A high water-resistant magnesium phosphate cement-based foam ceramic and a preparation method thereof

Abstract

This invention relates to the field of ceramic materials, specifically disclosing a high water-resistant magnesium phosphate cement-based foam ceramic and its preparation method. The foam ceramic comprises the following components: 100-150 parts magnesium phosphate cement, 1-5 parts retarder, 5-20 parts foaming agent, 1-5 parts foam stabilizer, 5-15 parts lutetium ion source, 1-8 parts methylene phosphonic acid component, and 30-60 parts water. The method includes: (1) mixing the lutetium ion source, methylene phosphonic acid component, and water to obtain a complex solution. (2) mixing the magnesium phosphate cement and foam stabilizer, then adding the complex solution to the mixture and mixing to obtain a slurry. (3) adding the foaming agent to the slurry and allowing it to stand for foaming, followed by curing to obtain the foam ceramic. This invention not only effectively reduces the solubility of magnesium phosphate cement hydration products, but also combines CO2 foaming to generate a low-solubility magnesium carbonate shell, significantly improving the long-term stability of the foam ceramic in an aquatic environment while maintaining high porosity.

Description

Technical Field

[0001] This invention relates to the field of ceramic materials, specifically to a high water-resistant magnesium phosphate cement-based foam ceramic and its preparation method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Foam ceramics are foam ceramic materials containing a large number of uniformly distributed pores. They possess characteristics such as lightweight, high porosity, high specific surface area, low thermal conductivity, and good permeability, showing broad application prospects in fields such as high-temperature flue gas filtration, catalyst carriers, sound absorption and heat insulation, biomedical scaffolds, and chemical separation. However, existing foam ceramics require high-temperature sintering to achieve sufficient mechanical strength, which is not only energy-intensive and complex in process, but also difficult to achieve low-energy and rapid manufacturing of large-sized, complex-shaped components. Therefore, developing a foam ceramic material that does not require high-temperature sintering, has a simple process, and can maintain excellent pore structure characteristics is of great significance.

[0004] Magnesium phosphate cement is a special cementitious material based on acid-base neutralization reactions, which bind particles into a dense structure through chemical reactions. Using magnesium phosphate cement as a matrix to prepare foam ceramics allows for room-temperature foaming and molding, effectively avoiding the energy consumption caused by the high-temperature sintering of traditional foam ceramics. Furthermore, the rapid solidification of magnesium phosphate cement after foaming and molding fixes the pore structure, effectively preventing pore wall collapse and bubble coalescence, resulting in excellent pore structure. In addition, magnesium phosphate cement has advantages such as good fluidity, high bonding strength, and low volume shrinkage, which are beneficial for the molding of complex-shaped foam ceramics and dimensional stability. However, the main hydration product of magnesium phosphate cement, struvite (MgNH4PO4·6H2O), gradually dissolves and hydrolyzes in water or humid environments, leading to instability of the ceramic skeleton structure and a decrease in strength. Moreover, the phosphate components often fail to react completely during the acid-base neutralization reaction of magnesium phosphate cement, and the rapid dissolution of residual phosphate upon contact with water further exacerbates the instability of the ceramic skeleton structure, severely restricting the widespread application of magnesium phosphate-based foam ceramics in humid environments, water treatment, and underwater engineering. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a high-water-resistant magnesium phosphate cement-based foam ceramic and its preparation method. This method not only effectively reduces the solubility of magnesium phosphate cement hydration products but also combines CO2 foaming to generate a low-solubility magnesium carbonate shell, significantly improving the long-term stability of the foam ceramic in an aquatic environment while maintaining high porosity. Specifically, the technical solution of this invention is as follows.

[0006] First, this invention discloses a high water-resistant magnesium phosphate cement-based foam ceramic, comprising the following components in the following proportions: 100-150 parts by weight of magnesium phosphate cement, 1-5 parts by weight of retarder, 5-20 parts by weight of foaming agent, 1-5 parts by weight of foam stabilizer, 5-15 parts by weight of lutetium ion source, 1-8 parts by weight of methylene phosphonic acid component, and 30-60 parts by weight of water.

