). Thus, a tile product is manufactured.

[0182] In other words, such tile products are preferably, "As the water necessary for kneading, we use kneading treatment water that contains at least water and carbon dioxide, The process includes a step for producing a lime-containing paste by kneading lime and clay together with the aforementioned kneading treatment water. The aforementioned lime-containing mixture is a tile material in its pre-fired state. A method for producing a lime-containing kneaded product that has undergone carbon dioxide absorption treatment, characterized by the following: (First technical feature).

[0183] And, even more preferably, "In the method for producing a carbon dioxide absorption treated lime-containing kneaded product of this first technical feature, The kneading treatment water is the treatment water produced by the treatment water production apparatus described in claim 1 of this application. A method for producing a carbon dioxide absorption treated lime-containing kneaded product characterized by the following: (Second technical feature) [Industrial applicability]

[0184] The treated water production apparatus according to the present invention can be used in various industrial fields such as agriculture, forestry and fisheries, construction, food service, and manufacturing, as well as in safety and health fields related to medical care and welfare. Examples of liquids used in these fields include water for biological cultivation, drinking water, purification of industrial wastewater, and environmental improvement.

[0185] Furthermore, the method for producing carbon dioxide-absorbing treated cement-containing compound according to the present invention is suitable for use in a wide range of industrial fields, primarily in the construction and civil engineering sectors, such as concrete structures including buildings such as office buildings and condominiums, roads and their gutters, bridges, railway tracks, tunnels, utility poles, and wave-dissipating blocks (tetrapods), as well as mortar and tile products coated with a carbon dioxide-containing coating agent. [Explanation of symbols]

[0186] 1. Treated water production equipment 2 Gas-liquid mixing container 2S interior space 3. Liquid supply section (liquid storage section) 4. Gas supply unit (gas storage unit) 6. Control Unit (Control Means) 11. Liquid supply pipe (liquid introduction pipeline / liquid introduction channel) 12 Circulation system pipe (liquid circulation pipe) 14. Gas supply pipe (gas introduction pipeline / gas introduction path) 15. Suction pipe (exhaust pipe) 21. Dispensing pump (pump) 22 Vacuum pump (gas exhaust means) 23 nozzles 24. Three-way switching valve (liquid flow control valve) 25 Temperature controller (liquid temperature adjustment means) 31. Flow control valve (gas flow control valve) 33X On / Off Valve (Gas Flow Control Valve) 60 Carbon dioxide recovery means 61 Carbon dioxide recovery and storage unit (carbon dioxide recovery means) T Set temperature L liquid G Required gas (carbon dioxide) LG gas-liquid mixture SQ substituted gas solution TW treated water F,F2 Liquid circulation system F1 First channel F2 Second channel

Claims

1. As a type of dissolved gas replacement apparatus, which removes unwanted dissolved gases from a liquid and dissolves the necessary gases as replacement gases into the liquid to produce a replacement gas solution, A gas-liquid mixing container capable of containing the required gas and the liquid in its internal space, A gas storage unit for storing the aforementioned required gas under high pressure exceeding atmospheric pressure, A gas introduction pipeline connecting the gas storage section and the gas-liquid mixing container includes a gas flow control valve that controls the flow of the required gas, A liquid storage section for storing the aforementioned liquid, A liquid introduction pipeline connecting the liquid storage section and the gas-liquid mixing container includes a liquid flow control valve for controlling the flow of the liquid, A pump for dispensing the aforementioned liquid, A nozzle capable of atomizing and dispensing the aforementioned liquid, The aforementioned gas-liquid mixing container includes a liquid temperature control means capable of adjusting the liquid to a set temperature, A gas exhaust means capable of drawing in the gas-liquid mixing container and exhausting the gas to the outside, An exhaust pipe passage connecting the gas exhaust means and the gas-liquid mixing container includes a gas flow control valve that controls the flow of the gas, Equipped with control means, The nozzle is disposed in the internal space of the gas-liquid mixing container, communicating with the liquid introduction pipeline, and the gas-liquid mixing container has a liquid circulation system that allows the gas-liquid mixture of the liquid contained in the internal space and the required gas to be circulated and flowed by the pump. The control means, using the gas exhaust means, evacuates the liquid mixture container to a pressure lower than atmospheric pressure, and in the same container, the liquid temperature is controlled by the liquid temperature control means. The control means then sprays the liquid, whose temperature has been controlled by the liquid temperature control means, from the nozzle while circulating it using the pump, and simultaneously supplies the necessary gas from the gas introduction pipe in a manner that allows it to come into contact with the sprayed mist-like liquid. The dissolved gas replacement apparatus is a treated water production apparatus that produces treated water by dissolving the required gas, carbon dioxide, in at least one of the liquid, water, or an aqueous solution of a basic substance, as the replaced gas solution. A treated water production device characterized by the following.

