Sound insulation mortar, preparation method, sound insulation mortar system and construction technology

Abstract

The invention discloses sound insulation mortar, a preparation method, a sound insulation mortar system and a construction technology, and belongs to the field of building materials. The phosphogypsum-based low-carbon thermal insulation and sound insulation mortar is prepared from the following raw materials in parts by weight: 50 to 60 parts of phosphogypsum, 20 to 30 parts of filler, 10 to 15 parts of inorganic admixture, 10 to 15 parts of glass beads, 5 to 10 parts of aerogel, 0.1 to 0.5 part of water-retaining agent, 1 to 4 parts of polymer rubber powder, 0.02 to 0.05 part of retarder and 0.2 to 0.5 part of water reducing agent. The ardealite-based low-carbon thermal insulation and sound insulation mortar is compact in structure and good in crack resistance, and has an excellent sound insulation effect on the premise of ensuring that the mechanical property reaches the standard. The thermal-insulation and sound-insulation material is good in fire resistance and outstanding in aging resistance and durability in the long-term use process, has convenient construction performance and can fully meet the comprehensive use requirements of constructional engineering for thermal-insulation and sound-insulation materials.

Description

Technical Field

[0001] This application relates to the field of building materials technology, and in particular to a sound-insulating mortar, its preparation method, sound-insulating mortar system, and construction process. Background Technology

[0002] With the continuous upgrading of building energy conservation and environmental protection standards, the resource utilization of industrial by-products has become an important development direction in the building materials industry. Among them, phosphogypsum, as a large-scale solid waste generated in the wet-process phosphoric acid production process, has a huge annual output. For a long time, phosphogypsum has been disposed of mainly through stockpiling, which not only occupies a large amount of land resources, but its impurities may also cause environmental risks such as soil and water pollution. How to achieve its efficient resource utilization has become an urgent issue for the industry to solve.

[0003] On the other hand, the rapid pace of urbanization has made noise pollution from industrial production and transportation increasingly prominent in the living environment of residents, making building sound insulation performance one of the key indicators for measuring residential comfort. Currently, sound insulation in the building sector mainly relies on two types of technologies: structural sound insulation and material sound insulation. Structural sound insulation requires special design and construction of the building structure, which is complex and costly, making it difficult to apply on a large scale in ordinary civil buildings. While commonly used organic sound insulation materials can achieve a certain level of sound insulation, they generally suffer from poor fire resistance, easy aging after long-term use, and insufficient durability. Furthermore, the environmental friendliness of some organic materials during production is poor, which is inconsistent with the current low-carbon and environmentally friendly development concept in the building sector.

[0004] Therefore, developing a new material that uses phosphogypsum as the main raw material to realize the resource utilization of industrial solid waste, and that combines good sound insulation performance with excellent environmental protection and fire safety, is of great practical significance and application value for meeting the needs of building energy conservation and noise reduction, promoting the development of low-carbon building materials, and solving the environmental problems of phosphogypsum storage. Summary of the Invention

[0005] This application discloses a sound-insulating mortar, its preparation method, a sound-insulating mortar system, and a construction process to solve the aforementioned technical problems existing in related technologies.

[0006] To solve the above problems, this application adopts the following technical solution: In a first aspect, embodiments of this application provide a phosphogypsum-based low-carbon thermal insulation and soundproofing mortar, comprising, by weight, the following raw materials: 50-60 parts phosphogypsum, 20-30 parts filler, 10-15 parts inorganic admixture, 10-15 parts vitrified microspheres, 5-10 parts aerogel, 0.1-0.5 parts water-retaining agent, 1-4 parts polymer powder, 0.02-0.05 parts retarder, and 0.2-0.5 parts water-reducing agent.

[0007] Secondly, embodiments of this application provide a method for preparing phosphogypsum-based low-carbon thermal insulation and soundproofing mortar, comprising the following steps: Step A1: Mix phosphogypsum, inorganic admixtures, vitrified microspheres, fillers, and aerogel evenly to obtain the first mixture; Step A2: Add polymer powder, retarder, water-reducing agent and water-retaining agent to the first mixture, mix evenly to obtain the second mixture; Step A3: Mix the second mixture with water at a mass ratio of 100:35 to 100:40 to obtain phosphogypsum-based low-carbon thermal insulation and soundproofing mortar.

[0008] Thirdly, embodiments of this application provide a phosphogypsum-based thermal insulation and sound insulation mortar system, including a first mortar layer formed by the above-mentioned phosphogypsum-based low-carbon thermal insulation and sound insulation mortar and a sound insulation coating compounded on the surface of the first mortar layer. Wherein: the sound insulation coating is formed by applying a sound insulation paint, which comprises the following raw materials in parts by weight: 20-30 parts of waterborne polyurethane; 30-40 parts of waterborne acrylic resin; 30-40 parts of heavy calcium carbonate powder; 20-40 parts of rubber powder; the solid content of the waterborne polyurethane is 45%-55%; the solid content of the waterborne acrylic resin is 40%-50%.

[0009] Fourthly, embodiments of this application provide a construction process for a phosphogypsum-based thermal insulation and soundproofing mortar system, comprising the following steps: Step S1: Provide the mortar layer application slurry and the sound insulation coating paste for application: The phosphogypsum-based low-carbon thermal insulation and soundproofing mortar prepared above is used as the construction slurry; After mixing the sound-insulating coating with water at a mass ratio of 1:0.8 to 1:1.2, a paste-like coating is obtained. The sound-insulating coating comprises the following raw materials in parts by weight: 20-30 parts waterborne polyurethane; 30-40 parts waterborne acrylic resin; 30-40 parts heavy calcium carbonate powder; and 20-40 parts rubber powder; wherein the solid content of the waterborne polyurethane is 45%-55%; and the solid content of the waterborne acrylic resin is 40%-50%. Step S2: Spread the construction slurry on a clean substrate to form a first mortar layer of 25mm-35mm thickness, and cure it until it is fully hardened; Step S3: Apply a 0.5mm-3mm thick paste coating to the surface of the first mortar layer and cure it to form a sound insulation coating; Step S4: Lay a second mortar layer 15mm-25mm thick on the sound insulation coating and cure it until it is fully hardened.

[0010] The technical solutions adopted in the embodiments of this application can achieve the following beneficial effects: (1) The phosphogypsum-based low-carbon thermal insulation and sound insulation mortar provided in this application forms a dense and crack-resistant overall structure through the compounding and functional synergy of cementitious materials, active admixtures, fillers and additives. Furthermore, while ensuring that the mechanical properties of the materials meet the standards, it can also take into account the adaptability of construction operations. Specifically: ① As a core cementitious material, phosphogypsum provides mortar with basic setting strength and excellent fire resistance. Meanwhile, fly ash, with its micro-aggregate effect and potential alkali-activated activity, allows its fine particles to fill the gaps in the phosphogypsum hydration products, optimizing the internal pore structure to improve density and promoting full hydration reaction, thus complementing the properties of phosphogypsum. This combination not only achieves the rational utilization of two types of industrial solid waste but also effectively improves the tendency of phosphogypsum to shrink and crack, thereby significantly enhancing the compressive and flexural strength of the mortar.

