Carbon sequestration concrete solid brick prepared from coal-based solid waste and preparation method of carbon sequestration concrete solid brick

Abstract

The invention relates to the technical field of building materials, in particular to a carbon sequestration concrete solid brick prepared from coal-based solid waste and a preparation method of the carbon sequestration concrete solid brick. The carbon sequestration concrete solid brick is prepared from the following raw materials in parts by weight: 20 to 30 parts of fly ash, 65 to 75 parts of furnace bottom slag and 5 parts of cement, wherein the fly ash is secondary ash, the particle size of the furnace bottom slag is smaller than or equal to 4.75 mm, and the mark number of the cement is P.O 42.5. The method comprises the following steps: firstly, enabling carbon dioxide to react with alkaline components such as dicalcium silicate in the fly ash to form carbonate so as to realize effective carbon sequestration; and then through secondary mineralization maintenance, carbon dioxide, active components such as calcium and magnesium in the cement and dicalcium silicate which is not completely reacted in the fly ash are subjected to carbonation reaction, so that a product layer filling effect is realized. According to the invention, the building material with good carbon sequestration performance and excellent mechanical properties is prepared by utilizing industrial solid waste and carbon dioxide, so that energy conservation and emission reduction are realized, meanwhile, greenhouse gas emission is reduced, and the performance of the building solid waste brick is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and in particular to a carbon-fixing concrete solid brick made from coal-based solid waste and a preparation method thereof. Background Art

[0002] Fly ash and bottom ash are the main solid wastes emitted by coal-fired power plants. It is estimated that coal-fired power plants nationwide generate over 700 million tons of fly ash and 150 million tons of bottom ash annually. In recent years, the slow development of the construction industry has indirectly led to a sharp decline in the resource utilization of coal-fired solid waste, forcing some to be disposed of by stockpiling or landfilling. However, large-scale stockpiling or landfilling not only consumes land resources but also pollutes the air, soil, and water, seriously impacting the human living environment.

[0003] Coal-fired power plants not only produce large amounts of solid waste, but also emit flue gas containing significant amounts of carbon dioxide, which directly contributes to the greenhouse effect and raises global temperatures. Currently, carbon emission reduction has become a complex issue of economic, energy, and environmental concern to all international stakeholders. Therefore, carbon emission reduction is urgent.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a coal-based solid waste carbon-fixing concrete solid brick and a preparation method thereof, which can solve the above-mentioned technical problems.

[0006] The present invention provides a solid carbon-fixing concrete brick made from coal-based solid waste, comprising the following raw materials in parts by weight: 20-30 parts of fly ash, 65-75 parts of bottom ash and 5 parts of cement, wherein the fly ash is secondary ash and is pre-mineralized.

[0007] Preferably, the particle size of the bottom ash is less than or equal to 4.75 mm.

[0008] Preferably, the cement has a grade of PO 42.5.

[0009] The present invention also provides a method for preparing the above-mentioned carbon-fixing concrete solid brick, comprising the following steps:

[0010] S1: Mix fly ash and appropriate amount of water evenly, and place the evenly mixed wet fly ash into a mineralization curing kettle for primary mineralization treatment;

[0011] S2: taking out the fly ash after the primary mineralization treatment and storing it in a sealed manner;

[0012] S3: Mixing mineralized fly ash, cement and bottom slag according to the designed mix ratio, adding water and stirring evenly to obtain a mixture;

[0013] S4: After the mixture is loaded into the brick machine mold, it is vibrated to ensure that the mixture is evenly distributed in the mold;

[0014] S5: Pressing is performed according to the preset molding pressure and holding time to obtain a sample;

[0015] S6: Remove the sample from the mold and place it at room temperature for pre-curing;

[0016] S7: placing the pre-cured sample into a mineralization curing kettle for secondary mineralization treatment;

[0017] S8: Take out the sample after the secondary mineralization treatment and carry out natural curing at room temperature.

