Carbon mineralization material and method for preparing the same

Abstract

The present application relates to a kind of carbon mineralization material and its preparation method.The carbon mineralization material includes carbon mineralization mineral layer and toughening layer arranged in turn alternately, then is prepared by carbon dioxide maintenance, the material of carbon mineralization mineral layer is solid waste, silicate mineral or hydroxide, and the toughening layer is flexible polymer phase layer or gel layer.The present application improves the transmission channel of CO2 by introducing interlayer polymer, so that the mineralization degree and performance of material are greatly increased.Moreover, polymer cooperates with calcium carbonate crystal growth in carbonation process, and crystal is embedded in polymer crosslinking network, forming mechanical interlocking effect, which significantly improves the compressive strength and toughness of material.

Description

Technical Field

[0001] This invention belongs to the field of cement materials technology, and specifically relates to a carbon mineralization material and its preparation method. Background Technology

[0002] As the world's second-largest consumer of cement, cement production presents significant environmental challenges, accounting for 6.5% of global carbon dioxide emissions, equivalent to 2.3 billion tons annually. While the cement industry's carbon footprint has prompted extensive emissions reduction efforts, recent focus has shifted to combining process emissions reduction with carbon sequestration potential through accelerated carbon mineralization curing building materials technologies.

[0003] Existing carbon mineralization curing building material technology mainly adopts compression molding technology and controls the reaction conditions of carbon mineralization to expose the sample to a carbon dioxide-rich environment, thereby achieving high strength in a short period of time. However, the current carbon mineralization curing building material technology still has the following limiting factors: (1) Insufficient carbon mineralization reaction. The external bearing surface reacts with CO2 first, while the internal structure of the matrix is ​​relatively loose, resulting in the carbon mineralized sample being "strong on the outside but weak on the inside". (2) Volume expansion problem. In particular, for alkaline minerals reacting with CO2 to produce calcium carbonate as the main product, the internal stress of the specimen after carbon mineralization will generate microcracks. This phenomenon is particularly obvious in large-volume carbon mineralized specimens. (3) The shell structure limits the further development of strength. Therefore, it is urgent to improve the various properties of carbon mineralized materials, which is particularly crucial for their engineering applications. Summary of the Invention

[0004] This invention provides a carbon mineralization material with sufficient carbon mineralization reaction and excellent performance, as well as a method for preparing the same, to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A carbon mineralization material comprising alternating layers of carbon mineralization minerals and a toughening layer, which are then cured with carbon dioxide. The carbon mineralization mineral layers are made of solid waste, silicate minerals, or hydroxides, and the toughening layer is a flexible polymer phase layer or a gel layer.

[0007] In the above scheme, the solid waste includes red mud, magnesium slag, carbide slag, or steel slag.

[0008] In the above scheme, the silicate minerals include dicalcium γ-silicate, magnesium olivine, tricalcium disilicate, wollastonite, or magnesium rhodochrosite.

[0009] In the above scheme, the material of the flexible polymer phase layer includes a flexible polymer phase, which is polyacrylamide, hydroxypropyl methylcellulose or polyvinyl alcohol fiber.

[0010] In the above scheme, the material of the gel layer includes a gel, and the gel is a nano-silica gel layer.

[0011] In the above scheme, the total number of carbon mineralized mineral layers and toughening layers is 5-20.

[0012] In the above scheme, the hydroxide includes magnesium hydroxide or calcium hydroxide.

[0013] In the above scheme, the thickness of each carbon mineral layer is 2-4 mm.

[0014] In the above scheme, the thickness of each toughening layer is 0.05 mm.

[0015] In the above scheme, the mass of each toughening layer is 0.4%-0.6% of the total mass of the carbon mineralized mineral layer.

[0016] The method for preparing the carbon mineralization material includes the following steps:

[0017] 1) Mix solid waste, silicate minerals, or hydroxides with water to obtain a first mixture;

[0018] 2) Mix the polymer phase or gel with water to obtain a second mixture;

[0019] 3) Weigh a predetermined amount of the first mixture and place it in the mold, then pre-press the surface flat to form a carbon mineralized mineral pre-layer;

[0020] 4) Weigh a predetermined amount of the second mixture and coat it onto the carbon mineralized mineral prefabricated layer to form a toughened prefabricated layer;

[0021] 5) Repeat steps 3) and 4) until the specified number of layers is reached, pressurize to 15-20 MPa, hold the pressure for 50-100 seconds to obtain a molded part with alternating carbon mineral prefabricated layers and toughening prefabricated layers;

[0022] 6) Place the molded part in a carbonization reactor and cure it with CO2 to obtain the carbonized mineralized material.