[0011] ② Quartz sand, as a rigid filler, can fill the voids between phosphogypsum, fly ash, and lightweight aggregates, compensating for the insufficient strength of vitrified microspheres and aerogel due to their porous and lightweight characteristics, thus enhancing the overall structural stability and wear resistance of the mortar. Furthermore, by controlling the dosage of vitrified microspheres and aerogel within a reasonable range, the advantages of lightweight materials are leveraged to reduce density while avoiding excessive addition that could damage the overall structural integrity. The synergy of these three elements achieves a balance between lightweight and high strength, ensuring that while the dry density of the mortar is reduced, the 28-day compressive strength still meets the requirements for use in construction projects.

[0012] ③ Water-reducing agents reduce the amount of mixing water through dispersion, thereby increasing the density of the mortar and indirectly enhancing its mechanical strength; the use of water-retaining agents locks in the moisture of the mortar, ensuring sufficient hydration reaction and improving material cohesion, preventing structural loosening due to rapid moisture loss during construction; the polymer film formed after hydration of polymer powder fills internal pores and strengthens the adhesion between components, significantly improving the mortar's crack resistance and substrate bonding strength; retarders can specifically adjust the setting time, extending the construction window and preventing structural defects caused by excessively rapid setting. The phosphogypsum-based low-carbon thermal and sound insulation mortar provided in this application has self-leveling construction characteristics and good self-flowing properties. It can be directly poured and spread during construction without complex vibration procedures, making it convenient and efficient to operate and significantly shortening the construction cycle. The synergistic effect of various admixtures and main materials ultimately forms a fully hydrated, dense, firmly bonded, and crack-resistant overall structure, ensuring the long-term stability of the mortar.

[0013] (2) The phosphogypsum-based low-carbon thermal insulation and sound insulation mortar provided in this application also has excellent sound insulation performance, specifically: ① Vitrified microspheres are spherical closed porous structures. Their internal closed pores can effectively block the transmission of sound waves, while the energy of low and medium frequency sound waves is consumed by the vibration and friction of the pore walls. Aerogel particles, as nanoscale porous materials, have extremely high porosity and specific surface area, and can accurately capture high frequency sound waves. The combination of the two forms a full-band sound insulation system that blocks low and medium frequencies and absorbs high frequencies. ② The cementitious system composed of phosphogypsum and fly ash, with the synergistic effect of admixtures such as water-reducing agents and water-retaining agents, can form a dense base layer, which can shorten the sound wave penetration path and strengthen the sound insulation foundation. Vitrified microspheres and aerogel are dispersed in the dense base layer, forming a uniform porous area. Sound waves are repeatedly reflected and refracted in the alternating structure of the dense layer and the porous area, and the energy is gradually consumed, which can further improve the sound insulation effect. At the same time, the rigid filling of quartz sand optimizes the uniformity of pore distribution, avoids the sound insulation weakness caused by excessively large local pores, and can ensure the stability of the overall sound insulation performance of the mortar. ③ Phosphogypsum itself has excellent fire resistance, and aerogel is a non-combustible material. The two work together to make the mortar reach the Class A non-combustible standard, which solves the problem of poor fire resistance of traditional organic sound insulation materials. Moreover, the chemical stability of inorganic components ensures that the sound insulation performance is not affected by environmental factors in the long term, avoiding the decay of sound insulation effect caused by the aging of organic materials. It can not only achieve long-term stable sound insulation performance, but also has the advantages of reliable fire safety, which can meet the long-term use needs of buildings. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 These are schematic diagrams of the construction structures of Examples 1-7, Comparative Examples 1, 2 and 4 of this application; Figure 2 This is a schematic diagram of the construction structure of Comparative Example 3 of this application.

[0016] In the diagram: 10, first mortar layer; 20, sound insulation coating; 30, second mortar layer; 40, floor slab. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] In one aspect, this application provides a phosphogypsum-based low-carbon thermal insulation and soundproofing mortar, which, by weight, comprises the following raw materials: 50-60 parts of phosphogypsum, 20-30 parts of filler, 10-15 parts of inorganic admixture, 10-15 parts of vitrified microspheres, 5-10 parts of aerogel, 0.1-0.5 parts of water-retaining agent, 1-4 parts of polymer powder, 0.02-0.05 parts of retarder, and 0.2-0.5 parts of water-reducing agent.

[0019] In some embodiments, the weight parts of each raw material are as follows: 52-58 parts phosphogypsum, 22-28 parts filler, 12-14 parts inorganic admixture, 12-14 parts vitrified microspheres, 6-9 parts aerogel, 0.2-0.4 parts water-retaining agent, 2-3 parts polymer powder, 0.03-0.04 parts retarder, and 0.3-0.4 parts water-reducing agent.

[0020] In some embodiments, the phosphogypsum has a purity of ≥90% and a specific surface area of ​​600-800 m². 2 / kg; The inorganic admixture is fly ash, with a loss on ignition ≤5%; The filler is quartz sand with a particle size range of 60-80 mesh. The vitrified microspheres are 50-90 mesh closed-cell vitrified microspheres; The aerogel is composed of silica aerogel particles with a porosity ≥90% and a particle size range of 50-100 mesh. In terms of overall structure and strength: the high purity of phosphogypsum reduces the interference of impurities on the hydration reaction, while its suitable specific surface area ensures full hydration activity; synergistically with Grade I fly ash with a loss on ignition ≤5%, it further enhances the reaction efficiency and structural density of the cementitious system, contributing to increased strength. The quartz sand, with a particle size of 60-80 mesh, matches the overall particle size distribution of the mortar, allowing for more uniform filling of the gaps between components. Combined with the porous structure of vitrified microspheres, it enhances interparticle embedding without significantly increasing density, compensating for the insufficient strength of lightweight aggregates. In terms of sound insulation: Firstly, vitrified microspheres (50-90 mesh) have a spherical, closed-loop porous structure. Their internal closed pores effectively block sound wave transmission, while simultaneously dissipating mid-to-low frequency sound wave energy through vibration and friction of the pore walls. Combined with silica aerogel particles (50-100 mesh) with a porosity ≥90%, these nano-sized porous materials possess extremely high porosity and specific surface area, enabling precise capture of high-frequency sound waves. Furthermore, their internal nano-sized closed-pore structure forms a dual closed-pore sound insulation system with the spherical closed pores of the vitrified microspheres: on one hand, the closed-pore structure effectively blocks the straight-line transmission path of sound waves, causing multiple reflections and refractions at the pore interface; on the other hand, the vibration and friction of the closed-pore walls dissipates mid-to-high frequency sound wave energy, complementing the dissipation effect of the vitrified microspheres on mid-to-low frequency sound waves. The synergistic effect of these two closed-pore materials broadens the effective frequency band for sound wave absorption, enhancing the full-frequency sound insulation effect of the mortar. Furthermore, the particle size gradient matching between quartz sand (60-80 mesh) and silica aerogel particles (50-100 mesh) ensures a more uniform distribution of pores within the mortar, preventing weak points in sound insulation caused by excessively large or small pores and guaranteeing the stability of sound insulation performance. Simultaneously, the dense base layer formed by high-purity phosphogypsum and low-loss-on-ignition fly ash, in synergy with porous aggregates, can construct a dense, porous alternating structure, extending the sound wave propagation path and improving sound insulation efficiency. Finally, the high porosity of silica aerogel and the non-combustible properties of phosphogypsum work together to enhance sound insulation performance while ensuring the material's fire safety, avoiding the performance degradation problems of traditional organic sound insulation materials, and guaranteeing long-term stable sound insulation effects.

