Solid waste-based polymer material and method for preparing the same

Abstract

This invention discloses a solid waste-based polymer material and its preparation method, belonging to the field of industrial solid waste resource utilization technology. It includes basic components, an activation liquid, a synergist, and a dopant. The basic components consist of the following raw materials in parts by weight: 40-70 parts fly ash, 8-12 parts desulfurized gypsum, 20-30 parts slag, and 10-35 parts red mud. The activation liquid is a sodium silicate solution, the synergist is urea, and the dopant is mercapto-modified hydrogen-containing polymethylsiloxane. This solid waste-based polymer material, using fly ash, desulfurized gypsum, slag, and red mud as basic components, achieves a high-proportion synergistic utilization of bulk industrial solid waste. The activation liquid in this solid waste-based polymer material is a sodium silicate solution, which can effectively activate the depolymerization and condensation reactions of silicon-aluminum precursors at room temperature, achieving room-temperature curing of the material. This eliminates the need for high-energy-consuming processes such as high-temperature sintering or high-pressure molding, significantly reducing energy consumption and carbon emissions during the preparation process.

Description

Technical Field

[0001] This invention belongs to the field of industrial solid waste resource utilization technology, specifically relating to a solid waste-based polymer material and its preparation method. Background Technology

[0002] In the resource utilization of industrial solid waste, the annual production of bulk industrial by-products such as fly ash, red mud, desulfurization gypsum and slag is huge, but their comprehensive utilization rate, especially the utilization level of alkaline solid wastes such as red mud, has long been at a low level.

[0003] Existing technologies mainly include the following resource utilization methods: The first type is the high-temperature sintering method: solid wastes such as fly ash and red mud are mixed and sintered at high temperatures to produce ceramsite or aggregates. Although this method can achieve physical shaping of solid wastes and vitrification of some heavy metals, it has extremely high energy consumption, requires the construction of fixed tunnel kilns or rotary kilns, and involves large equipment investment. It is difficult to deploy flexibly on a low-cost, small-scale basis at the solid waste generation site, and the high-temperature process is accompanied by considerable carbon emissions. The second type is the high-pressure pressing method: solid wastes are mixed with cementitious materials and then pressed into block products by a high-pressure brick press. Although this method does not require high-temperature treatment, the equipment and molds suffer from high wear and tear, and the products have a dense block structure, which does not have the appropriate porosity and agglomeration required for soil or lightweight aggregates. The first type is the microbial improvement method, which uses microbial agents to transform solid waste under natural conditions. Although it is theoretically environmentally friendly, the reaction cycle is long and significantly affected by environmental factors such as temperature and humidity. Moreover, highly alkaline solid waste environments such as red mud will severely inhibit microbial activity, which greatly limits its applicability. The second type is the cement solidification method, which directly mixes silicate cement into solid waste as a cementing material for solidification. This method is simple, but cement production itself is a high-carbon emission process, and the cement hydration products are highly alkaline with poor water absorption and air permeability, which will severely inhibit plant root growth when used for soil improvement and other scenarios.

[0004] Alkali-activated geopolymer technology uses silicon-aluminum-rich industrial solid waste as a precursor. Under the action of an alkaline activator, it dissolves and condenses to form a three-dimensional aluminosilicate network, which can be solidified at room temperature and pressure. However, existing alkaline activation schemes still have shortcomings, such as uneven reaction and poor product consistency during production; some schemes are not efficient in utilizing low-activity solid waste, and the adaptability of raw materials is limited. Therefore, it is necessary to study a solid waste geopolymer material that can be granulated in one step under room temperature and pressure, while ensuring that the product has soil-like functions and good water absorption and air permeability. Summary of the Invention

[0005] The purpose of this invention is to provide a solid waste-based polymer material and its preparation method to solve the problems of low solid waste utilization rate and the lack of soil function in the product.

