Bi-component magnesium phosphate cement spraying foaming material and preparation method thereof

Abstract

The invention relates to a bi-component magnesium phosphate cement spraying foaming material and a preparation method thereof, the bi-component magnesium phosphate cement spraying foaming material comprises a component A and a component B in a dry powder mass ratio of 100: (70-80), the component A comprises dead burned magnesium oxide, slag, a water reducing agent, a thickening agent, a foam stabilizer and a carbonate foaming agent; and the component B comprises phosphate, fly ash and a retarder. During use, the component A slurry and the component B slurry are atomized and sprayed out through a double-head spray gun and are mixed outside a nozzle, a chemical reaction is immediately carried out, foaming expansion and condensation hardening are completed, and a lightweight porous structure is formed. Compared with the prior art, the problems that a single-component foaming material is out of control in foaming, hardened in advance, difficult to spray and the like are effectively solved, and rapid spraying forming of the inorganic thermal insulation material is achieved. The prepared material is adjustable in dry density and uniform in pore size distribution, has the characteristics of high strength, low heat conductivity, small shrinkage rate, high durability and the like, meets the A-level non-combustible standard, and can be widely applied to building wall and roof thermal insulation engineering.

Description

Technical Field

[0001] The present invention relates to the field of building materials, and in particular to a spray foaming material based on two-component magnesium phosphate cement and a preparation method thereof. More specifically, the present invention relates to a high-performance magnesium phosphate cement spray foaming material suitable for spray construction applications, capable of foaming and expanding and rapidly coagulating and hardening in a short period of time. Background Art

[0002] Foamed concrete materials play an important role in improving the thermal insulation performance of building envelope structures and reducing the energy consumption of building heating and air-conditioning systems. However, the existing foamed concrete materials in wall areas mainly rely on prefabrication and masonry, which requires a large amount of labor, a long construction period, and low efficiency during construction. As my country enters a deeply aging society, the problem of labor shortage in the construction industry is becoming increasingly prominent, and there is an urgent need to develop efficient construction technologies to alleviate labor pressure. Spray foaming, as a more efficient construction method, can increase construction speed by 3 to 5 times. If spray foaming of cement materials can be achieved, it is expected to completely change the construction mode of traditional insulation materials, significantly improve construction efficiency and thermal insulation performance, and is of great significance to building energy conservation and innovation in construction methods.

[0003] Existing cement foam materials still face many bottlenecks in spraying applications: the premixed physical foaming method will cause a large amount of defoaming during the spraying process, and the chemical foaming method materials must complete foaming and expansion in a very short time and quickly condense on the vertical substrate surface, otherwise it is easy to cause slurry to fall off, but the rapid foaming and condensation itself will cause the material to expand and harden prematurely in the storage tank.

[0004] Based on the technical experience of polyurethane spray foam, it can be seen that spray-type foaming materials need to divide the raw materials into two components, A and B, during the preparation stage, and add a chemical foaming agent to one of the components; during the spraying stage, the two components are atomized and sprayed out by a spray gun and mixed in the air, and then adhere to the surface of the substrate; during the molding stage, the foaming agent reacts with the other component to instantly release gas, causing the slurry to expand and eventually solidify and harden.

[0005] Magnesium phosphate cement is a fast-hardening inorganic cementitious material. It uses dead-burned magnesium oxide and acid phosphate as its main raw materials. After acid-base neutralization reaction, it quickly forms struvite and other products. It has the following spray foaming advantages: (1) The initial system is acidic and can react violently with carbonate foaming agents such as NaHCO3. Foaming can be completed within two minutes, which is much shorter than the 10-30 minutes foaming time of traditional foaming agents such as hydrogen peroxide and aluminum powder. (2) Magnesium oxide and phosphate can be separated into two components, A and B. The carbonate foaming agent can be stably present in component A and does not react with acid phosphate in an early stage. (3) MPC has the characteristics of ultra-fast solidification and hardening within a few minutes, which can prevent the slurry from falling off and bubbles from becoming unstable and collapsing due to long-term suspension after spraying; (4) The material itself is light and high-strength, with high specific strength. Its bonding strength with the base material is 1.5 to 2.5 times higher than that of silicate cement.

