An environment-friendly composite material prepared from household garbage incineration fly ash, an ocean engineering prefabricated part containing the same, and a preparation method thereof

Abstract

The present application relates to waste resource utilization technical field, concretely is a kind of through preparation of environmental protection composite material of domestic waste incineration fly ash, ocean engineering prefabricated part comprising it and its preparation method;The environmental protection composite material comprises the following components by weight parts: 35-45 weight parts of the domestic waste incineration fly ash that is purified and surface functionalization treatment, 20-30 weight parts of activated mineral powder, 10-15 weight parts of activated sulfur-fixing ash slag, 5-10 weight parts of composite activator, 2-5 weight parts of modifier and 10-20 weight parts of the recycled aggregate that is surface functionalization treatment.

Description

Technical Field

[0001] This invention relates to the field of waste resource utilization technology, specifically to an environmentally friendly composite material prepared from fly ash from municipal solid waste incineration, marine engineering prefabricated components containing the composite material, and a method for preparing the same. Background Technology

[0002] Municipal solid waste incineration (including power generation) is a major development trend in municipal solid waste treatment. The incineration process inevitably generates a large amount of fly ash. This fly ash contains dioxins and heavy metals, making it a hazardous solid waste. If released into the environment, it will cause serious pollution. Currently, the main methods for treating fly ash include secure landfill and cement solidification. The former occupies a large amount of land and still poses environmental risks; the latter, due to the presence of large amounts of soluble salts, results in unstable solidified products that are difficult to utilize effectively, and its storage also poses environmental safety risks. Existing treatment methods are essentially harmless treatments. Fly ash contains a large number of useful substances and is a valuable resource. Developing methods for the resource utilization of fly ash is of great value and is a problem that urgently needs to be solved in China and globally.

[0003] Precast marine engineering components are prefabricated parts designed and manufactured specifically for marine engineering projects. They have specific shapes, functions, and performance characteristics to meet the unique requirements of the marine environment. These precast components are typically prefabricated in factories and then transported to the offshore construction site for assembly and installation, thereby improving construction efficiency and reducing construction difficulty and costs.

[0004] Therefore, it is possible to design a material that uses fly ash from municipal solid waste incineration as raw material to prepare prefabricated marine engineering components. Summary of the Invention

[0005] The purpose of this invention is to provide an environmentally friendly composite material prepared from fly ash of municipal solid waste incineration, marine engineering prefabricated components containing the composite material, and a method for preparing the same, in order to address the shortcomings of related technologies.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] According to a first aspect of the present disclosure, an environmentally friendly composite material prepared from fly ash from municipal solid waste incineration is provided, the environmentally friendly composite material comprising the following components in parts by weight:

[0008] 35-45 parts by weight of purified and surface-functionalized municipal solid waste incineration fly ash, 20-30 parts by weight of activated mineral powder, 10-15 parts by weight of activated sulfur-fixing ash, 5-10 parts by weight of composite activator, 2-5 parts by weight of modifier, and 10-20 parts by weight of surface-functionalized recycled aggregate.

[0009] In one aspect of the present disclosure, the environmentally friendly composite material further comprises 1-10 parts by weight of an interface reinforcing material.

[0010] In one aspect of this disclosure, the environmentally friendly composite material comprises the following components in parts by weight:

[0011] 40-45 parts by weight of purified and surface-functionalized municipal solid waste incineration fly ash, 20-25 parts by weight of activated mineral powder, 10-15 parts by weight of activated sulfur-fixing ash, 5-8 parts by weight of composite activator, 2-5 parts by weight of modifier, 2-6 parts by weight of interface reinforcement material, and 10-15 parts by weight of surface-functionalized recycled aggregate.

[0012] In one aspect of this disclosure, the purified and surface-functionalized municipal solid waste incineration fly ash is prepared through the following steps:

[0013] Step 1-1: Soak the fly ash from municipal solid waste incineration in an organic solvent to remove heavy metals and some organic pollutants from the fly ash.

[0014] Step 1-2: The product obtained in Step 1-1 is subjected to pyrolysis to remove the remaining organic pollutants, resulting in purified municipal solid waste incineration fly ash.

[0015] Steps 1-3: Add the purified municipal solid waste incineration fly ash to water, then add polyvinyl alcohol, stir and let stand, then filter and dry to obtain the purified and surface-functionalized municipal solid waste incineration fly ash.

