Maintenance and seepage-proofing integrated film as well as preparation method and application thereof

Abstract

The invention provides a curing and seepage-proofing integrated film and a preparation method and application thereof, and the curing and seepage-proofing integrated film comprises the following components in parts by weight: 16-25 parts of a curing component, 16-25 parts of an adsorption component, 30-76 parts of a polymer cementing component, and 3-7 parts of a modified component, the curing component is water-quenched blast furnace slag powder, the adsorption component is clinoptilolite powder and charcoal, the polymer cementing component is an alkaline degradable polymer, and the modified component is triethanolamine and hydroxypropyl methyl cellulose. The maintenance and seepage-proofing integrated film can achieve the integrated functions of water retention maintenance, base plane enhancement, seepage-proofing isolation and pollutant adsorption, the maintenance effect of a phosphogypsum roadbed or a base layer is improved, and the construction efficiency is improved.

Description

Technical Field

[0001] This invention relates to the fields of solid waste resource utilization and road engineering technology, and more specifically, to an integrated maintenance and seepage prevention membrane, its preparation method, and its application. Background Technology

[0002] As a byproduct of the phosphoric acid industry, phosphogypsum has accumulated to a stockpile exceeding 900 million tons in my country. Its large-scale disposal and resource utilization have become urgent environmental and resource issues. Using phosphogypsum in roadbed or base filling is an effective way to achieve large-scale disposal. However, phosphogypsum poses a risk of leaching of characteristic pollutants such as easily soluble fluorine and phosphorus. Furthermore, its hydration and hardening process requires continuous moisture retention and maintenance, and the roadbed structure must have anti-seepage and isolation functions to prevent pollutant migration.

[0003] In related technologies, traditional plastic films or geotextiles are often used for the maintenance of phosphogypsum subgrades or base courses. However, plastic films or geotextiles can only achieve surface water retention, and they have poor compatibility with the phosphogypsum matrix, are prone to wrinkling during installation, and require manual removal later, increasing construction costs. For seepage prevention, they rely on separately laid geomembranes, which are functionally separate from the maintenance materials and cannot work synergistically. Furthermore, traditional plastic films or geotextiles lack the ability to actively adsorb and retain pollutants. Summary of the Invention

[0004] The present invention aims to provide an integrated maintenance and seepage prevention membrane, its preparation method and application. The integrated maintenance and seepage prevention membrane can realize the integrated functions of water retention and maintenance, base surface reinforcement, seepage prevention and isolation and pollutant adsorption, which is beneficial to improve the maintenance effect of phosphogypsum subgrade or base layer and improve construction efficiency.

[0005] To address the above problems, a first aspect of the present invention provides an integrated curing and seepage-proof membrane, wherein, by weight, the integrated curing and seepage-proof membrane comprises:

[0006] The curing component is 16 to 25 parts, the adsorption component is 16 to 25 parts, the polymer cementing component is 30 to 76 parts, and the modifying component is 3 to 7 parts.

[0007] The solidification component is water-quenched blast furnace slag powder, the adsorption component is clinoptilolite powder and biochar, the polymer cementing component is an alkaline biodegradable polymer, and the modifying component is triethanolamine and hydroxypropyl methylcellulose.

[0008] A second aspect of the present invention provides a method for preparing an integrated curing and seepage-proof membrane, used to prepare the integrated curing and seepage-proof membrane as described in the first aspect, the method comprising the following steps:

[0009] Prepare materials according to the weight proportions of each component;

[0010] The polymer cement component is prepared into a polymer cement component solution, the adsorption component and the curing component are stirred and mixed uniformly to obtain a mixture, the polymer cement component solution and the modification component are added into the mixture to obtain a slurry;

[0011] The slurry is coated on a substrate to form a film layer on the substrate, and the film layer is separated from the substrate after drying to obtain the maintenance and anti-seepage integrated film.

[0012] The third aspect of the present application provides an application of the maintenance and anti-seepage integrated film, the maintenance and anti-seepage integrated film as described in the first aspect, or the maintenance and anti-seepage integrated film prepared by the preparation method as described in the second aspect, is used for wrapping a phosphogypsum roadbed or used for wrapping a phosphogypsum base layer.

[0013] The maintenance anti-seepage integrated film, the preparation method and the application thereof mainly consist of a solidification component, an adsorption component and a polymer cementation component, the water-quenched blast furnace slag powder is used as the solidification component, the water-quenched blast furnace slag powder has excellent grindability, can ensure the suitable particle size and the uniformity of the particle size of the water-quenched blast furnace slag powder, and is beneficial to volatilizing the potential cementation activity of the water-quenched blast furnace slag powder. The alkaline degradable polymer is used as the polymer cementation component, the alkaline degradable polymer has the time-delay degradation characteristic, can play different roles in different stages, in the early stage, the alkaline degradable polymer has not been degraded, the composite film structure formed by the alkaline degradable polymer and the water-quenched blast furnace slag powder is complete, the hydrogen bonds between the molecular chains of the alkaline degradable polymer and the hydroxypropyl methyl cellulose in the modified component jointly play a role, efficient water conservation and maintenance are realized, the humidity condition required by the phosphogypsum roadbed / base layer hydration hardening can be met, and the phosphogypsum roadbed / base layer is successfully hydrated and formed. In the middle stage, the alkaline degradable polymer is gradually degraded, can release the alkaline substances to stimulate the hydration reaction of the water-quenched blast furnace slag powder, generate cementation products such as hydrated calcium silicate (C-S-H) and hydrated calcium aluminate (C-A-H), these cementation products not only can improve the compactness of the maintenance anti-seepage integrated film, but also can fill the pores of the surface layer of the phosphogypsum roadbed / base layer, can enhance the compactness of the phosphogypsum roadbed / base layer, at the same time, the sulfate component (CaSO4·2H2O) contained in the phosphogypsum roadbed / base layer as an auxiliary activator forms a synergistic effect with the alkali activation system, greatly accelerates the hydration rate of the water-quenched blast furnace slag powder, improves the generation amount of the cementation products, makes the cementation products permeable to the interface area between the phosphogypsum roadbed / base layer and other structural layers (such as the cushion layer and the subbase layer), enhances the interlayer bonding strength between the phosphogypsum roadbed / base layer and other structural layers through the chemical bond effect, forms a synergistic stress system of 'phosphogypsum roadbed / base layer-maintenance anti-seepage integrated film-other structural layer', and enhances the structural strength of the phosphogypsum roadbed / base layer. Moreover, in the process of the gradual degradation of the alkaline degradable polymer, the adsorption sites of the biochar and the clinoptilolite powder in the adsorption component are fully exposed, the biochar and the clinoptilolite powder can efficiently intercept the characteristic pollutants such as easily soluble fluorine and phosphorus leached from the phosphogypsum.In the later stage, the alkaline degradable polymer is degraded completely, the cementation product generated by the water quenching of the blast furnace slag powder is fully fused with the phosphogypsum roadbed / base, and a dense cementation protective layer is formed on the surface of the phosphogypsum roadbed / base, which can significantly improve the waterproof and anti-seepage performance of the phosphogypsum roadbed / base, reduce the erosion of external water to the structure of the phosphogypsum roadbed / base, and the biochar and clinoptilolite powder in this stage have adsorbed a large amount of characteristic pollutants, the cementation product penetrates into the pores of the biochar and clinoptilolite powder, so that these characteristic pollutants form stable compounds (such as fluorine aluminum salt and calcium phosphate) under the wrapping and solidification of the cementation product, and through the cooperation of the adsorption of the biochar and clinoptilolite powder and the wrapping and solidification of the cementation product, a stable solidification and isolation barrier of the characteristic pollutants can be formed, which fundamentally blocks the migration path of the characteristic pollutants and avoids the secondary leaching of the characteristic pollutants.

