Reactive mixture capable of fixing carbon dioxide, injection material for construction, and apparatus for manufacturing mixture

Abstract

The present invention relates to a reactive mixture, an injection material for construction comprising the reactive mixture, and an apparatus for manufacturing the reactive mixture The reactive mixture according to the present invention is a material for forming an injection material for construction by being mixed with cement, and is characterized by comprising calcium carbonate formed through a carbon mineralization reaction by injecting carbon dioxide into a slurry prepared by mixing and stirring water with powdery industrial by-products consisting of 15 wt % or more of CaO, 25 wt % or more of SiO2, 30 wt % or less of Al2O3, and 15 wt % or less of Fe2O3.

Description

Reactive mixture capable of carbon dioxide fixation, construction injection material, and mixture manufacturing device

[0001] The present invention relates to a composition of a construction injection material, and more specifically, to a construction injection material that can be used for various purposes, such as ground injection materials and backfill materials for TBM tunnels, and to an apparatus for manufacturing the same.

[0002]

[0003] Achieving a net emission of zero carbon dioxide is referred to as carbon neutrality or "Net-Zero." South Korea is making various attempts to achieve carbon neutrality by 2050. However, due to South Korea's geological conditions, there are limitations to underground storage of carbon dioxide, and carbon dioxide sequestration through carbon mineralization is not yielding results as expected.

[0004] Recently, there have been attempts to treat carbon dioxide by directly injecting it into concrete or grout used in construction to mineralize it. This approach stems from the idea that since cement, the main ingredient in concrete and grout, contains a significant amount of calcium, mineralization would be possible through a reaction with carbon dioxide. However, this idea faces technical challenges.

[0005] Although the total amount of calcium contained in cement is very large, there is not much calcium available in a form that can actually react with carbon dioxide. For the carbon mineralization reaction to occur, carbon dioxide must be leached into water and converted into a divalent ion form; however, the calcium in cement that can be converted into an ion form is limited to free CaO and divalent calcium ions generated during the cement hydration process, meaning most of the calcium does not participate in the carbon mineralization reaction. Therefore, the actual amount of carbon dioxide removed through the carbon mineralization reaction is not significant. Furthermore, since the reaction between carbon dioxide and calcium to form calcium carbonate is an exothermic reaction, if this reaction occurs directly in the grout material, it becomes difficult to control the gel time of the grout, and the early strength does not develop quickly, which may lead to delays in construction.

[0006] Consequently, the method of directly injecting carbon dioxide into grout or concrete to react with the calcium components in the cement is difficult to apply in the current state.

[0007]

[0008] The present invention aims to solve the aforementioned problems by providing a construction injection material that can utilize construction materials such as grout or concrete for carbon dioxide treatment while also ensuring their inherent function as construction materials, and a reactive mixture included in the construction injection material.

[0009] Another objective of the present invention is to provide a manufacturing apparatus capable of producing reactive mixtures and construction injection materials directly at a construction site.

[0010] Meanwhile, other unspecified objects of the present invention will be further considered to the extent that they can be easily inferred from the following detailed description and effects.

[0011]

[0012] The reactive mixture according to the present invention for achieving the above objective is intended to form a construction injection material by mixing with cement, and is characterized by comprising calcium carbonate formed through a carbon mineralization reaction by injecting carbon dioxide into a slurry made by mixing and stirring water with a powdered industrial byproduct composed of 15 wt% or more of CaO, 25 wt% or more of SiO2, 30 wt% or less of Al2O3, and 15 wt% or less of Fe2O3.

[0013] In one example of the present invention, to promote calcium leaching from the industrial byproduct, the method further comprises a first accelerator composed of one or a combination of DEG (Diethylene Glycol), DEA (Diethalolamine), and TEA (Triethalolamine), and a second accelerator composed of one or a combination of sulfuric acid (H2SO4), potassium sulfate (K2SO4), and sodium sulfate (Na2SO4), wherein the accelerator is additionally mixed in a ratio of 0.1 to 5 weight percent with respect to the entire industrial byproduct. In particular, the first accelerator may be mixed in a ratio of 0.01 to 1.0 weight percent with respect to the entire industrial byproduct, and the second accelerator may be mixed in a ratio of 0.5 to 5.0 weight percent with respect to the entire industrial byproduct.

[0014] In one example of the present invention, the industrial by-product has a maximum particle size of 1 mm or less and a Blaine specific surface area of ​​2000 cm² 2 It is desirable that it be greater than / g.