[0018] Preferably, in step S1, water is added to a water-solid ratio of 0.2, the stirring speed is 80 r / min, and the stirring time is 3-5 min.

[0019] Preferably, in step S1, the primary mineralization treatment conditions include: mineralization curing at room temperature, a mineralization curing pressure of 1 MPa, a mineralization curing time of 4-6 hours, and a carbon dioxide concentration greater than 99%.

[0020] Preferably, in step S3, water is added until the moisture content of the mixture is 15%-19%, and the stirring speed is 200 r / min.

[0021] Preferably, in step S5, the preset molding pressure value is 15 MPa, and the holding time is 5-10 s.

[0022] Preferably, in step S6, the pre-curing time is 24-48 hours.

[0023] Preferably, in step S7, the secondary mineralization treatment conditions include: mineralization curing at room temperature, a mineralization curing pressure of 1 MPa, a mineralization curing time of 8-10 hours, and a carbon dioxide concentration of >99%.

[0024] The technical principles of the above-mentioned primary mineralization treatment and secondary mineralization treatment are as follows:

[0025] Primary Mineralization: Fly ash is a solid waste product from coal-fired power plants. Its main components are silicon dioxide (SiO2), calcium oxide (CaO), and aluminum oxide (Al2O3). Dicalcium silicate (2CaO·SiO2, or C2S) is a common alkaline mineral component in fly ash and is highly chemically active. Under wet or semi-dry carbonation conditions, C2S reacts with CO2 to form calcium carbonate (CaCO3) and amorphous silica gel (SiO2·nH2O). The CO2 is converted into a stable carbonate mineral (CaCO3), enabling long-term storage.

[0026] Secondary mineralization: Active minerals such as tricalcium silicate (C3S) and tricalcium aluminate (C3A) contained in cement release Ca during hydration or carbonation. 2+ Mg 2+ Plasma. Unreacted C2S in fly ash and active components in cement continue to react with CO2 during secondary mineralization. Calcium and magnesium ions in cement directly react with CO2 to form carbonates, and unreacted C2S further carbonates. Carbonate minerals (such as CaCO3 and MgCO3) fill the material's pores and cracks in the form of microcrystals, forming a dense structure that significantly improves the material's compressive strength, durability, and impermeability.

[0027] Beneficial effects:

[0028] The present invention first utilizes carbon dioxide to react with alkaline components such as dicalcium silicate in fly ash to form carbonates, thereby achieving effective carbon fixation. Then, through secondary mineralization and curing, carbon dioxide is used to react with active components such as calcium and magnesium in cement, as well as unreacted dicalcium silicate in fly ash, to undergo a carbonation reaction, thereby achieving a product layer filling effect. The present invention uses bulk solid waste as the main raw material, and utilizes industrial solid waste in conjunction with carbon dioxide to produce building materials with excellent carbon fixation performance and excellent physical properties. This is beneficial to the resource utilization of industrial waste residues, achieving both energy conservation and emission reduction, while also reducing greenhouse gas emissions. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular also includes the plural. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] The raw materials used in each embodiment are as follows:

[0033] Fly ash: The main chemical components are: SiO2, Al2O3, FeO, Fe2O3, CaO, TiO2; the average particle size is 45μm, and the apparent density is 1900-2400kg / m 3 , bulk density is 600-1000kg / m 3 ;

[0034] Bottom slag: The main chemical components are: SiO2, CaO, Al2O3, Fe2O3; the particle size range is 0-4.75mm;

[0035] Cement: PO 42.5 is used, and its main chemical components are: CaO, SiO2, Al2O3, Fe2O3.

[0036] Example 1

[0037] The carbon-fixing concrete solid bricks of this embodiment include the following raw materials in parts by weight: 20 parts of fly ash, 75 parts of bottom ash, and 5 parts of cement.