[0014] The maintenance and anti-seepage integrated film provided in the present application has the functions of water retention, continuous maintenance and surface enhancement through the synergistic effect of the solidification component, the adsorption component, the polymer cementation component and the modification component, the soluble fluorine adsorption rate is greater than or equal to 92%, the soluble phosphorus adsorption rate is greater than or equal to 90%, the pollution problem of soluble fluorine and phosphorus leaching of the phosphogypsum can be effectively solved, the integrated function target of “maintenance-enhancement-pollution control” of the phosphogypsum roadbed / base can be realized, the F- concentration in the leaching solution of the phosphogypsum is less than or equal to 1.0 mg / L, the PO43- concentration is less than or equal to 0.2 mg / L, the long-term compliance with the Class III standard of the Environmental Quality Standards for Surface Water (GB3838-2002) is realized, the safe service of the phosphogypsum roadbed / base in the whole life cycle is realized, the key support for the large-scale and environmentally friendly use of the phosphogypsum in the roadbed / base filling is provided, the high-value utilization of the phosphogypsum is realized. In addition, the compatibility of the maintenance and anti-seepage integrated film with the phosphogypsum roadbed / base is good, the film is not easy to wrinkle during paving, the quality of paving can be ensured, and after paving, manual removal is not required, the natural degradation can be realized and the long-term service can be realized, the additional construction cost and process caused by the poor compatibility of the traditional maintenance materials (such as plastic film and geotextile) and the need for removal are reduced, the construction efficiency is improved, and in addition to the large amount of phosphogypsum solid waste, the storage pollution of the blast furnace slag powder and biochar solid waste is also reduced, the resource utilization of multiple types of solid waste is realized, the dependence on natural raw materials is reduced, and the resource mining and transportation cost is saved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The process flow chart for preparing the maintenance and anti-seepage integrated film provided in the embodiments of the present application is provided.

[0016] Figure 2 The structure schematic diagram of the maintenance and anti-seepage integrated film wrapping the phosphogypsum roadbed / base provided in the embodiments of the present application is provided. DETAILED DESCRIPTION

[0017] In order to make the above objectives, characteristics and advantages of the present application more apparent, concrete embodiments of the present application will be described in detail below with reference to the drawings.

[0018] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0019] In addition, the terms "comprising", "including", "containing", "having" are non-limiting, i.e. other steps and other components can be added without affecting the results. Unless otherwise specified, the materials, devices, reagents are commercially available.

[0020] In addition, although the present application describes each step in the preparation in the form of S110, S120, S130, etc., this description is only for the convenience of understanding, and the form of S110, S120, S130 does not mean a limitation on the sequence of each step.

[0021] The first aspect of the embodiment of the present application provides a curing and anti-seepage integrated film, which comprises, by weight parts:

[0022] 16-25 parts of a curing component, 16-25 parts of an adsorption component, 30-76 parts of a polymer cement component, and 3-7 parts of a modified component;

[0023] The curing component is a water-quenched blast furnace slag powder, the adsorption component is clinoptilolite powder and biochar, the polymer cement component is an alkaline degradable polymer, and the modified component is triethanolamine and hydroxypropyl methyl cellulose.

[0024] The water-quenched blast furnace slag powder is a molten calcium aluminate slag discharged from an iron-making blast furnace, which is formed into a glass body particle after water quenching and rapid cooling, and then is made into a powder product through drying and grinding. The water-quenched blast furnace slag powder has excellent grindability, which can ensure that it is ground to a suitable particle size and ensure the uniformity of the particle size. At the same time, the water-quenched blast furnace slag powder, as a high calcium alumina-silica raw material, can form a cementitious product through hydration reaction in an alkaline environment, and the excellent grindability can better utilize its potential cementitious activity. In addition, the water-quenched blast furnace slag powder has good chemical stability and can resist the erosion of various chemicals in the environment, which is conducive to improving the service life of the curing and anti-seepage integrated film.

[0025] The alkaline degradable polymer refers to a polymer material capable of being decomposed through biological, chemical or physical action under natural environmental conditions, finally being converted into harmless substances (such as carbon dioxide, water and small molecule organic substances) and not causing secondary pollution, and capable of providing an alkaline environment in the process of degradation. The alkaline degradable polymer has good adhesion and film forming property, can uniformly disperse the granular water quenched blast furnace slag powder in the alkaline degradable polymer through the wrapping effect, and form a stable composite film. Moreover, the alkaline degradable polymer has a delayed degradation characteristic, can ensure the integrity of the composite film structure in the early non-degradation stage, and can realize the anchoring of water molecules through the hydrogen bond action between the molecular chains of the alkaline degradable polymer, and realize the moisturizing and curing effect. In the medium-term degradation stage, the alkaline degradable polymer is degraded in the natural environment, provides an alkaline environment for the water quenched blast furnace slag powder, promotes the alkali-activated hydration reaction of the water quenched blast furnace slag powder, generates cementitious products such as calcium silicate hydrate (C-S-H) and calcium aluminate hydrate (C-A-H), and with the gradual degradation of the alkaline degradable polymer, the degradation products can create a local alkaline microenvironment at the phosphogypsum roadbed / base layer interface, and provide conditions for the continuous hydration of the water quenched blast furnace slag powder.