[0015] Meanwhile, the construction injection material according to the present invention is characterized by being mixed in a ratio of 40 to 90 weight% of a cement slurry obtained by mixing and stirring cement and water; and 10 to 60 weight% of the reactive mixture, and manufactured and used directly at the construction site.

[0016] A reactive mixture manufacturing apparatus for achieving another objective of the present invention is characterized by comprising: a stirring tank for mixing and stirring the industrial byproduct and water to form a slurry; a circulation reaction unit that connects the outlet at the bottom of the stirring tank and the inlet at the top to circulate the slurry up and down, and injects carbon dioxide to form calcium carbonate while the slurry passes through; a supply tank for injecting carbon dioxide into the circulation reaction unit; and a cooling unit for cooling the circulation reaction unit.

[0017] In one example of the present invention, the circulating reaction unit is maintained at 20°C or lower by the cooling unit, and the stirring tank is preferably maintained at 25°C or lower.

[0018] In one example of the present invention, a pH sensor for measuring the pH of the slurry may be further provided to check whether calcium carbonate is produced in the stirring tank.

[0019] In one example of the present invention, a carbon dioxide collection line is provided on the upper side of the stirring tank to discharge gaseous carbon dioxide that is not dissolved in the slurry, and the collected carbon dioxide is preferably reintroduced into the circulation reactor.

[0020]

[0021] As explained above, the present invention has the advantage of being able to process a large amount of carbon dioxide by utilizing industrial by-products as ground injection materials and fixing carbon dioxide in the form of calcium carbonate.

[0022] In addition, the reuse of industrial by-products offers the advantage of improved economic efficiency compared to existing cement-based ground injection materials, and since physical properties are guaranteed to be equivalent to those of existing materials, active application is expected.

[0023] Meanwhile, it should be added that even if an effect is not explicitly mentioned here, the effects described in the following specification and the provisional effects expected by the technical features of the present invention are treated as described in the specification of the present invention.

[0024]

[0025] Figure 1 is a table showing the change in pH during the preparation of a reactive mixture.

[0026] Figure 2 shows the XRD analysis results of the reactive mixture.

[0027] Figure 3 shows the results of the thermogravimetric analysis of the reactive mixture.

[0028] FIG. 4 is a schematic diagram of a reactive mixture manufacturing apparatus according to an example of the present invention.

[0029] ※ It should be noted that the attached drawings are provided as examples for reference to help understand the technical concept of the present invention, and the scope of the rights of the present invention is not limited by them.

[0030]

[0031] In describing the present invention, detailed descriptions of related known functions are omitted if they are deemed obvious to a person skilled in the art and could unnecessarily obscure the essence of the invention.

[0032] First, a reactive mixture and a construction injection material according to an example of the present invention will be described with reference to the attached drawings, and then a manufacturing apparatus for producing the above materials on-site will be described.

[0033] The reactive mixture according to the present invention is a material that is mixed in a slurry state with the construction injection material described later, and also performs the function of fixing carbon dioxide through a carbon mineralization reaction.

[0034] In the present invention, the reactive mixture may use slag generated from steel mills or ash (fly ash, bottom ash) generated from power plants; however, not all slag or ash may be used, and it must satisfy the compositional components described below.

[0035] The industrial byproduct used in this invention consists of components composed of at least 15 wt% CaO, at least 25 wt% SiO2, 30 wt% or less Al2O3, and 15 wt% or less Fe2O3. The CaO content is particularly important. That is, since calcium components capable of leaching into water are required for carbon dioxide fixation (described in detail later), the CaO content among the above industrial byproduct components must be at least 15 wt%, preferably 20 wt% or more, to increase the carbon dioxide processing capacity. SiO2 acts as an aggregate that increases the strength of construction injection materials as a sand component. If the Al2O3 content is high enough to form ettringite or calcium aluminosilicate, the Ca that must be used for the mineralization of CO2 2+ Since ions can be consumed and CO2 storage capacity can be reduced, it is desirable to have 30 weight% or less. If Fe2O3 is high, the possibility of Fe in metallic form being present increases, and since metallic Fe can degrade the performance of the injection material due to expansion caused by oxidation over the long term, it is desirable to have 15 weight% or less.

[0036] In the present invention, industrial by-products are used as the main material of the mixture, so the content of the four main components above may vary slightly depending on the characteristics of the industrial by-products, but it is desirable to satisfy the content standards for the upper and lower limits above.