[0021] In some embodiments, the water-retaining agent is hydroxypropyl ethyl cellulose or hydroxypropyl methyl cellulose; The polymer powder is a redispersible latex powder, made from vinyl acetate-ethylene copolymer; The retarder is a polypeptide retarder; The water-reducing agent is a naphthalene-based water-reducing agent or a polycarboxylate-based water-reducing agent.

[0022] Secondly, this application provides a method for preparing phosphogypsum-based low-carbon thermal insulation and soundproofing mortar, comprising the following steps: Step A1: Mix phosphogypsum, inorganic admixtures, vitrified microspheres, fillers, and aerogel evenly to obtain the first mixture; Step A2: Add polymer powder, retarder, water-reducing agent and water-retaining agent to the first mixture, mix evenly to obtain the second mixture; Step A3: Mix the second mixture with water at a mass ratio of 100:35 to 100:40 to obtain phosphogypsum-based low-carbon thermal insulation and soundproofing mortar. It is understandable that in step A1, phosphogypsum, inorganic admixtures (fly ash), vitrified microspheres, and fillers (quartz sand) are mixed first. These components have relatively small differences in particle size and density, and mixing them first helps form a uniform skeletal structure. In step A2, polymer powder, retarders, and other powder additives are added to minimize the risk of localized agglomeration caused by direct mixing of powder additives with large solid particles, ensuring that each powder additive is evenly dispersed in the skeletal structure and fully utilizing its regulatory properties. The second mixture is mixed with water at a mass ratio of 100:35 to 100:40. This ratio satisfies the water requirements for the phosphogypsum hydration reaction and, through the synergistic effect of water-reducing and water-retaining agents, avoids structural looseness due to excessive moisture or construction difficulties caused by insufficient moisture. This ratio ensures that the mortar has a dense structure after molding, while maintaining good spreadability, ensuring that the performance of each component is fully utilized during construction, and ultimately achieving the required comprehensive performance in terms of strength, thermal insulation, and sound insulation.

[0023] Thirdly, this application provides a phosphogypsum-based thermal insulation and sound insulation mortar system, including a first mortar layer 10 formed by the above-mentioned phosphogypsum-based low-carbon thermal insulation and sound insulation mortar and a sound insulation coating 20 composited on the surface of the first mortar layer 10. Wherein: the sound insulation coating 20 is formed by applying a sound insulation paint, which comprises the following raw materials in parts by weight: 20-30 parts waterborne polyurethane; 30-40 parts waterborne acrylic resin; 30-40 parts heavy calcium carbonate powder; 20-40 parts rubber powder; the solid content of the waterborne polyurethane is 45%-55%; the solid content of the waterborne acrylic resin is 40%-50%. It can be understood that this thermal insulation and sound insulation mortar system, through the composite structure design of the phosphogypsum-based low-carbon thermal insulation first mortar layer 10 and the sound insulation coating 20, achieves synergistic enhancement of thermal insulation and sound insulation performance, while also considering the environmental friendliness and stability of the materials. Specifically: (1) Regarding the sound insulation coating used in the sound insulation coating 20: First, waterborne polyurethane and waterborne acrylic resin together constitute the core film-forming base material of the sound insulation coating. The combination of the two provides basic damping performance for the sound insulation of the coating. Waterborne polyurethane has excellent elasticity and viscoelasticity. When sound waves act on the surface of the coating, its molecular chains will rub and deform, converting sound energy into heat energy and consuming it, which can effectively suppress structural resonance. Waterborne acrylic resin can improve the adhesion and weather resistance of the coating to the substrate, and at the same time help to enhance the damping effect. After being combined with waterborne polyurethane, it can broaden the frequency range of the damping effect. Second, heavy calcium carbonate powder, as a high-density inorganic filler, mainly relies on the mass law to enhance the sound insulation ability of the coating. The surface density of the coating is positively correlated with the sound insulation effect. The greater the surface density, the stronger the reflection and blocking effect of sound waves. Therefore, the addition of heavy calcium carbonate powder can significantly improve the blocking effect of the coating on mid-to-high frequency noise such as speech and environmental noise. Meanwhile, the heavy calcium carbonate powder particles filling the molecular gaps in the resin matrix increase the propagation path and scattering frequency of sound waves within the coating, causing sound energy to gradually attenuate during multiple reflections, further improving the overall sound insulation efficiency. Third, rubber powder, an elastic filler with both sound absorption and vibration damping functions, captures incident sound waves through its porous structure, causing them to be repeatedly reflected and lost within the pores. This mechanism is particularly effective at absorbing high-frequency noises such as sharp instrument sounds and whistles. Furthermore, the elastic properties of rubber powder synergistically enhance the damping and vibration reduction performance of the coating, strengthening the suppression of vibration-related noise. Simultaneously, the addition of rubber powder improves the coating's toughness, alleviating the problem of excessive coating rigidity caused by the high-density filling of heavy calcium carbonate powder, preventing coating cracking, and ensuring the durability of the sound insulation effect.

[0024] (2) The sound insulation coating 20 in this application complements the porous sound insulation of the first mortar layer 10, achieving efficient blocking of noise across the entire frequency band. Specifically: ① The rigidity of the first mortar layer 10 prevents the sound insulation coating 20 from cracking or peeling due to substrate deformation or external forces, providing a reliable carrier for the stable functioning of the coating; the flexibility of the sound insulation coating 20 can buffer structural vibrations caused by sound waves, compensating for the inherent defects of the mortar layer being brittle and lacking damping. In this application, the combination of rigid support (first mortar layer 10) and flexible vibration reduction (sound insulation coating 20) enables the composite system to possess both solid structural stability and flexible sound energy attenuation capability.