[0038] The preparation method of the carbon-fixing concrete solid brick of this embodiment comprises the following steps:

[0039] Step 1: fly ash and water were weighed and mixed in proportion, wherein the water-to-solid ratio was 0.2, and then stirred at a stirring speed of 80 r / min for 5 minutes to obtain uniformly mixed wet fly ash;

[0040] Step 2: sending the evenly mixed wet fly ash to a mineralization curing kettle for mineralization curing at room temperature (primary mineralization treatment), wherein the mineralization curing pressure is 1 MPa and the mineralization curing time is 4 hours;

[0041] Step 3: Pre-mineralized (primary mineralization treatment) fly ash, bottom ash and cement are weighed and mixed in proportion, and then water is added and stirred until the moisture content of the mixture is 15%, and then stirred at a stirring speed of 200 r / min for 5 minutes to obtain a uniform mixture;

[0042] Step 4: Pour the mixture into the brick machine mold and vibrate it to ensure that the mixture is evenly distributed in the mold;

[0043] Step 5: After the material is laid, press the pressure button to lower the upper die head and continue to pressurize. When the molding pressure reaches the preset 15MPa, maintain the pressure for 10 seconds.

[0044] Step 6: Remove the specimen from the mold and place it at room temperature for pre-curing. After pre-curing for 48 hours, send the specimen to the mineralization curing kettle for room temperature mineralization curing (secondary mineralization treatment) and mineralization curing for 10 hours under a CO2 pressure of 1 MPa.

[0045] Step 7: After the secondary mineralization treatment is completed, the gas is exhausted, the sample is taken out, and placed indoors for natural curing to obtain a carbon-fixing concrete solid brick.

[0046] The compressive strength of the carbon-fixing concrete solid bricks was tested using the axial compressive strength test method, and the carbon fixation content of the carbon-fixing concrete solid bricks was tested using the apparent carbon fixation rate calculation method. The results showed that the compressive strength of the carbon-fixing solid bricks in this embodiment was 15.2 MPa and the carbon fixation content was 5.2%.

[0047] Example 2

[0048] The carbon-fixing concrete solid bricks of this embodiment include the following raw materials in parts by weight: 20 parts of fly ash, 75 parts of bottom ash, and 5 parts of cement.

[0049] The preparation method of the carbon-fixing concrete solid brick of this embodiment comprises the following steps:

[0050] Step 1: fly ash and water were weighed and mixed in proportion, wherein the water-to-solid ratio was 0.25, and then stirred at a stirring speed of 80 r / min for 5 minutes to obtain uniformly mixed wet fly ash;

[0051] Step 2: sending the evenly mixed wet fly ash to a mineralization curing kettle for mineralization curing at room temperature (primary mineralization treatment), wherein the mineralization curing pressure is 1 MPa and the mineralization curing time is 4 hours;

[0052] Step 3: Pre-mineralized (primary mineralization treatment) fly ash, bottom ash and cement are weighed and mixed in proportion, and then water is added and stirred until the moisture content of the mixture is 15%, and then stirred at a stirring speed of 200 r / min for 5 minutes to obtain a uniform mixture;

[0053] Step 4: Pour the mixture into the brick machine mold and vibrate it to ensure that the mixture is evenly distributed in the mold;

[0054] Step 5: After the material is laid, press the pressure button to lower the upper die head and continue to pressurize. When the molding pressure reaches the preset 15MPa, maintain the pressure for 10 seconds.

[0055] Step 6: Remove the specimen from the mold and place it at room temperature for pre-curing. After pre-curing for 48 hours, send the specimen to the mineralization curing kettle for room temperature mineralization curing (secondary mineralization treatment) and mineralization curing for 10 hours under a CO2 pressure of 1 MPa.

[0056] Step 7: After the mineralization curing is completed, the gas is exhausted and the sample is taken out and placed indoors for natural curing to obtain a carbon-fixing concrete solid brick.