[0006] At present, some inventions in related fields in China have attempted to apply magnesium phosphate cement to two-component systems, but two-component foaming has not yet been achieved. For example, patent CN111592328A proposes a two-liquid magnesium phosphate material, and patent CN112174634A discloses a magnesium phosphate cement-based two-liquid grouting material. Although these inventions adopt the A and B component packaging strategy, the application direction does not involve the spraying process, nor does it introduce the foaming reaction. In addition, patent CN107344841B attempts to apply magnesium phosphate cement to the spray foaming scene, and discloses a sprayable ultra-light foam concrete system using a ratio of sodium bicarbonate, ammonium dihydrogen phosphate, magnesium oxide, and fly ash. However, the system adopts a single-component one-time mixing slurry method, which cannot avoid the carbonate foaming agent starting to react after stirring, resulting in foaming in the storage tank in advance, which can easily cause the spray gun to be blocked or the system to fail.

[0007] In summary, the existing technology has not yet realized the process of two-liquid packaging-external mixing spraying-on-site chemical foaming-rapid hardening based on magnesium phosphate cement. Summary of the Invention

[0008] The purpose of the present invention is to provide a two-component magnesium phosphate cement spray foaming material and a preparation method thereof, which are adapted to the spray foaming construction scene, have efficient and controlled reaction, rapid strength development, and strong construction adaptability, aiming to promote the transformation of inorganic thermal insulation materials to intelligent, rapid, and mechanized construction, and serve the dual goals of building energy conservation and engineering efficiency.

[0009] The object of the present invention can be achieved by the following technical solution: a two-component magnesium phosphate cement spray foam material and a preparation method thereof, wherein the two-component magnesium phosphate cement spray foam material comprises component A and component B with a dry powder mass ratio of 100: (70-80). The specific technical solution is as follows: (1) Composition of component A (alkaline component) The dry powder raw materials of component A include the following components (parts by mass): Dead-burned magnesia (MgO): 59-99 parts (can be replaced by slag at a ratio of 0%-40%); the particle size of the dead-burned magnesia is less than 200 μm; The slag is granulated blast furnace slag powder with a particle size of less than 200 μm; the slag content is 0-40 parts; Water reducer: at least one selected from polycarboxylate water reducer, naphthalene water reducer, lignin sulfonate water reducer, preferably polycarboxylate water reducer, with a dosage of 0.05-0.3 parts; Thickener: selected from hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose (HEC) or a mixture thereof, with a dosage of 0.05 to 0.15 parts; Foam stabilizer: calcium stearate or sodium lauryl sulfate, dosage is 0.25-1.0 parts; Carbonate foaming agent: one or more selected from sodium bicarbonate, ammonium bicarbonate or calcium bicarbonate, with a dosage of 0.1 to 2.0 parts; After mixing the dry powder raw materials of component A, water is added, and the amount of water added is controlled so that the water-to-solid ratio of component A is controlled at 0.25-0.35:1.

[0010] Among them, MgO reacts rapidly with the phosphate ions in component B to form struvite, achieving rapid hardening; partial replacement of slag helps shorten the setting time and enhance early strength; water reducers can significantly reduce the viscosity of the slurry and improve pumping and spraying performance; thickeners such as HPMC can effectively inhibit water exudation; carbonate foaming agents react rapidly with the acidic component B to release CO2, which is the key to achieving rapid foaming in this system; foam stabilizers such as calcium stearate can stabilize the foam structure and refine the pore size during the slurry expansion process.

[0011] (2) Composition of component B (acidic component) Component B consists of the following dry powder raw materials (parts by weight): Phosphate: ammonium dihydrogen phosphate (NH4H2PO4) or potassium dihydrogen phosphate (KH2PO4) powder, preferably with a particle size of less than 200 μm, and a dosage of 49 to 89 parts; Fly ash: low calcium fly ash, meeting the technical requirements of Class II or Class III, with a dosage of 10 to 50 parts; Retarder: at least one selected from borax, boric acid, and citric acid, preferably borax, with a dosage of 1 to 5 parts; After mixing the dry powder raw materials of component B, water is added, and the amount of water added is controlled to make the water-to-solid ratio of component B controlled at 0.25-0.35:1.

[0012] Among them, the phosphate in component B acts as an acid source, reacting with the carbonate foaming agent in component A to release CO2 gas, while providing phosphate radicals for MgO to participate in the hardening reaction; fly ash, as an inorganic filler, not only improves fluidity through the ball effect, but also acts as a crystal nucleus to promote the dense structure of the hydration product; retarders such as borax can react with the Ca in fly ash to form a solid solution. 2+ Form a complex to enhance the stability of component B.

