Phosphogypsum water-permeable material, preparation method and application thereof

Abstract

This invention relates to the field of permeable materials technology, providing a phosphogypsum permeable material, its preparation method, and its application. The method involves mixing and grinding gypsum powder, gypsum retarder, and water as main raw materials. Immediately after grinding, water is added for granulation to obtain aggregate blanks. These aggregate blanks are then immediately placed in a mold, vibrated, and hardened to obtain the permeable material. The raw materials do not contain any external binders. The time from the start of mixing to the start of vibration is controlled to be ≤10 minutes, allowing the aggregate blanks to undergo a hydration reaction and further harden during vibration. The permeable material obtained by this invention has high permeability (permeability is twice or more than that of traditional materials) and good mechanical properties. Furthermore, the aggregate surface of this invention is smooth, ensuring strong permeability while preventing clogging.

Description

Technical Field

[0001] This invention relates to the field of permeable materials technology, and in particular to a phosphogypsum permeable material, its preparation method, and its application. Background Technology

[0002] Traditional cities often employ large-scale construction of hard buildings and paving during urbanization, which prevents rainwater from fully infiltrating and circulating naturally, leading to problems such as urban flooding, water pollution, and water shortages. To achieve sustainable urban development, protect water resources, improve the water environment, prevent floods, protect the ecosystem, and enhance the quality of life for urban residents, permeable materials for sponge cities are gradually gaining market attention.

[0003] Cement-based permeable concrete is an eco-friendly concrete with continuous porosity, prepared by mixing cement, water, aggregates, admixtures, additives, and inorganic pigments in a specific ratio. In the preparation of cement-based permeable concrete, the aggregate gradation design, paste volume, and paste rheology need to be strictly controlled. In particular, the paste needs to have sufficient fluidity to fully coat the aggregate surface, facilitating construction and ensuring sufficient concrete strength. However, excessive paste rheology can easily lead to segregation during concrete forming. Under gravity and other factors, the paste flows towards the lower part of the structure, causing blockage of the pores in the lower part of the concrete and affecting its permeability. Based on this, patent application CN113152193A proposes mixing surface-wetted concrete aggregate with cementitious material powder, causing the cementitious material powder to coat the surface of the concrete aggregate into a shell. Further compaction is then used to interlock the aggregates, with the cementitious material shells overlapping and tightly bonded. This improves the accuracy of cementitious material dosage, preventing insufficient strength due to insufficient dosage and avoiding waste due to excessive dosage clogging of permeable pores. Furthermore, no cementitious material slurry is formed during the preparation of permeable concrete, eliminating the need for water-cement ratio design and greatly simplifying material design. However, the dense structure of the cementitious material adhering to the surface of the pre-wetted aggregate in this technical solution reduces the porosity, resulting in low permeability. In addition, while pressure molding can stimulate the hydration reaction of the cementitious material, it can also lead to aggregate breakage and powder generation, further affecting the molding strength and permeability of the permeable material.

[0004] Therefore, this invention is proposed. Summary of the Invention

[0005] Compared to permeable materials synthesized using the properties of traditional aggregates and cementitious materials, or dense skeleton permeable materials formed by applying external force with traditional aggregates and cementitious materials at a certain water-cement ratio, the present invention provides a phosphogypsum permeable material, its preparation and application, which abandons traditional aggregates and cementitious materials and uses gypsum powder as a raw material for the first time to prepare permeable materials. The resulting permeable material not only does not require the consumption of a large amount of natural resources such as sand and gravel aggregates, but also avoids the use of external cementitious materials. More importantly, the resulting permeable material has excellent permeability, high strength and is not easily clogged.

[0006] Specifically, the present invention provides a method for preparing a permeable material, comprising: mixing gypsum powder, gypsum retarder and water as the main raw materials and then grinding them; immediately after grinding, adding water to granulate the mixture to obtain an aggregate blank; and immediately placing the aggregate blank into a mold, vibrating and hardening it to obtain the permeable material.

[0007] The raw materials do not contain any external binders (such as cement, lime, mineral powder, fly ash, etc.);

[0008] The gypsum powder is a powdered gypsum with a hemihydrate gypsum content of more than 60% and a dihydrate gypsum content of no more than 5%. The amount of water added during mixing is 10% to 15% of the total mass of the powdered gypsum, and the total amount of water used from mixing to molding is 27% to 33% of the total mass of the powdered gypsum.

[0009] The time from the start of mixing to the start of vibration is ≤10 minutes, preferably ≤5 minutes, so that the aggregate blank undergoes a hydration reaction and further hardens and forms during vibration.