[0026] The clinoptilolite powder in the adsorption component has a unique crystal structure, and the framework structure is composed of silicon oxygen tetrahedron and aluminum oxygen tetrahedron, so that the clinoptilolite powder has Al 3+ , Si 4+ active sites, and the clinoptilolite powder has a large specific surface area and rich pore structure, and through the dual action of the active sites and the pore structure, the clinoptilolite powder can adsorb fluoride ions (F - ). The biochar has rich pore structure, and these pore structures provide a large number of adsorption sites for phosphate ions (PO4 3- ), and the surface of the biochar has rich surface active sites, and through chemical adsorption and ion exchange, the biochar can realize efficient adsorption of phosphate ions (PO4 3- ). Through the cooperation of the clinoptilolite powder and the biochar, the easily soluble fluorine and phosphorus and other characteristic pollutants leached from the phosphogypsum can be efficiently intercepted.

[0027] The triethanolamine in the modification component changes the surface charge of the biochar and clinoptilolite powder through protonation, reduces the surface charge repulsion, increases the surface hydroxyl and amino groups of the biochar and clinoptilolite powder, and improves the activity of the biochar and clinoptilolite powder. At the same time, the triethanolamine can form hydrogen bonds and chemical bonds with the alkaline degradable polymer, so as to improve the interfacial bonding force between the adsorption component and the degradable polymer. The hydroxypropyl methyl cellulose can be adsorbed and anchored on the surface of the biochar and clinoptilolite powder, so as to form a hydrophilic coating layer on the surface of the biochar and clinoptilolite powder, improve the hydrophilicity of the biochar and clinoptilolite powder, and thus reduce the interfacial repulsion between the modification component and the degradable polymer. By combining the improvement of the interfacial bonding force and the reduction of the interfacial repulsion through the cooperation of the triethanolamine and the hydroxypropyl methyl cellulose, the compatibility defects between the adsorption component and the degradable polymer can be significantly improved, the structural integrity of the maintenance and anti-seepage integrated film can be improved, and the structural strength of the maintenance and anti-seepage integrated film can be improved.

[0028] The maintenance and anti-seepage integrated film provided in the embodiment mainly consists of a solidification component, an adsorption component and a polymer cementation component. The water-quenched blast furnace slag powder is used as the solidification component. The water-quenched blast furnace slag powder has excellent grindability, can ensure the appropriate particle size and uniformity of the water-quenched blast furnace slag powder, and is beneficial to volatilize the potential cementing activity of the water-quenched blast furnace slag powder. The alkaline degradable polymer is used as the polymer cementation component. The alkaline degradable polymer has the time-delay degradation characteristic, can play different roles in different stages, in the early stage, the alkaline degradable polymer has not been degraded, the composite film structure formed by the alkaline degradable polymer and the water-quenched blast furnace slag powder is complete, the hydrogen bonds between the molecular chains of the alkaline degradable polymer and the hydroxypropyl methyl cellulose in the modified component jointly play a role, efficient water-retention maintenance is realized, the humidity condition required by the phosphogypsum roadbed / base layer for hydration and hardening can be met, and the phosphogypsum roadbed / base layer is successfully hydrated and formed. In the middle stage, the alkaline degradable polymer is gradually degraded, can release the alkaline substances to stimulate the hydration reaction of the water-quenched blast furnace slag powder, and generate cementitious products such as hydrated calcium silicate (C-S-H) and hydrated calcium aluminate (C-A-H). These cementitious products can not only improve the compactness of the maintenance and anti-seepage integrated film, but also fill the pores of the surface layer of the phosphogypsum roadbed / base layer, can enhance the compactness of the phosphogypsum roadbed / base layer. At the same time, the sulfate component (CaSO4·2H2O) contained in the phosphogypsum roadbed / base layer acts as an auxiliary activator, forms a synergistic effect with the alkali activation system, greatly accelerates the hydration rate of the water-quenched blast furnace slag powder, and improves the generation amount of the cementitious product. The cementitious product can permeate the interface area between the phosphogypsum roadbed / base layer and other structural layers (such as cushion layer and subbase layer), enhances the interlayer bonding strength between the phosphogypsum roadbed / base layer and other structural layers through the chemical bonding effect, forms a synergistic stress system of "phosphogypsum roadbed / base layer-maintenance and anti-seepage integrated film-other structural layers", and enhances the structural strength of the phosphogypsum roadbed / base layer. Moreover, in the process of the gradual degradation of the alkaline degradable polymer, the adsorption sites of the biochar and clinoptilolite powder in the adsorption component are fully exposed, and the biochar and clinoptilolite powder can efficiently intercept the characteristic pollutants such as easily soluble fluorine and phosphorus leached from the phosphogypsum. In the later stage, the alkaline degradable polymer is completely degraded, and the cementitious product generated by the water-quenched blast furnace slag powder is fully integrated with the phosphogypsum roadbed / base layer, and forms a dense cementitious protective layer on the surface layer of the phosphogypsum roadbed / base layer, which can significantly improve the waterproof and anti-seepage performance of the phosphogypsum roadbed / base layer, reduce the erosion of external water to the structure of the phosphogypsum roadbed / base layer, and the biochar and clinoptilolite powder in this stage have adsorbed a large amount of characteristic pollutants. The cementitious product permeates the pores of the biochar and clinoptilolite powder, so that these characteristic pollutants form stable complexes (such as fluoroaluminate and calcium phosphate) under the wrapping and solidification of the cementitious product. Through the synergistic effect of the adsorption of the biochar and clinoptilolite powder and the wrapping and solidification of the cementitious product, a stable solidification and isolation barrier of the characteristic pollutants can be formed, which fundamentally blocks the migration path of the characteristic pollutants and avoids the secondary leaching of the characteristic pollutants.

