Domestic waste incineration fly ash-based geopolymer and preparation method thereof

Abstract

The invention discloses a household garbage incineration fly ash based geopolymer and a preparation method thereof, and relates to the technical field of household garbage incineration fly ash. The household garbage incineration fly ash based geopolymer is prepared from the following raw materials in percentage by mass: 31.1 to 34.94 percent of fly ash, 2.2 to 7.51 percent of dolomite powder, 9.98 to 11.1 percent of metakaolin, 4 to 4.47 percent of sodium hydroxide, 24.9 to 28.09 percent of liquid water glass and 17.36 to 26.7 percent of deionized water. The prepared fly ash-based geopolymer has a good curing effect on chloride ions and can meet high-standard environmental protection requirements, the mixing amount of fly ash in the fly ash-based geopolymer reaches 31.1-34.94%, the preparation cost of the fly ash-based geopolymer is reduced, economic benefits are improved, and the fly ash-based geopolymer is suitable for large-scale production and application.

Description

Technical Field

[0001] The present application relates to the technical field of fly ash from the incineration of domestic waste, and in particular to a domestic waste incineration fly ash-based polymer and a preparation method thereof. Background Art

[0002] With the acceleration of urbanization, the problem of domestic waste disposal has become increasingly prominent. Incineration, as an effective way of waste disposal, can significantly reduce the volume and weight of waste, but it also produces a large amount of fly ash. Fly ash contains a large amount of pollutants such as heavy metals and dioxins, as well as a large amount of soluble chloride salts. If not properly handled, it will threaten the natural environment and human safety.

[0003] At present, the main methods for treating fly ash include solidification, stabilization and landfill. Solidification and stabilization technologies fix harmful substances in fly ash by adding solidifying agents such as cement and chelating agents to reduce its environmental risks, but these methods have high processing costs and are difficult to achieve resource utilization of fly ash. Although the landfill method is simple, it has long-term environmental risks and does not utilize the valuable components in fly ash, which is also difficult to achieve resource utilization of fly ash.

[0004] Geopolymer is a new type of inorganic polymer material with excellent mechanical properties and durability. The preparation of geopolymer usually involves mixing raw materials containing aluminum and silicon with alkaline activators to form a three-dimensional network structure through polymerization reaction. In recent years, researchers have tried to use fly ash as a raw material for geopolymer to realize the resource utilization of fly ash, such as CN116003009B and CN115557735A. However, the existing fly ash-based polymer preparation method has the following problems: 1. The prepared geopolymer has poor curing effect on chloride ions and is difficult to meet high environmental protection requirements; 2. The fly ash dosage in the existing preparation method is low, the cost of the prepared geopolymer is high, and the economic benefit is not obvious, which limits its application in large-scale production. Summary of the invention

[0005] The purpose of the present application is to provide a domestic waste incineration fly ash-based polymer and a preparation method thereof, so as to solve the problem that the existing fly ash-based polymer has a poor solidification effect on chloride ions.

[0006] The technical solution adopted by this application to solve its technical problem is:

[0007] In a first aspect, a fly ash-based polymer from the incineration of domestic waste is provided, wherein the fly ash-based polymer is made of the following raw materials in percentage by mass: 31.1-34.94% fly ash, 2.2-7.51% dolomite powder, 9.98-11.1% metakaolin, 4-4.47% sodium hydroxide, 24.9-28.09% liquid water glass, and 17.36-26.7% deionized water.

[0008] Furthermore, the fly ash-based polymer is made of the following raw materials in percentage by mass: 32.5-34.94% fly ash, 5-7.5% dolomite powder, 9.98-10% metakaolin, 4.1-4.44% sodium hydroxide, 25.9-28% liquid water glass, and 17.64-20% deionized water.

[0009] Furthermore, the particle size of the dolomite powder is less than 1000 mesh.

[0010] Furthermore, the content of SiO2 and Al2O3 in the metakaolin is ≥95%.