[0006] The objective of this invention can be achieved through the following technical solutions: The first aspect of this invention provides a solid waste-based polymer material, comprising a basic component, an activation liquid, a synergist, and a dopant; the basic component comprises the following raw materials in parts by weight: 40-70 parts fly ash, 8-12 parts desulfurized gypsum, 20-30 parts slag, and 10-35 parts red mud; the activation liquid is a sodium silicate solution, the synergist is urea, and the dopant is mercapto-modified hydrogen-containing polymethylsiloxane.

[0007] This invention provides a solid waste-based polymer material, which uses fly ash, desulfurized gypsum, slag, and red mud as its basic components, achieving a high-proportion synergistic utilization of bulk industrial solid waste. The activation liquid in this solid waste-based polymer material is a sodium silicate solution, which can be activated and solidified at room temperature. The synergist is urea, a latent catalyst that slowly hydrolyzes under alkaline conditions to generate carbonate ions, which react with calcium ions (in the initial stage of the alkaline activation reaction, the desulfurized gypsum partially dissolves; furthermore, calcium-containing minerals such as hydrated garnet in the red mud can also be partially dissolved under alkaline conditions to supplement calcium). 2+ This generates nanoscale calcium carbonate crystal nuclei, providing uniform nucleation sites for the condensation deposition of aluminosilicate gels, thereby improving the uniformity and strength of the particles. The dopant is a thiol-modified hydrogen-containing polymethylsiloxane, which retains both active Si-H bonds and thiol groups (-SH) in its molecules. In the strongly alkaline environment of the geopolymer, the Si-H bonds rapidly hydrolyze, releasing hydrogen gas. This in-situ foaming process forms a highly porosity and well-connected porous structure within the matrix, thereby improving the water absorption and air permeability of the formed solid waste geopolymer material.

[0008] In some possible implementations, the basic components include the following raw materials in parts by weight: 50-60 parts fly ash, 10-11 parts desulfurized gypsum, 15-25 parts slag, and 15-20 parts red mud.

[0009] In some possible implementations, the amount of activating liquid used is 6%–8% of the total mass of the base components, the modulus of the sodium silicate solution is 2.8–3.4, and the sodium silicate solution is diluted to a modulus of 1.5 before use; The dosage of the synergist is 0.5%–1% of the total mass of the base components; The amount of dopant used is 0.5%–1.5% of the total mass of the base components.

[0010] In some possible implementations, the mercapto-modified hydrogen-containing polymethylsiloxane is obtained by ring-opening polymerization under acidic conditions using octamethylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane and γ-mercaptopropyltrimethoxysilane as raw materials and hexamethyldisiloxane as a capping agent.

[0011] In some possible implementations, the solid waste-based polymer material also includes a foam stabilizer, the amount of which is 0.1% to 0.5% of the total mass of the base components.

[0012] In some possible implementations, the foam stabilizer is an amide surfactant. The foam stabilizer is obtained by reacting a fatty acid ester and an amino monomer under alkaline conditions.

[0013] Amide surfactants are prepared by the following steps: fatty acid esters and amino monomers are mixed, an alkaline catalyst is added, and the mixture is heated to 135-140℃ and reacted for 2-3 hours. After the reaction is completed, the amide surfactant is obtained.

[0014] The molar ratio of fatty acid ester to amino monomer is 1:1.1-1.2; the alkaline catalyst is an aqueous solution of potassium hydroxide, and the ratio of potassium hydroxide to fatty acid ester is 5:1. The fatty acid ester is methyl laurate, and the amino monomer is aminoimidazole, such as 1-(3-aminopropyl)imidazole and 2-aminoimidazole.