[0007] Further, the magnesium phosphate cement comprises magnesium oxide and phosphate. Optionally, the phosphate comprises at least one of ammonium dihydrogen phosphate, potassium dihydrogen phosphate, etc.

[0008] Furthermore, the mass ratio of magnesium oxide to phosphate is 1:0.5~2.

[0009] Furthermore, the retarder includes at least one of glucono-δ-lactone (GDL), sodium phytate, borax, etc.

[0010] Furthermore, the foaming agent includes at least one of sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, and basic magnesium carbonate, which can generate CO2 gas during the foaming process. This CO2 gas forms a low-solubility magnesium carbonate shell with magnesium ions, coating the surface of struvite, a hydration product of magnesium phosphate cement, thus significantly improving the long-term stability of foam ceramics in aquatic environments.

[0011] Furthermore, the foam stabilizer includes at least one of calcium stearate, sodium dodecyl sulfate, cellulose ether, etc.

[0012] Furthermore, the lutetium ion source includes at least one of lutetium nitrate, lutetium chloride, and lutetium sulfate, and is transmitted via Lu 3+ Replace Mg in the struvite lattice 2+ It can effectively improve its water resistance.

[0013] Further, the methylene phosphonic acid component includes at least one of the following: methylene diphosphonic acid (H4L), aminotrimethylene phosphonic acid (ATMP), ethylenediaminetetramethylene phosphonic acid (EDTMP), diethylenetriaminepentamethylene phosphonic acid (DTPMPA), etc., wherein its phosphonate group can be reacted with Lu 3+ Forming coordination complexes, Lu 3+ Anchored at the crystal growth interface of the guanostone.

[0014] Secondly, the present invention discloses a method for preparing the high water-resistant magnesium phosphate cement-based foam ceramic, comprising the following steps: (1) The lutetium ion source, methylene phosphonic acid component and water are mixed to obtain Lu 3+ -Methylenephosphonic acid component complex solution, for later use.

[0015] (2) After mixing the magnesium phosphate cement, retarder, and foam stabilizer, add the Lu to it.3+ -Methylenephosphonic acid component complex solution, mix well to obtain slurry, for later use.

[0016] (3) After adding the foaming agent to the slurry, let it stand and wait for foaming. After completion, cure it to obtain foam ceramic.

[0017] Furthermore, in step (3), the foaming temperature is 20~40℃ and the standing time is 5~30min.

[0018] Furthermore, in step (3), the relative humidity of the curing is 50-70%, the temperature is 20-25℃, and the standing time is 2-24 hours.

[0019] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects: This invention uses methylene phosphonic acid as the anchoring molecule, utilizing its phosphonic acid group (-PO3H2) as a polydentate ligand, while lutetium ions (Lu) are also involved. 3+ It possesses the characteristics of Lewis hard acid, and its strong oxyphilicity allows it to coordinate with the phosphonic acid group, thereby enabling the methylene phosphonic acid component to interact with Lu. 3+ Forming various complexes and coordination polymers to facilitate the synthesis of Lu 3+ It actively anchors to the crystal lattice of struvite, a hydration product of magnesium phosphate cement. This is due to the phosphonic acid groups reacting with Mg in the cement hydration environment. 2+ They exhibit good adsorption affinity. Therefore, Lu 3+ Complexes with methylene phosphonic acid components can act as "molecular bridges" during struvite crystal growth, allowing the phosphonic acid groups to interact with the Mg in the struvite crystals. 2+ Or, surface hydroxyl groups may bond together, bringing Lu 3+ It is fixed at the crystal growth front, so that it can be captured in situ and enter the crystal lattice when struvite precipitates. 3+ Entering Mg 2+ After site formation, lutetium phosphate (LuPO4) with extremely low solubility product is formed, thus significantly reducing the overall lattice energy of the formed "lutetium-doped struvite" and greatly decreasing its water solubility. This fundamentally solves the problem of easy dissolution of traditional magnesium phosphate cement hydration products in humid or aquatic environments. Meanwhile, Lu... 3+ The incorporation of [a substance] can serve as a nucleation site, inducing struvite crystals to transform into finer morphologies, filling the capillaries in the hardened slurry, forming a denser microstructure, reducing water intrusion, and improving water resistance.