[0011] Furthermore, the purity of the sodium hydroxide is analytically pure.

[0012] Furthermore, the modulus of the liquid water glass is 3.2 to 3.26.

[0013] Furthermore, the fly ash includes 90% of particles with a particle size less than 87.5 μm generated by a municipal solid waste incineration power plant.

[0014] In a second aspect, a method for preparing a domestic waste incineration fly ash-based polymer is provided, comprising:

[0015] S1, mixing solid sodium hydroxide and liquid water glass and stirring evenly to obtain an alkali activator;

[0016] S2, mixing fly ash, dolomite powder and metakaolin and stirring evenly, then adding alkali activator and deionized water and stirring evenly to obtain geopolymer slurry; wherein the liquid-to-solid ratio of the geopolymer slurry is 0.59-0.62;

[0017] S3, stirring the geopolymer slurry to a gel state to obtain a geopolymer gel; pouring the geopolymer gel into a mold and performing curing after vibrating on a vibrating table.

[0018] Furthermore, in step S3, the compaction frequency is 55 to 60 times / min, and the compaction time is 10 to 20 min.

[0019] Furthermore, in step S3, the curing method includes: firstly wrapping the mold containing the geopolymer gel with a plastic film and then placing it in a curing box with a temperature of 60±2°C and a humidity of 90-95% for curing for 3-6 hours, then taking it out of the curing box, demoulding it, and curing it under natural conditions to a specified age.

[0020] Beneficial effects of this application:

[0021] 1. The fly ash-based polymer prepared in this application has a good curing effect on chloride ions and can meet high standards of environmental protection requirements.

[0022] 2. The fly ash content in the fly ash-based polymer prepared in the present application reaches 31.1-34.94%, which reduces the preparation cost of the fly ash-based polymer, improves the economic benefit, and is suitable for large-scale production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of a method for preparing a domestic waste incineration fly ash-based polymer. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0025] The embodiment of the present application provides a fly ash-based polymer from the incineration of domestic waste. The fly ash-based polymer is made of the following raw materials in percentage by mass: 31.1-34.94% fly ash, 2.2-7.51% dolomite powder, 9.98-11.1% metakaolin, 4-4.47% sodium hydroxide, 24.9-28.09% liquid water glass, and 17.36-26.7% deionized water.

[0026] In some embodiments, the fly ash-based polymer is made of the following raw materials in percentage by weight: 32.5-34.94% fly ash, 5-7.5% dolomite powder, 9.98-10% kaolin, 4.1-4.44% sodium hydroxide, 25.9-28% liquid water glass, and 17.64-20% deionized water.

[0027] In some embodiments, the particle size of dolomite powder is less than 1000 mesh, the content of SiO2 and Al2O3 in the metakaolin is ≥95%, the purity of sodium hydroxide is analytically pure, and the modulus of liquid water glass is 3.2-3.26; the fly ash includes 90% of particles with a particle size less than 87.5 μm generated by a domestic waste incineration power plant. The Ca content in the fly ash is about 34.5%, and the soluble chloride ion content is about 24%.

[0028] See also Figure 1 The present application provides a method for preparing a polymer based on fly ash from the incineration of domestic waste, comprising the following steps:

[0029] S1, mixing solid sodium hydroxide and liquid water glass and stirring evenly to obtain an alkali activator;

[0030] S2, mixing fly ash, dolomite powder and metakaolin and stirring evenly, then adding alkali activator and deionized water and stirring evenly to obtain geopolymer slurry; wherein the liquid-to-solid ratio of the geopolymer slurry is 0.59-0.62;

[0031] S3, stirring the geopolymer slurry to a gel state to obtain a geopolymer gel; pouring the geopolymer gel into a mold and performing curing after vibrating on a vibrating table.

[0032] In some embodiments, in step S3, the compaction frequency is 55 to 60 times / min, and the compaction time is 10 to 20 minutes; the curing method includes: first wrapping the mold containing the geopolymer gel with a plastic film and placing it in a curing box with a temperature of 60±2°C and a humidity of 90 to 95% for 3 to 6 hours, then taking it out of the curing box and demolding it, and curing it under natural conditions to a specified age.