[0057] After testing, the compressive strength of the carbon-fixing concrete solid brick of this embodiment is 15.0 MPa, and the carbon-fixing amount is 5.4%.

[0058] Example 3

[0059] The carbon-fixing concrete solid bricks of this embodiment include the following raw materials in parts by weight: 20 parts of fly ash, 75 parts of bottom ash, and 5 parts of cement.

[0060] The preparation method of the carbon-fixing concrete solid brick of this embodiment comprises the following steps:

[0061] Step 1: fly ash and water were weighed and mixed in proportion, wherein the water-to-solid ratio was 0.2, and then stirred at a stirring speed of 80 r / min for 5 minutes to obtain uniformly mixed wet fly ash;

[0062] Step 2: sending the evenly mixed wet fly ash to a mineralization curing kettle for mineralization curing at room temperature (primary mineralization treatment), wherein the mineralization curing pressure is 1 MPa and the mineralization curing time is 6 hours;

[0063] Step 3: Pre-mineralized (primary mineralization treatment) fly ash, bottom ash and cement are weighed and mixed in proportion, and then water is added and stirred until the moisture content of the mixture is 15%, and then stirred at a stirring speed of 200 r / min for 5 minutes to obtain a uniform mixture;

[0064] Step 4: Pour the mixture into the brick machine mold and vibrate it to ensure that the mixture is evenly distributed in the mold;

[0065] Step 5: After the material is laid, press the pressure button to lower the upper die head and continue to pressurize. When the molding pressure reaches the preset 15MPa, maintain the pressure for 10 seconds.

[0066] Step 6: Remove the specimen from the mold and place it at room temperature for pre-curing. After pre-curing for 48 hours, send the specimen to the mineralization curing kettle for room temperature mineralization curing (secondary mineralization treatment) and mineralization curing for 10 hours under a CO2 pressure of 1 MPa.

[0067] Step 7: After the mineralization curing is completed, the gas is exhausted and the sample is taken out and placed indoors for natural curing to obtain a carbon-fixing concrete solid brick.

[0068] After testing, the compressive strength of the carbon-fixing concrete solid brick of this embodiment is 14.9 MPa, and the carbon-fixing amount is 5.3%.

[0069] Example 4

[0070] The carbon-fixing concrete solid bricks of this embodiment include the following raw materials in parts by weight: 20 parts of fly ash, 75 parts of bottom ash, and 5 parts of cement.

[0071] The preparation method of the carbon-fixing concrete solid brick of this embodiment comprises the following steps:

[0072] Step 1: fly ash and water were weighed and mixed in proportion, wherein the water-to-solid ratio was 0.2, and then stirred at a stirring speed of 80 r / min for 5 minutes to obtain uniformly mixed wet fly ash;

[0073] Step 2: sending the evenly mixed wet fly ash to a mineralization curing kettle for mineralization curing at room temperature (primary mineralization treatment), wherein the mineralization curing pressure is 1 MPa and the mineralization curing time is 4 hours;

[0074] Step 3: Pre-mineralized (primary mineralization treatment) fly ash, bottom ash and cement are weighed and mixed in proportion, and then water is added and stirred until the moisture content of the mixture reaches 17%, and then stirred at a stirring speed of 200 r / min for 5 minutes to obtain a uniform mixture;

[0075] Step 4: Pour the mixture into the brick machine mold and vibrate it to ensure that the mixture is evenly distributed in the mold;

[0076] Step 5: After the material is laid, press the pressure button to lower the upper die head and continue to pressurize. When the molding pressure reaches the preset 15MPa, maintain the pressure for 10 seconds.

[0077] Step 6: Remove the specimen from the mold and place it at room temperature for pre-curing. After pre-curing for 48 hours, send the specimen to the mineralization curing kettle for room temperature mineralization curing (secondary mineralization treatment) and mineralization curing for 10 hours under a CO2 pressure of 1 MPa.