[0025] ② The first mortar layer 10 forms the foundation for the full-frequency sound insulation system, while the sound insulation coating suppresses the resonance of the first mortar layer 10 through damping and vibration reduction, and further attenuates mid-to-high frequency noise, ultimately achieving efficient noise blocking across the entire frequency band.

[0026] (3) The phosphogypsum-based thermal insulation and sound insulation mortar system in this application is mainly composed of industrial solid waste such as phosphogypsum, water-based polymers and inorganic fillers. It does not release volatile harmful substances. The resource utilization of phosphogypsum is in line with the concept of low-carbon development. Moreover, both phosphogypsum and coating substrate have good fire resistance. This allows the system to achieve excellent thermal insulation and sound insulation effects while meeting the requirements of building environmental protection and fire safety. It is suitable for the ground structure and enclosure structure of various civil buildings and industrial buildings.

[0027] In some embodiments, a second mortar layer 30 is also included on the surface of the sound insulation coating 20. The second mortar layer 30 is formed by applying self-leveling mortar, which can be any self-leveling mortar available in the prior art.

[0028] In some embodiments, the particle size of the heavy calcium carbonate powder ranges from 200 mesh to 300 mesh; The particle size range of the rubber powder is 60 mesh to 80 mesh; The thickness of the first mortar layer 10 is 25mm-35mm; The thickness of the sound insulation coating 20 is 0.5mm-3mm; The thickness of the second mortar layer 30 is 15mm-25mm; The weight parts of each raw material in the sound insulation coating are as follows: 22-28 parts of waterborne polyurethane; 32-38 parts of waterborne acrylic resin; 32-38 parts of heavy calcium carbonate powder; and 25-35 parts of rubber powder.

[0029] Fourthly, this application provides a construction process for a phosphogypsum-based thermal insulation and soundproofing mortar system, comprising the following steps: Step S1: Provide the construction slurry for the first mortar layer 10, the slurry coating for the sound insulation coating 20, and the self-leveling mortar for the second mortar layer 30: The phosphogypsum-based low-carbon thermal insulation and soundproofing mortar prepared above is used as the construction slurry; After mixing the sound-insulating coating with water at a mass ratio of 1:0.8 to 1:1.2, a paste-like coating is obtained. The sound-insulating coating comprises the following raw materials in parts by weight: 20-30 parts waterborne polyurethane; 30-40 parts waterborne acrylic resin; 30-40 parts heavy calcium carbonate powder; and 20-40 parts rubber powder; wherein the solid content of the waterborne polyurethane is 45%-55%; and the solid content of the waterborne acrylic resin is 40%-50%. Step S2: Spread the construction slurry on a clean substrate to form a first mortar layer 10 with a thickness of 25mm-35mm, and cure it until it is completely hardened; Step S3: Apply a 0.5mm-3mm thick paste coating to the surface of the first mortar layer 10 and cure it to form a sound insulation coating 20; Step S4: Lay a 15mm-25mm thick second mortar layer 30 on the sound insulation coating 20 and cure it until fully hardened. It can be understood that this construction process, through the three-layer composite structure design of the first mortar layer 10, the sound insulation coating 20, and the second mortar layer 30, not only ensures the full utilization of the system's overall performance but also takes into account construction feasibility and engineering stability. From a structural forming perspective, step S2 involves laying a 25mm-35mm thick first mortar layer 10 and curing it until fully hardened. This thickness design meets the basic requirements for building insulation and heat insulation, while also achieving initial noise blocking across the entire frequency band through its porous internal structure. Step S3 involves coating the hardened mortar layer with a 0.5mm-3mm thick paste-like coating. This thickness ensures the sound insulation coating 20 forms a dense film, fully utilizing the mid-to-high frequency sound insulation advantages of the water-based polyurethane and water-based acrylic resin composite system to suppress resonance and attenuate mid-to-high frequency noise. It also avoids cracking or peeling from the substrate due to excessive coating thickness. Step S4 involves laying a 15mm-25mm thick second mortar layer 30 to form a surface protection layer. This enhances the overall structural strength and flatness of the system and works in conjunction with the first mortar layer 10 and the sound insulation coating 20 to reduce sound wave diffraction, further improving the sound insulation effect and achieving efficient noise blocking across the entire frequency band. From a performance perspective, the laying of the second mortar layer 30 provides physical protection for the sound insulation coating 20, preventing it from being worn or damaged by the external environment. It also works with the first mortar layer 10 to enhance the thermal insulation and sound insulation effects. Through the thermal insulation and sound insulation effects of the double mortar layers and the auxiliary barrier of the intermediate coating, the heat transfer coefficient is further reduced and the sound insulation effect is improved. The entire construction process requires no special equipment, the procedures are simple and clear, and the material ratio is easy to control. It is suitable for industrialized batch construction and can ensure the consistency of project quality. At the same time, the construction slurry used for the first mortar layer 10 and the paste-like coating used for the sound insulation coating 20 in this application are both environmentally friendly and can reduce pollutant emissions during the construction stage, which meets the development requirements of low-carbon construction in buildings.

[0030] In some embodiments, during steps S2 and S4, when constructing the first mortar layer 10 and the second mortar layer 30, the following steps are performed sequentially: scraper-assisted leveling and defoaming roller to eliminate surface air bubbles. Scraper-assisted leveling ensures uniform thickness of the first mortar layer 10 and the second mortar layer 30, improves surface smoothness, and avoids uneven thickness affecting the consistency of thermal insulation and sound insulation. The defoaming roller effectively eliminates air bubbles on the mortar surface, reduces internal pore defects, and enhances interlayer adhesion and structural density. This ensures the stable performance of the mortar's thermal insulation and sound insulation properties, and also strengthens the overall structural strength of the system, reducing the risk of later cracking.

[0031] In some embodiments, in step S1, the weight parts of each raw material of the sound insulation coating are as follows: 22-28 parts of waterborne polyurethane; 32-38 parts of waterborne acrylic resin; 32-38 parts of heavy calcium carbonate powder; 25-35 parts of rubber powder; the particle size range of heavy calcium carbonate powder is 200-300 mesh; and the particle size range of rubber powder is 60-80 mesh.

[0032] In some implementations, the curing time in step S2 is 60-84 hours.

[0033] In some embodiments, in step S3, the coating of the paste is applied by scraping or spraying, and the curing time is 40-55 hours.

[0034] In some embodiments, in step S4, the second mortar layer 30 is formed by applying self-leveling mortar. The curing time is 48-72 hours.

[0035] The following detailed embodiments illustrate the sound-insulating mortar, its preparation method, its system, and its construction process provided in this application.