[0020] Meanwhile, this invention uses a CO2-type component as a foaming agent for magnesium phosphate cement-based foam ceramics. After releasing CO2 in the acidic environment provided by phosphate in the magnesium phosphate cement, it further reacts with magnesium ions in the slurry to generate hydrated magnesium carbonate. xMg(OH)2· y MgCO3· z H2O) coats the surface of the "lutetium-doped guanoite" to form a recalcitrant outer shell, further preventing moisture from eroding the internal hydration products. In addition, the foaming agent avoids the problems of bubble coalescence and collapse caused by traditional mechanical foaming, resulting in a foam ceramic of this invention with a uniform pore structure and high closed-cell rate. In summary, this invention utilizes Lu... 3+ Combined with methylene phosphonic acid components, Lu 3+ Actively anchoring to the lattice of hydration products fundamentally reduces the solubility of struvite from the crystal structure. Combined with the synergistic protective effect of CO2 foaming to generate a low-solubility magnesium carbonate shell, it significantly improves the water resistance of magnesium phosphate foam ceramics while ensuring high porosity and excellent pore structure characteristics, laying the foundation for its application in humid environments, water treatment, underwater engineering, marine engineering and other fields. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention and do not constitute an undue limitation of the invention.

[0022] Figure 1 The image shows a sample of magnesium phosphate cement-based foam ceramic prepared in Example 1 below.

[0023] Figure 2 The following is a graph showing the compressive strength test results of magnesium phosphate cement-based foam ceramics in Example 1.

[0024] Figure 3 The image shows a sample of magnesium phosphate cement-based foam ceramic prepared in Example 2 below.

[0025] Figure 4 The following is a graph showing the compressive strength test results of magnesium phosphate cement-based foam ceramics in Example 2.

[0026] Figure 5 The image shows a sample of magnesium phosphate cement-based foam ceramic prepared in Example 3 below.

[0027] Figure 6 The following is a graph showing the compressive strength test results of magnesium phosphate cement-based foam ceramics in Example 3.

[0028] Figure 7 The image shows a sample of magnesium phosphate cement-based foam ceramic prepared in Example 4 below.

[0029] Figure 8 The following is a graph showing the compressive strength test results of magnesium phosphate cement-based foam ceramics in Example 4.

[0030] Figure 9 The image shows a sample of magnesium phosphate cement-based foam ceramic prepared in Example 5 below.

[0031] Figure 10 The following is a graph showing the compressive strength test results of magnesium phosphate cement-based foam ceramics in Example 5.

[0032] Figure 11 The image shows a sample of magnesium phosphate cement-based foam ceramic prepared in Example 6 below.

[0033] Figure 12 The following is a graph showing the compressive strength test results of magnesium phosphate cement-based foam ceramics in Example 6.

[0034] Figure 13 The image shows a sample of magnesium phosphate cement-based foam ceramic prepared in Example 7 below.

[0035] Figure 14 The following is a graph showing the compressive strength test results of magnesium phosphate cement-based foam ceramics in Example 7. Detailed Implementation

[0036] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the invention. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as those skilled in the art. The preferred embodiments and materials described in this invention are for illustrative purposes only. The technical solutions of the present invention will now be further described with reference to specific embodiments.

[0037] Example 1 A highly water-resistant magnesium phosphate cement-based foam ceramic and its preparation method include the following steps: (1) The following components are prepared in the following proportions: 130 parts by weight of magnesium phosphate cement, 3 parts by weight of retarder, 10 parts by weight of foaming agent, 3.5 parts by weight of foam stabilizer, 11 parts by weight of lutetium ion source, 6 parts by weight of methylene phosphonic acid component, and 45 parts by weight of water. Wherein: the magnesium phosphate cement is prepared by mixing recalcined magnesium oxide powder and ammonium dihydrogen phosphate at a mass ratio of 1:1.5. The retarder is glucono-δ-lactone, the foaming agent is sodium bicarbonate, the foam stabilizer is calcium stearate, the lutetium ion source is lutetium nitrate, and the methylene phosphonic acid component is methylene diphosphonic acid.