[0078] Step 7: After the mineralization curing is completed, the gas is exhausted and the sample is taken out and placed indoors for natural curing to obtain a carbon-fixing concrete solid brick.

[0079] After testing, the compressive strength of the carbon-fixing concrete solid brick of this embodiment is 15.5 MPa, and the carbon-fixing amount is 5.3%.

[0080] Example 5

[0081] The carbon-fixing concrete solid bricks of this embodiment include the following raw materials in parts by weight: 20 parts of fly ash, 75 parts of bottom ash, and 5 parts of cement.

[0082] The preparation method of the carbon-fixing concrete solid brick of this embodiment comprises the following steps:

[0083] Step 1: fly ash and water were weighed and mixed in proportion, wherein the water-to-solid ratio was 0.2, and then stirred at a stirring speed of 80 r / min for 5 minutes to obtain uniformly mixed wet fly ash;

[0084] Step 2: sending the evenly mixed wet fly ash to a mineralization curing kettle for mineralization curing at room temperature (primary mineralization treatment), wherein the mineralization curing pressure is 1 MPa and the mineralization curing time is 4 hours;

[0085] Step 3: Pre-mineralized (primary mineralization treatment) fly ash, bottom ash and cement are weighed and mixed in proportion, and then water is added and stirred until the moisture content of the mixture is 15%, and then stirred at a stirring speed of 200 r / min for 5 minutes to obtain a uniform mixture;

[0086] Step 4: Pour the mixture into the brick machine mold and vibrate it to ensure that the mixture is evenly distributed in the mold;

[0087] Step 5: After the material is laid, press the pressure button to lower the upper die head and continue to pressurize. When the molding pressure reaches the preset 15MPa, maintain the pressure for 10 seconds.

[0088] Step 6: Remove the specimen from the mold and place it at room temperature for pre-curing. After pre-curing for 24 hours, send the specimen to the mineralization curing kettle for room temperature mineralization curing (secondary mineralization treatment) and mineralization curing for 10 hours under a CO2 pressure of 1 MPa.

[0089] Step 7: After the mineralization curing is completed, the gas is exhausted and the sample is taken out and placed indoors for natural curing to obtain a carbon-fixing concrete solid brick.

[0090] After testing, the compressive strength of the carbon-fixing concrete solid brick of this embodiment is 14.9 MPa, and the carbon-fixing amount is 4.8%.

[0091] Example 6

[0092] The carbon-fixing concrete solid bricks of this embodiment include the following raw materials in parts by weight: 25 parts of fly ash, 70 parts of bottom ash, and 5 parts of cement.

[0093] The preparation method of the carbon-fixing concrete solid brick of this embodiment comprises the following steps:

[0094] Step 1: fly ash and water were weighed and mixed in proportion, wherein the water-to-solid ratio was 0.2, and then stirred at a stirring speed of 80 r / min for 5 minutes to obtain uniformly mixed wet fly ash;

[0095] Step 2: sending the evenly mixed wet fly ash to a mineralization curing kettle for mineralization curing at room temperature, wherein the mineralization curing pressure is 1 MPa and the mineralization curing time is 4 hours;

[0096] Step 3: Pre-mineralized fly ash, bottom ash, and cement were weighed and mixed according to a certain proportion, and then water was added and stirred until the moisture content of the mixture reached 15%. The mixture was then stirred at a stirring speed of 200 r / min for 5 minutes to obtain a uniform mixture.

[0097] Step 4: Pour the mixture into the brick machine mold and vibrate it to ensure that the mixture is evenly distributed in the mold;

[0098] Step 5: After the material is laid, press the pressure button to lower the upper die head and continue to pressurize. When the molding pressure reaches the preset 15MPa, maintain the pressure for 10 seconds.

[0099] Step 6: Remove the specimen from the mold and place it at room temperature for pre-curing. After pre-curing for 48 hours, send the specimen to the mineralization curing kettle for mineralization curing at room temperature and at a CO2 pressure of 1 MPa for 10 hours.