[0015] In some possible implementations, the mercapto-modified hydrogen-containing polymethylsiloxane is prepared by the following steps: Octamethylcyclotetrasiloxane, hexamethyldisiloxane, tetramethyltetrahydrocyclotetrasiloxane, an acidic catalyst, and deionized water were mixed and reacted at 75-85℃ for 2-3 hours. Then, γ-mercaptopropyltrimethoxysilane was added, and the mixture was stirred for another 2-3 hours while maintaining the temperature, yielding a mercapto-modified hydrogen-containing polymethylsiloxane. The material of this invention synergistically inhibits the loss of heavy metal ions through a hydrophobic effect. The silanol groups (Si) generated after hydrolysis of the mercapto-containing hydrogen-containing polymethylsiloxane... OH) undergoes a condensation reaction with the hydroxyl groups on the surface of the geopolymer gel to form stable Si. O Si covalent bonds are used to firmly graft the hydrophobic polymethylsiloxane backbone onto the matrix surface, constructing a continuous and dense hydrophobic layer. This hydrophobic layer effectively reduces the material's water absorption and capillary permeability, minimizing the risk of water dissolving and carrying away internally chelated heavy metal ions. Simultaneously, the hydrophobic environment helps maintain the stability of local chemical microregions in the porous solution, preventing disruption of ion exchange equilibrium due to water flow. Meanwhile, γ... Although mercaptopropyltrimethoxysilane contains a propyl hydrophobic segment, its molecular structure lacks a continuous long-chain hydrophobic backbone, making it unable to form a complete hydrophobic barrier. As a result, it has poor water resistance and a high risk of metal ion loss.

[0016] The acidic catalysts are trifluoromethanesulfonic acid, concentrated sulfuric acid, and a strong acid ion exchange resin. When concentrated sulfuric acid or trifluoromethanesulfonic acid is used as the catalyst, most of the catalyst is removed by separation, and then sodium bicarbonate powder is added and stirred to neutralize the residual catalyst. The mixture is then filtered to obtain the crude product. When a strong acid ion exchange resin is used as the catalyst, the solid catalyst is removed by filtration to obtain the crude product. Finally, both crude products are distilled under reduced pressure at 150°C for 3 hours to remove low-boiling-point substances.

[0017] In some possible implementations, the ratio of octamethylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane, γ-mercaptopropyltrimethoxysilane, trifluoromethanesulfonic acid, and deionized water is 150g: 20-40g: 4-10g: 0.8-0.9g: 1-2g.

[0018] A second aspect of this invention provides a method for preparing a solid waste-based polymer material, comprising the following steps: Raw material pretreatment: Fly ash passes through an 80-mesh sieve with a moisture content of <5%; red mud passes through a 20-mesh sieve to remove large lumps; desulfurized gypsum passes through a 40-mesh sieve; and slag is crushed and passes through a 10-mesh sieve. Gradient dry mixing: Add slag, fly ash, desulfurized gypsum, and red mud into a horizontal twin-shaft mixer. First, stir at low speed (30~40 rpm) for 0.5~1 min to allow the materials to initially diffuse, then stir at medium speed (50~60 rpm) for 1~2 min until homogenized.

[0019] Atomized spraying and wet mixing: The activating liquid and synergist are mixed evenly before use and then sprayed evenly onto the surface of the material being stirred through a multi-point fan-shaped atomizing nozzle. The spraying adopts an intermittent pulse mode (spray for 20 seconds → stop for 5 seconds → spray for 20 seconds, and repeat), with an atomization pressure of 0.4~0.6MPa. Then, the dopant (dispersed with water) is sprayed. The total liquid-to-solid ratio is controlled at 0.20~0.25 throughout the process.

[0020] Stale ball bearings: After spraying, close the adjustable baffle at the discharge port and switch the mixer to low speed (30~40 rpm). The material continues to tumble and collide in the closed cavity: the wet powder first forms 1~3 mm micronuclei, and the micronuclei continue to tumble and adhere to more powder, until the target particle size of 5~15 mm is reached.