[0023] In the above scheme, the CO2 curing pressure is 0.3-0.5 MPa.

[0024] In the above scheme, the solid waste or silicate minerals or hydroxides in step 1) are mixed evenly with water at a water-ash ratio of 0.05-0.1.

[0025] In the above scheme, the polymer phase or gel in step 2) is mixed evenly with water at a water-gel ratio of 0.16-0.2.

[0026] In the above scheme, in step 4), the second mixture is applied by spraying.

[0027] In the above scheme, in step 6), the curing temperature is 25-60℃ and the curing time is 1-24h.

[0028] The mechanism of this invention is as follows:

[0029] The alternating layering method continuously provides CO2 transport channels between layers, while simultaneously replenishing moisture lost due to increased carbonization temperature, thus extending the duration of the carbonization reaction. During the carbonization process, internal stress from crystallization prevents cracking of the sample. After the carbonization reaction, the interfacial design of the alternating polymer phase layers or gel layers provides energy dissipation, enhancing the material's various properties. This preparation method is simple, rapid, low-cost, and widely applicable, and holds promise for promoting the large-scale industrial application of carbonized materials.

[0030] In the above technical solution, the present invention has the following beneficial effects:

[0031] (1) This method is applicable to any building material products that require carbon mineralization curing. The sources of materials are wide-ranging, including calcium magnesium-based materials and bulk industrial solid waste. Calcium magnesium-based materials include calcium magnesium silicate minerals, and bulk solid wastes include red mud, magnesium slag, carbide slag, steel slag, magnesium oxide, calcium hydroxide, etc.

[0032] (2) By introducing polymers into the interlayer, the CO2 transport channels are improved, resulting in a significant increase in the mineralization degree and performance of the material. Furthermore, the polymers synergistically promote the growth of calcium carbonate crystals during carbonization, and the crystals are embedded in the polymer cross-linking network, forming a mechanical interlocking effect, which significantly improves the compressive strength and toughness of the material.

[0033] (3) Compared with traditional molding methods, this method can effectively solve the problem of expansion and cracking of samples caused by the internal stress generated by calcium carbonate during carbon mineralization. The cracking problem is particularly obvious in carbon mineralized large products. This preparation method can solve the problem of carbon mineralization cracks in large samples and is expected to promote the industrial application of carbon mineralization materials.

[0034] (4) This molding method is simple and quick, can be completed at room temperature, and is inexpensive.

[0035] (5) The sample prepared by this molding method can solve the problem of insufficient internal reaction in carbon mineralization samples, and the overall sample has a "core-shell" structure. The homogeneous enhancement mechanism provided by this preparation method enables carbon mineralization building materials to have a high performance improvement. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the carbon mineralization material provided by the present invention.

[0037] Figure 2The dimensions are 20×20×20mm 3 Examples of samples.

[0038] Figure 3 The dimensions are 40×40×40mm. 3 Examples and comparative samples (the comparative sample was obviously cracked).

[0039] Figure 4 The dimensions are 40×40×160mm. 3 Examples and comparative samples (the comparative sample is significantly swollen). Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0041] like Figure 1 As shown, this is a carbon mineralization material provided by the present invention. The carbon mineralization material is prepared by carbon dioxide curing of alternating carbon mineralization mineral layers 1 and toughening layers 2.

[0042] The material of carbon mineralized layer 1 is solid waste, silicate minerals, or hydroxides. Solid waste includes red mud, magnesium slag, carbide slag, steel slag, etc. Solid waste mainly refers to solid waste containing alkaline earth metal oxides such as magnesium oxide or calcium oxide. Silicate minerals include dicalcium γ-silicate, magnesium olivine, tricalcium silicate, wollastonite, and magnesium rhodochrosite, etc. Hydroxides include magnesium hydroxide or calcium hydroxide. The thickness of each carbon mineralized layer 1 is 2-4 mm, and the thickness of toughening layer 2 is 0.05 mm.