2. In the treated water production apparatus described in claim 1, The carbon dioxide gas in question is gaseous carbon dioxide originating from exhaust gas generated by external equipment. A treated water production device characterized by the following.

3. In the treated water production apparatus described in claim 1, The system includes a carbon dioxide recovery means for recovering and storing the carbon dioxide remaining in the gas-liquid mixing container after the production of the treated water. A treated water production device characterized by the following.

4. As the water added for hydraulic hardening, treated water produced by mixing carbon dioxide and water is used. The process includes a first cement-containing compound manufacturing step, which involves mixing cement and aggregate together with the aforementioned hydraulically treated water to produce a cement-containing compound in a first state. The cement-containing mixture in the first state is fresh concrete or mortar. A method for producing a cement-containing paste that has undergone carbon dioxide absorption treatment.

5. In the method for producing a carbon dioxide absorption treated cement-containing kneaded product as described in claim 4, The invention includes a cement-containing mixture purification step, which involves adding a basic substance to the cement-containing mixture in the first state and kneading it to produce a cement-containing mixture in a second state obtained by purifying the cement-containing mixture in the first state to an alkaline state. A method for producing a cement-containing paste that has undergone carbon dioxide absorption treatment.

6. In the method for producing a carbon dioxide absorption treated cement-containing kneaded product as described in claim 4, In the first cement-containing compound manufacturing process, the cement, aggregate, and hydraulically treated water are mixed in a state in which the internal space of the mixing container used to manufacture the cement-containing compound in the first state is evacuated to a pressure lower than atmospheric pressure. A method for producing a cement-containing paste that has undergone carbon dioxide absorption treatment.

7. For the water hardening process, treated water produced by mixing carbon dioxide, water, and a basic substance is used. The process includes a second step in manufacturing a cement-containing mixture, in which cement and aggregate are mixed together with the aforementioned hydraulically treated water to produce a third state cement-containing mixture. The cement-containing mixture in the third state described above is fresh concrete or mortar. A method for producing a cement-containing paste that has undergone carbon dioxide absorption treatment.

8. In the method for producing a carbon dioxide absorption treated cement-containing kneaded product according to claim 7, The aforementioned hydraulically treated water is a hydraulically treated primary water consisting of water and the basic substance, which is then prepared to have a pH of 11 or higher, and to which carbon dioxide is dissolved in the hydraulically treated primary water, thereby creating a hydraulically treated secondary water. The aforementioned water hardening secondary treatment water is produced with a pH within the range of 6 to 8. A method for producing a cement-containing paste that has undergone carbon dioxide absorption treatment.

9. In the method for producing a carbon dioxide absorption treated cement-containing kneaded product according to claim 7, In the second cement-containing compound manufacturing process, the cement, aggregate, and hydraulically treated water are mixed in a state in which the internal space of the mixing container for manufacturing the cement-containing compound in the third state is evacuated to a pressure lower than atmospheric pressure. A method for producing a cement-containing paste that has undergone carbon dioxide absorption treatment.

10. In a method for producing a carbon dioxide absorption treated cement-containing kneaded product according to claim 4 or claim 7, The water hardened water is the treated water produced by the treated water production apparatus described in claim 1. A method for producing a cement-containing paste that has undergone carbon dioxide absorption treatment.

11. In a method for producing a carbon dioxide absorption treated cement-containing kneaded product according to claim 4 or claim 7, The basic substance is a salt containing a metal belonging to the alkali metal or alkaline earth metal group, or a basic amino acid. A method for producing a cement-containing paste that has undergone carbon dioxide absorption treatment.

12. In a method for producing a carbon dioxide absorption treated cement-containing kneaded product according to claim 4 or claim 7, To the cement-containing mixture in the first state or the cement-containing mixture in the third state, fine silica particles (SiO₂) with an average particle size of 0.2 to 10 μm and a spherical shape are added as an admixture. ２ ) is added, A method for producing a cement-containing paste that has undergone carbon dioxide absorption treatment.

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