[0010] This invention proposes adding a retarder and water to powdered gypsum with hemihydrate gypsum as the main component, followed by mixing and kneading. The amount of water added, the mixing process, and the kneading time are carefully controlled to maintain the powdered gypsum in a good processing state and with a high degree of homogenization, which is beneficial for subsequent molding processes. In particular, it ensures that water is gradually and evenly distributed around the hemihydrate gypsum molecules, which is crucial for forming a product with high homogeneity and high strength in subsequent molding. In this invention, powdered gypsum refers to gypsum products formed naturally or produced through specific processes, such as byproducts of the phosphate industry and certain other industries. These products contain more than 60% hemihydrate gypsum by mass, with the remainder being anhydrous gypsum, dihydrate gypsum, and other impurities, wherein the dihydrate gypsum content should not exceed 5%.

[0011] In existing methods for preparing hardened gypsum bodies, water, as a necessary raw material for the hydration reaction of hemihydrate gypsum, is often added all at once. Moreover, the amount of water added far exceeds the theoretical water requirement of the fully hydrated product (i.e., dihydrate gypsum). In practice, it has been found that reducing the water-to-gypsum ratio helps to improve the mechanical properties of hardened gypsum bodies, such as compressive strength and flexural strength. When using existing techniques, insufficient water can lead to unsatisfactory workability during gypsum molding, resulting in waste. Therefore, this invention, through extensive experimentation, discovered that multiple water additions help reduce water consumption while maintaining the material's hydration reaction and workability. However, the need for precise control over the number of water additions and the amount added each time hinders the industrial application of this technology. Further research revealed that adding a retarder and water to powdered gypsum (primarily hemihydrate gypsum), followed by mixing and kneading, and controlling the amount of water added during mixing, the kneading time, and the timing of the second water addition, can effectively reduce the total water consumption for converting the powdered gypsum into a hardened gypsum body. Furthermore, it can control the hydration process of the gypsum powder. Based on these findings, this invention… The invention also unexpectedly discovered that the vibration compaction process can bond gypsum aggregate blanks that are not yet fully hydrated together during their hydration process, resulting in high bond strength. Compared to high-pressure molding, the vibration compaction process exerts less force on the aggregate blanks, preserving their basic shape. The lateral and longitudinal vibrations generated during compaction cause adjacent aggregate blanks to be compressed under gravity. Because the aggregate blanks are not fully hydrated, the contact area between adjacent aggregate blanks gradually increases during compression. Accompanying the hydration reaction of the aggregate blanks, this contact area becomes a highly efficient, integrated bond, hardening and forming without the need for external slurries such as gelling agents. This integral structure has inherent longitudinal and lateral pores, greatly simplifying the process flow and raw material selection for permeable materials, providing a completely new preparation process. Furthermore, the experiments showed that the vibration force makes the surface of the hardened aggregate blanks smoother and rounder, significantly reducing surface friction. Compared to traditional permeable materials, this greatly avoids clogging, improving the lifespan and quality of the material while reducing costs, which is of great technical significance.

[0012] According to the method for preparing permeable materials provided by the present invention, the particle size of the powdered gypsum is ≤50μm.

[0013] According to the method for preparing permeable materials provided by the present invention, the mass ratio of gypsum powder, gypsum retarder and water is 100:(0.01~0.03):(27~33).

[0014] According to the method for preparing permeable materials provided by the present invention, by adding gypsum water-reducing agent, the present invention can promote the workability of gypsum powder with less water, so that the permeable material can be effectively granulated and formed with a unit water volume, and the gaps between the aggregate blanks in the mold are maximized. Preferably, the mass ratio of gypsum powder to gypsum water-reducing agent is 100:(0.01~0.05).

[0015] This invention, by adding a gypsum waterproofing agent, can promote the secondary softening of gypsum powder after crystal formation when exposed to water with a small amount of water. This results in a permeable material that has both high-temperature integrity and solves the problem of softening when exposed to water in traditional gypsum air-hardening materials, thus successfully producing a gypsum-based permeable material. Preferably, the mass ratio of gypsum powder to gypsum waterproofing agent is 100:(0.01~0.05).

[0016] According to the method for preparing permeable materials provided by the present invention, the raw materials consist of gypsum powder, gypsum retarder, gypsum water-reducing agent, gypsum waterproofing agent and water;

[0017] Preferably, the mass parts of gypsum powder, gypsum retarder, gypsum water-reducing agent, gypsum waterproofing agent, and water are 100 parts, 0.03 parts, 0.03 parts, 0.05 parts, and 30 parts, respectively. The permeable material prepared under this formula exhibits excellent strength, good permeability, and is not easily clogged.