[0037] In this invention, the possibility of artificially composing a material that meets the above conditions by mixing industrial by-products generated from multiple facilities, rather than using industrial by-products from a single facility alone, is not excluded. Furthermore, while it is possible to artificially create the above composition without using industrial by-products, doing so may diminish the advantages of this invention, such as the reuse of industrial by-products and economic viability. Since this invention offers economic benefits by replacing a portion of the construction injection material with a reactive mixture, it is desirable to select an industrial by-product that satisfies the above composition. For example, fly ash generated from a circulating fluidized bed boiler in a thermal power plant can be cited.

[0038] In addition, industrial by-products may additionally contain other components such as SO3, MgO, P2O5, Cl, and Na2O in addition to the four main ingredients mentioned above.

[0039] For reference, in the present invention, the standard values ​​for the upper or lower limits specified for each component of the industrial byproduct are important, but if the upper and lower limits are specified together for each component, for example, the ranges may be CaO 15~45 wt%, SiO2 25~50 wt%, Al2O3 15~30 wt%, and Fe2O3 35~15 wt%.

[0040] The above industrial by-products have a maximum particle size of 1 mm or less and a Blaine specific surface area of ​​2000 cm² 2 It is desirable that it be formed at a level of / g or higher. In other words, the higher the specific surface area, the greater the Ca from industrial by-products. 2+ This is because the ease of ion elution enables faster CaCO3 formation, and properties such as pumpability, injectability, and resistance to material separation are advantageous for use as an injection material.

[0041] Meanwhile, an accelerator may be added in addition to the above industrial by-products. The accelerator functions to promote the leaching of calcium from CaO into water. Since the leaching of CaO into water may be hindered by an insoluble film, the accelerator causes cracks in the insoluble film to promote the leaching of calcium. The first accelerator and the second accelerator may be used individually or in combination. The first accelerator may be any one of DEG (Diethylene Glycol), DEA (Diethalolamine), or TEA (Triethalolamine), or a combination of these. In particular, DEG is more effective because it promotes the dissolution of carbon dioxide into water in addition to promoting the leaching of calcium. As the second accelerator, any one of sulfuric acid (H2SO4), potassium sulfate (K2SO4), or sodium sulfate (Na2SO4), or a combination of these may be used.

[0042] The accelerator is blended in a ratio of 0.1 to 5.0 weight percent relative to the total powder material containing industrial by-products and other components. Here, when the first accelerator is used alone, it is blended in a ratio of 0.01 to 1.0 weight percent relative to the total powder material, and when the second accelerator is used alone, it is blended in a ratio of 0.5 to 5.0 weight percent. If the first accelerator and the second accelerator are used together, it is desirable to mix them in the range of 0.1 to 5.0 weight percent, which is the total blending ratio of the accelerators mentioned above, while satisfying the blending ratio when used alone. This is because if the amount of accelerator is less than the above range, calcium leaching may be insufficient, and if it exceeds the above range, the increase in the film removal effect relative to the input amount is not significant.

[0043] The reactive mixture according to the present invention is completed by forming a slurry from a material containing the aforementioned industrial by-product and accelerator by mixing and stirring it with water, and by injecting carbon dioxide to form solid calcium carbonate. Water is mixed at a ratio of 100 to 250% relative to the weight of the industrial by-product. When the industrial by-product and accelerator are mixed with water, calcium divalent ions (Ca 2+ It is leached out in the form of ). When carbon dioxide is injected into water, it dissolves and becomes CO3 2- It is transformed into a specific form. Calcium ions and carbonate ions dissolved in water combine to form calcium carbonate crystals smaller than a few micrometers. The reactive admixture is subsequently mixed into the ground injection material; calcium carbonate not only improves the penetration of the ground injection material into the soil but also plays a role in aiding the formation of calcium silicate hydrates and crystal growth by acting as a seed that facilitates the precipitation of these hydrates during the process of forming calcium silicate hydrates in cement. More importantly, from the perspective of environmental protection, it functions to fix and remove carbon dioxide, a greenhouse gas.

[0044] As described above, the reactive mixture is completed by injecting carbon dioxide into a mixture of industrial byproducts and an accelerator in water to form calcium carbonate. That is, the reactive mixture ultimately contains calcium carbonate and is formed in a slurry state.

[0045] The research team of the present invention conducted an experiment to verify whether calcium carbonate is formed by reacting industrial by-products with carbon dioxide.

[0046] The industrial byproduct used in the experiment is fly ash from biomass fuel of a thermal power plant, and its composition is as shown in [Table 1] below.