[0013] (3) Two-component spraying construction Preparation stage: After weighing the raw materials of component A and component B according to the above proportions, add the corresponding water and stir for 1 to 3 minutes until the slurry is uniform and fine; after mixing the obtained slurry A and slurry B, the overall mass ratio of M (magnesium oxide + slag + fly ash) to phosphate (M / P) is 1.5 to 4:1, and the overall water-solid ratio is 0.25 to 0.35:1.

[0014] During the spraying phase, slurries A and B are delivered at a constant flow rate by two peristaltic pumps to an external-mix double-head spray gun. Compressed air (at a pressure of 0.5-0.8 MPa) atomizes and mixes the slurries at the nozzle, forming droplets ≤200 μm in size. These droplets are then sprayed onto the substrate surface, where they react through stacking contact. The carbonates in group A react with the phosphates in group B, releasing CO2 that propels the slurries to expand by 50%-400% within 2 minutes. MgO reacts with phosphates to form struvite, which solidifies within 3-10 minutes, ensuring a vertical spray without shedding.

[0015] During construction, spray the paint layer by layer, in 20-40 mm thicknesses. Once the initial set of the first layer is stable, apply subsequent layers until the desired total thickness is reached. To ensure spray quality, control the spray gun distance (20-40 cm, with a 12-degree angle between the two nozzles), the angle (preferably 90 degrees, perpendicular to the surface being sprayed), and the wind speed (≤ 2 m / s) to prevent droplet drift.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention prepares the main components of magnesium phosphate cement—dead-burned magnesium oxide and slag—along with phosphates—into fine-particle slurries, forming Component A and Component B. A carbonate foaming agent is stably incorporated into Component A. By introducing a water reducer and thickener into Component A and a retarder into Component B, the system can maintain its fluidity, hydration, and stability for over one hour at room temperature and pressure, ensuring stability during on-site storage and construction.

[0017] 2. Through a two-component external mixing spraying method, components A and B undergo an immediate chemical reaction upon atomization and mixing, achieving complete foaming and expansion within 2 minutes and initial setting and hardening within 5-10 minutes, forming a stable cell structure. This rapid reaction significantly reduces problems such as sagging, running, and collapsing of the spray coating on vertical substrates. It is suitable for rapid spraying on a variety of complex surfaces, such as walls and ceilings, breaking through the limitations of traditional foam concrete, which can only be prefabricated in factories or poured on-site.

[0018] 3. The construction efficiency of the spray foaming method of the present invention is 3 to 5 times higher than that of the traditional paving or masonry method, which can reduce labor input and construction period, and solve the problems of labor shortage and rising labor costs in current construction.

[0019] 4. The spray foaming of inorganic materials eliminates the flammability and aging defects of traditional organic insulation materials. The resulting material features uniform pore size distribution, adjustable dry density, high mechanical strength, low thermal conductivity, minimal shrinkage, and excellent durability. It contains no organic combustible components, meets Class A non-combustibility standards, and has a lifespan comparable to the building.

[0020] 5. The design of components A and B in this invention allows for wide adjustment of the ratios: the dead-burned magnesia and slag in component A can be flexibly mixed, and the ratios of phosphate and fly ash in component B can also be adjusted. Adjusting the slag content in component A or the retarder content in component B can control the setting time. Adjusting the foaming agent content allows for fine-tuning of performance indicators such as expansion ratio, dry density, compressive strength, and thermal conductivity, meeting the insulation performance requirements of different engineering scenarios. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0022] It should be noted that, without departing from the scope of the present invention, those skilled in the art may make appropriate adjustments or improvements to the ratio of the components, the type of additives, and the manner of use, and such changes and improvements shall be deemed to be within the scope of protection of the present invention. The following examples illustrate that the present invention provides a feasible technical solution for practical engineering. Example 1

[0023] Formula of component A: 0 kg of slag, 0.2 kg of polycarboxylate water reducer, 0.1 kg of HPMC (thickener), 0.5 kg of calcium stearate (foam stabilizer), 0.2 kg of sodium bicarbonate (foaming agent), 99 kg of dead-burned magnesium oxide;

[0024] Formula of component B: 21.7 kg fly ash, 0.72 kg borax, 49.9 kg diammonium phosphate; water-solid ratio w / s=0.26.