[0043] The toughening layer 2 is either a flexible polymer phase layer or a gel layer. The flexible polymer phase layer is made of a flexible polymer phase, such as polyacrylamide, hydroxypropyl methylcellulose, or polyvinyl alcohol fiber. The gel layer is made of a gel, specifically a nano-silica gel.

[0044] The total number of carbon mineralized mineral layers and toughening layers is 5-20. Figure 1 The diagram shows 9 layers, ensuring that the top and bottom layers are both carbon-mineralized mineral layers.

[0045] This invention also provides a method for preparing the carbon mineralization material, comprising the following steps:

[0046] 1) Mix solid waste, silicate minerals, or hydroxides with water to obtain a first mixture;

[0047] 2) Mix the polymer phase or gel with water to obtain a second mixture;

[0048] 3) Weigh a predetermined amount of the first mixture and place it in the mold. Use a pressure of 1 MPa to pre-press the surface flat to form a carbon mineralized mineral pre-layer.

[0049] 4) Weigh a predetermined amount of the second mixture and coat it onto the carbon mineralized mineral prefabricated layer to form a toughened prefabricated layer;

[0050] 5) Repeat steps 3) and 4) until the specified number of layers is reached, pressurize to 15-20 MPa, hold the pressure for 50-100 seconds to obtain a molded part with alternating carbon mineral prefabricated layers and toughening prefabricated layers;

[0051] 6) Place the molded part in a carbonization reactor and cure it with CO2 to obtain the carbonized mineralized material.

[0052] In step 1) above, the solid waste, silicate minerals, or hydroxides are mixed with water at a water-ash ratio of 0.05-0.1 until homogeneous.

[0053] In step 2) above, the polymer phase or gel and water are mixed evenly at a water-gel ratio of 0.16-0.2.

[0054] In step 4) above, the second mixture is applied by spraying.

[0055] In step 6) above, the curing temperature is 25-60℃, the curing time is 1-24h, and the CO2 pressure is 0.3-0.5MPa.

[0056] In the above scheme, when the curing is not fully completed, the carbon mineralized mineral layer is called the carbon mineralized mineral precast layer, and the toughening layer is called the toughening precast layer.

[0057] The preparation method of the carbon mineralization material of the present invention will be described in detail below through specific embodiments.

[0058] The dicalcium γ-silicate and calcium hydroxide used in the following examples are derived from conventional silicate minerals and calcium hydroxides with carbonization activity prepared in the laboratory.

[0059] Example 1

[0060] This embodiment provides a method for preparing a carbon mineralization material, including the following steps:

[0061] (1) Weigh a certain amount of γ-dicalcium silicate mineral, mix it with water at a water-cement ratio of 0.1 to obtain a mixture;

[0062] (2) Polyacrylamide was selected as the polymer phase layer, the water-to-gel ratio was 0.2, and a polyacrylamide solution was obtained after uniform mixing;

[0063] (3) Place the mixture obtained in step (1) in a 20×20×20 mm sieve. 3 In the mold, the weight is controlled at 1.6g, and the surface is pre-pressed flat with a pressure of 1MPa to form a carbon mineral pre-layer;

[0064] (4) Weigh 0.075g of the polyacrylamide solution obtained in step (2) and spray it onto the carbon mineral prefabricated layer to obtain the toughened prefabricated layer;

[0065] (5) Continue to weigh the wet mixture obtained in step (1) and put it into the mold with the same mass as in step (3), and use a pressure of 1 MPa to pre-press the surface flat.

[0066] (6) Repeat steps (4) and (5) above. When the specified number of layers of 19 is reached, pressurize to 15 MPa and hold the pressure for 60 seconds to obtain a molded part with alternating carbon mineral prefabricated layers and toughening prefabricated layers.

[0067] (7) Place the molded part in a carbonization reactor, introduce CO2 into the carbonization reactor for curing, set the CO2 pressure to 0.3 MPa, the temperature to 60°C, and the carbonization time to 24 h.