[0018] According to the method for preparing permeable materials provided by the present invention, the aggregate blanks are selected before being placed into the mold so that the gradation of the aggregate blanks placed into the mold is 5-20 or 5-31.5; preferably, a single gradation of 5-10, 10-20 or 20-31.5. In practical applications, the gradation can be selected according to actual needs. Generally, the more uniform the material is when placed into the mold, the more uniform the contact points between the materials, the more uniform the gaps in the blanks, and the more uniform the appearance quality. Therefore, a single particle size distribution is better in ensuring good appearance quality and the overall strength and effect of the molded block, such as 5-10, 10-20, 10-31.5, etc.

[0019] Preferably, before molding, the aggregate blank is selected to ensure that the sphericity of the aggregate blank is ≥0.85, preferably ≥0.9. Experiments have shown that sphericity has a significant impact on the permeability and strength of the permeable material of this invention; the closer the sphericity is to 1, the higher the strength of the permeable material and the better the permeability.

[0020] According to the method for preparing permeable materials provided by the present invention, the vibration is low-frequency vibration and / or lateral impact vibration;

[0021] Preferably, the low-frequency vibration is vertical vibration performed using a vibration table;

[0022] More preferably, the vibration is intermittent low-frequency vibration.

[0023] According to the preparation method of the permeable material provided by the present invention, the preparation method is to use gypsum powder, gypsum retarder and water as the main raw materials to be mixed, ground, granulated, shaped, put into mold, intermittent low frequency vibration and static hardening in sequence to obtain the material.

[0024] Preferably, the intermittent low-frequency vibration refers to an interval of ≥30 seconds between two adjacent low-frequency vibrations; preferably, the intermittent low-frequency vibration is: each vibration lasts 1-3 seconds followed by a pause of 30 seconds or more; more preferably, as the number of vibrations increases, the corresponding pause time is extended, for example: vibration for 1-3 seconds, pause for 1-2 minutes, then vibration for 1-3 seconds, pause for 2-5 minutes.

[0025] The requirement can also be achieved by using a lateral manual tapping method. For example, a metal round probe with a diameter of 20mm and a length of 40-50cm can be used to tap the mold at a frequency of 15-25 times per minute. The material surface should be displaced but not completely adhered together.

[0026] The present invention also provides a permeable material prepared by the method described above.

[0027] The present invention also provides the application of the permeable material as described above in permeable bricks.

[0028] This invention provides a phosphogypsum permeable material, its preparation, and its application. By employing a vibration process, the gypsum aggregate blanks that have not yet fully hydrated can be bonded together during the hydration process. The permeable material obtained by this invention has high permeability (the permeability rate is twice or more than that of traditional materials), and the permeability of traditional permeable bricks is adjusted from the top and bottom to both the longitudinal and transverse directions. In addition, the aggregate surface of this invention is smooth, which makes it less prone to clogging while ensuring strong permeability. Traditional permeable bricks are prone to clogging due to the complex process of adding cementitious materials and the large amount of cementitious materials used, which can lead to caking.

[0029] The permeable material obtained by this invention has a permeability coefficient ≥10, flexural strength ≥1.5MPa, strength loss rate ≤11% after 25 freeze-thaw cycles, mass loss rate ≤5.5% after 25 freeze-thaw cycles, abrasion resistance ≤30mm, water erosion resistance ≥80, softening coefficient ≥0.85, high overall strength (≥5MPa), good permeability, no secondary environmental pollution, and heavy metal leaching fully meets the standard requirements. It has a good substitution effect for traditional permeable bricks made of sand and gravel aggregates and has outstanding ecological and environmental protection performance. More preferably, the permeable material of this invention has a permeability coefficient ≥10, flexural strength ≥2.5MPa, strength loss rate ≤10% after 25 freeze-thaw cycles, mass loss rate ≤3% after 25 freeze-thaw cycles, abrasion resistance ≤20mm, and water erosion resistance ≥90%. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in this invention 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is one of the structural schematic diagrams of the mixing and running-in device used in this invention;

[0032] Figure 2 This is the second schematic diagram of the device used for mixing and running-in in this invention;

[0033] Figure 3 This is the third schematic diagram of the device used for mixing and running-in in this invention;

[0034] Figure 4 This is a structural diagram of the permeable brick prepared in Example 1 of this invention;

[0035] Figure 5 This is a structural diagram of the permeable brick prepared in Example 6 of the present invention.