[0025] Preparation process: First, stir the powders of each component in Component A until uniformly dispersed. Then, add water, controlling the water-to-solid ratio (w / s) to 0.26, and stir for 1 minute to obtain Slurry A. Mix the powders of each component in Component B until uniformly dispersed. Then, add water, controlling the water-to-solid ratio (w / s) to 0.26 to obtain Slurry B. After standing for 1 hour, the fluidity of Components A and B, measured using a truncated cone mold in accordance with GB / T 8077-2023, "Test Method for Homogeneity of Concrete Admixtures," remained at 236 mm and 227 mm, respectively, indicating no significant bleeding.

[0026] Spraying process: Slurry A and slurry B were loaded into separate storage tanks. Two peristaltic pumps delivered the slurries at a constant flow rate of 5 mL / s through pipelines to an external-mix double-head spray gun. They were simultaneously atomized and sprayed onto the vertical concrete slab surface at a pressure of 0.6 MPa. The carbonate foaming agent in component A reacted rapidly with the phosphate in component B, expanding to form a closed-cell foam structure within two minutes. Simultaneously, the MgO reacted with the phosphate, completing initial set and hardening in approximately five minutes. The sprayed coating remained tactile and non-sagable. Example 2

[0027] Formula of component A: 20 kg of slag, 0.2 kg of polycarboxylate water reducer, 0.1 kg of HPMC, 0.5 kg of calcium stearate, 0.2 kg of sodium bicarbonate, 79 kg of dead-burned magnesium oxide; water-solid ratio w / s=0.26.

[0028] Formula of component B: 22.7 kg fly ash, 0.76 kg borax, 52.1 kg diammonium phosphate; water-solid ratio w / s=0.26.

[0029] According to GB / T 8077-2023 "Test method for homogeneity of concrete admixtures", the fluidity of components A and B was measured using a truncated cone mold within 1 hour and remained at 240 mm and 227 mm, respectively, with no obvious bleeding. Example 3

[0030] Formula of component A: 40 kg of slag, 0.2 kg of polycarboxylate water reducer, 0.1 kg of HPMC, 0.5 kg of calcium stearate, 0.2 kg of sodium bicarbonate, 59 kg of dead-burned magnesium oxide; water-solid ratio w / s=0.26.

[0031] Formula of component B: 22.9 kg fly ash, 0.76 kg borax, 52.7 kg diammonium phosphate; water-solid ratio w / s=0.26.

[0032] According to GB / T 8077-2023 "Test method for homogeneity of concrete admixtures", the fluidity of components A and B was measured using a truncated cone mold within 1 hour and remained at 244mm and 227mm respectively, with no obvious bleeding. Example 4

[0033] Formula of component A: 20 kg of slag, 0.2 kg of polycarboxylate water reducer, 0.1 kg of HPMC, 0.5 kg of calcium stearate, 1.0 kg of sodium bicarbonate, 78.2 kg of dead-burned magnesium oxide; water-solid ratio w / s=0.27.

[0034] Formula of component B: 22.9 kg fly ash, 0.76 kg borax, 52.6 kg diammonium phosphate; water-solid ratio w / s=0.26.

[0035] According to GB / T 8077-2023, "Test Method for Homogeneity of Concrete Admixtures," the fluidity of components A and B, measured using a truncated cone mold, remained at 242 mm and 227 mm, respectively, within one hour, with no noticeable bleeding. Due to the high foaming agent content, the core temperature is lower, resulting in a later initial setting and hardening after spraying. Example 5

[0036] Formula of component A: 30 kg of slag, 0.05 kg of polycarboxylate water reducer, 0.05 kg of HPMC, 1 kg of calcium stearate, 0.1 kg of sodium bicarbonate, 68.8 kg of dead-burned magnesium oxide; water-solid ratio w / s=0.27.

[0037] Formula of component B: 7.6 kg fly ash, 3.8 kg borax, 64.5 kg diammonium phosphate; water-solid ratio w / s=0.26. Example 6

[0038] Formula of component A: 25 kg of slag, 0.3 kg of polycarboxylate water reducer, 0.15 kg of HPMC, 1 kg of calcium stearate, 2 kg of sodium bicarbonate, 71.55 kg of dead-burned magnesium oxide; water-solid ratio w / s = 0.27.