[0068] Example 2

[0069] This embodiment provides a method for preparing a carbon mineralization material, including the following steps:

[0070] (1) Weigh a certain amount of γ-dicalcium silicate mineral, mix it with water at a water-cement ratio of 0.1 to obtain a mixture;

[0071] (2) Polyacrylamide was selected as the polymer phase layer, the water-to-gel ratio was 0.2, and a polyacrylamide solution was obtained after uniform mixing;

[0072] (3) Place the wet mixture obtained in step (1) in a 20×20×20 mm sieve. 3 In the mold, the weight is controlled at 3.2g, and the surface is pre-pressed flat with a pressure of 1MPa to form a carbon mineral pre-layer;

[0073] (4) Weigh 0.075g of the polyacrylamide solution obtained in step (2) and spray it onto the carbon mineral prefabricated layer to obtain the toughened prefabricated layer;

[0074] (5) Continue to weigh the wet mixture obtained in step (1) and put it into the mold with the same mass as in step (3), and use a pressure of 1 MPa to pre-press the surface flat.

[0075] (6) Repeat steps (4) and (5) above. When the specified number of layers (9) is reached, pressurize to 15 MPa and hold the pressure for 60 seconds to obtain a molded part with alternating carbon mineral prefabricated layers and toughening prefabricated layers.

[0076] (7) Place the molded part in a carbonization reactor, introduce CO2 into the carbonization reactor for curing, set the CO2 pressure to 0.3 MPa, the temperature to 60°C, and the carbonization time to 24 h.

[0077] Example 3

[0078] This embodiment provides a method for preparing a carbon mineralization material, including the following steps:

[0079] (1) Weigh a certain amount of γ-dicalcium silicate mineral, mix it with water at a water-cement ratio of 0.05 to obtain a mixture;

[0080] (2) Polyacrylamide was selected as the polymer phase layer, the water-to-gel ratio was 0.16, and a polyacrylamide solution was obtained after uniform mixing.

[0081] (3) Place the wet mixture obtained in step (1) in a 20×20×20 mm sieve. 3 In the mold, the weight is controlled at 3.2 g, and the surface is pre-pressed flat with a pressure of 1 MPa to form a carbon mineral pre-layer;

[0082] (4) Weigh 0.075g of the polyacrylamide solution obtained in step (2) and spray it onto the carbon mineral prefabricated layer to obtain the toughened prefabricated layer;

[0083] (5) Continue to weigh the wet mixture obtained in step (1) and put it into the mold with the same mass as in step (3), and use a pressure of 1 MPa to pre-press the surface flat.

[0084] (6) Repeat steps (4) and (5) above. When the specified number of layers (9) is reached, pressurize to 15MPa and hold the pressure for 60s to obtain a molded part with alternating carbon mineral prefabricated layers and toughening prefabricated layers.

[0085] (7) Place the molded part in a carbonization reactor, introduce CO2 into the carbonization reactor for curing, set the CO2 pressure to 0.3 MPa, the temperature to 25°C, and the carbonization time to 24 h.

[0086] Example 4

[0087] This embodiment provides a method for preparing a carbon mineralization material, including the following steps:

[0088] (1) Weigh a certain amount of γ-dicalcium silicate mineral, mix it with water at a water-cement ratio of 0.1 to obtain a mixture;

[0089] (2) Polyacrylamide was selected as the polymer phase layer, the water-to-gel ratio was 0.16, and a polyacrylamide solution was obtained after uniform mixing.

[0090] (3) Place the wet mixture obtained in step (1) in a 40×40×40 mm sieve. 3 In the mold, the weight is controlled at 25.6 g, and the surface is pre-pressed flat with a pressure of 1 MPa to form a carbon mineral pre-layer;

[0091] (4) Weigh 0.6 g of the polyacrylamide solution obtained in step (2) and spray it onto the carbon mineralized mineral prefabricated layer to obtain the toughened prefabricated layer;

[0092] (5) Continue to weigh the wet mixture obtained in step (1) and put it into the mold with the same mass as in step (3), and use a pressure of 1 MPa to pre-press the surface flat.

[0093] (6) Repeat steps (4) and (5) above. When the specified number of layers (9) is reached, pressurize to 15MPa and hold the pressure for 60s to obtain a molded part with alternating carbon mineral prefabricated layers and toughening prefabricated layers.

[0094] (7) Place the molded part in a carbonization reactor, introduce CO2 into the carbonization reactor for curing, set the CO2 pressure to 0.3 MPa, the temperature to 25°C, and the carbonization time to 24 h.