[0029] The maintenance and anti-seepage integrated film provided in the embodiment has water retention performance to provide sustained maintenance and surface enhancement, and has a soluble fluorine adsorption rate of ≥92% and a soluble phosphorus adsorption rate of ≥90%, which can effectively solve the pollution problem of soluble fluorine and phosphorus leaching from phosphogypsum, can achieve the integrated function of "maintenance-enhancement-pollution control" of the phosphogypsum subgrade / base, and can ensure that the F- concentration in the leaching solution of the phosphogypsum is ≤1.0 mg / L and the PO43- concentration is ≤0.2 mg / L, which meets the Class III standard of the Environmental Quality Standard for Surface Water (GB3838-2002) for a long time, realizes the safe service of the phosphogypsum subgrade / base in the whole life cycle, provides key support for the large-scale and environmentally friendly use of phosphogypsum in road subgrade / base filling, realizes the high-value use of phosphogypsum, and has good compatibility with the phosphogypsum subgrade / base. When laid, it is not easy to wrinkle, can ensure the quality of laying, does not need to be manually removed after laying, can realize natural degradation and long-term service, reduces the additional construction cost and process caused by the poor compatibility of traditional maintenance materials (such as plastic film and geotextile) which need to be removed, is beneficial to improving the construction efficiency, can absorb a large amount of phosphogypsum solid waste, can reduce the storage pollution of water-quenched blast furnace slag powder and biochar, realizes the resource utilization of multiple types of solid waste, reduces the dependence on natural raw materials, saves resource mining and transportation costs, and has the advantages of being easy to use, good compatibility, and the like.

[0030] In the above embodiment, as an optional implementation manner, the specific surface area of the water-quenched blast furnace slag powder is 500 m 2 / kg to 600 m 2 / kg, the particle size is 450 mesh to 550 mesh (i.e. D50 = 18-28 μm), the 7d activity index is ≥85%, and the chemical composition of the water-quenched blast furnace slag powder satisfies CaO≥35%, SiO2≥30% and Al2O3≥12%. The chemical composition of the water-quenched blast furnace slag powder can be obtained through a detection report before leaving the factory. Thus, the particle size of the water-quenched blast furnace slag powder in the above range can ensure that it is uniformly dispersed in the alkaline degradable polymer and can form a good interfacial bond with the alkaline degradable polymer, effectively avoiding the agglomeration of the water-quenched blast furnace slag powder particles, thereby being beneficial to the water-quenched blast furnace slag powder to exert its potential cementing activity. In addition, the particle size of the water-quenched blast furnace slag powder in the above range can form a complementary pore with the clinoptilolite powder and biochar, which is beneficial to improving the compactness and structural strength of the maintenance and anti-seepage integrated film. In addition, the water-quenched blast furnace slag powder with the above chemical composition has high activity, which is complementary to the porous structure of the clinoptilolite powder and biochar, and uses SiO2 as a rigid skeleton to support the pore structure, which can ensure the adsorption space of the clinoptilolite powder and biochar without sacrificing the overall strength of the maintenance and anti-seepage integrated film.

[0031] On the basis of the above-mentioned embodiments, as an optional implementation, the weight ratio of clinoptilolite powder to biochar in the adsorption component is 1:2 to 1:1; wherein the clinoptilolite powder is obtained after calcination treatment, the particle size of the clinoptilolite powder is 600-800 mesh (i.e. D50 = 15-20 μm); the biochar is obtained after acid washing treatment, and the particle size of the biochar is 800-1000 mesh (i.e. D50 = 10-15 μm). Thus, by calcining the clinoptilolite powder, the silicate-aluminate framework on the surface of the clinoptilolite powder is slightly restructured, more Al 3+ , Si 4+ active sites are exposed, providing sufficient binding sites for ion exchange of fluoride ions (F-). By acid washing the biochar, during the acid washing process, the acid slightly etches part of the carbon framework of the biochar, forming new micropores or mesopores on the basis of the original pores, thereby increasing the porosity of the biochar, providing sufficient adsorption space for macromolecular pollutants such as phosphate ions (PO4 3- ), and after acid washing, the carbon-hydrogen bonds on the surface of the biochar are broken, generating a large number of acidic functional groups such as carboxyl groups (-COOH), hydroxyl groups (-OH), aldehyde groups (-CHO), and the surface Zeta potential decreases from -10 to -15 mV to -30 to -40 mV, significantly increasing the negative charge density of the biochar, which can enhance the adsorption capacity of PO4 3- through electrostatic attraction. By setting the particle size of the clinoptilolite powder to 600-800 mesh and the particle size of the biochar to 800-1000 mesh, on the one hand, the slightly larger clinoptilolite powder can fill the pores between the water-quenched blast furnace slag powder particles, and the smaller biochar can fill the remaining pores, and by gradually reducing the particle size of the water-quenched blast furnace slag powder, clinoptilolite powder and biochar, it is beneficial to improve the compactness of the maintenance and anti-seepage integrated film, and on the other hand, it can increase the specific surface area of the clinoptilolite powder and the biochar to enhance the adsorption performance of the two.

[0032] On the basis of the above-mentioned embodiments, as an optional implementation, the clinoptilolite powder is calcined by the following method: calcining the clinoptilolite powder at 350-400°C for 2h, and then grinding the calcined clinoptilolite powder to 600-800 mesh (D50 = 15-20 μm).

[0033] On the basis of the above-mentioned embodiments, as an optional implementation, the biochar is one or a combination of straw-based biochar, sawdust-based biochar, rice husk-based biochar and bamboo chip-based biochar. The biochar is acid washed by the following method: placing the biochar in 1.5-2 mol / L hydrochloric acid, refluxing at 80°C for 1h for acid washing, washing to neutral with water after acid washing is completed, and then grinding the water-washed biochar to 800-1000 mesh (D50 = 10-15 μm).

[0034] On the basis of the above-mentioned embodiments, as an optional implementation, the alkaline degradable polymer comprises one or a combination of linear polyamide, polyaspartic acid-polylysine copolymer and polyethylene glycol modified poly-β-amino ester, which is alkaline by itself or after compounding, and the pH value of its aqueous solution ranges from 10.0 to 11.0. Specifically, the pH value of 2% aqueous solution of linear polyamide (PAAs) is 10.2-10.8, and its water solubility is ≥95%; the pH value of aqueous solution of polyaspartic acid-polylysine copolymer (PASP-PLL) is 10.1-10.9 (the specific pH value can be adjusted by adjusting the molar ratio of PASP to PLL, for example, when the molar ratio of PASP to PLL is 3:1, the pH value of PASP-PLL is 10.1, and when the molar ratio of PASP to PLL is 1:1, the pH value of PASP-PLL is 10.9), and the molecular weight of PASP-PLL is 80000-120000, wherein the solid content of PASP is ≥40%, and the purity of PLL is ≥95%; polyethylene glycol modified poly-β-amino ester (PEG-PBAE) is a compounded polymer, and the pH value of its aqueous solution is 10.0-10.6 (wherein the molar ratio of PEG to PBAE is 1-2:9-8), and the solubility of PEG is ≥50g / L to avoid stratification during preparation of PEG-PBAE. Thus, the above-mentioned substances as alkaline degradable polymers not only provide an alkaline environment during degradation, but also have high adhesion and film-forming properties, which are beneficial to achieve efficient water retention and maintenance in the early stage, and can enhance the interlayer bonding strength between the maintenance and anti-seepage integrated film and phosphogypsum subgrade / base, and between the phosphogypsum subgrade / base and other structural layers in the middle and late stages.