[0021] Storage and aging (7-14 days): The discharged pellets are piled up to a height of ≤1.5 m, covered with a polyethylene film to retain moisture (relative humidity ≥90%), and aged at room temperature. During this period, the geopolymerization reaction continues, the gel network densifies, and the pellets acquire mechanical strength.

[0022] The beneficial effects of this invention are: This invention provides a solid waste-based polymer material, which uses fly ash, desulfurized gypsum, slag, and red mud as its basic components, achieving a high-proportion synergistic utilization of bulk industrial solid waste. The activating liquid in this solid waste-based polymer material is a sodium silicate solution, which can effectively activate the depolymerization and condensation reactions of silicon-aluminum precursors at room temperature, enabling the material to solidify and form at room temperature. This eliminates the need for high-energy-consuming processes such as high-temperature sintering or high-pressure molding, significantly reducing energy consumption and carbon emissions during the preparation process.

[0023] The synergist in the raw materials of the solid waste-based polymer material is urea, a latent additive. Under alkaline conditions, urea slowly hydrolyzes to generate carbonate ions, which react with calcium ions in the system to form nanoscale calcium carbonate crystal nuclei. The calcium ions mainly originate from the partial dissolution of desulfurized gypsum in the initial stage of the alkaline-activated reaction. Additionally, calcium-containing minerals such as hydrated garnet in red mud can also dissolve in small amounts to supplement calcium ions under alkaline conditions. The nanoscale calcium carbonate crystal nuclei provide uniform nucleation sites for the condensation deposition of aluminosilicate gels, effectively improving the uniformity and strength of the particles. The dopant is a mercapto-modified hydrogen-containing polymethylsiloxane. This molecule retains active Si-H bonds. In the strongly alkaline environment of the geopolymer, the Si-H bonds rapidly hydrolyze and release hydrogen gas. This in-situ foaming process forms a highly porosity and well-connected porous structure within the matrix, thereby improving the water absorption and air permeability of the molded solid waste-based polymer material, making it more suitable for applications such as soil improvement and ecological restoration. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] The following is a detailed description of a solid waste-based polymer material and its preparation method according to an embodiment of this application.

[0026] The following is a detailed description with reference to specific examples.

[0027] Example 1 This embodiment provides a solid waste-based polymer material, comprising a basic component, an activation liquid, a synergist, and a dopant. The basic component comprises the following raw materials in parts by weight: 40 parts fly ash, 8 parts desulfurized gypsum, 20 parts slag, and 10 parts red mud. The activation liquid is a sodium silicate solution, the synergist is urea, and the dopant is mercapto-modified hydrogen-containing polymethylsiloxane. The amount of activation liquid is 7% of the total mass of the basic component, and the sodium silicate solution is diluted to a modulus of 1.5. The amount of synergist is 0.5% of the total mass of the basic component, and the amount of dopant is 1% of the total mass of the basic component.

[0028] The mercapto-modified hydrogen-containing polymethylsiloxane is prepared through the following steps: Octamethylcyclotetrasiloxane, hexamethyldisiloxane, tetramethyltetrahydrocyclotetrasiloxane, trifluoromethanesulfonic acid, and deionized water were mixed and reacted at 80°C for 2 hours. Then, γ-mercaptopropyltrimethoxysilane was added, and the mixture was stirred for another 2 hours while maintaining the temperature to obtain mercapto-modified hydrogen-containing polymethylsiloxane. The ratio of octamethylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane, γ-mercaptopropyltrimethoxysilane, trifluoromethanesulfonic acid, and deionized water was 150 g: 20 g: 5 g: 0.8 g: 1 g.

[0029] The preparation method of the polymer material for this solid waste site includes the following steps: Raw material pretreatment: fly ash passes through an 80-mesh sieve with a moisture content of <5%; red mud passes through a 20-mesh sieve to remove large lumps; desulfurized gypsum passes through a 40-mesh sieve; and slag is crushed and passed through a 10-mesh sieve. Gradient dry mixing: Add slag, fly ash, desulfurized gypsum, and red mud into a horizontal twin-shaft mixer. First, mix at low speed (30 rpm) for 1 minute to allow the materials to initially diffuse, then mix at medium speed (60 rpm) for 2 minutes until homogenized.