[0038] (2) The lutetium ion source, methylene phosphonic acid component and water are mixed and stirred evenly to obtain Lu. 3+ -Methylenephosphonic acid component complex solution, for later use.

[0039] (3) Mix the magnesium phosphate cement, retarder and foam stabilizer evenly, and then add the Lu to the obtained powder. 3+ The methylene phosphonic acid component complex solution was stirred evenly to obtain a slurry for later use.

[0040] (4) Add the foaming agent to the slurry and stir evenly. Then let it stand for foaming. The temperature of the foaming environment is set at 30℃, and the standing time is 20 minutes. After completion, cure for 12 hours under conditions of 60% relative humidity and 25℃ to obtain foamed ceramic, such as... Figure 1 As shown.

[0041] Performance testing: The following methods were used to test the various properties of the foam ceramic prepared in this embodiment: (1) Compressive strength: The test was conducted according to GB / T 1964-2023 "Test method for room temperature compressive strength of porous ceramics" (e.g. Figure 2 (2) Water absorption rate: tested according to GB / T 39693-2020 "Foamed Ceramic Insulation Board". (3) Water resistance strength retention rate: the sample was soaked in water at 25℃±2℃ for 7 days, and after being taken out, the surface moisture was wiped off. Then the compressive strength was tested according to GB / T 1964-2023, and the strength retention rate was calculated based on the compressive strength before and after soaking. It was used as the water resistance index. The higher the value, the better the water resistance. The test results of the above indicators are shown in Table 1 below.

[0042] Table 1 Performance indicators 28-day compressive strength Water absorption rate Water resistance strength retention rate Test Results 3.05MPa 6.8% 94.6% Example 2 A highly water-resistant magnesium phosphate cement-based foam ceramic and its preparation method include the following steps: (1) The following components are prepared in the following proportions: 150 parts by weight of magnesium phosphate cement, 5 parts by weight of retarder, 20 parts by weight of foaming agent, 5 parts by weight of foam stabilizer, 15 parts by weight of lutetium ion source, 8 parts by weight of methylene phosphonic acid component, and 60 parts by weight of water. Wherein: the magnesium phosphate cement is prepared by mixing recalcined magnesium oxide powder and ammonium dihydrogen phosphate at a mass ratio of 1:2. The retarder is sodium phytate, the foaming agent is ammonium carbonate, the foam stabilizer is sodium dodecyl sulfate, the lutetium ion source is lutetium chloride, and the methylene phosphonic acid component is aminotrimethylene phosphonic acid.

[0043] (2) The lutetium ion source, methylene phosphonic acid component and water are mixed and stirred evenly to obtain Lu. 3+ -Methylenephosphonic acid component complex solution, for later use.

[0044] (3) Mix the magnesium phosphate cement, retarder and foam stabilizer evenly, and then add the Lu to the obtained powder. 3+ The methylene phosphonic acid component complex solution was stirred evenly to obtain a slurry for later use.

[0045] (4) Add the foaming agent to the slurry and stir evenly. Then let it stand for foaming. The temperature of the foaming environment is set to 40℃, and the standing time is 5 minutes. After completion, cure for 24 hours under conditions of 50% relative humidity and 25℃ to obtain foamed ceramic, such as... Figure 3 As shown.

[0046] Performance testing: The various performance indicators of the foam ceramic prepared in this embodiment were tested using the same method as in Example 1 above, including the compressive strength as shown in the figure. Figure 4 As shown in Table 2 below, the test results for each of the above indicators are as follows.