[0095] Example 5

[0096] This embodiment provides a method for preparing a carbon mineralization material, including the following steps:

[0097] (1) Weigh a certain amount of calcium hydroxide and mix it with water at a water-cement ratio of 0.1 to obtain a mixture;

[0098] (2) Polyacrylamide was selected as the polymer phase layer, the water-to-gel ratio was 0.2, and a polyacrylamide solution was obtained after uniform mixing;

[0099] (3) Place the wet mixture obtained in step (1) in a 40×40×160 mm sieve. 3 In the mold, the weight is controlled at 60g, and the surface is pre-pressed flat with a pressure of 1MPa to form a carbon mineral pre-layer;

[0100] (4) Weigh 3.0 g of the polyacrylamide solution obtained in step (2) and spray it onto the carbon mineralized mineral prefabricated layer to obtain the toughened prefabricated layer;

[0101] (5) Continue to weigh the wet mixture obtained in step (1) and put it into the mold with the same mass as in step (3), and use a pressure of 1 MPa to pre-press the surface flat.

[0102] (6) Repeat steps (4) and (5) above. When the specified number of layers of 19 is reached, pressurize to 10MPa and hold the pressure for 60s to obtain a molded part with alternating carbon mineral prefabricated layers and toughening prefabricated layers.

[0103] (7) Place the molded part in a carbonization reactor, introduce CO2 into the carbonization reactor for curing, set the CO2 pressure to 0.3 MPa, the temperature to 60°C, and the carbonization time to 24 h.

[0104] Comparative Example 1

[0105] (1) Weigh a certain amount of γ-dicalcium silicate mineral, mix it with water at a water-cement ratio of 0.05 to obtain a mixture;

[0106] (2) Place the wet mixture obtained in step (1) in a 40×40×40 mm sieve. 3 In the mold, the weight is controlled at 128g, and the part is pressed into a thickness of approximately 40mm using a pressure of 15 MPa; no toughening layer is provided.

[0107] (3) Place the above-mentioned molded parts in a carbonization reactor, introduce CO2 into the carbonization reactor for curing, set the CO2 pressure to 0.3MPa, the temperature to 25℃, and the carbonization time to 24h.

[0108] Comparative Example 2

[0109] (1) Weigh a certain amount of γ-dicalcium silicate mineral, mix it with water at a water-cement ratio of 0.1 to obtain a mixture;

[0110] (2) Place the wet mixture obtained in step (1) in a 40×40×40 mm sieve. 3 In the mold, the weight is controlled at 128g, and the part is pressed into a thickness of approximately 40mm using a pressure of 15 MPa; no toughening layer is provided.

[0111] (3) Place the above-mentioned molded parts in a carbonization reactor, introduce CO2 into the carbonization reactor for curing, set the CO2 pressure to 0.3MPa, the temperature to 60℃, and the carbonization time to 24h.

[0112] Comparative Example 3

[0113] This comparative example provides a method for preparing a carbon mineralization material, comprising the following steps:

[0114] (1) Weigh a certain amount of calcium hydroxide and mix it with water at a water-cement ratio of 0.1 to obtain a mixture;

[0115] (2) Polyacrylamide was selected as the polymer phase layer, the water-to-gel ratio was 0.2, and a polyacrylamide solution was obtained after uniform mixing;

[0116] (3) Place the wet mixture obtained in step (1) in a 40×40×160 mm sieve. 3 In the mold, the weight is controlled at 40g, and the surface is pre-pressed flat with a pressure of 1MPa to form a carbon mineral pre-layer;

[0117] (4) Weigh 3.0 g of the polyacrylamide solution obtained in step (2) and spray it onto the carbon mineralized mineral prefabricated layer to obtain the toughened prefabricated layer;

[0118] (5) Continue to weigh the wet mixture obtained in step (1) and put it into the mold with the same mass as in step (3), and use a pressure of 1 MPa to pre-press the surface flat.

[0119] (6) Repeat steps (4) and (5) above. When the specified number of layers of 29 is reached, pressurize to 10MPa and hold the pressure for 60s to obtain a molded part with alternating carbon mineral prefabricated layers and toughening prefabricated layers.

[0120] (7) Place the molded part in a carbonization reactor, introduce CO2 into the carbonization reactor for curing, set the CO2 pressure to 0.3 MPa, the temperature to 60°C, and the carbonization time to 24 h.