[0030] Atomized spraying and wet mixing: The activator and synergist are mixed evenly before use and then sprayed evenly onto the surface of the material being stirred through multi-point fan-shaped atomizing nozzles. The spraying adopts an intermittent pulse mode (spray for 20 seconds → stop for 5 seconds → spray for 20 seconds, cycle), with an atomization pressure of 0.5 MPa. Then, the admixture (dispersed with water) is sprayed. The total liquid-to-solid ratio is controlled at 0.20 throughout the process.

[0031] Rolling and tumbling in a closed chamber: After spraying, close the adjustable baffle at the discharge port and switch the mixer to low speed (30 rpm). The material continues to roll and collide in the closed chamber: the wet powder first forms 1~3 mm micro-nuclei, and the micro-nuclei continue to roll and adhere to more powder, until the target particle size of 5~15 mm is reached.

[0032] Stacking and aging (7 days): The height of the discharged particles is ≤1.5 m, the surface is covered with polyethylene film to keep moist (relative humidity ≥90%), and aged at room temperature.

[0033] Example 2 This embodiment provides a solid waste-based polymer material, comprising a base component, an activating liquid, a synergist, and a dopant. The base component comprises the following raw materials in parts by weight: 70 parts fly ash, 12 parts desulfurized gypsum, 30 parts slag, and 35 parts red mud. The remaining raw materials and preparation process are the same as in Example 1.

[0034] Example 3 This embodiment provides a solid waste-based polymer material, comprising a base component, an activating liquid, a synergist, and a dopant. The base component comprises the following raw materials in parts by weight: 50 parts fly ash, 10 parts desulfurized gypsum, 15 parts slag, and 15 parts red mud. The remaining raw materials and preparation process are the same as in Example 1.

[0035] Example 4 The difference between this embodiment and Example 1 is that the amount of synergist used is 1% of the total mass of the basic components; the remaining raw materials and preparation process are the same as in Example 1. Example 5 Example 5 The difference between this embodiment and Embodiment 1 is that the amount of dopant used is 1.5% of the total mass of the base components.

[0036] Example 6 Compared with Example 1, the mercapto-modified hydrogen-containing polymethylsiloxane in this embodiment is prepared by the following steps: Octamethylcyclotetrasiloxane, hexamethyldisiloxane, tetramethyltetrahydrocyclotetrasiloxane, trifluoromethanesulfonic acid, and deionized water were mixed and reacted at 80°C for 2 hours. Then, γ-mercaptopropyltrimethoxysilane was added, and the mixture was stirred for another 2 hours while maintaining the temperature to obtain mercapto-modified hydrogen-containing polymethylsiloxane. The ratio of octamethylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane, γ-mercaptopropyltrimethoxysilane, trifluoromethanesulfonic acid, and deionized water was 150 g: 40 g: 10 g: 0.9 g: 2 g.

[0037] Example 7 Compared with Example 1, the solid waste-based polymer material in this embodiment also includes a foam stabilizer, and the amount of foam stabilizer added is 0.3% of the total mass of the base components. The foam stabilizer is prepared by the following steps: mixing fatty acid esters and amino monomers, adding an alkaline catalyst, heating to 140°C and reacting for 2 hours, and after the reaction is completed, obtaining an amide surfactant.

[0038] The molar ratio of fatty acid ester to amino monomer is 1:1.1; the alkaline catalyst is an aqueous solution of potassium hydroxide, and the ratio of potassium hydroxide to fatty acid ester is 5:1; the fatty acid ester is methyl laurate, and the amino monomer is 1-(3-aminopropyl)imidazolium. This foam stabilizer is added simultaneously with the dopant, and the remaining raw materials and preparation process are the same as in Example 1.