[0047] Table 2 Performance indicators 28-day compressive strength Water absorption rate Water resistance strength retention rate Test Results 3.17MPa 7.5% 92.2% Example 3 A highly water-resistant magnesium phosphate cement-based foam ceramic and its preparation method include the following steps: (1) The following components are prepared in the following proportions: 100 parts by weight of magnesium phosphate cement, 1 part by weight of retarder, 5 parts by weight of foaming agent, 1 part by weight of foam stabilizer, 5 parts by weight of lutetium ion source, 1 part by weight of methylenephosphonic acid component, and 30 parts by weight of water. Wherein: the magnesium phosphate cement is prepared by mixing recalcined magnesium oxide powder and potassium dihydrogen phosphate at a mass ratio of 1:0.5. The retarder is glucono-δ-lactone, the foaming agent is ammonium bicarbonate, the foam stabilizer is hydroxypropyl methylcellulose, the lutetium ion source is lutetium sulfate, and the methylenephosphonic acid component is diethylenetriaminepentamethylenephosphonic acid.

[0048] (2) The lutetium ion source, methylene phosphonic acid component and water are mixed and stirred evenly to obtain Lu. 3+ -Methylenephosphonic acid component complex solution, for later use.

[0049] (3) Mix the magnesium phosphate cement, retarder and foam stabilizer evenly, and then add the Lu to the obtained powder. 3+ The methylene phosphonic acid component complex solution was stirred evenly to obtain a slurry for later use.

[0050] (4) Add the foaming agent to the slurry and stir evenly. Then let it stand for foaming. The temperature of the foaming environment is set at 20℃, and the standing time is 30 minutes. After completion, cure for 2 hours at a relative humidity of 70% and a temperature of 20℃ to obtain foamed ceramic, such as... Figure 5 As shown.

[0051] Performance testing: The various performance indicators of the foam ceramic prepared in this embodiment were tested using the same method as in Example 1 above, including the compressive strength as shown in the figure. Figure 6 As shown in the table below, the test results for each of the above indicators are as follows.

[0052] Table 3 Performance indicators 28-day compressive strength Water absorption rate Water resistance strength retention rate Test Results 3.42MPa 6.2% 95.3% Example 4 A highly water-resistant magnesium phosphate cement-based foam ceramic and its preparation method include the following steps: (1) The following components are prepared in the following proportions: 130 parts by weight of magnesium phosphate cement, 3 parts by weight of retarder, 10 parts by weight of foaming agent, 3.5 parts by weight of foam stabilizer, 6 parts by weight of methylene phosphonic acid component, and 45 parts by weight of water. Wherein: the magnesium phosphate cement is prepared by mixing recalcined magnesium oxide powder and ammonium dihydrogen phosphate at a mass ratio of 1:1.5. The retarder is glucono-δ-lactone, the foaming agent is sodium bicarbonate, the foam stabilizer is calcium stearate, and the methylene phosphonic acid component is methylene diphosphonic acid.

[0053] (2) Mix the methylene phosphonic acid component with water and stir until homogeneous to obtain a methylene phosphonic acid component complex solution for later use.

[0054] (3) Mix the magnesium phosphate cement, retarder and foam stabilizer evenly, then add the methylene phosphonic acid component complex solution to the obtained powder, stir evenly to obtain slurry, and set aside.

[0055] (4) Add the foaming agent to the slurry and stir evenly. Then let it stand for foaming. The temperature of the foaming environment is set at 30℃, and the standing time is 20 minutes. After completion, cure for 12 hours under conditions of 60% relative humidity and 25℃ to obtain foamed ceramic, such as... Figure 7 As shown.

[0056] Performance testing: The various performance indicators of the foam ceramic prepared in this embodiment were tested using the same method as in Example 1 above, including the compressive strength as shown in the figure. Figure 8 As shown in Table 4 below, the test results for each of the above indicators are as follows.

[0057] Table 4 Performance indicators 28-day compressive strength Water absorption rate Water resistance strength retention rate Test Results 2.73MPa 15.3% 67.8% Example 5

[0058] A highly water-resistant magnesium phosphate cement-based foam ceramic and its preparation method include the following steps: (1) The following components are prepared in the following proportions: 150 parts by weight of magnesium phosphate cement, 5 parts by weight of retarder, 20 parts by weight of foaming agent, 5 parts by weight of foam stabilizer, 15 parts by weight of lutetium ion source, and 60 parts by weight of water. Wherein: the magnesium phosphate cement is prepared by mixing recalcined magnesium oxide powder and ammonium dihydrogen phosphate at a mass ratio of 1:2. The retarder is sodium phytate, the foaming agent is ammonium carbonate, the foam stabilizer is sodium dodecyl sulfate, and the lutetium ion source is lutetium chloride.