[0016] In one aspect of the embodiments of this disclosure, preferably, in step 1-1, the organic solution comprises a solvent and a solute; the solvent is selected from methanol, ethanol, n-propanol, isopropanol or n-butanol; preferably n-butanol; the solute is selected from ethylenediaminetetraacetic acid (EDTA) and its derivatives, citric acid, diethyltriaminepentaacetic acid or oxalic acid; preferably oxalic acid.

[0017] In one aspect of the embodiments of this disclosure, specifically, the thermal decomposition includes the following steps: in a nitrogen environment, the temperature is increased from room temperature to 500°C at a rate of 5°C / min and held for 1.5 hours; then the temperature is increased from room temperature to 800°C at a rate of 10°C / min and held for 0.5 hours, and then the temperature is allowed to cool naturally to room temperature.

[0018] In one aspect of this disclosure, specifically, pyrolysis can be carried out in a tubular furnace, a rotary kiln, or a fluidized bed.

[0019] In one aspect of this disclosure, the activated mineral powder is prepared by the following steps:

[0020] Step 2-1: Provide mineral powder; after passing the mineral powder through an 80-100 mesh sieve, add it to water, add polyvinyl alcohol, stir and let stand, then filter and dry to obtain the activated mineral powder.

[0021] In one aspect of this disclosure, the activated sulfur-fixing ash is prepared by the following steps:

[0022] Step 3-1: Provide sulfur-fixing ash residue; grind the sulfur-fixing ash residue together with polyvinyl alcohol and ethanol solution to obtain the activated sulfur-fixing ash residue.

[0023] In one aspect of the embodiments of this disclosure, the ethanol solution is a 95% ethanol solution; preferably, the mass ratio of the desulfurization ash, polyvinyl alcohol, and 95% ethanol solution is selected from (1.5-2.5):(0.5-1.5):(2-5); specifically, the mass ratio of the desulfurization ash, polyvinyl alcohol, and 95% ethanol solution is selected from 2:1:4.

[0024] In one aspect of this disclosure, the composite activator comprises phosphogypsum or desulfurized gypsum, and the composite activator further comprises sodium hydroxide, sodium sulfate, and sodium silicate.

[0025] In one aspect of the present disclosure, preferably, the total mass of sodium hydroxide, sodium sulfate and sodium silicate is 10%-25% of the mass of the sieved mineral powder.

[0026] In one aspect of the embodiments of this disclosure, preferably, the mass ratio of sodium hydroxide, sodium sulfate and sodium silicate is selected from (1-3):(0.5-2):(2-5); specifically, the mass ratio of sodium hydroxide, sodium sulfate and sodium silicate is selected from 2:1:3.

[0027] In one aspect of the embodiments of this disclosure, specifically, the mass ratio of phosphogypsum, sodium hydroxide, sodium sulfate and sodium silicate is 8:2:1:3.

[0028] In one aspect of this disclosure, the interface reinforcing material is selected from polypropylene fibers, polyethylene fibers, or polyimide fibers. Specifically, the interface reinforcing material is polypropylene fiber.

[0029] In one aspect of this disclosure, the modifier is selected from titanate coupling agents, aluminate coupling agents, or organochromium complex coupling agents. Preferably, the modifier is selected from tetrabutyl titanate.

[0030] In one aspect of this disclosure, the surface-functionalized recycled aggregate is prepared by the following steps:

[0031] Step 4-1: Add acrylate, triethanolamine, calcium lignosulfonate and silane coupling agent to water to obtain a surface functionalization treatment solution;

[0032] Step 4-2: Provide recycled aggregate, immerse the recycled aggregate in the surface functionalization solution for 2-5 hours; then remove it and let it stand for 1-2 hours; then dry it to obtain the surface functionalized recycled aggregate.

[0033] In one aspect of this disclosure, the silane coupling agent is selected from KH550, KH792, or KH560; preferably, the silane coupling agent is selected from KH560.

[0034] According to a second aspect of the present disclosure, a marine engineering prefabricated component is provided, the marine engineering prefabricated component comprising the aforementioned environmentally friendly composite material.

[0035] According to a third aspect of the present disclosure, a method for preparing the aforementioned marine engineering precast component is provided. The method includes: mixing the environmentally friendly composite material with metakaolin and river sand evenly, then adding calcium dihydrogen phosphate, water and a water-reducing agent, stirring and then adding the mixture into a mold, letting it stand for 20-30 hours, then demolding and curing for 7-14 days to obtain the marine engineering precast component.