[0039] Example 8 Compared with Example 1, the solid waste base polymer material in this embodiment also includes a foam stabilizer, and the amount of foam stabilizer added is 0.3% of the total mass of the base components.

[0040] The amide surfactant was prepared by the following steps: a fatty acid ester and an amino monomer were mixed, an alkaline catalyst was added, and the mixture was heated to 140°C and reacted for 2 hours. After the reaction was completed, the amide surfactant was obtained. The molar ratio of fatty acid ester to amino monomer was 1:1.2; the alkaline catalyst was an aqueous solution of potassium hydroxide, and the ratio of potassium hydroxide to fatty acid ester was 5:1; the fatty acid ester was methyl lauryl ester, and the amino monomer was 2-aminoimidazole. This foam stabilizer was added simultaneously with the dopant, and the remaining raw materials and preparation process were the same as in Example 1.

[0041] Example 9 Compared with Example 7, the amount of foam stabilizer added in this example is 0.5% of the total mass of the basic components, while the remaining raw materials and preparation process are the same as in Example 7.

[0042] Comparative Example 1 Compared with Example 1, no dopant was added to this comparative example, but the other raw materials and preparation process remained the same as in Example 1.

[0043] Comparative Example 2 Compared with Example 1, this comparative example replaces the mercapto-modified hydrogen-containing polymethylsiloxane with a hydrogen-containing polymethylsiloxane, and γ-mercaptopropyltrimethoxysilane is not added during the preparation process: Octamethylcyclotetrasiloxane, hexamethyldisiloxane, tetramethyltetrahydrocyclotetrasiloxane, trifluoromethanesulfonic acid and deionized water were mixed and reacted at 80°C for 2 hours.

[0044] The acidic catalyst was trifluoromethanesulfonic acid, and the ratio of octamethylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane, trifluoromethanesulfonic acid, and deionized water was 155g:20g:0.8g:0.8g:1g. The remaining raw materials and preparation process were the same as in Example 1.

[0045] Comparative Example 3 Compared with Example 7, the amount of foam stabilizer added in this comparative example is 2%, while the remaining raw materials and preparation process are the same as in Example 7.

[0046] Comparative Example 4 The mercapto-modified hydrogen-containing polymethylsiloxane was replaced with γ-mercaptopropyltrimethoxysilane, while the remaining raw materials and preparation process remained the same as in Example 1.

[0047] Test Example 1 Water absorption rate: The test samples prepared in Examples 1-9 and Comparative Examples 1-4 were dried at 40°C to constant weight and the initial weight was recorded. Then, they were placed in water for 3 days, taken out, wiped dry, weighed, and the water absorption rate was calculated.

[0048] Crushing value: Place the 9.5-13.2mm sample into the mold, and uniformly load it to 400kN at a rate of 1kN / s on the press. After unloading after 5s of pressure stabilization, remove the sample and sieve the crushed fine material with a 2.36 mm sieve. Calculate the crushing value: Crushing value = mass of crushed fine material smaller than 2.36mm / total mass of sample before test × 100%.

[0049] The results are shown in Table 1: Table 1

[0050] As shown in Table 1, the material in Comparative Example 1 without added dopants is dense, with the lowest water absorption and crushing value. In Example 1, which incorporates thiol-modified hydrogen-containing polymethylsiloxane, the in-situ foaming increases porosity, resulting in a moderate increase in both indicators. Adding an appropriate amount of imidazolium amide foam stabilizer (Examples 7-9) optimizes the pore structure, forming uniform closed pores, significantly reducing water absorption and crushing value. Performance is optimal when the amount of foam stabilizer increases to the optimal level. Excessive foam stabilizer in Comparative Example 3 causes uncontrolled foaming and the appearance of oversized interconnected pores, leading to a sharp deterioration in both indicators. Comparative Example 2, without thiol-modified hydrogen-containing polymethylsiloxane, has similar foaming and hydrophobic effects, and its performance is basically the same as that of Example 1. In Comparative Example 4, γ... mercaptopropyltrimethoxysilane does not contain Si H bonds prevent in-situ foaming and pore formation. The overall density of the material is close to that of Comparative Example 1 without dopants. However, the surface polarity is slightly changed after silane hydrolysis and condensation, and a small amount of grafted propyl chains provide weak hydrophobicity, making the water absorption rate slightly higher than that of Comparative Example 1, but much lower than that of Example 1 after foaming.

