Process for mineralizing concrete mixture by using carbonic acid solution and process method thereof

Abstract

The invention discloses a process for mineralizing a concrete mixture by using a carbonic acid solution and a process method thereof. The process comprises a heat exchange module, a gas-liquid mixing module, an ion additive dissolving module and a mixture mineralizing module, after the carbonic acid solution passes through the heat exchange module, the gas-liquid mixing module and the ion assistant dissolving module, an ion enhanced carbonic acid solution is output; through the mixture mineralization module, concrete, gravel and cement raw materials are mixed with an ion-enhanced carbonic acid solution, and a carbonic acid solution mineralized concrete mixture is prepared. As only equipment of the carbonic acid solution needs to be additionally arranged on an existing concrete production line, carbon dioxide atmosphere curing does not need to be carried out after the concrete is hardened, the fluidity of a concrete mixture is not affected, the construction performance of the concrete can be guaranteed, and no negative influence is caused to an existing premixed concrete pouring forming process.

Description

Technical Field

[0001] The invention relates to a process for mineralizing concrete mixture by using a carbonate solution. Background Art

[0002] Concrete is a widely used building material with excellent mechanical properties and durability. However, the production and use of concrete also brings some environmental problems, the most serious of which is the emission of carbon dioxide. It is estimated that the production and use of concrete accounts for about 8% of global carbon dioxide emissions. Therefore, how to reduce the carbon footprint of concrete and improve the environmental friendliness of concrete is an important topic in current concrete technology.

[0003] At present, there are two main processes for carbon dioxide mineralization of concrete. One is to directly introduce carbon dioxide gas into the concrete mixture, and the other is to cure the hardened concrete in a carbon dioxide atmosphere. Both processes have some disadvantages. The process of directly introducing carbon dioxide gas usually leaks a large amount of carbon dioxide, causing waste of resources and environmental pollution, and affects the fluidity of the concrete mixture, resulting in a decrease in the construction performance of the concrete; the carbon dioxide atmosphere curing method needs to be carried out after the concrete has hardened, and requires a special mineralization curing kettle, which increases the construction time and cost, and can only mineralize the surface of the concrete, and cannot use the alkalinity inside the concrete to mineralize the entire volume.

[0004] Therefore, a new process for carbon dioxide mineralized concrete is needed that can overcome the above shortcomings and improve the utilization rate of carbon dioxide and the performance of concrete. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides a process for mineralizing concrete mixtures using a carbonate solution and a process method thereof, wherein bicarbonate ions in the carbonate solution can react quickly with alkaline components in concrete to form stable carbonate minerals, fill the pores of the concrete, increase the density of the concrete, inhibit the alkali-aggregate reaction of the concrete, and improve the crack resistance of the concrete; the construction process is simplified and costs are saved, because the present invention only requires the installation of equipment for carbonate solution in the existing concrete production line, and does not require carbon dioxide atmosphere curing after the concrete hardens.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a process for mineralizing a concrete mixture using a carbonate solution, comprising a heat exchange module, a gas-liquid mixing module, an ion aid dissolution module and a mixture mineralization module; after passing through the heat exchange module, the gas-liquid mixing module and the ion aid dissolution module, the carbonate solution is output; through the mixture mineralization module, the concrete sand, gravel and cement raw materials are mixed with the carbonate solution to prepare a concrete mixture mineralized with the carbonate solution.

[0007] As a preferred technical solution of the present invention, the gas-liquid mixing module includes a CO2 regulating valve, a CO2 flowmeter and a venturi tube. The pure CO2 liquid in the gas cylinder is gasified to a selected pressure through the CO2 regulating valve, and the amount of gas entering the gas-liquid mixing module is regulated by the CO2 flowmeter, mixed with cooled pure water at the venturi tube, and a carbonate solution is output.

[0008] As a preferred technical solution of the present invention, the ion aid dissolution module includes a dissolution kettle connected to a venturi, and a discharge end of the dissolution kettle is connected to a storage tank via a feed pipe.

[0009] As a preferred technical solution of the present invention, the mixture mineralization module includes a stirrer, the feed end of the stirrer is connected to the storage tank through a material pipe, and a carbonate solution flow meter is provided on the material pipe.