[0036] Compared with the prior art, the beneficial effects of the present invention are: an environmentally friendly composite material with both good corrosion resistance and structural rigidity that can be used for marine engineering prefabrication components has been prepared. Detailed Implementation

[0037] The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The embodiments described herein are illustrative in nature and are used to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0039] For the sake of brevity, this article only discloses a few specific numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0040] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0041] In this description, unless otherwise stated, "above" and "below" include the stated number.

[0042] Unless otherwise stated, the terms used in this disclosure have their common meanings as commonly understood by those skilled in the art. Unless otherwise stated, the values ​​of the parameters mentioned in this disclosure can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this disclosure).

[0043] The term "about" is used to describe and indicate small variations. When used in conjunction with an event or situation, the term may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately. For example, when used in conjunction with numerical values, the term may refer to a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. Additionally, quantities, ratios, and other numerical values ​​are sometimes presented in range format herein. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly to include not only numerical values ​​explicitly specified as range limits but also all individual numerical values ​​or subranges covered within the range, as if each numerical value and subrange were explicitly specified.

[0044] The list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another instance, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single component or multiple components. Item B may contain a single component or multiple components. Item C may contain a single component or multiple components.

[0045] The present disclosure is further illustrated below with reference to embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the disclosure.

[0046] In this disclosure, the "drying" step refers to drying in an oven at 60°C until the weight does not change.

[0047] Examples and comparative examples:

[0048] Example 1:

[0049] Example 1 includes the following steps:

[0050] The fly ash from municipal solid waste incineration is soaked in a n-butanol solution containing oxalic acid to remove heavy metals and some organic pollutants. The n-butanol solution should completely cover the fly ash, and the solubility of oxalic acid in the n-butanol solution is approximately 5%. The product is then filtered and dried, followed by a two-step pyrolysis to remove remaining organic pollutants. Specifically, the product is first crushed to a particle size of less than 1 mm to increase the specific surface area and improve pyrolysis efficiency; then it is placed in a rotary kinematic reactor... In the kiln, under nitrogen atmosphere, the temperature is increased from room temperature to 500℃ at 5℃ / min and held for 1.5h; then the temperature is increased from room temperature to 800℃ at 10℃ / min and held for 0.5h, and then naturally cooled to room temperature to obtain purified municipal solid waste incineration fly ash; then the purified municipal solid waste incineration fly ash is added to 8 times its mass of water, and then an equal mass of polyvinyl alcohol is added. After stirring for 2h, it is allowed to stand for 8h, and then filtered and dried to obtain purified and surface-functionalized municipal solid waste incineration fly ash.

[0051] Provide mineral powder; after passing the mineral powder through an 80-mesh sieve, add it to 10 times its weight of water, and add an equal weight of polyvinyl alcohol. After stirring, let it stand, and then filter and dry to obtain activated mineral powder.

[0052] A desulfurization ash residue is provided; the desulfurization ash residue is ground together with polyvinyl alcohol and an ethanol solution to obtain activated desulfurization ash residue. The ethanol solution is a 95% ethanol solution, and the mass ratio of the desulfurization ash residue, polyvinyl alcohol, and ethanol solution is selected as 2:1:4; the ball-to-material ratio of the desulfurization ash residue and the grinding balls is 1:3; the grinding balls are 15mm zirconia grinding balls.

[0053] Sodium acrylate, triethanolamine, calcium lignosulfonate, and silane coupling agent KH550 were added to water to obtain a surface functionalization solution. Regenerated aggregate was provided and immersed in the surface functionalization solution for 4 hours. Then it was removed and allowed to stand for 1.5 hours. Then it was dried to obtain surface functionalized recycled aggregate. The mass ratio of sodium acrylate, triethanolamine, calcium lignosulfonate, and silane coupling agent KH550 was 1:0.2:0.35:4.

[0054] 45 parts by weight of purified and surface-functionalized municipal solid waste incineration fly ash, 20 parts by weight of activated mineral powder, 15 parts by weight of activated desulfurization ash, 5 parts by weight of composite activator (a combination of phosphogypsum, sodium hydroxide, sodium sulfate, and sodium silicate, with a mass ratio of 8:2:1:3), 3 parts by weight of modifier tetrabutyl titanate, 4 parts by weight of interface reinforcement material polypropylene fiber, and 15 parts by weight of surface-functionalized recycled aggregate were mixed evenly to obtain the environmentally friendly composite material of Example 1. Then, the environmentally friendly composite material of Example 1 was mixed evenly with 50 parts by weight of metakaolin and 85 parts by weight of river sand, and then 5 parts by weight of calcium dihydrogen phosphate, 15 parts by weight of water, and 5 parts by weight of water-reducing agent (polycarboxylate superplasticizer) were added. After stirring, the mixture was poured into a mold, left to stand for 24 hours, then demolded and cured for 14 days to obtain the marine engineering precast component of Example 1.