[0051] Test Example 2 Preparation of heavy metal contaminated soil: Heavy metal nitrate reagent was completely dissolved in distilled water, then thoroughly mixed with uncontaminated dry soil. The prepared contaminated soil was then sealed in a polyethylene bag for 4 days. The contaminating ions in the heavy metal contaminated soil were Pb and Cd, with a Pb ion concentration of 1000 mg / kg and a Cd ion concentration of 2000 mg / kg. The heavy metal contaminated soil was mixed with the solid waste-based polymer materials prepared in Example 1 and Comparative Examples 1-4, with a doping ratio of 10%, meaning the solid waste-based polymer materials accounted for 10% of the total mass of the test sample.

[0052] Glacial acetic acid (pH 2.64 ± 0.05) was used as the extraction solution. 10 g of the sample was weighed and placed in a tilting flask, and 200 mL of the prepared glacial acetic acid solution was added at a solid-liquid ratio of 1:20. The flask was then incubated at 23 ± 2 °C and 30 rpm for 18 h. The supernatant was centrifuged at 4000 rpm for 20 min, filtered through a 0.45 μm filter, and the concentration of heavy metals in the solution was determined using ICP-OES.

[0053] Q = ( C 0- C 1) / C 0×100% In the formula: Q Adsorption rate; C 0 represents the leaching concentration of heavy metals before treatment; C 1 represents the leaching concentration of heavy metals after treatment; Control group: Heavy metal contaminated soil.

[0054] Performance tests were conducted on Example 1 and Comparative Examples 1-3, and the results are shown in Table 2: Table 2

[0055] As shown in Table 2, Comparative Example 1, lacking any chemical chelating effect, had a leaching concentration close to the control group. In Comparative Example 2, the dopant was a hydrogen-containing polymethylsiloxane without thiol groups. While it possessed some hydrophobicity and foaming properties, it lacked the strong coordination chelation of thiol groups. In Comparative Example 3, the foam stabilizer was excessively added at 2%, leading to severe structural deterioration (ultra-large interconnected pores and extremely thin pore walls). Although thiol groups were retained, a large number of effective chelating sites were exposed and lost due to structural collapse. The structural damage resulted in a significant decrease in thiol group efficiency, although some effect remained. In Comparative Example 4, although thiol groups were introduced, it lacked foaming function and had a low specific surface area. After trimethoxyl hydrolysis, single-point or oligomer connections were formed, which were easily partially broken in strong alkalis. It lacked a continuous hydrophobic barrier, resulting in poor long-term stability.

[0056] Hydrogen-containing polymethylsiloxane molecules with thiol groups retain both active Si-H bonds and thiol groups (-SH). In the strongly alkaline environment of the geopolymer, Si... The rapid hydrolysis of H bonds releases hydrogen gas, and this in-situ foaming process forms a highly porosity and well-connected porous structure within the matrix. The formation of this porous structure significantly increases the specific surface area of ​​the material, providing ample exposure space and adsorption sites for thiol functional groups, thereby significantly enhancing the adsorption capacity for Pb. 2+ Cd 2+The chelating ability of heavy metal ions. In contrast, the directly added γ-mercaptopropyltrimethoxysilane does not contain Si-H bonds, cannot actively foam and create pores, has a limited specific surface area, low thiol site density, and significantly insufficient chelating efficiency.