[0035] On the basis of the above-mentioned embodiments, as an optional implementation, the molecular weight of the alkaline degradable polymer is 80000-120000. Thus, the alkaline degradable polymer has good cementing strength and degradation rate within the above-mentioned range, so as to continuously provide conditions for the hydration of water quenched blast furnace slag powder.

[0036] On the basis of the above-mentioned embodiments, as an optional implementation, the mass ratio of triethanolamine and hydroxypropyl methyl cellulose in the modified component is 1:2 to 1:3, and the viscosity of the hydroxypropyl methyl cellulose is 4000 mPa.s to 6000 mPa.s. In this way, by setting the amount of triethanolamine and hydroxypropyl methyl cellulose within the above-mentioned range, not only is it beneficial to improve the defect of insufficient compatibility between the adsorption component and the degradable polymer, but also the relatively more hydroxypropyl methyl cellulose can further meet the humidity conditions required for the hydration hardening of the phosphogypsum roadbed / base by its water retention function, ensuring the smooth hydration molding of the phosphogypsum roadbed / base. The viscosity of the hydroxypropyl methyl cellulose is 4000 mPa.s to 6000 mPa.s, which can ensure the casting molding property of the maintenance and anti-seepage integrated film.

[0037] On the basis of the above-mentioned embodiments, as an optional implementation, the weight ratio of the solidification component to the adsorption component is 1:0.8 to 1:1.2. In this way, by setting the amount of the solidification component and the adsorption component within the above-mentioned range, the adsorption component with a smaller particle size can be filled between the pores of the solidification component with a larger particle size, on the one hand, a dense structure of large particle skeleton-small particle filling can be formed, which is beneficial to improve the quality of the maintenance and anti-seepage integrated film, and on the other hand, the adsorption component adsorbing the characteristic pollutants can be wrapped by the gel product formed by the solidification component, so as to further isolate the characteristic pollutants and reduce the secondary leaching risk of the characteristic pollutants.

[0038] On the basis of the above-mentioned embodiments, as an optional implementation, the weight of the polymer cementing component is 1 to 1.5 times the sum of the mass of the solidification component and the adsorption component, that is, if the sum of the mass of the solidification component and the adsorption component is a, then the mass of the polymer cementing component is 1a to 1.5a. In this way, by setting the weight of the polymer cementing component to be 1 to 1.5 times the sum of the mass of the solidification component and the adsorption component, it can be ensured that the polymer cementing component can sufficiently wrap the solidification component and the adsorption component to form a composite structure and improve the overall structural strength of the maintenance and anti-seepage integrated film.

[0039] In combination with Figure 1 The second aspect of the embodiments of the present application provides a preparation method of the maintenance and anti-seepage integrated film, which is used for preparing the maintenance and anti-seepage integrated film of the first aspect, and the preparation method comprises the following steps:

[0040] In step S110, the components are prepared according to the weight parts;

[0041] First, the following components are pretreated, specifically:

[0042] The water-quenched blast furnace slag powder is ground to 450-550 mesh by using an airflow pulverizer, and is dried at 105°C for 2h to have a water content of ≤0.3%, as the solidification component;

[0043] The clinoptilolite powder is calcined at 350-400℃ for 2h, and then the calcined clinoptilolite powder is ground to 600-800 mesh; the biochar is placed in 1.5-2 mol / L hydrochloric acid, and is subjected to acid washing by refluxing at 80℃ for 1h, and after the acid washing is completed, the biochar is washed to neutral with water, and then the washed biochar is ground to 800-1000 mesh; then the pretreated clinoptilolite powder and the biochar are mixed in a mass ratio of 1:2-1 as the adsorption component;

[0044] The alkaline degradable polymer is used as the polymer cementing component;

[0045] The triethanolamine and the hydroxypropyl methyl cellulose are mixed uniformly in a mass ratio of 1:2 to 1:3 as the modification component.

[0046] Then, each component is weighed according to 16-25 parts of the curing component, 16-25 parts of the adsorption component, 30-76 parts of the polymer cementing component, and 3-7 parts of the modification component.

[0047] In step S120, the polymer cementing component is prepared into a polymer cementing component solution, the adsorption component and the curing component are stirred and mixed uniformly to obtain a mixture, the polymer cementing component solution and the modification component are added to the mixture to obtain a slurry;

[0048] Specifically, the alkaline degradable polymer is added to deionized water at 80-90℃ (the solid-liquid ratio can be adjusted to 1:8 to 1:12 according to actual film preparation requirements) and stirred for 30min to dissolve, forming a polymer cementing component solution; the adsorption component and the curing component are added to a double-planetary stirrer and stirred at 200r / min for 15-20min to control the particle size distribution variation coefficient to be ≤5%, obtaining a mixture; the polymer cementing component solution and the modification component are added to the mixture and stirred at 350-500r / min for 30-40min, and the slurry viscosity is detected every 10min during the stirring until the slurry viscosity is 5000-8000mPa.s. In this way, by first mixing the adsorption component and the curing component uniformly, and then adding the polymer cementing component solution and the modification component, the curing component, the adsorption component and the modification component can be uniformly dispersed in the polymer cementing component solution, which is beneficial to the full wrapping of the curing component and the adsorption component by the polymer cementing component.

[0049] In step S130, the slurry is coated on a substrate to form a film layer on the substrate, and the film layer is separated from the substrate after drying to obtain a curing and anti-seepage integrated film.