[0055] Example 2:

[0056] Example 2 includes the following steps:

[0057] The fly ash from municipal solid waste incineration is soaked in a n-butanol solution containing oxalic acid to remove heavy metals and some organic pollutants. The n-butanol solution should completely cover the fly ash, and the solubility of oxalic acid in the n-butanol solution is approximately 5%. The product is then filtered and dried, followed by a two-step pyrolysis to remove remaining organic pollutants. Specifically, the product is first crushed to a particle size of less than 1 mm to increase the specific surface area and improve pyrolysis efficiency; then it is placed in a rotary kinematic reactor... In the kiln, under nitrogen atmosphere, the temperature is increased from room temperature to 500℃ at 5℃ / min and held for 1.5h; then the temperature is increased from room temperature to 800℃ at 10℃ / min and held for 0.5h, and then naturally cooled to room temperature to obtain purified municipal solid waste incineration fly ash; then the purified municipal solid waste incineration fly ash is added to 8 times its mass of water, and then an equal mass of polyvinyl alcohol is added. After stirring for 2h, it is allowed to stand for 8h, and then filtered and dried to obtain purified and surface-functionalized municipal solid waste incineration fly ash.

[0058] Provide mineral powder; after passing the mineral powder through an 80-mesh sieve, add it to 10 times its weight of water, add an equal weight of polyvinyl alcohol, stir and let stand, then filter and dry to obtain activated mineral powder.

[0059] A desulfurization ash residue is provided; the desulfurization ash residue is ground together with polyvinyl alcohol and an ethanol solution to obtain activated desulfurization ash residue. The ethanol solution is a 95% ethanol solution, and the mass ratio of the desulfurization ash residue, polyvinyl alcohol, and ethanol solution is selected as 2:1:4; the ball-to-material ratio of the desulfurization ash residue and the grinding balls is 1:3; the grinding balls are 15mm zirconia grinding balls.

[0060] Sodium acrylate, triethanolamine, calcium lignosulfonate, and silane coupling agent KH792 were added to water to obtain a surface functionalization solution. Regenerated aggregate was provided and immersed in the surface functionalization solution for 4 hours. Then it was removed and allowed to stand for 1.5 hours. Then it was dried to obtain surface functionalized recycled aggregate. The mass ratio of sodium acrylate, triethanolamine, calcium lignosulfonate, and silane coupling agent KH792 was 1:0.2:0.35:4.

[0061] 45 parts by weight of purified and surface-functionalized municipal solid waste incineration fly ash, 20 parts by weight of activated mineral powder, 15 parts by weight of activated desulfurization ash, 5 parts by weight of composite activator (a combination of phosphogypsum, sodium hydroxide, sodium sulfate, and sodium silicate, with a mass ratio of 8:2:1:3), 3 parts by weight of modifier tetrabutyl titanate, 4 parts by weight of interface reinforcement material polypropylene fiber, and 15 parts by weight of surface-functionalized recycled aggregate were mixed evenly to obtain the environmentally friendly composite material of Example 2. Then, the environmentally friendly composite material of Example 2 was mixed evenly with 50 parts by weight of metakaolin and 85 parts by weight of river sand, and then 5 parts by weight of calcium dihydrogen phosphate, 15 parts by weight of water, and 5 parts by weight of water-reducing agent (polycarboxylate superplasticizer) were added. After stirring, the mixture was poured into a mold, allowed to stand for 24 hours, demolded, and cured for 14 days to obtain the marine engineering precast component of Example 2.

[0062] Example 3:

[0063] The steps in Example 3 are the same as those in Example 1, except that Example 3 uses KH560 of the same mass instead of KH550 used in Example 1.