[0033] Embodiment 1:

[0034] 1) Weighing:

[0035] According to the mass percentage of fly ash 31.1%, dolomite powder 2.2%, kaolin 11.1%, sodium hydroxide 4%, liquid water glass 24.9% and deionized water 26.7%, 70g fly ash, 5g dolomite powder, 25g kaolin, 8.9g sodium hydroxide, 26.1g liquid water glass and 60g deionized water were weighed respectively.

[0036] 2) Preparation of geopolymer slurry:

[0037] Solid sodium hydroxide and liquid water glass are mixed and stirred evenly to obtain an alkali activator; fly ash, dolomite powder and kaolin are put into a mixing tank, stirred evenly, and then the alkali activator and deionized water are added to the mixing tank, and stirred evenly again to obtain a viscous geopolymer slurry with good fluidity; wherein the liquid-to-solid ratio of the geopolymer slurry is 0.6.

[0038] 3) Forming and curing:

[0039] Continue stirring the geopolymer slurry until it becomes gel-like to obtain a geopolymer gel; pour the geopolymer gel into a cubic mold with a side length of 40mm×40mm×40mm, place the mold on a vibration table and vibrate it at a frequency of 60 times / min for 10 minutes to release the bubbles in the geopolymer gel; first wrap the mold containing the geopolymer gel with a plastic film and place it in a curing box with a temperature of 60±2°C and a humidity of 95% for curing for 3 to 6 hours, then take it out of the curing box and demould it, and continue to cure it under natural conditions to 3 days, and finally obtain a solidified body of the fly ash-based polymer.

[0040] Embodiment 2:

[0041] 1) Weighing:

[0042] According to the mass percentage of fly ash 34.94%, dolomite powder 5%, kaolin 9.98%, sodium hydroxide 4.44%, liquid water glass 28% and deionized water 17.64%, 210g fly ash, 30g dolomite powder, 60g kaolin, 26.75g sodium hydroxide, 168.25g liquid water glass and 106g deionized water were weighed respectively.

[0043] 2) Preparation of geopolymer slurry:

[0044] Solid sodium hydroxide and liquid water glass are mixed and stirred evenly to obtain an alkali activator; fly ash, dolomite powder and kaolin are put into a mixing tank, stirred evenly, and then the alkali activator and deionized water are added to the mixing tank, and stirred evenly again to obtain a viscous geopolymer slurry with good fluidity; wherein the liquid-to-solid ratio of the geopolymer slurry is 0.59.

[0045] 3) Forming and curing:

[0046] The geopolymer slurry is continuously stirred until it becomes gel-like to obtain a geopolymer gel; the geopolymer gel is poured into a cubic mold with a side length of 40 mm×40 mm×40 mm, and the mold is placed on a vibration table and vibrated at a frequency of 55 times / min for 20 minutes to release bubbles in the geopolymer gel; the mold containing the geopolymer gel is first wrapped with a plastic film and then placed in a curing box with a temperature of 60±2°C and a humidity of 90% for curing for 3 to 6 hours, then taken out from the curing box and demolded, and then continued to be cured under natural conditions to 3 days of age, and finally a solidified body of the fly ash-based polymer is obtained.

[0047] Embodiment 3:

[0048] 1) Weighing:

[0049] According to the mass percentage of fly ash 32.5%, dolomite powder 7.5%, kaolin 10%, sodium hydroxide 4.1%, liquid water glass 25.9% and deionized water 20%, 195g fly ash, 45g dolomite powder, 60g kaolin, 24.7g sodium hydroxide, 155.3g liquid water glass and 120g deionized water were weighed respectively.