[0059] (2) The lutetium ion source is mixed with water and stirred until homogeneous to obtain Lu.3+ Solution, for later use.

[0060] (3) Mix the magnesium phosphate cement, retarder and foam stabilizer evenly, and then add the Lu to the obtained powder. 3+ The solution is stirred until homogeneous to obtain a slurry, which is then set aside.

[0061] (4) Add the foaming agent to the slurry and stir evenly. Then let it stand for foaming. The temperature of the foaming environment is set to 40℃, and the standing time is 5 minutes. After completion, cure for 24 hours under conditions of 50% relative humidity and 25℃ to obtain foamed ceramic, such as... Figure 9 As shown.

[0062] Performance testing: The various performance indicators of the foam ceramic prepared in this embodiment were tested using the same method as in Example 1 above, including the compressive strength as shown in the figure. Figure 10 As shown in the table below, the test results for each of the above indicators are as follows.

[0063] Table 5 Performance indicators 28-day compressive strength Water absorption rate Water resistance strength retention rate Test Results 2.64MPa 13.8% 71.4% Example 6 A highly water-resistant magnesium phosphate cement-based foam ceramic and its preparation method include the following steps: (1) The following components are prepared in the following proportions: 130 parts by weight of magnesium phosphate cement, 3 parts by weight of retarder, 10 parts by weight of foaming agent, 3.5 parts by weight of foam stabilizer, 11 parts by weight of lutetium ion source, 6 parts by weight of methylene phosphonic acid component, and 45 parts by weight of water. Wherein: the magnesium phosphate cement is prepared by mixing recalcined magnesium oxide powder and ammonium dihydrogen phosphate at a mass ratio of 1:1.5. The retarder is glucono-δ-lactone, the foaming agent is azodicarbonamide, the foam stabilizer is calcium stearate, the lutetium ion source is lutetium nitrate, and the methylene phosphonic acid component is methylene diphosphonic acid.

[0064] (2) The lutetium ion source, methylene phosphonic acid component and water are mixed and stirred evenly to obtain Lu. 3+ -Methylenephosphonic acid component complex solution, for later use.

[0065] (3) Mix the magnesium phosphate cement, retarder and foam stabilizer evenly, and then add the Lu to the obtained powder. 3+ The methylene phosphonic acid component complex solution was stirred evenly to obtain a slurry for later use.

[0066] (4) Add the foaming agent to the slurry and stir evenly. Then let it stand for foaming. The temperature of the foaming environment is set at 30℃, and the standing time is 20 minutes. After completion, cure for 12 hours under conditions of 60% relative humidity and 25℃ to obtain foamed ceramic, such as... Figure 11 As shown.

[0067] Performance testing: The various performance indicators of the foam ceramic prepared in this embodiment were tested using the same method as in Example 1 above, including the compressive strength as shown in the figure. Figure 12 As shown in the table below, the test results for each of the above indicators are as follows.

[0068] Table 6 Performance indicators 28-day compressive strength Water absorption rate Water resistance strength retention rate Test Results 2.76MPa 10.7% 84.5% Example 7 A highly water-resistant magnesium phosphate cement-based foam ceramic and its preparation method include the following steps: (1) The following components are prepared in the following proportions: 100 parts by weight of magnesium phosphate cement, 1 part by weight of retarder, 5 parts by weight of foaming agent, 1 part by weight of foam stabilizer, 5 parts by weight of iron ion source, 1 part by weight of methylenephosphonic acid component, and 30 parts by weight of water. Wherein: the magnesium phosphate cement is prepared by mixing recalcined magnesium oxide powder and potassium dihydrogen phosphate at a mass ratio of 1:0.5. The retarder is glucono-δ-lactone, the foaming agent is ammonium bicarbonate, the foam stabilizer is hydroxypropyl methylcellulose, the iron ion source is ferric sulfate, and the methylenephosphonic acid component is diethylenetriaminepentamethylenephosphonic acid.