[0010] As a preferred technical solution of the present invention, the heat exchange module includes a heat exchanger connected to a water pump through a water pipe, a compressor, a condenser and an expansion valve are sequentially arranged on the evaporation circuit of the heat exchanger, and the end of the heat exchanger away from the water pipe is connected to the Venturi tube.

[0011] As a preferred technical solution of the present invention, the CO2 regulating valve is connected to a control system to achieve regulation of the CO2 pressure.

[0012] A process method for mineralizing concrete mixture using carbonate solution, the specific steps are as follows: S1, preparing a carbonate solution, that is, cooling pure water to 4-10 degrees Celsius, and then passing it into a venturi tube to mix it with pressurized carbon dioxide gas, adding a certain proportion of ion additives into the solution, and dissolving it to obtain a prepared carbonate solution; S2. The prepared carbonate solution is directly introduced into a concrete mixer through a very short pipeline, and completely replaces water in the mix ratio, and is mixed with cement, sand, stone and other components to form a carbonate solution mineralized concrete mixture; S3. Perform conventional construction operations such as pouring, vibrating, and curing on the carbonate solution mineralized concrete mixture to obtain carbonate solution mineralized concrete.

[0013] Compared with the prior art, the beneficial effects that the present invention can achieve are: efficient utilization of carbon dioxide can be achieved, leakage of carbon dioxide can be avoided, the absorption of carbon dioxide can be increased, the carbon footprint of concrete can be reduced, and environmental protection is beneficial; bicarbonate ions in the carbonate solution can react quickly with alkaline components in concrete to form stable carbonate minerals, fill the pores of concrete, increase the density of concrete, inhibit the alkali-aggregate reaction of concrete, and improve the crack resistance of concrete; the construction process is simplified and costs are saved, because the present invention only needs to add equipment for carbonate solution to the existing concrete production line, and does not need to perform carbon dioxide atmosphere curing after the concrete hardens, and will not affect the fluidity of the concrete mixture, so the construction performance of the concrete can be guaranteed, and it will not have a negative impact on the current ready-mixed concrete casting and molding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a process flow chart of the present invention.

[0015] Among them: 1. heat exchange module; 2. gas-liquid mixing module; 3. ion aid dissolution module; 4. mixture mineralization module; 21. CO2 regulating valve; 22. CO2 flow meter; 23. Venturi tube. DETAILED DESCRIPTION

[0016] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention. The experimental methods in the following embodiments, unless otherwise specified, are conventional methods, and the materials, reagents, etc. used in the following embodiments, unless otherwise specified, can be obtained from commercial channels.

[0017] Example: like Figure 1 As shown, Example 1: Follow these steps to prepare carbonated solution mineralized concrete mix: 1. Prepare a carbonate solution, that is, cool pure water to 5 degrees Celsius, and then pass it into a venturi tube to mix it with pressurized carbon dioxide gas. The pressure of carbon dioxide is 0.5 MPa, the volume ratio of water to carbon dioxide is 8:1, the mixing time is 1 minute, and sodium bicarbonate powder is added. The mass ratio of sodium bicarbonate to water is 0.01:1 to obtain a carbonate solution containing a high concentration of carbonate ions. The content of dissolved carbon dioxide in the carbonate solution is measured by titration to be 9g / L; 2. The prepared carbonate solution is directly introduced into the concrete mixer through a very short pipeline, and completely replaces water in the mix ratio, and is mixed with cement, sand, stone and other components to form a carbonate solution mineralized concrete mixture. The mix ratio of concrete is: cement: fly ash: sand: stone: carbonate solution: water reducing agent = 1: 0.2: 2.3: 3: 0.53: 0.02. The type of cement is PO 42.5, the fineness modulus of sand is 2.6, and the maximum particle size of stone is 20mm; 3. Carry out conventional construction operations such as pouring, vibrating, and curing on the carbonate solution mineralized concrete mixture to obtain carbonate solution mineralized concrete. The curing conditions of the concrete are: humidity of 95%, temperature of 20 degrees Celsius, and curing time of 28 days.