[0039] Formula of component B: 37.9 kg fly ash, 0.76 kg borax, 37.1 kg ammonium dihydrogen phosphate; water-solid ratio w / s=0.26.

[0040] Comparative Example 1 Component A does not contain a carbonate foaming agent. The formula of component A is: 0 kg of slag, 0.2 kg of polycarboxylate water reducer, 0.1 kg of HPMC (thickener), 0.5 kg of calcium stearate (foam stabilizer), 0.2 kg of sodium bicarbonate (foaming agent), and 99.02 kg of dead-burned magnesium oxide; the rest is the same as in Example 1.

[0041] Comparative Example 2 Component B does not contain retarder, and the formula of component B is: Component B formula: 22.4 kg fly ash, 49.9 kg ammonium dihydrogen phosphate; the rest is the same as Example 1.

[0042] Comparative Example 3 The mass ratio of components A and B was adjusted so that the mass ratio of M (magnesium oxide + slag + fly ash) to phosphate (M / P) was 1:1; the rest was the same as in Example 1.

[0043] Comparative Example 4 The mass ratio of components A and B was adjusted so that the mass ratio of M (magnesium oxide + slag + fly ash) to phosphate (M / P) was 5:1; the rest was the same as in Example 1.

[0044] The porous magnesium phosphate materials prepared in Examples 1 to 4 were tested for dry density, setting time, compressive strength, thermal conductivity, and softening coefficient according to GB / T 43487-2023 “Test methods for foamed concrete and its products”. The results are shown in Table 1.

[0045] Table 1 Properties of porous magnesium phosphate materials prepared in Example

[0046] From the table above we can see that: (1) Examples 1 to 6 and Comparative Examples 3 and 4 all successfully prepared lightweight foam materials, and the cross-sections showed a uniform pore size distribution with no obvious large pores. Among them, Examples 4 and 6 used a higher amount of carbonate foaming agent, resulting in lower dry density values ​​for the prepared materials, and significantly reduced compressive strength and thermal conductivity. In contrast, Comparative Example 1 did not incorporate a foaming agent, and its dry density was approximately 1900 kg / m³, showing the effect of a dense coating rather than a porous thermal insulation material; Comparative Example 2 did not incorporate a retarder, and its setting time was only 1.1 minutes, resulting in premature setting before the gas-generating foaming reaction of the material was completed, resulting in low utilization efficiency of the foaming agent and a relatively high dry density of the material, and the conditions for accurately designing the foaming ratio or dry density were not met.

[0047] (2) From Example 1 to Example 3, the amount of slag added to replace magnesium oxide is 0%, 20%, and 40%, respectively. As the amount of slag added increases, the setting time gradually shortens, and the compressive strength first increases and then decreases. This shows that the addition of slag can provide a large amount of active calcium and react quickly with phosphate, thereby promoting the increase in reaction temperature and the acceleration of the overall reaction, and the appropriate amount of addition is beneficial to the improvement of strength. However, the excessive addition of slag will cause the reaction to be too fast, which will interfere with the normal hydration reaction of the magnesium phosphate cement system and lead to a decrease in strength. In addition, slag will also cause a slight increase in thermal conductivity.

[0048] As more slag is added, the softening coefficient of the material increases, even exceeding the compressive strength value before immersion. This shows that the slag generates new hydration products through secondary hydration reactions, which can further develop the strength of the material, compensating for or even exceeding the strength loss caused by the original immersion.

[0049] Based on this, we can see that if setting time is the main goal, the recommended slag content is 40%; if material strength is the main goal, this slag content should not be used.

[0050] (3) Observation of Example 1 and Comparative Examples 3 and 4 shows that as the magnesium-phosphorus ratio increases, the dry density and thermal conductivity of the material increase slightly, while the change in compressive strength is very dramatic. This shows that only an appropriate magnesium-phosphorus ratio is beneficial to the development of strength. Insufficient mass fractions of either magnesium oxide or phosphate will affect the final struvite content, resulting in a loose structure and insufficient bonding components at the micro level, which manifests as reduced strength at the macro level. In addition, when the phosphate is excessive, a large amount of unreacted residual phosphate will precipitate after the material is immersed in water, leaving microscopic pores, resulting in a softening coefficient of the material of only 0.65.