[0036] I. Raw Material Description: The raw materials used in the following examples and comparative examples all meet the following requirements: Phosphogypsum: purity ≥90%, specific surface area 600m² 2 / kg-800m 2 / kg; Quartz sand: particle size range of 60 mesh-80 mesh; Fly ash: Loss on ignition ≤5%; Vitrified microspheres: spherical closed porous structure with a particle size range of 50-90 mesh; Silica aerogel particles: porosity ≥90%, particle size range 50-100 mesh; Water-retaining agent: Hydroxypropyl ethyl cellulose or hydroxypropyl methyl cellulose with a viscosity of 300-1000 mPa·s.

[0037] Please see Figure 1 and Figure 2 : II. Example: Example 1: A construction process for a phosphogypsum-based thermal insulation and soundproofing mortar system includes the following steps: Step S1: Provide the construction slurry for the first mortar layer 10, the slurry coating for the sound insulation coating 20, and the self-leveling mortar for the second mortar layer 30: Construction slurry: Consists of a first powder and water, with a powder-to-water mass ratio of 100:37. The raw materials for the first powder include: 55 kg of phosphogypsum, 25 kg of quartz sand, 12.5 kg of fly ash, 12.5 kg of vitrified microspheres, 7.5 kg of silica aerogel particles, 0.3 kg of hydroxypropyl methylcellulose, 2.5 kg of vinyl acetate-ethylene copolymer, 0.03 kg of polypeptide retarder, and 0.3 kg of polycarboxylate superplasticizer. The preparation steps are as follows: Step A1: Add phosphogypsum, fly ash, vitrified microspheres, quartz sand, and silica aerogel particles into a mixer and stir at a stirring rate of 500 r / min for 8 minutes. After mixing evenly, the first mixture is obtained. Step A2: Add hydroxypropyl methylcellulose, polypeptide retarder, polycarboxylate superplasticizer and hydroxypropyl methylcellulose to the first mixture, and continue to stir at a stirring rate of 500 r / min for 12 minutes. After mixing evenly, the second mixture is obtained. Step A3: Add water to the second mixture. The mass ratio of the second mixture to water is 100:37. Stir at a stirring speed of 800 r / min for 5 minutes, let stand for 3 minutes, and then stir at a stirring speed of 500 r / min for 4 minutes. After mixing evenly, the construction slurry (i.e., phosphogypsum-based low-carbon thermal insulation and sound insulation mortar) is obtained.

[0038] Paste-like coating: It consists of sound-insulating coating and water, with a mass ratio of sound-insulating coating to water of 1:1; the raw materials of the sound-insulating coating include: 25 kg of water-based polyurethane (solid content of 50%), 35 kg of water-based acrylic resin (solid content of 45%), 35 kg of heavy calcium carbonate powder, and 30 kg of rubber powder; mix all the raw materials used in the sound-insulating coating evenly, and then add water and mix evenly.

[0039] Self-leveling mortar: Henan Jieyuan New Building Materials Co., Ltd., G25, gypsum-based self-leveling mortar.

[0040] Step S2: Spread the construction slurry on the clean base surface of the floor slab 40 (the thickness of the floor slab 40 is 100mm), use a scraper to assist in leveling and a defoaming roller to eliminate surface air bubbles, forming a 30mm thick first mortar layer 10, and cure it until it is completely hardened. The curing time is 72 hours. Step S3: Spray a 1mm thick paste coating onto the surface of the first mortar layer 10 and cure it to form a sound insulation coating 20. The curing time is 48 hours. Step S4: Lay a second mortar layer 30 on the sound insulation coating 20. Spread the self-leveling mortar on the sound insulation coating 20, use a scraper to assist leveling and a defoaming roller to eliminate surface air bubbles, forming a 20mm thick second mortar layer 30. Cure until fully hardened, the curing time is 60 hours; thus forming a phosphogypsum-based thermal insulation and sound insulation mortar system.

[0041] Example 2: A construction process for a phosphogypsum-based thermal insulation and soundproofing mortar system includes the following steps: Step S1: Provide the construction slurry for the first mortar layer 10, the slurry coating for the sound insulation coating 20, and the self-leveling mortar for the second mortar layer 30: Construction slurry: Consists of a first powder and water, with a mass ratio of first powder to water of 100:37. The raw materials for the first powder include: 50 kg of phosphogypsum, 20 kg of quartz sand, 15 kg of fly ash, 10 kg of vitrified microspheres, 10 kg of silica aerogel particles, 0.1 kg of hydroxypropyl methylcellulose, 1 kg of vinyl acetate-ethylene copolymer, 0.02 kg of polypeptide retarder, and 0.2 kg of polycarboxylate superplasticizer. The preparation steps are as follows: Step A1: Add phosphogypsum, fly ash, vitrified microspheres, quartz sand, and silica aerogel particles into a mixer and stir at a stirring rate of 600 r / min for 5 minutes. After mixing evenly, the first mixture is obtained. Step A2: Add hydroxypropyl methylcellulose, polypeptide retarder, polycarboxylate superplasticizer and hydroxypropyl methylcellulose to the first mixture, and continue to stir at a stirring rate of 600 r / min for 15 minutes. After mixing evenly, the second mixture is obtained. Step A3: Add water to the second mixture. The mass ratio of the second mixture to water is 100:37. Stir at a stirring speed of 700 r / min for 10 minutes, let stand for 3 minutes, and then stir at a stirring speed of 600 r / min for 3 minutes. After mixing evenly, the construction slurry (i.e., phosphogypsum-based low-carbon thermal insulation and sound insulation mortar) is obtained.

[0042] Paste-like coating: It consists of sound-insulating coating and water, with a mass ratio of sound-insulating coating to water of 1:1; The raw materials of the sound-insulating coating include: 20 kg of waterborne polyurethane (solid content of 50%), 40 kg of waterborne acrylic resin (solid content of 45%), 40 kg of heavy calcium carbonate powder, and 20 kg of rubber powder; Mix all the raw materials used in the sound-insulating coating evenly, and then add water and mix evenly.

[0043] Self-leveling mortar: Gongda Building Materials Co., Ltd., G20, gypsum-based self-leveling mortar.

[0044] Step S2: Spread the construction slurry on the clean base surface of the floor slab 40 (the thickness of the floor slab 40 is 100mm), use a scraper to assist in leveling and a defoaming roller to eliminate surface air bubbles, forming a 25mm thick first mortar layer 10, and cure it until it is completely hardened. The curing time is 72 hours. Step S3: Spray a 2mm thick paste coating onto the surface of the first mortar layer 10 and cure it to form a sound insulation coating 20. The curing time is 48 hours. Step S4: Lay a second mortar layer 30 on the sound insulation coating 20. Spread the self-leveling mortar on the sound insulation coating 20, use a scraper to assist leveling and a defoaming roller to eliminate surface air bubbles, forming a 25mm thick second mortar layer 30. Cure until fully hardened, the curing time is 72 hours; thus forming a phosphogypsum-based thermal insulation and sound insulation mortar system.