[0050] 2) Preparation of geopolymer slurry:

[0051] Solid sodium hydroxide and liquid water glass are mixed and stirred evenly to obtain an alkali activator; fly ash, dolomite powder and kaolin are put into a mixing tank, stirred evenly, and then the alkali activator and deionized water are added to the mixing tank, and stirred evenly again to obtain a viscous geopolymer slurry with good fluidity; wherein the liquid-to-solid ratio of the geopolymer slurry is 0.6.

[0052] 3) Forming and curing:

[0053] Continue stirring the geopolymer slurry until it becomes gel-like to obtain a geopolymer gel; pour the geopolymer gel into a cubic mold with a side length of 40mm×40mm×40mm, place the mold on a vibration table and vibrate it at a frequency of 60 times / min for 10 minutes to release the bubbles in the geopolymer gel; first wrap the mold containing the geopolymer gel with a plastic film and place it in a curing box with a temperature of 60±2°C and a humidity of 95% for curing for 3 to 6 hours, then take it out of the curing box and demould it, and continue to cure it under natural conditions to 3 days, and finally obtain a solidified body of the fly ash-based polymer.

[0054] Embodiment 4:

[0055] 1) Weighing:

[0056] According to the mass percentage of fly ash 32.55%, dolomite powder 7.51%, kaolin 10.02%, sodium hydroxide 4.47%, liquid water glass 28.09% and deionized water 17.36%, 195g fly ash, 45g dolomite powder, 60g kaolin, 26.75g sodium hydroxide, 168.25g liquid water glass and 104g deionized water were weighed respectively.

[0057] 2) Preparation of geopolymer slurry:

[0058] Solid sodium hydroxide and liquid water glass are mixed and stirred evenly to obtain an alkali activator; fly ash, dolomite powder and kaolin are put into a mixing tank, stirred evenly, and then the alkali activator and deionized water are added to the mixing tank, and stirred evenly again to obtain a viscous geopolymer slurry with good fluidity; wherein the liquid-to-solid ratio of the geopolymer slurry is 0.62.

[0059] 3) Forming and curing:

[0060] Continue stirring the geopolymer slurry until it becomes gel-like to obtain a geopolymer gel; pour the geopolymer gel into a cubic mold with a side length of 40mm×40mm×40mm, place the mold on a vibration table and vibrate it at a frequency of 60 times / min for 10 minutes to release the bubbles in the geopolymer gel; first wrap the mold containing the geopolymer gel with a plastic film and place it in a curing box with a temperature of 60±2°C and a humidity of 95% for curing for 3 to 6 hours, then take it out of the curing box and demould it, and continue to cure it under natural conditions to 3 days, and finally obtain a solidified body of the fly ash-based polymer.

[0061] Comparative Example 1:

[0062] 1) Weighing:

[0063] According to the mass percentage of fly ash 40%, metakaolin 10%, sodium hydroxide 5.7%, liquid water glass 19.3% and deionized water 25%, 80g of fly ash, 20g of metakaolin, 11.15g of sodium hydroxide, 38.65g of liquid water glass and 50g of deionized water were weighed respectively.

[0064] 2) Preparation of geopolymer slurry:

[0065] Solid sodium hydroxide and liquid water glass are mixed and stirred evenly to obtain an alkali activator; fly ash and metakaolin are put into a mixing tank, stirred evenly, and then the alkali activator and deionized water are added to the mixing tank, and stirred evenly again to obtain a viscous geopolymer slurry with good fluidity; wherein the liquid-to-solid ratio of the geopolymer slurry is 0.48.

[0066] 3) Forming and curing:

[0067] Continue stirring the geopolymer slurry until it becomes gel-like to obtain a geopolymer gel; pour the geopolymer gel into a cubic mold with a side length of 40mm×40mm×40mm, place the mold on a vibration table and vibrate it at a frequency of 60 times / min for 10 minutes to release the bubbles in the geopolymer gel; first wrap the mold containing the geopolymer gel with a plastic film and place it in a curing box with a temperature of 60±2°C and a humidity of 95% for curing for 3 to 6 hours, then take it out of the curing box and demould it, and continue to cure it under natural conditions to 3 days, and finally obtain a solidified body of the fly ash-based polymer.