[0050] Specifically, the slurry is poured into a casting machine tank to form a 1.5-2.5 mm thick film layer on the substrate at a casting speed of 0.5-0.8 m / min and a doctor blade gap of 2.0-3.0 mm; then, the film layer and the substrate are sent into a hot air drying oven, dried at 40-45 °C for 10 min, and then dried at 50-55 °C for 10-15 min, so that the moisture content of the dried film layer is 3-5%; and then the dried film layer and the substrate are separated to obtain a finished film, i.e., a curing and anti-seepage integrated film. The curing and anti-seepage integrated film has a thickness of 0.8-1.5 mm, and a thickness deviation of ≤±5%. As an optional embodiment, the substrate is a PET substrate. In this way, by controlling the drying temperature of the film layer to be 40-55 °C and by first drying the film layer at a low temperature and then drying the film layer at a higher temperature, the film layer can be prevented from cracking, which is conducive to maintaining the integrity of the film layer.

[0051] The preparation method of the curing and anti-seepage integrated film provided in this embodiment can avoid agglomeration of the adsorption component and agglomeration of the solidification component, which is conducive to improving the uniformity of the mixture of the adsorption component and the solidification component. The addition of the polymer cement component solution and the modification component can ensure that the solidification component, the adsorption component, and the modification component are uniformly dispersed in the polymer cement component solution, which is not only conducive to the full wrapping of the solidification component and the adsorption component by the polymer cement component, but also conducive to improving the stability of the slurry to optimize the rheological property of the slurry. By controlling the drying temperature of the film layer and by first drying at a low temperature and then drying at a higher temperature, the cracking of the film layer can be effectively avoided. The preparation method of this embodiment is not only conducive to improving the synergistic functions of water conservation, curing, base reinforcement, anti-seepage isolation, and pollutant adsorption of the curing and anti-seepage integrated film, but also can realize mass production of the curing and anti-seepage integrated film, which is conducive to reducing the production cost of the curing and anti-seepage integrated film.

[0052] In combination with Figure 2 The third aspect of the embodiments of the present application provides an application of a curing and anti-seepage integrated film. The curing and anti-seepage integrated film as described in the first aspect or prepared by the preparation method as described in the second aspect can be used to wrap a phosphogypsum roadbed or to wrap a phosphogypsum base layer.

[0053] In combination with Figure 2As shown, the maintenance and anti-seepage integrated film 3 is wrapped on the upper surface, lower surface and two side surfaces of the phosphogypsum roadbed / base layer 2, so that the phosphogypsum roadbed / base layer 2 is enclosed by the maintenance and anti-seepage integrated film 3, and the phosphogypsum roadbed / base layer 2 wrapped by the maintenance and anti-seepage integrated film 3 is placed on the other structural layer 1. Thus, the maintenance and anti-seepage integrated film 3 can efficiently maintain water for the phosphogypsum roadbed / base layer 2, can meet the humidity conditions required by the hydration and hardening of the phosphogypsum roadbed / base layer 2, and can guarantee the smooth hydration and molding of the phosphogypsum roadbed / base layer 2. Moreover, the maintenance and anti-seepage integrated film 3 forms a dense gel protective layer on the surface of the phosphogypsum roadbed / base layer 2, can significantly improve the waterproof and anti-seepage performance of the phosphogypsum roadbed / base layer 2, can reduce the erosion of external water to the structure of the phosphogypsum roadbed / base layer 2, can further form a stable characteristic pollutant solidification and isolation barrier, can fundamentally block the migration path of the characteristic pollutants, and can avoid the secondary leaching of the characteristic pollutants, so as to realize the integrated function target of “maintenance-strengthening-pollution control” of the phosphogypsum roadbed / base layer.

[0054] In order to further illustrate the present application, the present application will be further illustrated by combining specific examples. The experimental methods used in the examples in the present application are all conventional methods unless otherwise specified; and the materials, reagents and the like used in the examples in the present application are all obtained by market purchase unless otherwise specified.

[0055] Example 1

[0056] The present embodiment provides a maintenance and anti-seepage integrated film and a preparation method thereof, the maintenance and anti-seepage integrated film comprising:

[0057] 20 parts of a solidification component, 20 parts of an adsorption component, 60 parts of a polymer cementation component, and 5 parts of a modified component; wherein the solidification component is a water-quenched blast furnace slag powder (450 mesh) with a specific surface area of 500 m 2 / kg and a 7d activity index of 98%, the adsorption component is 10 parts of clinoptilolite powder (600 mesh) calcined at 380℃ and 10 parts of straw-based biochar (800 mesh) washed with 1.8 mol / L acid, the polymer cementation component is linear polyamide (the pH of its aqueous solution is 11.0), and the modified component is 2 parts of triethanolamine and 3 parts of hydroxypropyl methyl cellulose.

[0058] The preparation method of the maintenance and anti-seepage integrated film is as follows:

[0059] The linear polyamide is dissolved in deionized water at 85°C (solid-liquid ratio of 1:10) for 30 min to dissolve, forming a polymer cement component solution; the adsorption component and the solidification component are added into a double planetary mixer, stirred at 200 r / min for 18 min, the particle size distribution variation coefficient is controlled to be ≤5%, and a mixture is prepared; the polymer cement component solution and the modification component are added into the mixture, stirred at 400 r / min for 35 min, a slurry is prepared, and the viscosity of the slurry is detected every 10 min during stirring until the viscosity of the slurry is 5000-8000 mPa·s.

[0060] The slurry is poured into a casting machine tank, a 2.0 mm thick film layer is formed on the PET substrate at a casting speed of 0.5-0.8 m / min and a doctor blade gap of 2.0-3.0 mm; then, the film layer and the PET substrate are sent into a hot air drying oven, dried at 45°C for 10 min first, and then heated to 50°C for 12 min, so that the water content of the dried film layer is 3-5%; and then the dried film layer and the substrate are separated to obtain a finished film, and the thickness of the finished film is 1.2 mm.

[0061] Example 2

[0062] The present embodiment provides a curing and anti-seepage integrated film and a preparation method thereof, the curing and anti-seepage integrated film comprising:

[0063] The solidification component is 20 parts, the adsorption component is 20 parts, the polymer cement component is 60 parts, and the modification component is 5 parts; wherein the solidification component is a water-quenched blast furnace slag powder (450 mesh) with a specific surface area of 500 m 2 / kg and a 7d activity index of 98%, the adsorption component is 8 parts of clinoptilolite powder (600 mesh) calcined at 380°C and 12 parts of straw-based biochar (800 mesh) washed with 1.8 mol / L acid, the polymer cement component is linear polyamide (the pH of its aqueous solution is 11.0), and the modification component is 2 parts of triethanolamine and 3 parts of hydroxypropyl methyl cellulose.