[0045] Example 3: A construction process for a phosphogypsum-based thermal insulation and soundproofing mortar system includes the following steps: Step S1: Provide the construction slurry for the first mortar layer 10, the slurry coating for the sound insulation coating 20, and the self-leveling mortar for the second mortar layer 30: Construction slurry: Consists of a first powder and water, with a powder-to-water mass ratio of 100:37. The raw materials for the first powder include: 60 kg of phosphogypsum, 30 kg of quartz sand, 10 kg of fly ash, 15 kg of vitrified microspheres, 5 kg of silica aerogel particles, 0.5 kg of hydroxypropyl methylcellulose, 4 kg of vinyl acetate-ethylene copolymer, 0.05 kg of polypeptide retarder, and 0.5 kg of polycarboxylate superplasticizer. The preparation steps are as follows: Step A1: Add phosphogypsum, fly ash, vitrified microspheres, quartz sand, and silica aerogel particles into a mixer and stir at a stirring rate of 500 r / min for 10 minutes. After mixing evenly, the first mixture is obtained. Step A2: Add hydroxypropyl methylcellulose, polypeptide retarder, polycarboxylate superplasticizer and hydroxypropyl methylcellulose to the first mixture, and continue stirring at a stirring rate of 500 r / min for 10 minutes. After mixing evenly, the second mixture is obtained. Step A3: Add water to the second mixture. The mass ratio of the second mixture to water is 100:37. Stir at a stirring speed of 700 r / min for 5 minutes, let stand for 3 minutes, and then stir at a stirring speed of 500 r / min for 5 minutes. After mixing evenly, the construction slurry (i.e., phosphogypsum-based low-carbon thermal insulation and sound insulation mortar) is obtained.

[0046] Paste-like coating: It consists of sound-insulating coating and water, with a mass ratio of sound-insulating coating to water of 1:1; the raw materials of the sound-insulating coating include: 30 kg of water-based polyurethane (solid content of 50%), 30 kg of water-based acrylic resin (solid content of 45%), 30 kg of heavy calcium carbonate powder, and 40 kg of rubber powder; mix all the raw materials used in the sound-insulating coating evenly, and then add water and mix evenly.

[0047] Self-leveling mortar: Taishan Gypsum Co., Ltd., G25, gypsum-based self-leveling mortar.

[0048] Step S2: Spread the construction slurry on the clean base surface of the floor slab 40 (the thickness of the floor slab 40 is 100mm), use a scraper to assist in leveling and a defoaming roller to eliminate surface air bubbles, forming a 35mm thick first mortar layer 10, and cure it until it is completely hardened. The curing time is 84 hours. Step S3: Spray a 2mm thick paste coating onto the surface of the first mortar layer 10 and cure it to form a sound insulation coating 20 for 40 hours. Step S4: Lay a second mortar layer 30 on the sound insulation coating 20. Spread the self-leveling mortar on the sound insulation coating 20, use a scraper to assist leveling and a defoaming roller to eliminate surface air bubbles, forming a 20mm thick second mortar layer 30. Cure until fully hardened, the curing time is 72 hours; thus forming a phosphogypsum-based thermal insulation and sound insulation mortar system.

[0049] Example 4: The difference between this embodiment and Embodiment 1 is that: Construction slurry: The raw materials of the first powder material include: 52Kg phosphogypsum, 22Kg quartz sand, 14Kg fly ash, 12Kg vitrified microspheres, 8Kg silica aerogel particles, 0.4Kg hydroxypropyl methylcellulose, 2Kg vinyl acetate-ethylene copolymer, 0.04Kg polypeptide retarder, and 0.4Kg naphthalene-based water-reducing agent.

[0050] Paste-like coating: The raw materials for sound insulation coating include: 22 kg of waterborne polyurethane (50% solid content), 38 kg of waterborne acrylic resin (45% solid content), 38 kg of heavy calcium carbonate powder, and 22 kg of rubber powder.

[0051] Everything else is the same as in Example 1; a phosphogypsum-based thermal insulation and soundproofing mortar system is formed.

[0052] Example 5: The difference between this embodiment and Embodiment 1 is that: Construction slurry: The raw materials of the first powder material include: 58 kg of phosphogypsum, 28 kg of quartz sand, 12 kg of fly ash, 14 kg of vitrified microspheres, 6 kg of silica aerogel particles, 0.2 kg of hydroxypropyl ethyl cellulose, 3 kg of vinyl acetate-ethylene copolymer, 0.03 kg of polypeptide retarder, and 0.3 kg of polycarboxylate superplasticizer.

[0053] Paste-like coating: The raw materials for sound insulation coating include: 28 kg of waterborne polyurethane (50% solid content), 32 kg of waterborne acrylic resin (45% solid content), 32 kg of heavy calcium carbonate powder, and 28 kg of rubber powder.

[0054] Everything else is the same as in Example 1; a phosphogypsum-based thermal insulation and soundproofing mortar system is formed.

[0055] Example 6 The difference from Example 1 is: Construction grout: The mass ratio of the first powder to water is 100:36; Paste-like coating: The mass ratio of sound-insulating coating to water is 1:0.8; Everything else is the same as in Example 1; a phosphogypsum-based thermal insulation and soundproofing mortar system is formed.

[0056] Example 7 The difference from Example 1 is: Construction grout: The mass ratio of the first powder to water is 100:38; Paste-like coating: The mass ratio of sound-insulating coating to water is 1:1.2; Everything else is the same as in Example 1; a phosphogypsum-based thermal insulation and soundproofing mortar system is formed.

[0057] III. Comparative Examples: Comparative Example 1: The difference between this comparative example and Example 1 is that the weight of phosphogypsum in the construction slurry is 67.5 kg and the weight of fly ash is 0 kg. Everything else is the same as in Example 1; a phosphogypsum-based thermal insulation and soundproofing mortar system is formed.

[0058] Comparative Example 2: The difference between this comparative example and Example 1 is that vinyl acetate-ethylene copolymer is not added to the construction slurry; Everything else is the same as in Example 1; a phosphogypsum-based thermal insulation and soundproofing mortar system is formed.

[0059] Comparative Example 3: The difference between this comparative example and Example 1 is that step S3 is omitted, the sound insulation coating 20 is not applied, and the second mortar layer 30 is directly laid on the surface of the first mortar layer 10. Everything else is the same as in Example 1; a phosphogypsum-based thermal insulation and soundproofing mortar system is formed.

[0060] Comparative Example 4: The difference between this comparative example and Example 1 is that no rubber powder is added to the sound-insulating coating; Everything else is the same as in Example 1; a phosphogypsum-based thermal insulation and soundproofing mortar system is formed.