[0036] Figure label:

[0037] 1: Feed hopper; 2: Mixing device; 21: Mixing cylinder; 211: First cylinder body; 212: Second cylinder body; 213: Cover plate; 214: Guide pipe; 22: Mixing assembly; 23: First drive mechanism; 231: First motor; 232: Driving pulley; 233: Driven pulley; 24: Second drive mechanism; 3: Discharge hopper; 4: Running-in unit; 41: Pushing chamber; 42: Running-in chamber; 43: Fixed grinding disc; 44: Rotating grinding disc; 45: Third drive mechanism. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0039] The mixing and running-in process in this invention employs the following device structure:

[0040] like Figure 1 , Figure 2 and Figure 3 As shown, it includes: a feeding hopper 1, a stirring device 2, a water supply device, a discharge hopper 3, and a running-in device;

[0041] The mixing device 2 is used for mixing and includes a mixing drum 21, a mixing assembly 22, and a first drive mechanism 23. The mixing assembly 22 is rotatably disposed inside the mixing drum 21 and includes a mixing section, which includes a mixing shaft and mixing blades. The first drive mechanism 23 includes a first motor 231 and a transmission assembly. The first motor 231 is connected to the mixing assembly 22 through the transmission assembly. The transmission assembly includes a driving pulley 232, a driven pulley 233, and a belt. The first motor 231 drives the driving pulley 232 to rotate, thereby driving the driven pulley 233 and the mixing assembly 22 to rotate synchronously. The discharge hopper 3, the mixing drum 21, and the feeding hopper 1 are arranged sequentially in a vertical direction and are interconnected. The mixing drum 21 includes a drum body and a cover plate 213. A guide pipe 214 can be provided at the discharge port of the drum body, and the material in the mixing drum 21 flows into the discharge hopper 3 along the guide pipe 214. Multiple nozzles are installed on the cover plate 213 of the mixing drum 21. The water supply device includes multiple liquid supply pipes, which are connected to the multiple nozzles one by one for supplying water to the mixing drum. One end of the mixing drum 21 is connected to the feed hopper 1, and the other end of the mixing drum 21 is connected to the running-in device.

[0042] The running-in device is used for running-in and includes a first running-in unit and a second running-in unit. Two adjacent running-in units 4 are connected and can be used for multi-stage running-in. Taking one running-in unit 4 as an example, the running-in unit 4 has a push chamber 41 and a running-in chamber 42 that are interconnected. The push chamber 41 of the first running-in unit is connected to the outlet end of the discharge hopper 3, and the running-in chamber 42 of the first running-in unit is connected to the push chamber 41 of the second running-in unit. The running-in unit 4 includes a housing, a fixed grinding disc 43, a rotating grinding disc 44, and a third drive mechanism 45. The housing is formed by combining a cylindrical first housing and a fan-shaped second housing. The first housing is arranged horizontally, and the second housing is arranged vertically. A portion of the first housing is embedded in the second housing. The push chamber 41 is formed inside the first housing, and the running-in chamber 42 is formed inside the second housing. The push chamber 41 and the running-in chamber 42 are interconnected. The outlet end of the discharge hopper 3 extends into the first housing, thereby connecting the discharge hopper 3 with the push chamber 41. The bottom of the second housing has a discharge port. Both the fixed grinding disc 43 and the rotating grinding disc 44 are located in the running-in chamber 42. Both the fixed grinding disc 43 and the rotating grinding disc 44 are arranged in a vertical direction, and a running-in channel is formed between the opposite surfaces of the fixed grinding disc 43 and the rotating grinding disc 44. The driving end of the third driving mechanism 45 is connected to the rotating grinding disc 44. The third driving mechanism 45 is used to push the material in the pushing chamber 41 to the running-in channel and to drive the rotating grinding disc 44 to rotate relative to the fixed grinding disc 43 so as to run-in the material.

[0043] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0044] The gypsum powder in this invention contains 80% building gypsum, 8% anhydrous gypsum, and 4% dihydrate gypsum, with a particle size of 80–200 μm.