[0064] Example 4:

[0065] Example 4 includes the following steps:

[0066] The fly ash from municipal solid waste incineration is soaked in a n-butanol solution containing oxalic acid to remove heavy metals and some organic pollutants. The n-butanol solution should completely cover the fly ash, and the solubility of oxalic acid in the n-butanol solution is approximately 5%. The product is then filtered and dried, followed by a two-step pyrolysis to remove remaining organic pollutants. Specifically, the product is first crushed to a particle size of less than 1 mm to increase the specific surface area and improve pyrolysis efficiency; then it is placed in a rotary kinematic reactor... In the kiln, under nitrogen atmosphere, the temperature is increased from room temperature to 500℃ at 5℃ / min and held for 1.5h; then the temperature is increased from room temperature to 800℃ at 10℃ / min and held for 0.5h, and then naturally cooled to room temperature to obtain purified municipal solid waste incineration fly ash; then the purified municipal solid waste incineration fly ash is added to 8 times its mass of water, and then an equal mass of polyvinyl alcohol is added. After stirring for 2h, it is allowed to stand for 8h, and then filtered and dried to obtain purified and surface-functionalized municipal solid waste incineration fly ash.

[0067] Provide mineral powder; after passing the mineral powder through an 80-mesh sieve, add it to 10 times its weight of water, and add an equal weight of polyvinyl alcohol. After stirring, let it stand, and then filter and dry to obtain activated mineral powder.

[0068] A desulfurization ash residue is provided; the desulfurization ash residue is ground together with polyvinyl alcohol and an ethanol solution to obtain activated desulfurization ash residue. The ethanol solution is a 95% ethanol solution, and the mass ratio of the desulfurization ash residue, polyvinyl alcohol, and ethanol solution is selected as 2:1:4; the ball-to-material ratio of the desulfurization ash residue and the grinding balls is 1:3; the grinding balls are 15mm zirconia grinding balls.

[0069] Sodium acrylate, triethanolamine, calcium lignosulfonate, and silane coupling agent KH550 were added to water to obtain a surface functionalization solution. Regenerated aggregate was provided and immersed in the surface functionalization solution for 4 hours. Then it was removed and allowed to stand for 1.5 hours. Then it was dried to obtain surface functionalized recycled aggregate. The mass ratio of sodium acrylate, triethanolamine, calcium lignosulfonate, and silane coupling agent KH550 was 1:0.2:0.35:4.

[0070] 35 parts by weight of purified and surface-functionalized municipal solid waste incineration fly ash, 30 parts by weight of activated mineral powder, 15 parts by weight of activated desulfurization ash, 5 parts by weight of composite activator (a combination of phosphogypsum, sodium hydroxide, sodium sulfate, and sodium silicate, with a mass ratio of 8:2:1:3), 3 parts by weight of modifier tetrabutyl titanate, 4 parts by weight of interface reinforcement material polypropylene fiber, and 15 parts by weight of surface-functionalized recycled aggregate were mixed evenly to obtain the environmentally friendly composite material of Example 4. Then, the environmentally friendly composite material of Example 4 was mixed evenly with 50 parts by weight of metakaolin and 85 parts by weight of river sand, and then 5 parts by weight of calcium dihydrogen phosphate, 15 parts by weight of water, and 5 parts by weight of water-reducing agent (polycarboxylate water-reducing agent) were added. After stirring, the mixture was poured into a mold, left to stand for 24 hours, then demolded and cured for 14 days to obtain the marine engineering precast component of Example 4.

[0071] Example 5:

[0072] Example 5 includes the following steps:

[0073] The fly ash from municipal solid waste incineration is soaked in a n-butanol solution containing oxalic acid to remove heavy metals and some organic pollutants. The n-butanol solution should completely cover the fly ash, and the solubility of oxalic acid in the n-butanol solution is approximately 5%. The product is then filtered and dried, followed by a two-step pyrolysis to remove remaining organic pollutants. Specifically, the product is first crushed to a particle size of less than 1 mm to increase the specific surface area and improve pyrolysis efficiency; then it is placed in a rotary kinematic reactor... In the kiln, under nitrogen atmosphere, the temperature is increased from room temperature to 500℃ at 5℃ / min and held for 1.5h; then the temperature is increased from room temperature to 800℃ at 10℃ / min and held for 0.5h, and then naturally cooled to room temperature to obtain purified municipal solid waste incineration fly ash; then the purified municipal solid waste incineration fly ash is added to 8 times its mass of water, and then an equal mass of polyvinyl alcohol is added. After stirring for 2h, it is allowed to stand for 8h, and then filtered and dried to obtain purified and surface-functionalized municipal solid waste incineration fly ash.

[0074] Provide mineral powder; after passing the mineral powder through an 80-mesh sieve, add it to 10 times its weight of water, and add an equal weight of polyvinyl alcohol. After stirring, let it stand, and then filter and dry to obtain activated mineral powder.