[0047] [Table 1] Composition of Industrial By-products

[0048]

[0049] 500g of the above industrial byproduct was mixed with 1,000g of water to form a reactive mixture in the form of a slurry, and then carbon dioxide was injected to observe changes in pH. The experimental results are shown in the table in Figure 1. Referring to the table in Figure 1, the initial pH of the reactive mixture was 13, and it decreased gradually until about 80 minutes after the injection of carbon dioxide, and then dropped sharply thereafter. Since the industrial byproduct, which is the main ingredient of the reactive mixture, is alkaline, the pH is approximately 13; however, when carbon dioxide is injected, the concentration of carbonate ions in the slurry increases, causing the pH to decrease. It is understood that the pH is maintained until about 80 minutes because the carbon dioxide injected during this period forms calcium carbonate, preventing an increase in the concentration of carbonate ions in the slurry. It is understood that at the point where the calcium ions in the slurry are depleted and the carbon mineralization reaction no longer occurs, the pH decreases as the concentration of carbonate ions in the slurry increases due to the continuously injected carbon dioxide.

[0050] The results of XRD and TGA (Thermo-Gravimetric Analysis) analysis of the precipitate after carbon dioxide injection are shown in the graphs of Figures 2 and 3, respectively. The formation of calcium carbonate was confirmed by identifying a calcium carbonate peak in the XRD results of Figure 2. Additionally, referring to the thermal analysis in Figure 3, a weight loss of approximately 15% was confirmed due to the decarboxylation reaction of calcium carbonate in the range of 600–900°C. Through thermogravimetric analysis results, it was confirmed that about 75% of the total calcium in the CaO of the reactive mixture was converted into calcium carbonate. In terms of the total weight of the industrial byproduct, about 15% was converted into calcium carbonate. Since calcium and carbonate ions combine in a 1:1 ratio, a mole of carbonate ions equal to the mole of calcium participating in the reaction is removed. The amount of carbon dioxide removed (volume or weight) can be calculated based on the mole of carbonate ions.

[0051] The reactive mixture slurry, in which calcium carbonate is precipitated in this manner, is mixed into a construction injection material and used. The construction injection material according to the present invention is used by mixing a cement slurry and a reactive mixture. The cement slurry is prepared by mixing water with cement, with a water-to-c ratio (w / c) in the range of 100 to 250 weight percent. Additionally, the cement slurry is mixed in a ratio of 40 to 90 weight percent to 10 to 60 weight percent of the reactive mixture (slurry). In other words, compared to conventional ground injection materials that use 100% cement slurry, the reactive mixture replaces 10 to 60 percent. Since the reactive mixture is primarily composed of industrial by-products, it has the effect of significantly reducing the material costs of the construction injection material. Depending on the application, the construction injection material may additionally be mixed with quick-setting agents such as silica, special silica, and CA-based quick-setting agents in addition to the reactive mixture and cement slurry. Additionally, additives such as coagulation regulators like retarders or accelerators, and material separation inhibitors like thickeners or polymers may be mixed in.

[0052] As mentioned above, physical property tests were performed on a construction injection material mixed with a reactive admixture and a cement slurry. The mixing ratio of the reactive admixture and the cement slurry is as shown in [Table 2] below.

[0053] [Table 2]

[0054]

[0055] In experiment d, 3-hour bleeding (%), viscosity, reactive gel time, and 1-hour strength of the cured body were measured. The experimental results are shown in [Table 3] below.

[0056] [Table 3]

[0057]

[0058] Based on the experimental results above, it was confirmed that the construction injection material according to the present invention satisfied all standard values ​​and exhibited physical properties equivalent to those of conventional cement injection materials. In other words, while satisfying the same performance as conventional cement injection materials as a construction material, it can drastically reduce the amount of cement used. Since cement generates a large amount of carbon dioxide during the manufacturing process, reducing the amount of cement used has the effect of reducing carbon dioxide emissions. Furthermore, since the reactive admixture effectively removes carbon dioxide that has already been released into the atmosphere, the carbon dioxide reduction effect is considered to be very significant. In addition, since cement is replaced with industrial by-products, the effect of reducing material costs can also be expected.

[0059] Meanwhile, the reactive mixture and construction injection material according to the present invention are not manufactured in a factory but are manufactured directly on-site and injected directly into the ground. To this end, a reactive mixture manufacturing device is required.

[0060] A reactive mixture manufacturing apparatus according to the present invention is shown in FIG. 4.