[0069] (2) The iron ion source, methylene phosphonic acid component, and water are mixed and stirred until homogeneous to obtain Fe. 3+ -Methylenephosphonic acid component complex solution, for later use.

[0070] (3) Mix the magnesium phosphate cement, retarder and foam stabilizer evenly, and then add the Fe to the obtained powder. 3+ The methylene phosphonic acid component complex solution was stirred evenly to obtain a slurry for later use.

[0071] (4) Add the foaming agent to the slurry and stir evenly. Then let it stand for foaming. The temperature of the foaming environment is set at 20℃, and the standing time is 30 minutes. After completion, cure for 2 hours at a relative humidity of 70% and a temperature of 20℃ to obtain foamed ceramic, such as... Figure 13 As shown.

[0072] Performance testing: The various performance indicators of the foam ceramic prepared in this embodiment were tested using the same method as in Example 1 above, including the compressive strength as shown in the figure. Figure 14 As shown in the table below, the test results for each of the above indicators are as follows.

[0073] Table 7 Performance indicators 28-day compressive strength Water absorption rate Water resistance strength retention rate Test Results 2.51MPa 18.6% 54.2% The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A high water-resistant magnesium phosphate cement-based foam ceramic, characterized in that, The components include the following proportions: 100-150 parts by weight of magnesium phosphate cement, 1-5 parts by weight of retarder, 5-20 parts by weight of foaming agent, 1-5 parts by weight of foam stabilizer, 5-15 parts by weight of lutetium ion source, 1-8 parts by weight of methylene phosphonic acid component, and 30-60 parts by weight of water.

2. The high water-resistant magnesium phosphate cement-based foam ceramic according to claim 1, characterized in that, The magnesium phosphate cement comprises magnesium oxide and phosphate.

3. The high water-resistant magnesium phosphate cement-based foam ceramic according to claim 2, characterized in that, The mass ratio of magnesium oxide to phosphate is 1:0.5~2; or, the phosphate includes at least one of ammonium dihydrogen phosphate and potassium dihydrogen phosphate.

4. The high water-resistant magnesium phosphate cement-based foam ceramic according to claim 1, characterized in that, The retarder includes at least one of gluconate-δ-lactone, sodium phytate, and borax. Alternatively, the foaming agent may include at least one of sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, and basic magnesium carbonate.

5. The high water-resistant magnesium phosphate cement-based foam ceramic according to claim 1, characterized in that, The foam stabilizer includes at least one of calcium stearate, sodium dodecyl sulfate, and cellulose ether.

6. The high water-resistant magnesium phosphate cement-based foam ceramic according to claim 1, characterized in that, The lutetium ion source includes at least one of lutetium nitrate, lutetium chloride, and lutetium sulfate.

7. The high water-resistant magnesium phosphate cement-based foamed ceramic according to any one of claims 1-6, characterized in that, The methylene phosphonic acid component includes at least one of the following: methylene diphosphonic acid, aminotrimethylene phosphonic acid, ethylenediaminetetramethylene phosphonic acid, and diethylenetriaminepentamethylene phosphonic acid.

8. The method for preparing high water-resistant magnesium phosphate cement-based foam ceramics according to any one of claims 1-7, characterized in that, Includes the following steps: (1) The lutetium ion source, methylene phosphonic acid component and water are mixed to obtain Lu 3+ -Methylenephosphonic acid component complex solution, for later use; (2) After mixing the magnesium phosphate cement, retarder, and foam stabilizer, add the Lu to it. 3+ -Methylenephosphonic acid component complex solution, mix well to obtain slurry, for later use; (3) After adding the foaming agent to the slurry, let it stand and wait for foaming. After completion, it is cured to obtain foam ceramic.

9. The method for preparing the high water-resistant magnesium phosphate cement-based foam ceramic according to claim 8, characterized in that, In step (3), the foaming temperature is 20~40℃ and the standing time is 5~30min.

10. The method for preparing the high water-resistant magnesium phosphate cement-based foam ceramic according to claim 8, characterized in that, In step (3), the relative humidity of the curing is 50-70%, the temperature is 20-25℃, and the standing time is 2-24 hours.

Images