[0068] Comparative Example 2:

[0069] 1) Weighing:

[0070] According to the mass percentage of fly ash 35.9%, dolomite powder 12.8%, kaolin 2.6%, sodium hydroxide 2.5%, liquid water glass 15.4% and deionized water 30.8%, 70g fly ash, 25g dolomite powder, 5g kaolin, 4.8g sodium hydroxide, 30.2g liquid water glass and 60g deionized water were weighed respectively.

[0071] 2) Preparation of geopolymer slurry:

[0072] Solid sodium hydroxide and liquid water glass are mixed and stirred evenly to obtain an alkali activator; fly ash, dolomite powder and kaolin are put into a mixing tank, stirred evenly, and then the alkali activator and deionized water are added to the mixing tank, and stirred evenly again to obtain a viscous geopolymer slurry with good fluidity; wherein the liquid-to-solid ratio of the geopolymer slurry is 0.58.

[0073] 3) Forming and curing:

[0074] Continue stirring the geopolymer slurry until it becomes gel-like to obtain a geopolymer gel; pour the geopolymer gel into a cubic mold with a side length of 40mm×40mm×40mm, place the mold on a vibration table and vibrate it at a frequency of 60 times / min for 10 minutes to release the bubbles in the geopolymer gel; first wrap the mold containing the geopolymer gel with a plastic film and place it in a curing box with a temperature of 60±2°C and a humidity of 95% for curing for 3 to 6 hours, then take it out of the curing box and demould it, and continue to cure it under natural conditions to 3 days, and finally obtain a solidified body of the fly ash-based polymer.

[0075] Comparative Example 3:

[0076] 1) Weighing:

[0077] According to the mass percentage of fly ash 37.45%, metakaolin 9.36%, flaky sodium hydroxide 6.48%, instant powdered sodium silicate 15.81% and deionized water 30.9%, that is, the silicon-aluminum ratio is 7, the sodium-silicon ratio is 0.82, and the water-ash ratio is 0.66, 240g of fly ash, 60g of metakaolin, 41.55g of flaky sodium hydroxide, 101.36g of instant powdered sodium silicate and 198.09g of deionized water are weighed respectively.

[0078] 2) Preparation of alkaline activator:

[0079] Place deionized water on a magnetic stirrer and heat it to about 40°C, pour sodium silicate and flaky sodium hydroxide into the deionized water in 5 to 6 portions, and stir continuously with a glass rod until most of the particles are dissolved, place the stirred mixed solution on a magnetic stirrer and stir magnetically for 15 minutes, until the solution color becomes transparent and clear and no sodium silicate and flaky sodium hydroxide particles are visible, finally take out the evenly stirred mixed solution, seal the cup with a polyethylene film and age it for 3 hours to obtain an alkali activator.

[0080] 3) Prepare geopolymer slurry:

[0081] Pour the fly ash and kaolin into a dry stirring pot, turn on the switch, and stir slowly for 1 minute until the fly ash and kaolin are evenly mixed. Then pour the aged alkali activator evenly into the stirring pot, turn on the switch and stir quickly for 1 minute until the geopolymer slurry is fully stirred.

[0082] 4) Molding and maintenance:

[0083] The inside and surface of the triple mold were cleaned in advance to ensure that there was no dirt, and then the inner wall was evenly coated with oil. The obtained geopolymer slurry was poured into one-half of the triple mold, placed on a vibration table and vibrated for 1 min, and then the remaining half was filled and vibrated for another 1 min. Then, the surface was scraped flat with a scraper to ensure that no bubbles were generated. After the test block was molded, it was left to stand at room temperature for 24 hours before demolding and placed in a standard curing box for curing at 55°C until the age of 3 days.