[0100] Step 7: After the mineralization curing is completed, the gas is exhausted and the sample is taken out and placed indoors for natural curing to obtain a carbon-fixing concrete solid brick.

[0101] After testing, the compressive strength of the multi-solid waste unfired bricks of this embodiment is 15.5 MPa, and the carbon fixation content is 5.4%.

[0102] It can be seen from Example 6 and Example 1 that appropriately increasing the amount of pre-mineralized fly ash is beneficial to the carbon fixation rate and strength development.

[0103] Comparative Example 1

[0104] The carbon-fixing concrete solid bricks of this comparative example include the following raw materials in parts by weight: 20 parts of unpremineralized fly ash, 75 parts of bottom slag, and 5 parts of cement.

[0105] The preparation method of the carbon-fixing concrete solid brick of this comparative example comprises the following steps:

[0106] Step 1: Unmineralized fly ash, bottom ash, and cement are weighed and mixed in proportion, and then water is added and stirred until the moisture content of the mixture reaches 15%, and then stirred at a stirring speed of 200 r / min for 5 minutes to obtain a uniform mixture;

[0107] Step 2: Pour the mixture into the brick machine mold and vibrate it to ensure that the mixture is evenly distributed in the mold;

[0108] Step 3: After the material is laid, press the pressure button to lower the upper die head and continue to pressurize. When the molding pressure reaches the preset 15MPa, maintain the pressure for 10 seconds.

[0109] Step 4: Remove the specimen from the mold and place it at room temperature for pre-curing. After pre-curing for 48 hours, send the specimen to the mineralization curing kettle for mineralization curing at room temperature and at a CO2 pressure of 1 MPa for 10 hours.

[0110] Step 5: After the mineralization curing is completed, the gas is exhausted and the sample is taken out and placed indoors for natural curing to obtain a carbon-fixing concrete solid brick.

[0111] According to the test, the compressive strength of the carbon-fixing concrete solid brick of this comparative example is 15.7 MPa, and the carbon-fixing amount is 4.6%.

[0112] It can be seen from Comparative Example 1 and Example 1 that the strength of solid bricks can be appropriately improved without pre-mineralization of fly ash, but the carbon fixation amount will be reduced.

[0113] Comparative Example 2

[0114] The carbon-fixing concrete solid bricks of this comparative example include the following raw materials in parts by weight: 20 parts of fly ash and 80 parts of bottom slag.

[0115] The preparation method of the carbon-fixing concrete solid bricks in this comparative example refers to Example 1.

[0116] According to the test, the compressive strength of the carbon-fixing concrete solid brick of this comparative example is 10.3 MPa, and the carbon-fixing amount is 3.5%.

[0117] Comparative Example 3

[0118] Raw materials: by weight, 10 parts fly ash, 80 parts bottom slag, 10 parts cement;

[0119] Preparation method: same as Example 1, testing method: same as Example 1;

[0120] Test results: compressive strength: 12.8MPa, carbon fixation: 4.1%.

[0121] Comparative Example 4

[0122] Raw materials: the same as in Example 1;

[0123] Preparation method adjustment: Step 2: The mineralization curing pressure in the primary mineralization treatment is 0.5 MPa and the time is 4 hours; the test method is the same as that in Example 1;

[0124] Test results: compressive strength: 13.5MPa, carbon fixation: 3.8%.

[0125] Comparative Example 5

[0126] Raw materials: the same as in Example 1;

[0127] Preparation method adjustment: delete step 6 and retain only the primary mineralization treatment; test method: the same as Example 1;

[0128] Test results: compressive strength: 10.4MPa, carbon fixation: 2.1%.

[0129] Comparative Example 6

[0130] Raw materials: the same as in Example 1;

[0131] Preparation method adjustment: Step 5: molding pressure 10 MPa, holding pressure 10 s; testing method: the same as Example 1;

[0132] Test results: compressive strength: 9.7MPa, carbon fixation: 4.6%.