[0018] The carbonate solution mineralized concrete prepared according to the above steps has a 28-day strength of 48.4 MPa, which is 18% higher than the 28-day strength of ordinary concrete with the same mix ratio. The carbon fixation analysis was performed using thermogravimetric method, and the carbon dioxide absorption of the carbonate solution mineralized concrete was measured to be 1.66 kg / m 3 .

[0019] Embodiment 2: Follow these steps to prepare carbonated solution mineralized concrete mix: 1. Prepare a carbonate solution, that is, cool pure water to 4 degrees Celsius, and then pass it into a venturi tube to mix it with pressurized carbon dioxide gas. The pressure of carbon dioxide is 0.6 MPa, the volume ratio of water to carbon dioxide is 8:1, the mixing time is 1 minute, and sodium bicarbonate powder is added. The mass ratio of sodium bicarbonate to water is 0.02:1, and a carbonate solution containing a high concentration of carbonate ions is obtained. The carbon dioxide content in the carbonate solution is 10g / L; 2. The prepared carbonate solution is directly introduced into the concrete mixer through a very short pipeline, and completely replaces water in the mix ratio, and is mixed with cement, sand, stone and other components to form a carbonate solution mineralized concrete mixture. The mix ratio of concrete is: cement: fly ash: sand: stone: carbonate solution: water reducing agent = 1: 0.2: 1.5: 2.5: 0.45: 0.02. The type of cement is PO 42.5, the fineness modulus of sand is 2.8, and the maximum particle size of stone is 25mm; 3. Carry out conventional construction operations such as pouring, vibrating, and curing on the carbonate solution mineralized concrete mixture to obtain carbonate solution mineralized concrete. The curing conditions of the concrete are: humidity of 95%, temperature of 20 degrees Celsius, and curing time of 28 days.

[0020] The carbonate solution mineralized concrete prepared according to the above steps has a 28-day strength of 51.2 MPa, which is 18.6% higher than the 28-day strength of ordinary concrete with the same mix ratio. The carbon fixation analysis was performed using thermogravimetric method, and the carbon dioxide absorption was measured to be 2 kg / m 3 .

[0021] Embodiment 3: Follow these steps to prepare carbonated solution mineralized concrete mix: 1. Prepare a carbonate solution, that is, cool pure water to 10 degrees Celsius, and then pass it into a venturi tube to mix it with pressurized carbon dioxide gas. The pressure of carbon dioxide is 0.4 MPa, the volume ratio of water to carbon dioxide is 10:1, the mixing time is 1 minute, and sodium bicarbonate powder is added. The mass ratio of sodium bicarbonate to water is 0.015:1, and a carbonate solution containing a high concentration of carbonate ions is obtained. The carbon dioxide content in the carbonate solution is 7.0 g / L; 2. Directly introduce the prepared carbonate solution into the concrete mixer through a very short pipeline, and completely replace water in the mix ratio, and mix it with cement, fly ash, sand, stone and other components to form a carbonate solution mineralized concrete mixture. The mix ratio of concrete is: cement: fly ash: sand: stone: carbonate solution: water reducing agent = 1: 0.2: 1.6: 2.4: 0.52: 0.02. The type of cement is PO 42.5, the fineness modulus of sand is 2.85, and the maximum particle size of stone is 25mm; 3. Carry out conventional construction operations such as pouring, vibrating, and curing on the carbonate solution mineralized concrete mixture to obtain carbonate solution mineralized concrete. The curing conditions of the concrete are: humidity of 95%, temperature of 20 degrees Celsius, and curing time of 28 days.

[0022] The carbonate solution mineralized concrete prepared according to the above steps has a 28-day strength of 45.3 MPa, which is 10.7% higher than the 28-day strength of ordinary concrete. The carbon fixation analysis using thermogravimetric method measured the carbon dioxide absorption to be 1.45 kg / m 3 .

[0023] Comparative Example 1: Follow the steps below to prepare CO2 gas mineralized concrete mix: 1. Mix concrete in a mixer with a mix ratio of cement: sand: stone: water = 1:1.5:2.5:0.4. The type of cement is PO 42.5, the fineness modulus of sand is 2.8, and the maximum particle size of stone is 20 mm. 2. Reduce the pressure of liquid CO2 to 0.6MPa through a pressure reducing valve, pass it into the mixed concrete mixture, stir and ventilate for 3 minutes.