[0064] The preparation method of the curing and anti-seepage integrated film is the same as that in Example 1.

[0065] Example 3

[0066] The present embodiment provides a curing and anti-seepage integrated film and a preparation method thereof, the curing and anti-seepage integrated film comprising:

[0067] The solidification component is 25 parts, the adsorption component is 25 parts, the polymer cement component is 50 parts, and the modification component is 5 parts; wherein the solidification component is a water-quenched blast furnace slag powder (450 mesh) with a specific surface area of 500 m 2 / kg, 98% 7d active index of water quenched blast furnace slag powder (450 mesh), the adsorption component is 12.5 parts of clinoptilolite powder (600 mesh) calcined at 380℃ and 12.5 parts of straw-based biochar (800 mesh) washed with 1.8 mol / L acid, the polymer cementing component is linear polyamide (pH of its aqueous solution is 10.0-11.0), and the modification component is 2 parts of triethanolamine and 3 parts of hydroxypropyl methyl cellulose.

[0068] The preparation method of the maintenance and anti-seepage integrated film is the same as that in Embodiment 1.

[0069] Embodiment 4

[0070] The present embodiment provides a maintenance and anti-seepage integrated film and a preparation method thereof, the maintenance and anti-seepage integrated film comprising:

[0071] 20 parts of a curing component, 20 parts of an adsorption component, 60 parts of a polymer cementing component, and 5 parts of a modification component; wherein the curing component is blast furnace slag powder (450 mesh) with a specific surface area of 500 m 2 / kg, 98% 7d active index of water quenched blast furnace slag powder (450 mesh), the adsorption component is 12.5 parts of clinoptilolite powder (600 mesh) calcined at 380℃ and 12.5 parts of straw-based biochar (800 mesh) washed with 1.8 mol / L acid, the polymer cementing component is linear polyamide (pH of its aqueous solution is 10.0-11.0), and the modification component is 2 parts of triethanolamine and 3 parts of hydroxypropyl methyl cellulose.

[0072] The preparation method of the maintenance and anti-seepage integrated film is the same as that in Embodiment 1.

[0073] Embodiment 5

[0074] The present embodiment provides a maintenance and anti-seepage integrated film and a preparation method thereof, the maintenance and anti-seepage integrated film comprising:

[0075] 20 parts of a curing component, 20 parts of an adsorption component, 60 parts of a polymer cementing component, and 5 parts of a modification component; wherein the curing component is blast furnace slag powder (450 mesh) with a specific surface area of 500 m 2 / kg, 98% 7d active index of water quenched blast furnace slag powder (450 mesh), the adsorption component is 12.5 parts of clinoptilolite powder (600 mesh) calcined at 380℃ and 12.5 parts of straw-based biochar (800 mesh) washed with 1.8 mol / L acid, the polymer cementing component is linear polyamide (pH of its aqueous solution is 10.0-11.0), and the modification component is 2 parts of triethanolamine and 3 parts of hydroxypropyl methyl cellulose.

[0076] The preparation method of the maintenance and anti-seepage integrated film is the same as that in Embodiment 1.

[0077] Embodiment 6

[0078] The present embodiment provides a curing and anti-seepage integrated film and a preparation method thereof, the curing and anti-seepage integrated film comprising:

[0079] The curing component is 20 parts, the adsorption component is 20 parts, the polymer cementing component is 60 parts, and the modifying component is 5 parts; wherein the curing component is a water-quenched blast furnace slag powder (450 mesh) with a specific surface area of 500 m 2 / kg and a 7d activity index of 98%, the adsorption component is 10 parts of clinoptilolite powder (600 mesh) calcined at 380°C and 10 parts of rice husk-based biochar (800 mesh) washed with 1.8 mol / L acid, the polymer cementing component is linear polyamide (the pH of its aqueous solution is 11.0), and the modifying component is 2 parts of triethanolamine and 3 parts of hydroxypropyl methyl cellulose.

[0080] The preparation method of the curing and anti-seepage integrated film is the same as that in Embodiment 1.

[0081] Comparative Example 1

[0082] The present comparative example provides a curing and anti-seepage integrated film and a preparation method thereof, the curing and anti-seepage integrated film comprising:

[0083] The curing component is 30 parts, the adsorption component is 30 parts, the polymer cementing component is 40 parts, and the modifying component is 5 parts; wherein the curing component is a water-quenched blast furnace slag powder (450 mesh) with a specific surface area of 500 m 2 / kg and a 7d activity index of 98%, the adsorption component is 15 parts of clinoptilolite powder (600 mesh) calcined at 380°C and 15 parts of straw-based biochar (800 mesh) washed with 1.8 mol / L acid, the polymer cementing component is linear polyamide (the pH of its aqueous solution is 11.0), and the modifying component is 2 parts of triethanolamine and 3 parts of hydroxypropyl methyl cellulose.

[0084] The preparation method of the curing and anti-seepage integrated film is the same as that in Embodiment 1.

[0085] Comparative Example 2

[0086] The present comparative example provides a curing and anti-seepage integrated film and a preparation method thereof, the curing and anti-seepage integrated film comprising:

[0087] The curing component is 15 parts, the adsorption component is 10 parts, the polymer cementing component is 75 parts, and the modifying component is 5 parts; wherein the curing component is a water-quenched blast furnace slag powder (450 mesh) with a specific surface area of 500 m 2kg, 7d activity index 98% of water quenched blast furnace slag powder (450 mesh), adsorption component is 5 parts of clinoptilolite powder (600 mesh) calcined at 380°C and 5 parts of straw-based biochar (800 mesh) washed with 1.8 mol / L acid, polymer cementing component is linear polyamide (pH of its aqueous solution is 11.0), and modifying component is 2 parts of triethanolamine and 3 parts of hydroxypropyl methyl cellulose.

[0088] The preparation method of the maintenance anti-seepage integrated film is the same as that in Example 1.

[0089] In order to compare the performance of the maintenance anti-seepage integrated films in Examples 1 to 6 and Comparative Examples 1 and 2, the water retention rate, tensile strength, bonding strength (referring to the interfacial bonding strength of the maintenance anti-seepage integrated film and the phosphogypsum roadbed / base), and absorption rate of fluorine and phosphorus of the maintenance anti-seepage integrated films in Examples 1 to 6 and Comparative Examples 1 and 2 are tested, and the results are shown in Table 1.