[0061] IV. Experimental Examples: 1. The performance of the construction slurry (phosphogypsum-based low-carbon thermal insulation and sound insulation mortar) in Examples 1-7 and Comparative Examples 1-4 was tested; ① Testing standards: Impact noise reduction: JC / T 2707-2022 "Sound Insulation Mortar" was adopted; Compressive strength: conforms to JC / T 2707-2022 "Sound Insulation Mortar"; Fire resistance rating: conforms to JC / T 2707-2022 "Sound Insulation Mortar"; Thermal conductivity: conforms to JC / T2706-2022 "Gypsum Insulation Mortar".

[0062] ②The test results are shown in Table 1 below.

[0063] Table 1. Performance Test Results of Phosphogypsum-Based Low-Carbon Thermal and Sound Insulation Mortar As shown in Table 1: (1) Improvement in impact sound (frequency range of 100Hz-5000Hz): The improvement in impact sound in Examples 1-7 is concentrated in the range of 9.1dB-9.3dB, with very small fluctuations, indicating that the phosphogypsum-based low-carbon thermal insulation and sound-absorbing mortar in this application has a stable effect on suppressing impact sound caused by structural vibration. The impact sound improvement in Comparative Example 1 was 8.2 dB, which was 1.0 dB lower than the average value of the Examples. This further confirms that the addition of fly ash can enhance the vibration reduction performance of the system, suggesting that its porous structure and particle morphology can effectively buffer the transmission of vibration energy. Comparative Example 2 showed an improvement of only 7.2 dB in impact sound, which is 1.9 dB lower than the average of the examples, indicating a significant reduction. The absence of the vinyl acetate-ethylene copolymer led to this significant decrease in performance, suggesting that the vinyl acetate-ethylene copolymer can improve the elasticity and damping characteristics of the phosphogypsum-based low-carbon thermal insulation and sound-absorbing mortar in this application, thereby enhancing its ability to absorb and attenuate impact vibrations.

[0064] (2) Compressive strength: The compressive strength of Examples 1-7 ranges from 5.0MPa to 5.6MPa, with an average of approximately 5.2MPa. The strength performance is balanced and meets the structural load-bearing requirements of the building base. Comparative Example 1 showed a compressive strength of 3.3 MPa, which was 1.9 MPa lower than the average value of the examples, indicating a significant decrease in strength. The absence of fly ash disrupted the skeletal integrity of the phosphogypsum-based system, leading to insufficient strength. This demonstrates that fly ash can be used as an active filler to improve the system's density and structural strength. Comparative Example 2 showed a compressive strength of 2.9 MPa, which was 2.3 MPa lower than the average value of the examples, indicating a more significant strength reduction. The absence of vinyl acetate-ethylene copolymer, a bonding and reinforcing component, led to a decrease in interparticle bonding strength within the mortar, resulting in poorer overall structural integrity and consequently affecting compressive strength.

[0065] In summary, the phosphogypsum-based low-carbon thermal insulation and sound insulation mortar in this application achieves a balanced optimization of sound insulation, thermal insulation, mechanical and fire resistance performance through the synergistic effect of phosphogypsum, fly ash and vinyl acetate-ethylene copolymer, with stable and excellent performance in all indicators.

[0066] 2. Performance tests were conducted on the phosphogypsum-based thermal insulation and sound insulation mortar systems formed in Examples 1-7 and Comparative Examples 1-4.

[0067] ① Testing standards: Impact noise reduction: JC / T2707-2022 "Sound Insulation Mortar" was adopted; Fire resistance rating: conforms to JC / T 2707-2022 "Sound Insulation Mortar".

[0068] ②The test results are shown in Table 2 below.

[0069] Table 2 Performance test results of phosphogypsum-based thermal insulation and soundproofing mortar system As shown in Table 2: Impact sound improvement: In Examples 1-7, the improvement in impact sound ranged from 12.1 dB to 12.6 dB, with minimal fluctuations. This demonstrates that the phosphogypsum-based thermal insulation and sound insulation mortar system in this application possesses stable sound insulation performance. It also indicates that the structure and raw materials of the phosphogypsum-based thermal insulation and sound insulation mortar system in this application can work synergistically to construct a mortar system with uniform pore structure and high sound energy loss efficiency. At the same time, the sound reflection barrier function of the sound insulation coating is fully demonstrated.

[0070] In Comparative Example 1 (fly ash removed, single phosphogypsum system), the improvement in impact sound was 11.2 dB, the highest value among the comparative examples, but still lower than the lowest value of 0.9 dB in the Example Group. This indicates that the combination of phosphogypsum and fly ash is a fundamental element in improving sound insulation performance, and the porous structure of fly ash can help attenuate sound energy. The pore structure optimization of the single phosphogypsum system is insufficient.

[0071] In Comparative Example 2 (without vinyl acetate-ethylene copolymer), the improvement in impact sound was 10.3, a decrease of 2.0 compared to Example 1. This demonstrates that the copolymer is a key additive for optimizing the internal structure of the mortar; its absence leads to decreased component adhesion, uneven pore distribution, increased sound energy penetration channels, and a significant reduction in sound insulation performance.

[0072] In Comparative Example 3 (with the sound insulation coating omitted), the improvement in impact sound was 9.3 dB, the lowest among all test groups, a decrease of 3.0 dB compared to Example 1. This data directly demonstrates that the sound insulation coating is the core guarantee of the sound insulation performance of the phosphogypsum-based thermal insulation and sound insulation mortar system in this application. Without the sound insulation coating, sound energy can directly penetrate the multi-layer mortar structure, failing to form an effective reflection barrier, resulting in the worst sound insulation effect.

[0073] In Comparative Example 4 (where rubber powder was removed from the sound-insulating coating), the improvement in impact sound was 10.3 dB, the same as in Comparative Example 2, but 2.0 dB lower than in Example 1. This indicates that the elastomeric properties of rubber powder can effectively absorb vibrational sound energy and optimize the vibration reduction effect of the sound-insulating coating; its absence will lead to a decrease in the sound insulation capability of the coating.

[0074] In summary, the components of the complete technical solution adopted in Examples 1-7 of this application exhibit significant synergistic effects. The compounding of phosphogypsum and fly ash constructs a uniform and porous basic structure for the mortar system, providing the necessary physical space for sound energy attenuation; the incorporation of vinyl acetate-ethylene copolymer strengthens the adhesion between the components, further optimizes the uniformity of pore distribution, and reduces the effective channels for sound energy penetration; the application of the sound insulation coating can directly form an efficient sound reflection barrier on the mortar surface, blocking the direct propagation of sound energy; the addition of rubber powder enhances the vibration reduction and sound absorption capacity of the sound insulation coating, achieving the dual effects of reflecting and absorbing impact sound, etc. The structure and the mutual cooperation and complementarity among the various raw materials not only ensure the efficient loss of internal sound energy in the phosphogypsum-based thermal insulation and soundproofing mortar system of this application, but also effectively block external sound energy. Ultimately, the impact sound improvement of Examples 1 to 7 of this application is maintained at a stable high level with minimal data fluctuation. Its comprehensive sound insulation effect is significantly better than that of the comparative examples that lack any single element, fully demonstrating the technical advantage of 1+1+1+1>4 under the synergistic effect of multiple elements.