[0057] The present invention not only enhances hydrophobic properties but also improves the capture efficiency of heavy metal ions by thiol groups through the synergistic effect of physical interception and adsorption on rough surfaces. Meanwhile, γ... Mercaptopropyltrimethoxysilane cannot induce the growth of such micro / nano structures, and its surface modification effect is limited to the molecular level, making it difficult to obtain a similar adsorption enhancement effect.

[0058] In summary, hydrogen-containing polymethylsiloxanes with thiol groups achieve efficient chelation and long-term fixation of heavy metal ions through foaming and pore formation, multi-site covalent anchoring, continuous hydrophobic barrier construction, and micro / nano rough surface formation. Their overall performance is significantly superior to that of directly adding γ-rays. Technical solution for mercaptopropyltrimethoxysilane.

[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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 process, method, article, or apparatus.

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A solid waste-based polymer material, characterized in that, It includes a basic component, an activating solution, a synergist, and a dopant; the basic component includes the following raw materials in parts by weight: 40-70 parts fly ash, 8-12 parts desulfurized gypsum, 20-30 parts slag, and 10-35 parts red mud; the activating solution is a sodium silicate solution, the synergist is urea, and the dopant is mercapto-modified hydrogen-containing polymethylsiloxane.

2. The solid waste base polymer material according to claim 1, characterized in that, The basic components include the following raw materials in parts by weight: 50-60 parts fly ash, 10-11 parts desulfurized gypsum, 15-25 parts slag, and 15-20 parts red mud.

3. The solid waste base polymer material according to claim 1, characterized in that, The amount of activating solution used is 6%–8% of the total mass of the basic components, and the modulus of the sodium silicate solution is 2.8–3.

4. The dosage of the synergist is 0.5%–1% of the total mass of the base components; The amount of dopant used is 0.5%–1.5% of the total mass of the base components.

4. The solid waste base polymer material according to claim 1, characterized in that, The mercapto-modified hydrogen-containing polymethylsiloxane is obtained by ring-opening polymerization under acidic conditions using octamethylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane and γ-mercaptopropyltrimethoxysilane as raw materials and hexamethyldisiloxane as the end-capping agent.

5. The solid waste base polymer material according to claim 1, characterized in that, The solid waste-based polymer material also includes a foam stabilizer, with the amount of foam stabilizer added being 0.1%–0.5% of the total mass of the base components.

6. The solid waste base polymer material according to claim 5, characterized in that, The foam stabilizer is an amide surfactant.

7. The solid waste base polymer material according to claim 1, characterized in that, The mercapto-modified hydrogen-containing polymethylsiloxane is prepared by the following steps: Octamethylcyclotetrasiloxane, hexamethyldisiloxane, tetramethyltetrahydrocyclotetrasiloxane, an acidic catalyst, and deionized water were mixed and reacted at 75-85℃ for 2-3 hours. Then, γ-mercaptopropyltrimethoxysilane was added, and the temperature was kept constant while stirring was continued for 2-3 hours to obtain mercapto-modified hydrogen-containing polymethylsiloxane.

8. The solid waste base polymer material according to claim 1, characterized in that, The ratio of octamethylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane, γ-mercaptopropyltrimethoxysilane, acidic catalyst and deionized water is 150g: 20-40g: 4-10g: 0.8-0.9g: 1-2g.

9. A method for preparing a solid waste-based polymer material, used to prepare the solid waste-based polymer material according to any one of claims 1-8, characterized in that, Includes the following steps: Gradient dry mixing: slag, fly ash, desulfurized gypsum and red mud are dry mixed, and then wet mixed, granulated and aged through atomized spraying of activating liquid and synergist to obtain solid waste base polymer material.

10. The method for preparing a solid waste-based polymer material according to claim 9, characterized in that, The aging time is 7 to 14 days.

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