[0075] A desulfurization ash residue is provided; the desulfurization ash residue is ground together with polyvinyl alcohol and an ethanol solution to obtain activated desulfurization ash residue. The ethanol solution is a 95% ethanol solution, and the mass ratio of the desulfurization ash residue, polyvinyl alcohol, and ethanol solution is selected as 2:1:4; the ball-to-material ratio of the desulfurization ash residue and the grinding balls is 1:3; the grinding balls are 15mm zirconia grinding balls.

[0076] Sodium acrylate, triethanolamine, calcium lignosulfonate, and silane coupling agent KH550 were added to water to obtain a surface functionalization solution. Regenerated aggregate was provided and immersed in the surface functionalization solution for 4 hours. Then it was removed and allowed to stand for 1.5 hours. Then it was dried to obtain surface functionalized recycled aggregate. The mass ratio of sodium acrylate, triethanolamine, calcium lignosulfonate, and silane coupling agent KH550 was 1:0.2:0.35:4.

[0077] 40 parts by weight of purified and surface-functionalized municipal solid waste incineration fly ash, 25 parts by weight of activated mineral powder, 10 parts by weight of activated desulfurization ash, 5 parts by weight of composite activator (a combination of phosphogypsum, sodium hydroxide, sodium sulfate, and sodium silicate, with a mass ratio of 8:2:1:3), 3 parts by weight of modifier tetrabutyl titanate, 4 parts by weight of interface reinforcement material polypropylene fiber, and 15 parts by weight of surface-functionalized recycled aggregate were mixed evenly to obtain the environmentally friendly composite material of Example 5. Then, the environmentally friendly composite material of Example 5 was mixed evenly with 50 parts by weight of metakaolin and 85 parts by weight of river sand, and then 5 parts by weight of calcium dihydrogen phosphate, 15 parts by weight of water, and 5 parts by weight of water-reducing agent (polycarboxylate superplasticizer) were added. After stirring, the mixture was poured into a mold, allowed to stand for 24 hours, demolded, and cured for 14 days to obtain the marine engineering precast component of Example 5.

[0078] Comparative Example 1:

[0079] Comparative Example 1 includes the following steps:

[0080] The fly ash from municipal solid waste incineration is soaked in a n-butanol solution containing oxalic acid to remove heavy metals and some organic pollutants. The n-butanol solution should completely cover the fly ash, and the solubility of oxalic acid in the n-butanol solution is approximately 5%. The product is then filtered and dried, followed by a two-step pyrolysis to remove remaining organic pollutants. Specifically, the product is first crushed to a particle size of less than 1 mm to increase the specific surface area and improve pyrolysis efficiency; then it is placed in a rotary kinematic reactor... In the kiln, under nitrogen atmosphere, the temperature is increased from room temperature to 500℃ at 5℃ / min and held for 1.5h; then the temperature is increased from room temperature to 800℃ at 10℃ / min and held for 0.5h, and then naturally cooled to room temperature to obtain purified municipal solid waste incineration fly ash; then the purified municipal solid waste incineration fly ash is added to 8 times its mass of water, and then an equal mass of polyvinyl alcohol is added. After stirring for 2h, it is allowed to stand for 8h, and then filtered and dried to obtain purified and surface-functionalized municipal solid waste incineration fly ash.

[0081] Provide mineral powder; after passing the mineral powder through an 80-mesh sieve, add it to 10 times its weight of water, add an equal weight of polyvinyl alcohol, stir and let stand, then filter and dry to obtain activated mineral powder.

[0082] A desulfurization ash residue is provided; the desulfurization ash residue is ground together with polyvinyl alcohol and an ethanol solution to obtain activated desulfurization ash residue. The ethanol solution is a 95% ethanol solution, and the mass ratio of the desulfurization ash residue, polyvinyl alcohol, and ethanol solution is selected as 2:1:4; the ball-to-material ratio of the desulfurization ash residue and the grinding balls is 1:3; the grinding balls are 15mm zirconia grinding balls.

[0083] 45 parts by weight of purified and surface-functionalized municipal solid waste incineration fly ash, 20 parts by weight of activated mineral powder, 15 parts by weight of activated desulfurization ash, 5 parts by weight of composite activator (a combination of phosphogypsum, sodium hydroxide, sodium sulfate, and sodium silicate, with a mass ratio of 8:2:1:3), 3 parts by weight of modifier tetrabutyl titanate, 4 parts by weight of interface reinforcement material polypropylene fiber, and 15 parts by weight of recycled aggregate were mixed evenly to obtain the environmentally friendly composite material of Comparative Example 1. Then, the environmentally friendly composite material of Comparative Example 1 was mixed evenly with 50 parts by weight of metakaolin and 85 parts by weight of river sand. Then, 5 parts by weight of calcium dihydrogen phosphate, 15 parts by weight of water, and 5 parts by weight of water-reducing agent (polycarboxylate superplasticizer) were added. After stirring, the mixture was poured into a mold, left to stand for 24 hours, demolded, and cured for 14 days to obtain the marine engineering precast component of Comparative Example 1.