[0061] Referring to FIG. 4, the reactive mixture manufacturing apparatus (100) according to the present invention comprises a stirring tank (10), a circulation reaction unit (20), a supply tank (not shown), and a cooling unit (30).

[0062] The stirring tank (10) mixes and stirs industrial by-products and water to form a slurry. Industrial by-products and water are each introduced into the stirring tank (10), and an outlet (11) is provided on one side for discharging the slurry formed from the reactive mixture. A stirrer (13) capable of stirring the slurry at a high speed of about 800 rpm is installed in the stirring tank (10). As the industrial by-products and the accelerator water are mixed in the stirring tank, calcium is leached from the industrial by-products to form divalent calcium ions.

[0063] The circulation reaction unit (20) circulates the slurry vertically by discharging the slurry from the outlet at the bottom of the stirring tank (10) and then introducing it back into the top of the stirring tank (10). In this example, the circulation reaction unit is configured through vertically arranged pipes. Additionally, the circulation reaction unit is provided with an inlet connected to a supply tank to introduce carbon dioxide into the circulation reaction unit, thereby inducing the formation of calcium carbonate in the slurry passing through the circulation reaction unit. The reason for introducing carbon dioxide into the circulation reaction unit rather than directly injecting it into the stirring tank (10) is to promote the calcium carbonate formation reaction. This will be briefly explained.

[0064] For the carbon mineralization reaction to proceed smoothly, carbon dioxide must be quickly dissolved in water and converted into carbonate ions. Since the leaching of calcium from industrial byproducts occurs relatively easily, the dissolution rate of carbon dioxide dominates the rate of the carbon mineralization reaction. The solubility of carbon dioxide in water increases as the temperature decreases. However, since the reaction in which calcium is leached from quicklime (CaO), an industrial byproduct, in the stirring tank is an exothermic reaction, the temperature of the stirring tank rises. Therefore, if carbon dioxide is injected directly into the stirring tank, it results in a decrease in the solubility of carbon dioxide. In other words, it is necessary to increase the initial solubility by injecting carbon dioxide under low temperature conditions. Accordingly, in the present invention, the circulation reaction unit is separated from the stirring tank and placed independently, and the slurry is circulated. Then, a cooling unit (30) is used to maintain the temperature of the circulation reaction unit at a low level of 20°C or lower. In this example, the cooling unit utilizes a cooling jacket that surrounds and cools the circulating reaction unit in the shape of a pipe. However, various cooling means other than the cooling jacket may be used. As the slurry in the stirring tank flows into the circulation reaction section, its temperature is rapidly lowered by the cooling jacket, and carbon dioxide is injected at that point. The carbon dioxide injected into the slurry rapidly dissolves under low temperature conditions and is converted into carbonate ions, which meet with calcium ions within the circulation reaction section to form calcium carbonate.

[0065] In addition, forming a circulating reaction section to maintain a low slurry temperature provides another advantage. The reactive mixture discharged from the mixing tank is transferred to the injection material mixing tank described later, where it is mixed with cement slurry to form ground injection material, which is then injected directly into the ground. When the temperature of the ground injection material is high, the viscosity increases and gel time control becomes difficult, leading to a problem of reduced injectability. By continuously lowering the temperature of the reactive mixture, it is possible to control the temperature of the ground injection material so that it does not rise. In this example, the temperature of the mixing tank is maintained at 25°C or lower.

[0066] The slurry flows while circulating in the up-and-down direction throughout the circulation reaction section and the stirring tank, and in the process, it meets carbon dioxide to form calcium carbonate. Once the formation of calcium carbonate is complete, the reactive mixture is discharged through the discharge port (11).

[0067] In the present invention, a pH sensor (40) is used to confirm that the formation of calcium carbonate in the stirring tank is complete. The pH sensor (40) is installed in the stirring tank and continuously measures the pH in the stirring tank. Since the slurry in the stirring tank is alkaline, the initial pH is formed at a high level of 13 or higher. When carbon dioxide dissolves and is converted into carbonate ions, it lowers the pH; however, while calcium carbonate is being formed, the carbonate ions react with calcium and precipitate, so the pH of the stirring tank is not lowered. However, when the formation of calcium carbonate is complete, the amount of carbonate ions in the slurry increases and lowers the pH. Accordingly, if the pH in the stirring tank drops rapidly, it can be inferred that the calcium carbonate formation reaction has been completed.