[0024] 3. The CO2 gas mineralized concrete mixture is subjected to conventional pouring, vibrating, curing and other construction operations to obtain CO2 gas mineralized concrete. The curing conditions of the concrete are: humidity of 95%, temperature of 20 degrees Celsius, and curing time of 28 days.

[0025] The CO2 gas mineralized concrete prepared according to the above steps has a 28-day strength of 41 MPa. The carbon fixation analysis using thermogravimetric method shows that the carbon dioxide absorption is 0.9 kg / m 3 .

[0026] Comparative Example 2: Follow these steps to prepare the dry ice mineralized concrete mix: 1. Mix concrete in a mixer with a mix ratio of cement: sand: stone: water = 1:1.5:2.5:0.4. The type of cement is PO 42.5, the fineness modulus of sand is 2.8, and the maximum particle size of stone is 20 mm. 2. Crush the dry ice into small pieces, add it to the mixed concrete mixture, and mix it with other components. The mass ratio of dry ice to cement is 0.01:1; 3. The dry ice mineralized concrete mixture is subjected to conventional construction operations such as pouring, vibrating, and curing to obtain dry ice mineralized concrete. The curing conditions of the concrete are: humidity of 95%, temperature of 20 degrees Celsius, and curing time of 28 days.

[0027] The dry ice mineralized concrete prepared according to the above steps has a 28-day strength of 43.2 MPa. The carbon fixation analysis was performed using thermogravimetric method, and the carbon dioxide absorption was measured to be 1.2 kg / m 3 .

[0028] The heat exchange module 1 uses a high-efficiency heat exchanger, which is designed with advanced heat transfer technology to maximize the transfer efficiency of heat energy while reducing energy consumption. The compressor uses variable frequency technology, which can dynamically adjust the compression force according to process requirements to optimize the efficiency of the refrigerant cycle. The condenser is designed as a multi-stage condensation system to improve the efficiency and speed of refrigerant liquefaction. The expansion valve uses intelligent control to accurately adjust the flow and pressure of the refrigerant to ensure the best heat exchange performance.

[0029] The gas-liquid mixing module 2 includes a high-precision CO2 regulating valve 21 and a flow meter 22 to ensure accurate CO2 supply and pressure. The regulating valve 21 uses micro-control technology to achieve fine pressure adjustment to adapt to different operating conditions. The flow meter 22 uses advanced sensing technology to monitor and adjust the flow of CO2 in real time to ensure the best mixing effect. The design of the venturi tube 23 takes into account the principles of fluid dynamics to maximize the solubility of CO2 in water, thereby generating a high-concentration carbonate solution.

[0030] After passing through the heat exchange module 1, the gas-liquid mixing module 2, and the ion-aid dissolution module 3, the ion-enhanced carbonate solution is output; through the mixture mineralization module 4, the concrete sand, gravel, and cement raw materials are mixed with the ion-enhanced carbonate solution to form a concrete mixture mineralized with carbonate solution. In the design and implementation of the ion-aid dissolution module 3, an innovative method is adopted to improve the efficiency and reactivity of the carbonate solution. This technology can accurately adjust the proportions and concentrations of multiple ion aids according to the original state of the concrete mixture to optimize the reaction efficiency of carbonate ions and alkali metal ions in the concrete mineralization process. The ion aids selected in this module are one or more of sodium bicarbonate, calcium carbonate, calcium hydroxide, etc.