[0090] The specific test methods are as follows:

[0091] (1) Water retention rate: the water content before the phosphogypsum roadbed / base is coated with the maintenance anti-seepage integrated film is tested, and after maintenance, the water content is tested again, and the water retention rate is calculated;

[0092] (2) Tensile strength: a universal material testing machine is used to perform uniaxial tension on the maintenance anti-seepage integrated film, and the maximum tension at the time of fracture is measured to calculate the tensile strength;

[0093] (3) Bonding strength: the maximum shear force of the interface between the maintenance anti-seepage integrated film and the phosphogypsum test block is measured by the tensile shear method to calculate the bonding strength;

[0094] (4) Absorption rate of fluorine and phosphorus: a simulated leaching solution containing fluorine and phosphorus is prepared by simulating the dissolution environment of fluorine and phosphorus in the phosphogypsum roadbed, and the maintenance anti-seepage integrated film is soaked therein, and the absorption rate is calculated by measuring the concentration change of fluorine and phosphorus in the leaching solution before and after soaking.

[0095] Table 1

[0096]

[0097]

[0098] As can be seen from Table 1, the maintenance and anti-seepage integrated film prepared in Examples 1 to 6 has good water retention rate, tensile strength and bonding strength, and also has high absorption rate of fluorine and phosphorus, and as can be seen from the comparison of Example 1, Example 4 and Example 5, different polymer cementing components have little effect on the performance of the maintenance and anti-seepage integrated film, but as can be seen from the comparison of Comparative Example 2 and Example 1, a higher content of the polymer cementing component can reduce the interfacial bonding strength of the maintenance and anti-seepage integrated film and the phosphogypsum roadbed / base. As can be seen from the comparison of Example 1 and Example 6, different biochar has little effect on the adsorption capacity of phosphorus, but as can be seen from the comparison of Example 1 and Example 3, and the comparison of Example 1 and Comparative Example 1, an increase in the content of biochar or clinoptilolite powder in the adsorption component can improve the adsorption rate of fluorine or phosphorus. As can be seen from the comparison of Example 1 and Example 3, a proper increase in the curing component can improve the interfacial bonding strength of the maintenance and anti-seepage integrated film and the phosphogypsum roadbed / base, but as can be seen from the comparison of Example 1 and Comparative Example 1, an excessive amount of the curing component can not only seriously affect the film-forming property of the maintenance and anti-seepage integrated film, but also affect the water retention rate and tensile strength of the maintenance and anti-seepage integrated film.

[0099] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited to this. Various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the present disclosure, and these changes and modifications shall fall within the protection scope of the present disclosure.

Claims

1. A combined maintenance and seepage prevention membrane, characterized in that, By weight, the integrated maintenance and seepage prevention membrane comprises: The curing component is 16 to 25 parts, the adsorption component is 16 to 25 parts, the polymer cementing component is 30 to 76 parts, and the modifying component is 3 to 7 parts. The solidification component is water-quenched blast furnace slag powder, the adsorption component is clinoptilolite powder and biochar, the polymer cementing component is an alkaline biodegradable polymer, and the modifying component is triethanolamine and hydroxypropyl methylcellulose.

2. The integrated maintenance and seepage prevention membrane according to claim 1, characterized in that, The specific surface area of ​​the water-quenched blast furnace slag powder is 500 m². 2 / kg to 600m 2 / kg, with a particle size of 450 to 550 mesh, a 7-day activity index ≥85%, and the chemical composition of the water-quenched blast furnace slag powder satisfies CaO ≥35%, SiO2 ≥30%, and Al2O3 ≥12%.

3. The integrated maintenance and seepage prevention membrane according to claim 1, characterized in that, The weight ratio of the clinoptilolite powder to the biochar in the adsorption component is 1:2 to 1:1; The clinoptilolite powder is obtained by calcination, and the particle size of the clinoptilolite powder is 600 mesh to 800 mesh. The biochar is obtained by acid washing, and the particle size of the biochar is 800 to 1000 mesh.

4. The integrated maintenance and seepage prevention membrane according to claim 1, characterized in that, The polymer binder component includes one or more of linear polyamide, polyaspartic acid-polylysine copolymer and polyethylene glycol-modified polyβ-amino ester, and the molecular weight of the polymer binder component is 80,000 to 120,000.

5. The integrated maintenance and seepage prevention membrane according to claim 1, characterized in that, The mass ratio of triethanolamine to hydroxypropyl methylcellulose in the modified component is 1:2 to 1:3, and the viscosity of the hydroxypropyl methylcellulose is 4000 mPa·s to 6000 mPa·s.

6. The integrated maintenance and seepage prevention membrane according to claim 1, characterized in that, The weight ratio of the solidified component to the adsorbed component is from 1:0.8 to 1:1.

2.

7. The integrated maintenance and seepage prevention membrane according to claim 1, characterized in that, The weight ratio of the sum of the masses of the curing component and the adsorption component to the weight of the polymer cementing component is 1:1 to 1:1.

5.

8. A method for preparing an integrated curing and seepage-proof membrane, characterized in that, The method for preparing the integrated geomembrane for curing and preventing seepage as described in any one of claims 1 to 7 comprises the following steps: Prepare materials according to the weight proportions of each component; The polymer binder component is prepared into a polymer binder component solution, and the adsorption component and the curing component are stirred and mixed evenly to obtain a mixture. The polymer binder component solution and the modifying component are added to the mixture to obtain a slurry. The slurry is coated onto a substrate to form a film layer. After the film layer is dried, it is separated from the substrate to obtain the integrated curing and seepage prevention membrane.

9. The method for preparing the integrated curing and seepage prevention membrane according to claim 8, characterized in that, The process of drying the membrane layer includes: drying the membrane layer at 40°C to 45°C for 10 minutes, then raising the temperature to 50°C to 55°C and drying for 10 to 15 minutes, so that the moisture content of the dried membrane layer is 3% to 5%. The thickness of the integrated maintenance and seepage prevention membrane is 0.8 mm to 1.5 mm.

10. An application of an integrated maintenance and seepage prevention membrane, characterized in that, The integrated curing and seepage prevention membrane as described in claims 1 to 7, or the integrated curing and seepage prevention membrane prepared by the preparation method as described in claim 8 or 9, is used to wrap phosphogypsum roadbeds or to wrap phosphogypsum base layers.

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