[0068] Meanwhile, in this example, a collection line (12) is provided on the upper side of the stirring tank (10) to discharge carbon dioxide gas that is not dissolved in water. Since the undissolved carbon dioxide is collected on the upper side of the stirring tank, it is reintroduced into the circulation reactor through the collection line. In this example, the stirring tank is maintained in a sealed state, but even if it is not completely sealed, carbon dioxide is lighter than air, so it is not released into the atmosphere and remains in the stirring tank. In other words, it is possible to prevent carbon dioxide from being released into the atmosphere during the process of manufacturing the reactive mixture.

[0069] The reactive mixture in a slurry state discharged from the mixing tank (10) is supplied to the injection material mixing tank (50). Water and cement are supplied to the injection material mixing tank (50) to form a cement slurry. The cement slurry and the reactive mixture are evenly mixed by a stirrer (53) in the mixing tank (50) to form a ground injection material. The ground injection material can be immediately injected into the ground through the discharge port (51).

[0070] As explained above, the present invention has the advantage of being able to process a large amount of carbon dioxide by utilizing industrial by-products as ground injection materials and fixing carbon dioxide in the form of calcium carbonate.

[0071] In addition, the reuse of industrial by-products offers the advantage of improved economic efficiency compared to existing cement-based ground injection materials, and since physical properties are guaranteed to be equivalent to those of existing materials, active application is expected.

[0072] The scope of protection of the present invention is not limited to the description and expression of the embodiments explicitly described above. Furthermore, it is added once again that the scope of protection of the present invention cannot be limited by obvious changes or substitutions in the technical field to which the present invention belongs.

Claims

1. As a reactive admixture for forming a construction injection material by mixing with cement, A reactive mixture characterized by comprising calcium carbonate formed through a carbon mineralization reaction by injecting carbon dioxide into a slurry made by mixing and stirring water with a powdered industrial byproduct composed of 15 wt% or more of CaO, 25 wt% or more of SiO2, 30 wt% or less of Al2O3, and 15 wt% or less of Fe2O3.

2. In Paragraph 1, In order to promote the leaching of calcium from the above industrial by-products, A reactive mixture characterized by further comprising at least one of a first accelerator composed of a combination of one or more of DEG (Diethylene Glycol), DEA (Diethalolamine), and TEA (Triethalolamine), and a second accelerator composed of a combination of one or more of sulfuric acid (H2SO4), potassium sulfate (K2SO4), and sodium sulfate (Na2SO4), wherein the accelerator is additionally mixed in a ratio of 0.1 to 5 weight percent with respect to the total industrial byproduct.

3. In Paragraph 2, The first accelerator is blended at a ratio of 0.01 to 1.0 weight percent with respect to the total industrial by-product, and A reactive mixture characterized in that the second accelerator is blended at a ratio of 0.5 to 5.0 weight percent with respect to the total industrial by-product.

4. In Paragraph 1, The above industrial by-product has a maximum particle size of 1 mm or less and a Blaine specific surface area of ​​2000 cm² 2 A reactive mixture characterized by having a content of / g or more.

5. A stirring tank for forming a slurry by mixing and stirring the industrial by-product and water described in any one of paragraphs 1 to 4; A circulation reaction unit that connects the lower outlet and the upper inlet of the stirring tank to circulate the slurry up and down, and injects carbon dioxide to form calcium carbonate while the slurry passes through; A supply tank for injecting carbon dioxide into the above-mentioned circulation reaction unit; and A reactive mixture manufacturing apparatus characterized by having a cooling unit for cooling the above-mentioned circulating reaction unit.

6. In Paragraph 5, A reactive mixture manufacturing apparatus characterized in that the above-mentioned circulating reaction unit is maintained at 20°C or lower by the above-mentioned cooling unit.

7. In Paragraph 5, A reactive mixture manufacturing apparatus characterized by further comprising a pH sensor for measuring the pH of the slurry to check whether calcium carbonate is generated in the stirring tank.

8. In Paragraph 5, A reactive mixture manufacturing apparatus characterized by having a collection line provided on the upper side of the stirring tank for discharging carbon dioxide gas not dissolved in the slurry, wherein the collected carbon dioxide is reintroduced into a circulation reactor.

9. 40~90 wt% of cement slurry obtained by mixing and stirring cement and water; and Mixed in a ratio of 10 to 60 weight% of the reactive mixture described in any one of claims 1 to 4 above, A construction injection material characterized by being manufactured and used directly at the construction site.

10. In Paragraph 8, A construction injection material characterized by being injected into the ground and used as a ground injection material for improving ground strength and filling cavities.

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