[0045] Example 1

[0046] A method for preparing a permeable material involves mixing and grinding 100 parts of gypsum powder, 0.03 parts of gypsum retarder (sodium citrate), 0.03 parts of gypsum water-reducing agent (polycarboxylate water-reducing agent), 0.05 parts of gypsum waterproofing agent (methyl silicone resin) and 10 parts of water as raw materials (using the above-mentioned device). Immediately after grinding, 17 parts of water are added for granulation to obtain aggregate blanks. The aggregate blanks are then immediately placed into molds, shaped, intermittently vibrated at low frequency, and allowed to harden at room temperature to obtain permeable bricks. Among them, when selecting the aggregate blanks, the gradation of the aggregate blanks to be put into the mold is 5 to 10 single gradation, and the sphericity of the aggregate blanks is ≥0.9; and the time from the start of mixing to the start of vibration is controlled to be 9 minutes, so that the aggregate blanks can undergo hydration reaction and further harden and form during vibration. This intermittent low-frequency vibration is a vertical vibration using a vibrating table (platform type 50Hz vibrator), specifically vibrating for 2 seconds, stopping for 1 minute, vibrating for 2 seconds again, stopping for 2 minutes, vibrating for 2 seconds again, stopping for 3 minutes.

[0047] Example 2

[0048] A method for preparing a permeable material involves mixing and grinding 100 parts gypsum powder, 0.03 parts gypsum retarder (sodium polyphosphate), 0.03 parts gypsum water-reducing agent (polycarboxylate water-reducing agent), 0.05 parts gypsum waterproofing agent (calcium stearate), and 12 parts water as raw materials. Immediately after grinding, 17 parts water are added for granulation to obtain aggregate blanks. The aggregate blanks are then immediately placed in a mold, shaped, intermittently vibrated at low frequency, and allowed to harden statically to obtain permeable bricks. During shaped selection, the aggregate blanks are designed to have a gradation of 5-10 single gradation and a sphericity of 0.9. The time from the start of mixing to the start of vibration is controlled to be 10 minutes, allowing the aggregate blanks to undergo a hydration reaction and further harden during vibration. The intermittent low-frequency vibration is performed using a vibrating table with vertical vibration, specifically: vibrate for 3 seconds, pause for 1 minute, vibrate for another 3 seconds, pause for 3 minutes, vibrate for another 3 seconds, and pause for 5 minutes.

[0049] Example 3

[0050] A method for preparing a permeable material involves mixing and grinding 100 parts gypsum powder, 0.03 parts gypsum retarder (potassium tartrate), 0.03 parts gypsum water-reducing agent (polycarboxylate water-reducing agent), 0.05 parts gypsum waterproofing agent (methyl silicone resin), and 13 parts water as raw materials. Immediately after grinding, 17 parts water are added for granulation to obtain aggregate blanks. The aggregate blanks are then immediately placed in a mold, shaped, intermittently vibrated at low frequency, and allowed to harden statically to obtain permeable bricks. During shaped selection, the aggregate blanks are designed to have a gradation of 10-20 (single gradation) and a sphericity of 0.85. The time from the start of mixing to the start of vibration is controlled to be 8 minutes, allowing the aggregate blanks to undergo a hydration reaction and further harden during vibration. The intermittent low-frequency vibration is performed using a vibrating table with vertical vibration, specifically: vibrate for 3 seconds, pause for 2 minutes, vibrate for 3 seconds, pause for 3 minutes, vibrate for 3 seconds, pause for 5 minutes.

[0051] Example 4

[0052] A method for preparing a permeable material is basically the same as that in Example 1, except that no gypsum water-reducing agent is added.

[0053] Example 5

[0054] A method for preparing a permeable material is basically the same as that in Example 1, except that no gypsum waterproofing agent is added.

[0055] Example 6

[0056] A method for preparing a permeable material is basically the same as that in Example 1, except that the aggregate blanks to be put into the mold are sized as 5 to 31.5 during the selection process.

[0057] Comparative Example 1

[0058] A method for preparing a permeable material is basically the same as that in Example 1, except that the amount of water added immediately after the mixing is increased to 35 parts for granulation to obtain aggregate blanks. It was found that during the granulation of aggregate blanks, large particles tend to eat small particles, resulting in the appearance of ultra-large particle size aggregate blanks, which makes it impossible to effectively form a good uniform skeleton and thus affects the formation of permeable bricks.

[0059] The permeable bricks prepared in Examples 1-6 and Comparative Example 1 were tested using the following methods:

[0060] Softening coefficient: determined in accordance with relevant national standards.

[0061] Flexural strength: GB / T 50081.

[0062] Permeability coefficient: JCT 2558-2020.

[0063] Freeze resistance: JCT 2558-2020.

[0064] Abrasion resistance: GB / T 12988.