[0084] Comparative Example 4:

[0085] 1) Formula of porous fly ash-based polymer by mass:

[0086] 51 parts of metakaolin, 9 parts of fly ash, 32.3 parts of sodium silicate, 16.9 parts of sodium hydroxide, and 16.91 ml of deionized water. In the formula, the mass ratio of fly ash to solid (fly ash to metakaolin) is 0.15:1, the mass ratio of total silicon to total aluminum is 0.899:1, the mass ratio of total silicon to total sodium is 0.827:1, and the mass ratio of water to solid (fly ash to metakaolin) is 0.635:1.

[0087] 2) Preparation method of porous fly ash-based polymer:

[0088] According to the formula, 16.9g of solid sodium hydroxide was added to 32.3g of sodium silicate, and stirred evenly to ensure that the NaOH solid was completely dissolved. After dissolution, it was placed to cool slightly to obtain an alkali activator. 51g of metakaolin and 9g of fly ash were added to the stirring pot, and the stirrer was turned on and stirred slowly (slow revolution speed: 62±5r / min, slow rotation speed: 140±5r / min) for 2min to mix them evenly. The alkali activator and 16.91ml of deionized water (water-ash ratio (L / S) 6.35 (mL): 10 (g)) were added, and the stirrer was turned on and stirred slowly (slow revolution speed: 62±5r / min, slow rotation speed: 140±5r / min) for 2min. The slurry on the pot wall and the stirrer blade was dropped with a stirring shovel, and then stirred quickly (fast revolution speed: 125±10r / min, fast rotation speed: 285±10r / min) until the slurry had good fluidity and viscosity to obtain a slurry.

[0089] 3) Molding and maintenance:

[0090] The entire slurry obtained in step 2 was injection molded (20 mm × 20 mm × 20 mm), compacted and the surface was scraped flat, and placed in an environment with a temperature of 25°C and a relative humidity of (60% ± 5%) for 24 hours until the slurry solidified and then demolded to obtain a fly ash-based polymer test block.

[0091] The mass percentages of the raw materials of the fly ash-based polymers prepared in Examples 1 to 4 and Comparative Examples 1 to 4 are shown in Table 1.

[0092] Table 1

[0093]

[0094] The solidified bodies of the fly ash-based polymers prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were subjected to chloride ion leaching tests, respectively. The results are shown in Table 2.

[0095] Table 2

[0096]

[0097] In Table 2, the chloride ion concentration in the leachate refers to the chloride ion concentration in the leachate obtained after the prepared fly ash-based polymer solidified body is subjected to a chloride ion leaching test. The soluble chloride ion content in the solidified body is obtained by converting the chloride ion concentration in the leachate. The actual chloride ion content in the solidified body refers to the chloride ion content in the prepared fly ash-based polymer solidified body. Chloride ion solidification rate = (actual chloride ion content in the solidified body - soluble chloride ion content) / actual chloride ion content in the solidified body.

[0098] As shown in Table 2, the solidification rate of the fly ash-based polymers prepared in Examples 1 to 4 for chloride ions is above 48%, and the solidification rate of the fly ash-based polymer prepared in Example 2 for chloride ions is as high as 72.6%. The solidification rate of the fly ash-based polymers prepared in Comparative Examples 1 to 4 for chloride ions is below 37%, and the solidification rate of the fly ash-based polymer prepared in Comparative Example 4 for chloride ions is as low as 14.7%. The chloride ion solidification rate of Examples 1 to 4 is at least 1.3 times that of Comparative Examples 1 to 4.

[0099] Therefore, the fly ash-based polymer prepared in the embodiment of the present application has a better curing rate for chloride ions, has an excellent curing effect, and can meet high standards of environmental protection requirements.

[0100] Heavy metal ion leaching tests were performed on the solidified bodies of the fly ash-based polymers prepared in Examples 1 to 4 and Comparative Examples 1 to 4, respectively. The results are shown in Table 3.