[0075] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A phosphogypsum-based low-carbon thermal and acoustic insulation mortar, characterized in that, The weight parts of each raw material are as follows: phosphogypsum 52-58 parts, filler 22-28 parts, inorganic admixture 12-14 parts, vitrified microsphere 12-14 parts, aerogel 6-8 parts, water retaining agent 0.2-0.4 parts, polymer glue powder 2-3 parts, retarder 0.03-0.04 parts, and water reducing agent 0.3-0.4 parts.

2. The phosphogypsum-based low-carbon thermal and acoustic insulation mortar according to claim 1, characterized in that, The weight parts of each raw material are as follows: phosphogypsum 52-58 parts, filler 22-28 parts, inorganic admixture 12-14 parts, vitrified microsphere 12-14 parts, aerogel 6-8 parts, water retaining agent 0.2-0.4 parts, polymer glue powder 2-3 parts, retarder 0.03-0.04 parts, and water reducing agent 0.3-0.4 parts.

3. The phosphogypsum-based low-carbon thermal and acoustic insulation mortar according to claim 1, characterized in that, The purity of the phosphogypsum is ≥ 90%, the specific surface area is 600 m 2 / kg-800 m 2 / kg; And / or, the filler is quartz sand, with a particle size range of 60-80 mesh; And / or, the inorganic admixture is fly ash, with a loss on ignition ≤5%; And / or, the vitrified microsphere is 50-90 mesh; And / or, the aerogel is silica aerogel particles, with a porosity ≥90% and a particle size range of 50-100 mesh; And / or, the water retaining agent is hydroxypropyl ethyl cellulose or hydroxypropyl methyl cellulose; And / or, the polymer glue powder is a redispersible latex powder, using a vinyl acetate-ethylene copolymer; And / or, the retarder is a polypeptide type retarder; And / or, the water reducing agent is a naphthalene type water reducing agent or a polycarboxylic acid type water reducing agent.

4. The method for preparing the phosphogypsum-based low-carbon thermal and sound insulation mortar according to any one of claims 1-3, characterized in that, The steps include: Step A1: uniformly mixing phosphogypsum, inorganic admixture, vitrified microsphere, filler, and aerogel to obtain a first mixture; Step A2: adding polymer glue powder, retarder, water reducing agent, and water retaining agent to the first mixture, uniformly mixing, and obtaining a second mixture; Step A3: uniformly mixing the second mixture with water at a mass ratio of 100:35 to 100:40 to obtain a phosphogypsum-based low-carbon thermal and sound insulation mortar.

5. A phosphogypsum-based thermal and acoustic insulation mortar system, characterized in that, The first mortar layer is formed by constructing the phosphogypsum-based low-carbon thermal and sound insulation mortar according to claim 4, and a sound insulation coating layer is compounded on the surface of the first mortar layer. The sound insulation coating layer is formed by coating a sound insulation coating material, and the sound insulation coating material includes the following raw materials by weight: 20-30 parts of water-based polyurethane; 30-40 parts of water-based acrylic resin; 30-40 parts of heavy calcium powder; and 20-40 parts of rubber powder.

6. The phosphogypsum-based thermal and acoustic insulation mortar system according to claim 5, characterized in that, The second mortar layer is compounded on the surface of the sound insulation coating layer and is formed by constructing a self-leveling mortar.

7. The phosphogypsum-based thermal and acoustic insulation mortar system according to claim 6, characterized in that, The particle size range of the heavy calcium powder is 200-300 mesh; And / or, the particle size range of the rubber powder is 60-80 mesh; And / or, the thickness of the first mortar layer is 25-35 mm; And / or, the thickness of the sound insulation coating layer is 0.5-3 mm; And / or, the thickness of the second mortar layer is 15-25 mm; And / or, the weight parts of each raw material of the sound insulation coating are as follows: 22-28 parts of water-based polyurethane; 32-38 parts of water-based acrylic resin; 32-38 parts of heavy calcium powder; and 25-35 parts of rubber powder.

8. A construction process of a phosphogypsum-based thermal and acoustic insulation mortar system, characterized in that, The method comprises the following steps: Step S1: providing a construction slurry for a first mortar layer, a slurry-like sound insulation coating, and a self-leveling mortar for a second mortar layer; The phosphogypsum-based low-carbon thermal and sound insulation mortar prepared in claim 4 is used as the construction slurry; The sound insulation coating is uniformly mixed with water at a mass ratio of 1:0.8 to 1:1.2 to obtain the slurry-like coating; The sound insulation coating comprises the following raw materials in the following weight parts: 20-30 parts of water-based polyurethane; 30-40 parts of water-based acrylic resin; 30-40 parts of heavy calcium powder; and 20-40 parts of rubber powder; the solid content of the water-based polyurethane is 45%-55%; and the solid content of the water-based acrylic resin is 40%-50%; Step S2: spreading the construction slurry on a clean base surface to form a first mortar layer with a thickness of 25-35 mm, and curing until complete hardening; Step S3: coating the slurry-like coating with a thickness of 0.5-3 mm on the surface of the first mortar layer, and curing to form a sound insulation coating; Step S4: laying a second mortar layer with a thickness of 15-25 mm on the sound insulation coating, and curing until complete hardening.

9. The process for construction of phosphogypsum based thermal and acoustic insulation mortar system as claimed in claim 8, wherein, In steps S2 and S4, during the construction of the first mortar layer and the second mortar layer, the following steps are sequentially performed: blade-assisted leveling and defoaming roller to eliminate surface bubbles.

10. The process for construction of phosphogypsum based thermal and acoustic insulation mortar system as claimed in claim 8, wherein, In step S1, the weight parts of each raw material of the sound insulation coating are as follows: 22-28 parts of water-based polyurethane; 32-38 parts of water-based acrylic resin; 32-38 parts of heavy calcium powder; and 25-35 parts of rubber powder; the particle size range of the heavy calcium powder is 200-300 meshes; and the particle size range of the rubber powder is 60-80 meshes. And / or, in step S2, the curing time is 60-84 hours. And / or, in step S3, the coating of the slurry-like coating is performed by using a blade coating or spraying process, and the curing time is 40-55 hours. And / or, in step S4, the curing time of the second mortar layer is 48-72 hours.

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