[0084] Comparative Example 2:

[0085] Comparative Example 2 includes the following steps:

[0086] Sodium acrylate, triethanolamine, calcium lignosulfonate, and silane coupling agent KH550 were added to water to obtain a surface functionalization solution. Regenerated aggregate was provided and immersed in the surface functionalization solution for 4 hours. Then it was removed and allowed to stand for 1.5 hours. Then it was dried to obtain surface functionalized recycled aggregate. The mass ratio of sodium acrylate, triethanolamine, calcium lignosulfonate, and silane coupling agent KH550 was 1:0.2:0.35:4.

[0087] 45 parts by weight of municipal solid waste incineration fly ash, 20 parts by weight of mineral powder, 15 parts by weight of desulfurization ash, 5 parts by weight of composite activator (a combination of phosphogypsum, sodium hydroxide, sodium sulfate, and sodium silicate in a mass ratio of 8:2:1:3), 3 parts by weight of modifier tetrabutyl titanate, 4 parts by weight of interface reinforcement material polypropylene fiber, and 15 parts by weight of surface-functionalized recycled aggregate were mixed evenly to obtain the environmentally friendly composite material of Comparative Example 2. Then, the environmentally friendly composite material of Comparative Example 2 was mixed evenly with 50 parts by weight of metakaolin and 85 parts by weight of river sand. Then, 5 parts by weight of calcium dihydrogen phosphate, 15 parts by weight of water, and 5 parts by weight of water-reducing agent (polycarboxylate superplasticizer) were added. After stirring, the mixture was poured into a mold, left to stand for 24 hours, demolded, and cured for 14 days to obtain the marine engineering precast component of Comparative Example 2.

[0088] Corrosion resistance and mechanical strength tests:

[0089] According to the test method in GB / T38140-2019, the specimens of the examples and comparative examples were placed in a 50℃ humid heat curing chamber and a container filled with water at 50℃±1℃ for curing for 7 days from the time the specimens were placed in the container. Then, the surface moisture of the specimens was wiped off, and the specimens were placed in a drying oven at 40℃ for 24 hours. After drying, the specimens were immediately placed in the specimen rack of the vacuum salt saturation equipment, and the vacuum pump was turned on. The specimens were aspirated at a negative pressure of 0.08MPa for 4 hours, and then the prepared simulated seawater erosion solution was added through the inlet, and the specimens were aspirated again at a negative pressure of 0.08MPa for 2 hours. Thereafter, the negative pressure of 0.08MPa was kept constant, and the specimens were allowed to stand in the simulated seawater erosion solution for 18 hours to reach full saturation. The specimens were then removed from the vacuum salt saturation equipment to complete one wet-dry cycle immersion test. The above steps were repeated 14 times within 28 days. The specimens were then removed, and their compressive strength was tested. The results are shown in Table 1.

[0090] Table 1

[0091]

[0092] It is evident that the corrosion resistance and mechanical strength of the embodiments are significantly superior to those of the comparative examples. This is because polyvinyl alcohol (PVA)-modified municipal solid waste incineration fly ash, mineral powder, and desulfurization ash can enhance their compatibility and adhesion with silane coupling agent-modified recycled aggregates. The encapsulation effect of PVA also reduces the leaching risk of residual harmful substances in fly ash, improving the corrosion resistance of the composite material. PVA modification helps increase the activity and contribution rate of mineral powder in the composite material, allowing it to better participate in the hydration reaction of the matrix, generating more hydration products, thereby improving the strength and durability of the composite material. It also reduces the agglomeration of mineral powder particles, ensuring uniform dispersion in the matrix and further optimizing the microstructure of the composite material. PVA modification can improve the stability of desulfurization ash, preventing secondary reactions or precipitation of sulfides and other components in the composite material, thus improving its durability and corrosion resistance. Enhancing the adhesion between desulfurization ash and the matrix allows the desulfurization ash to better exert its potential activity and filler function, contributing to the improvement of the overall mechanical properties of the composite material. Modification with silane coupling agents can reduce interfacial defects and microcracks in recycled aggregates, thereby enhancing the mechanical strength of composite materials. A hydrophobic protective film forms on the surface of recycled aggregates treated with silane coupling agents, effectively preventing the intrusion of harmful substances such as moisture and chloride ions, thus improving the corrosion resistance of the composite material. Furthermore, in addition to the above effects, polyvinyl alcohol (PVA) can bond to the surface of materials treated with silane coupling agents. The functional groups (such as amino and vinyl groups) at one end of the silane coupling agent react with active groups such as hydroxyl groups on the material surface to form chemical bonds; the organic functional groups at the other end can interact with the hydroxyl groups in the PVA molecular chain. This interaction includes hydrogen bonds and van der Waals forces, enabling PVA to stably bond to the surface of materials treated with silane coupling agents, thereby enhancing the bonding force between the two.