[0051] (4) Relying on a special construction process, the retarder dosage (B / M) of the above embodiment is much lower than the 6% to 12% retarder dosage of conventional magnesium phosphate cement, resulting in an extremely short setting time of setting within a few minutes and an early strength development rate with a 1-day compressive strength close to 80% of the 28-day strength.

[0052] In summary, the material prepared by the present invention has adjustable dry density and uniform pore size distribution, and has the characteristics of high strength, low thermal conductivity, small shrinkage, and strong durability. It meets the Class A non-combustible standard and can be widely used in building wall and roof insulation projects.

Claims

1. A two-component magnesium phosphate cement spray foaming material, characterized in that: It includes component A and component B with a dry powder mass ratio of 100: (70~80), The component A comprises: dead-burned magnesium oxide, slag, water reducer, thickener, foam stabilizer and carbonate foaming agent; Component B includes: phosphate, fly ash and retarder.

2. A two-component magnesium phosphate cement spray foaming material according to claim 1, characterized in that: The component A includes the following components in parts by mass: 59-99 parts of dead-burned magnesium oxide, 0-40 parts of slag, 0.05-0.3 parts of water reducer, 0.05-0.15 parts of thickener, 0.25-1.0 parts of foam stabilizer, and 0.1-2.0 parts of carbonate foaming agent.

3. A two-component magnesium phosphate cement spray foaming material according to claim 1, characterized in that: Water is added to the A component to form a slurry A with a water-to-solid ratio of 0.25 to 0.35:

1.

4. A two-component magnesium phosphate cement spray foaming material according to claim 1, characterized in that: The B component comprises the following components in parts by mass: the amount of phosphate is 49-89; the amount of fly ash is 10-50; and the amount of retarder is 1-5.

5. A two-component magnesium phosphate cement spray foaming material according to claim 1, characterized in that: Water is added to the B component to form a B slurry with a water-to-solid ratio of 0.25 to 0.35:

1.

6. A two-component magnesium phosphate cement spray foaming material according to claim 1, characterized in that: In the component A, the particle size of the dead-burned magnesium oxide is less than 200 μm; The slag is granulated blast furnace slag powder with a particle size of less than 200 μm; The water reducer is at least one of a polycarboxylate water reducer, a naphthalene water reducer, and a lignin sulfonate water reducer; The thickener is hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose (HEC) or a mixture thereof; The foam stabilizer is at least one of calcium stearate or sodium lauryl sulfate; The carbonate foaming agent is selected from one or more of sodium bicarbonate, ammonium bicarbonate and calcium bicarbonate.

7. The two-component magnesium phosphate cement spray foaming material according to claim 1, characterized in that: In the component B, the phosphate is ammonium dihydrogen phosphate or potassium dihydrogen phosphate powder with a particle size of less than 200 μm; The fly ash is low-calcium fly ash and meets the technical requirements of Class II or Class III; The retarder is selected from at least one of borax, boric acid or citric acid.

8. A method for preparing the two-component magnesium phosphate cement spray foam material according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Material preparation: weigh and mix the raw materials of component A and component B according to a predetermined ratio, add them into water and stir evenly to obtain slurry A and slurry B respectively; (2) Spraying: Slurry A and slurry B are respectively transported to the external mixing double-head spray gun through a peristaltic pump at a constant flow rate, atomized and mixed at the nozzle with the assistance of compressed air, and sprayed onto the surface of the substrate to form droplets.

9. The method for preparing the two-component magnesium phosphate cement spray foaming material according to claim 8, characterized in that: The M / P ratio of the obtained slurry A and slurry B after mixing is 1.5 to 4:1, wherein M represents the sum of the mass of dead-burned magnesium oxide, slag and fly ash, and P represents the mass of phosphate; After mixing slurry A and slurry B, the overall water-to-solid ratio is 0.25-0.35:

1.

10. The method for preparing a two-component magnesium phosphate cement spray foam material according to claim 8, characterized in that: The carbonate foaming agent in component A reacts with the hydrogen ions in component B to release CO2 gas to form bubbles, and magnesium oxide reacts with phosphate ions to form struvite (MgNH4PO4•6H2O). Foaming is completed within 2 minutes and condenses within 3 to 10 minutes. The resulting spray coating is suitable for continuous construction on vertical walls, ceilings and horizontal surfaces.

Images