[0065] Resistance to water erosion: JCT 2558-2020.

[0066] The test results are as follows:

[0067]

[0068] As can be seen from the table above, the addition of water-reducing agents and waterproofing agents has a significant impact on the softening coefficient, strength, mass loss rate, and resistance to water erosion of the molded permeable material. In particular, the adjustment of the waterproofing agent has a fairly significant effect on the indicators of the permeable material.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a permeable material, characterized in that, include: The permeable material is obtained by mixing and grinding gypsum powder, gypsum retarder, gypsum water-reducing agent, gypsum waterproofing agent and water as raw materials, and then immediately adding water to granulate the mixture to obtain aggregate blanks. The aggregate blanks are then immediately put into molds, vibrated and hardened to obtain the permeable material. The raw materials do not contain any external binders, and the external binders include cement, lime, mineral powder, and fly ash; The mass ratio of gypsum powder, gypsum retarder, and water is 100:(0.01~0.03):(27~33). The mass ratio of gypsum powder to gypsum water-reducing agent is 100:(0.01~0.05); the mass ratio of gypsum powder to gypsum waterproofing agent is 100:(0.01~0.05). Before being placed into the mold, the aggregate blanks are selected so that the gradation of the aggregate blanks placed into the mold is 5~20. The gypsum powder is a powdered gypsum with a hemihydrate gypsum content of more than 60% and a dihydrate gypsum content of no more than 5%. The amount of water added during mixing is 10% to 15% of the total mass of the powdered gypsum, and the total water used for mixing to molding is 27% to 33% of the total mass of the powdered gypsum. The time from the start of mixing to the start of vibration is ≤10 minutes, so that the aggregate blank undergoes a hydration reaction and further hardens and solidifies during vibration.

2. The method for preparing the permeable material according to claim 1, characterized in that, The particle size of the powdered gypsum is ≤50μm.

3. The method for preparing the permeable material according to claim 1, characterized in that, The mass fractions of gypsum powder, gypsum retarder, gypsum water-reducing agent, gypsum waterproofing agent, and water are 100 parts, 0.03 parts, 0.03 parts, 0.05 parts, and 30 parts, respectively.

4. The method for preparing the permeable material according to claim 2, characterized in that, The mass fractions of gypsum powder, gypsum retarder, gypsum water-reducing agent, gypsum waterproofing agent, and water are 100 parts, 0.03 parts, 0.03 parts, 0.05 parts, and 30 parts, respectively.

5. The method for preparing the permeable material according to any one of claims 1 to 4, characterized in that, Before being placed into the mold, the aggregate blanks are selected so that the gradation of the aggregate blanks placed into the mold is: 5~10 single gradation or 10~20 single gradation.

6. The method for preparing the permeable material according to claim 5, characterized in that, Before being placed into the mold, the aggregate blank is selected to ensure that the sphericity of the aggregate blank is ≥0.

85.

7. The method for preparing the permeable material according to claim 6, characterized in that, Before being placed into the mold, the aggregate blank is selected to ensure that the sphericity of the aggregate blank is ≥0.

9.

8. The method for preparing the permeable material according to any one of claims 1 to 4, 6, and 7, characterized in that, The vibration is low-frequency vibration and / or lateral impact vibration.

9. The method for preparing the permeable material according to claim 8, characterized in that, The low-frequency vibration is a vertical vibration performed using a vibration table.

10. The method for preparing the permeable material according to claim 9, characterized in that, The low-frequency vibration is intermittent low-frequency vibration.

11. The method for preparing the permeable material according to claim 5, characterized in that, The vibration is low-frequency vibration and / or lateral impact vibration.

12. The method for preparing the permeable material according to claim 11, characterized in that, The low-frequency vibration is a vertical vibration performed using a vibration table.

13. The method for preparing the permeable material according to claim 12, characterized in that, The low-frequency vibration is intermittent low-frequency vibration.

14. The method for preparing the permeable material according to claim 1, characterized in that, The preparation method involves mixing, grinding, granulating, selecting, molding, intermittent low-frequency vibration, and allowing to stand and harden gypsum powder, gypsum retarder, gypsum water-reducing agent, gypsum waterproofing agent, and water as raw materials in sequence.

15. The method for preparing the permeable material according to claim 14, characterized in that, The intermittent low-frequency vibration refers to an interval of ≥30 seconds between two adjacent low-frequency vibrations.

16. A permeable material prepared by the method of any one of claims 1 to 15.

17. The application of the permeable material according to claim 16 in permeable bricks.

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