[0093] Furthermore, it can be seen that Example 3, treated with silane coupling agent KH560, exhibits superior performance compared to Examples 1-2. This is because silane coupling agent KH560 can react with various resins to improve the adhesion and weather resistance of materials and can be used for polymer fiber surface treatment. In contrast, the examples used polypropylene fibers as interface reinforcement materials, thus silane coupling agent KH560 further modified the interface reinforcement materials. Therefore, Example 3 demonstrates superior performance.

[0094] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein.

Claims

1. An environmentally friendly composite material prepared from fly ash from municipal solid waste incineration, characterized in that, The environmentally friendly composite material contains the following components in parts by weight: 40-45 parts by weight of purified and surface-functionalized municipal solid waste incineration fly ash, 20-25 parts by weight of activated mineral powder, 10-15 parts by weight of activated desulfurization ash, 5-8 parts by weight of composite activator, 2-5 parts by weight of modifier, 2-6 parts by weight of interface reinforcement material, and 10-15 parts by weight of surface-functionalized recycled aggregate. The activated mineral powder is prepared through the following steps: Step 2-1: Provide mineral powder; after passing the mineral powder through an 80-100 mesh sieve, add it to water, add polyvinyl alcohol, stir and let stand, then filter and dry to obtain the activated mineral powder; The activated sulfur-fixing ash residue is prepared through the following steps: Step 3-1: Provide desulfurized ash residue; grind the desulfurized ash residue together with polyvinyl alcohol and ethanol solution to obtain the activated desulfurized ash residue; The surface-functionalized recycled aggregate is prepared through the following steps: Step 4-1: Add acrylate, triethanolamine, calcium lignosulfonate and silane coupling agent to water to obtain a surface functionalization treatment solution; Step 4-2: Provide recycled aggregate, immerse the recycled aggregate in the surface functionalization solution for 2-5 hours; then remove it and let it stand for 1-2 hours; then dry it to obtain the surface functionalized recycled aggregate.

2. The environmentally friendly composite material according to claim 1, characterized in that, The purified and surface-functionalized municipal solid waste incineration fly ash is prepared through the following steps: Step 1-1: Soak the fly ash from municipal solid waste incineration in an organic solvent to remove heavy metals and some organic pollutants from the fly ash. Step 1-2: The product obtained in Step 1-1 is subjected to pyrolysis to remove the remaining organic pollutants, resulting in purified municipal solid waste incineration fly ash. Steps 1-3: Add the purified municipal solid waste incineration fly ash to water, then add polyvinyl alcohol, stir and let stand, then filter and dry to obtain the purified and surface-functionalized municipal solid waste incineration fly ash.

3. The environmentally friendly composite material according to claim 1, characterized in that, The composite activator comprises phosphogypsum or desulfurized gypsum, and further comprises sodium hydroxide, sodium sulfate and sodium silicate; The interface reinforcement material is selected from polypropylene fiber, polyethylene fiber, or polyimide fiber; The modifier is selected from titanate coupling agents, aluminate coupling agents, or organochromium complex coupling agents.

4. A prefabricated component for marine engineering, characterized in that, The marine engineering prefabricated components include the environmentally friendly composite materials described in any one of claims 1-3.

5. A method for preparing the marine engineering prefabricated component according to claim 4, characterized in that, The method includes: mixing the environmentally friendly composite material with metakaolin and river sand evenly, then adding calcium dihydrogen phosphate, water and water-reducing agent, stirring and then adding it into a mold, letting it stand for 20-30 hours, then demolding and curing for 7-14 days; to obtain the marine engineering precast component.

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