[0031] Furthermore, ionic additives can promote the formation of carbonated microcrystals in concrete. In the microstructure of concrete, carbonated microcrystals play a key role in promoting, causing hydration products to grow in a directional manner along the nucleus. This phenomenon shows that carbonated microcrystals not only guide the deposition of hydration products as core points, but also affect their crystal growth path and structural arrangement at the microscopic level. This process effectively enhances the microstructural integrity and macroscopic mechanical properties of concrete, especially in improving the density and durability of the material. The ion-enhanced carbonate solution formed is mixed with raw materials such as machine-made sand, gravel, cement, and water reducer. This precisely controlled ionic carbonate solution contains high-concentration, high-mineralization active active ingredients, which can react with the raw materials in concrete to produce acid-base neutralization reactions to form stable carbonate products and fix CO2. The heat exchange module 1 also includes a temperature controller 15 for monitoring and regulating the water temperature in the high-efficiency heat exchanger 11 to ensure that a suitable temperature range is maintained during the preparation of the concrete mixture, which is conducive to the mineralization reaction of the carbonate solution. The CO2 regulating valve 21 in the gas-liquid mixing module 2 is connected to the control system to realize intelligent adjustment of the CO2 pressure to meet the production needs of different concrete mixtures and ensure a stable supply of carbonated solution. The dissolution rate in the ion aid dissolution module 3 can be adjusted by controlling the dosage of the ion aid and the stirring time to achieve precise control of the properties of the carbonated solution and improve the quality and performance of the concrete mixture. The ratio of raw materials such as machine-made sand, gravel, and cement in the mixture mineralization module 4 can be flexibly adjusted according to the purpose and strength requirements of the concrete to achieve customized design of the mixture performance. The ion-enhanced carbonated solution in the mixture mineralization module 4 reacts with the hydroxide ions in the cement during the mixing process with the concrete raw materials, thereby promoting the hydration reaction of the cement and further improving the strength and durability of the concrete.

[0032] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above implementation regulations. The above implementation regulations and descriptions are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A process for mineralizing a concrete mixture using a carbonate solution, characterized in that: It comprises a heat exchange module (1), a gas-liquid mixing module (2), an ion-aid dissolving module (3) and a mixture mineralization module (4); after passing through the heat exchange module (1), the gas-liquid mixing module (2) and the ion-aid dissolving module (3), a carbonate solution is output; The concrete sand, gravel and cement raw materials are mixed with the carbonate solution through the mixture mineralization module (4) to produce a concrete mixture mineralized with the carbonate solution.

2. The process for mineralizing concrete mixture using carbonate solution according to claim 1, characterized in that: The gas-liquid mixing module (2) comprises a CO2 regulating valve (21), a CO2 flowmeter (22) and a venturi tube (23). Pure CO2 liquid in the gas cylinder is gasified to a selected pressure through the CO2 regulating valve (21). The amount of gas entering the gas-liquid mixing module (2) is regulated by the CO2 flowmeter (22), and is mixed with cooled pure water at the venturi tube (23) to output a carbonated solution.

3. The process for mineralizing concrete mixture using carbonate solution according to claim 2, characterized in that: The ion auxiliary agent dissolution module (3) comprises a dissolution kettle connected to a venturi (23), and a discharge end of the dissolution kettle is connected to a storage tank via a feed pipe.

4. The process for mineralizing concrete mixture using carbonate solution according to claim 3, characterized in that: The mixture mineralization module (4) comprises a stirrer, wherein the feed end of the stirrer is connected to a storage tank via a material pipe, and a carbonate solution flow meter is provided on the material pipe.

5. The process for mineralizing concrete mixture using carbonate solution according to claim 4, characterized in that: The heat exchange module comprises a heat exchanger connected to a water pump through a water pipe, a compressor, a condenser and an expansion valve are sequentially arranged on the evaporation circuit of the heat exchanger, and the end of the heat exchanger away from the water pipe is connected to the venturi tube.

6. The process for mineralizing concrete mixture using carbonate solution according to claim 2, characterized in that: The CO2 regulating valve (21) is connected to a control system to adjust the CO2 pressure.

7. The process for producing a carbonate solution mineralized concrete mixture according to any one of claims 1 to 6, S1, preparing a carbonate solution, that is, cooling pure water to 4-10 degrees Celsius, and then passing it into a venturi tube to mix it with pressurized carbon dioxide gas, adding a certain proportion of ion additives into the solution, and dissolving it to obtain a prepared carbonate solution; S2. The prepared carbonate solution is directly introduced into a concrete mixer through a very short pipeline, and completely replaces water in the mix ratio, and is mixed with cement, sand, stone and other components to form a carbonate solution mineralized concrete mixture; S3. Perform conventional construction operations such as pouring, vibrating, and curing on the carbonate solution mineralized concrete mixture to obtain carbonate solution mineralized concrete.

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