[0121] Mechanical properties were tested for Examples 1-5 and Comparative Examples 1-3 according to the national standard (GB / T 17671-2021):

[0122] Test method: The mechanical properties were tested using a YAW-300 / 20 microcomputer-controlled compression testing machine. The compressive strength of the specimens after carbonization for 24 hours was tested, with a loading rate of 0.3 mm / min. Three specimens were measured, and the average value was taken.

[0123] CO2 curing amount tests were conducted on Examples 1-5 and Comparative Examples 1-3:

[0124] The mass of the sample before the carbonization reaction is taken as M1, and the mass of the sample after carbonization curing for 24 hours is taken as M2.

[0125] The formula for calculating the amount of CO2 solidified is: (M2-M1) / M1.

[0126] The test results are shown in Table 1:

[0127] Table 1

[0128]

[0129] Comparative Examples 1 and 2, relative to Examples 1, 2, and 3 ( Figure 2 In Comparative Examples 2 and 3, the method of synergistic lamination of carbon mineral layer and toughening layer was not adopted, but the traditional pressing molding method was used, which resulted in volume expansion and cracks on the sample surface. Figure 3 This is not conducive to performance development.

[0130] Comparative Example 3 is largely the same as Example 5, except that the number of layers was increased from 19 to 29. Analysis of the data in Table 1 shows that although the CO2 solidification amount in Comparative Example 3 increased slightly, the excessive introduction of toughening layers led to internal stress during carbon mineralization, resulting in volume expansion. Figure 4 This reduces the strength.

[0131] The results show that the preparation method of mineralized gradient stacking helps to improve the carbonization degree and mechanical properties of the sample, while also improving the expansion problem of the sample, and the improvement is particularly obvious in large samples.

[0132] The above embodiments are merely illustrative examples and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations; therefore, any obvious variations or modifications derived therefrom remain within the scope of protection of this invention.

Claims

1. A carbon mineralization material, characterized in that, The carbon mineralization material comprises alternating layers of carbon mineralization minerals and a toughening layer, which are then cured with carbon dioxide. The carbon mineralization mineral layer is made of solid waste, silicate minerals, or hydroxides. The toughening layer is a flexible polymer phase layer or a gel layer. The total number of carbon mineralization mineral layers and toughening layers is 5-20.

2. The carbon mineralization material as described in claim 1, characterized in that, The solid waste includes red mud, magnesium slag, carbide slag, or steel slag.

3. The carbon mineralization material as described in claim 1, characterized in that, The silicate minerals include dicalcium γ-silicate, magnesium olivine, tricalcium disilicate, wollastonite, or magnesium rhodochrosite.

4. The carbon mineralization material as described in claim 1, characterized in that, The material of the flexible polymer phase layer includes a flexible polymer phase, which is polyacrylamide, hydroxypropyl methylcellulose, or polyvinyl alcohol fiber.

5. The carbon mineralization material as described in claim 1, characterized in that, The material of the gel layer includes a gel, and the gel is a nano-silica gel layer.

6. The carbon mineralization material as described in claim 1, characterized in that, The thickness of each layer of carbonaceous mineral is 2-4 mm.

7. The carbon mineralization material as described in claim 1, characterized in that, The hydroxides include magnesium hydroxide or calcium hydroxide.

8. The method for preparing carbon mineralized materials as described in claim 1, characterized in that, Includes the following steps: 1) Mix solid waste, silicate minerals, or hydroxides with water to obtain a first mixture; 2) Mix the polymer phase or gel with water to obtain a second mixture; 3) Weigh a predetermined amount of the first mixture and place it in the mold, then pre-press the surface flat to form a carbon mineralized mineral pre-layer; 4) Weigh a predetermined amount of the second mixture and coat it onto the carbon mineralized mineral prefabricated layer to form a toughened prefabricated layer; 5) Repeat steps 3) and 4) until the specified number of layers is reached, pressurize to 15-20 MPa, hold the pressure for 50-100 seconds to obtain a molded part with alternating carbon mineral prefabricated layers and toughening prefabricated layers; 6) Place the molded part in a carbonization reactor and cure it with CO2 to obtain the carbonized mineralized material.

9. The preparation method according to claim 8, characterized in that, The pressure for CO2 curing is 0.3-0.5 MPa.

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