[0101] Table 3

[0102]

[0103] As can be seen from Table 3, the leaching concentration of heavy metal ions in the solidified bodies of the fly ash-based polymers prepared in Examples 1 to 4 is much lower than the requirements in the Technical Specifications for Pollution Control of Fly Ash from Incineration of Municipal Waste (HJ1134-2020). Therefore, the fly ash-based polymers prepared in the examples of the present application also have a good solidification effect on heavy metal ions and can meet high standards of environmental protection requirements.

[0104] The solidified bodies of the fly ash-based polymers prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were subjected to strength tests, respectively. The results are shown in Table 4.

[0105] Table 4

[0106]

[0107] As shown in Table 4, the compressive strength of the fly ash-based polymers prepared in Examples 1 to 4 is greater than that of the fly ash-based polymers prepared in Comparative Examples 1 to 4, indicating that Examples 1 to 4 have better curing effects. The fly ash-based polymer prepared in Example 2 has the highest compressive strength, further proving that it has the best curing effect.

[0108] The fly ash content in the fly ash-based polymer prepared in the embodiment of the present application reaches 31.1-34.94%, which reduces the preparation cost of the fly ash-based polymer, improves the economic benefit, and is suitable for large-scale production and application.

[0109] The above is only a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Based on the technical essence of the present application and within the spirit and principles of the present application, any simple modification, equivalent replacement and improvement of the above embodiments shall still fall within the protection scope of the technical solution of the present application.

Claims

1. A polymer based on fly ash from the incineration of domestic waste, It is characterized in that The fly ash-based polymer is made of the following raw materials in percentage by mass: 31.1-34.94% fly ash, 2.2-7.51% dolomite powder, 9.98-11.1% metakaolin, 4-4.47% sodium hydroxide, 24.9-28.09% liquid water glass and 17.36-26.7% deionized water.

2. The domestic waste incineration fly ash-based polymer according to claim 1, It is characterized in that The fly ash-based polymer is made of the following raw materials in percentage by mass: 32.5-34.94% fly ash, 5-7.5% dolomite powder, 9.98-10% metakaolin, 4.1-4.44% sodium hydroxide, 25.9-28% liquid water glass and 17.64-20% deionized water.

3. The domestic waste incineration fly ash-based polymer according to claim 1, It is characterized in that The particle size of the dolomite powder is less than 1000 mesh.

4. The domestic waste incineration fly ash-based polymer according to claim 1, It is characterized in that The SiO in the metakaolin 2 and Al 2 O 3 The content is ≥95%.

5. The domestic waste incineration fly ash-based polymer according to claim 1, It is characterized in that The purity of the sodium hydroxide is analytically pure.

6. The municipal solid waste incineration fly ash-based polymer according to claim 1, It is characterized in that The modulus of the liquid water glass is 3.2 to 3.

26.

7. The municipal solid waste incineration fly ash-based polymer according to claim 1, It is characterized in that The fly ash includes 90% of particles with a particle size less than 87.5 μm generated by a municipal waste incineration power plant.

8. A method for preparing a domestic waste incineration fly ash-based polymer according to any one of claims 1 to 7, It is characterized in that include: S1, mixing solid sodium hydroxide and liquid water glass and stirring evenly to obtain an alkali activator; S2, mixing fly ash, dolomite powder and metakaolin and stirring evenly, then adding alkali activator and deionized water and stirring evenly to obtain geopolymer slurry; wherein the liquid-to-solid ratio of the geopolymer slurry is 0.59-0.62; S3, stirring the geopolymer slurry to a gel state to obtain a geopolymer gel; pouring the geopolymer gel into a mold and performing curing after vibrating on a vibrating table.

9. The preparation method according to claim 8, It is characterized in that In step S3, the compaction frequency is 55 to 60 times / min, and the compaction time is 10 to 20 min.

10. The preparation method according to claim 8, It is characterized in that In step S3, the curing method includes: firstly wrapping the mold containing the geopolymer gel with a plastic film and then placing it in a curing box with a temperature of 60±2°C and a humidity of 90-95% for curing for 3-6 hours, then taking it out of the curing box, demoulding it, and curing it under natural conditions to a specified age.

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