[0133] Comparative Example 7

[0134] Raw materials: the same as in Example 1;

[0135] Preparation method adjustment: Delete step 2 and step 6, and do not perform any mineralization treatment; Test method: Same as Example 1;

[0136] Test results: compressive strength: 8.2MPa, carbon fixation: 0.3%.

[0137] Comparative Example 8

[0138] Raw materials: the same as in Example 1;

[0139] Preparation method adjustment: the water-to-solid ratio in step 1 is increased to 0.3, and the moisture content in step 3 is increased to 30%; test method: the same as in Example 1;

[0140] Test results: compressive strength: 7.5MPa, carbon fixation: 4.0%.

[0141] In summary, the preparation method of the carbon-fixing concrete solid brick provided by the present invention can be used to produce unfired and unsteamed bricks, which have obvious advantages such as efficient absorption of CO2 and disposal of solid waste.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solid brick made of coal-based solid waste to fix carbon, characterized in that: The method comprises the following raw materials in parts by weight: 20-30 parts of fly ash, 65-75 parts of bottom ash and 5 parts of cement. The fly ash is secondary ash and has been mineralized in advance.

2. The coal-based solid waste carbon-fixing concrete solid brick according to claim 1, characterized in that: The particle size of the bottom slag is less than or equal to 4.75 mm.

3. The coal-based solid waste carbon-fixing concrete solid brick according to claim 1, characterized in that: The cement has a designation of PO 42.

5.

4. The method for preparing a carbon-fixing concrete solid brick according to any one of claims 1 to 3, characterized in that: The steps include: S1: Mix fly ash and appropriate amount of water evenly, and place the evenly mixed wet fly ash into a mineralization curing kettle for primary mineralization treatment; S2: taking out the fly ash after the primary mineralization treatment and storing it in a sealed manner; S3: Mixing mineralized fly ash, cement and bottom slag according to the designed mix ratio, adding water and stirring evenly to obtain a mixture; S4: After the mixture is loaded into the brick machine mold, it is vibrated to ensure that the mixture is evenly distributed in the mold; S5: Pressing is performed according to the preset molding pressure and holding time to obtain a sample; S6: Remove the sample from the mold and place it at room temperature for pre-curing; S7: placing the pre-cured sample into a mineralization curing kettle for secondary mineralization treatment; S8: Take out the sample after the secondary mineralization treatment and carry out natural curing at room temperature.

5. The method for preparing carbon-fixing concrete solid bricks according to claim 4, characterized in that: In step S1, water is added to a water-to-solid ratio of 0.2, the stirring speed is 80 r / min, and the stirring time is 3-5 min.

6. The method for preparing carbon-fixing concrete solid bricks according to claim 4, characterized in that: In step S1, the primary mineralization treatment conditions include: mineralization curing at room temperature, a mineralization curing pressure of 1 MPa, a mineralization curing time of 4-6 hours, and a carbon dioxide concentration of >99%.

7. The method for preparing carbon-fixing concrete solid bricks according to claim 4, characterized in that: In step S3, water is added until the moisture content of the mixture reaches 15%-19%, and the stirring speed is 200 r / min.

8. The method for preparing carbon-fixing concrete solid bricks according to claim 4, characterized in that: In step S5, the molding pressure is preset to 15 MPa, and the holding time is 5-10 s.

9. The method for preparing carbon-fixing concrete solid bricks according to claim 4, characterized in that: In step S6, the pre-curing time is 24-48 hours.

10. The method for preparing carbon-fixing concrete solid bricks according to claim 4, characterized in that: In step S7, the secondary mineralization treatment conditions include: mineralization curing at room temperature, mineralization curing pressure of 1 MPa, mineralization curing time of 8-10 hours, and carbon dioxide concentration >99%.