3D printed lightweight brick partition wall based on carbide slag-slag solidified phosphogypsum sludge material and its manufacturing method

Abstract

The present invention belongs to the technical field of building materials, and specifically relates to a 3D printed lightweight brick partition wall based on a carbide slag-slag solidified phosphogypsum sludge material and a manufacturing method thereof. The carbide slag-slag solidified phosphogypsum sludge material used for the 3D printed lightweight porous brick includes carbide slag, slag, dredged sludge, phosphogypsum and water; the dosage of carbide slag is 4% of the mass of the dredged sludge; the dosage of slag is 10% of the mass of the dredged sludge; the dosage of phosphogypsum is 5% - 70% of the mass of the dredged sludge; the water content in the carbide slag-slag solidified phosphogypsum sludge material accounts for 90 - 100% of the dry weight of the dredged sludge. The present invention uses the carbide slag-slag solidified phosphogypsum sludge as a gelling material for 3D printing, further improving the technical level and efficiency of the resource utilization of the four solid wastes of carbide slag, slag, phosphogypsum and sludge, and at the same time expanding its utilization scope in the construction field; through formula optimization, a 3D printed lightweight brick partition wall with high printing efficiency, high strength and good sound insulation performance is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and particularly relates to a 3D printing lightweight brick partition wall based on a carbide slag-slag solidified phosphogypsum sludge material and a manufacturing method thereof. Background Art

[0002] Utilizing sludge, phosphogypsum, slag, and carbide slag as renewable resources and conducting research on solidifying sludge with industrial waste such as phosphogypsum is beneficial for solving the problem of excessive stacking of sludge and the above-mentioned industrial waste, effectively resource-utilizing sludge and industrial waste, reducing pollution, protecting the ecological environment, and reducing project costs.

[0003] Due to the characteristics of high water content, large compressibility, and low strength of dredged sludge, when it is directly applied to engineering, large deformations and settlements will occur. Mixing phosphogypsum and dredged sludge into matrix soil can reduce the water content of dredged sludge, but since phosphogypsum is not activated, the strength of this matrix soil is relatively low and cannot meet the engineering requirements. At the same time, heavy metal ions, as well as unutilized phosphorus and fluoride ions contained in phosphogypsum, will leach out with water and pollute the surrounding soil and groundwater, causing pollution to the surrounding environment.

[0004] Currently, traditional building materials may generate a large amount of waste during production and construction. Using 3D printing technology can reduce waste generation because materials can be precisely added to the required locations, reducing waste. 3D printing technology can achieve rapid automated production, greatly shortening the time for partition wall manufacturing. This is very beneficial for projects that require rapid construction. Applying 3D printing technology to lightweight partition bricks allows for customized porous bricks during the design and manufacturing stages.

[0005] Carbide slag and slag are usually industrial by-products. By using them in 3D printing, effective utilization of waste can be achieved, promoting sustainable development and environmental protection. As by-products, the acquisition cost of carbide slag and slag may be relatively low, which helps to reduce 3D printing costs, especially during large-scale production. Phosphogypsum usually has a certain strength and durability, making it a suitable choice when constructing 3D printing models. The mixing ratio of sludge can be adjusted to regulate the performance of the printing material. Phosphogypsum can also become a suitable 3D printing material and be used in the field of lightweight partition walls to highlight its durable performance. Phosphogypsum may exhibit good stability in some chemical aspects, which is important for 3D printing applications in masonry engineering environments.

[0006] Currently, although there are also technologies for 3D printing wall materials, there has been no technology that simultaneously utilizes four kinds of waste, namely carbide slag, slag, dredged sludge, and phosphogypsum, to construct materials suitable for 3D printing and can meet the performance requirements such as wall strength and sound insulation. Moreover, the amount of phosphogypsum used in the existing technology is relatively small, which is not conducive to improving the utilization of solid waste. Summary of the Invention

[0007] The object of the present invention is to provide a 3D printed lightweight brick partition wall based on a carbide slag-slag solidified phosphogypsum sludge material and a manufacturing method thereof. The phosphogypsum sludge solidified by carbide slag-slag is used as a gelling material for 3D printing, which improves the technical level and efficiency of the resource utilization of the four major solid wastes of carbide slag, slag, phosphogypsum and sludge. At the same time, through formula optimization, a 3D printed lightweight brick partition wall with high printing efficiency, high strength and good sound insulation performance is obtained, and the use of a large amount of phosphogypsum can be realized, improving the flexibility of phosphogypsum utilization.

[0008] To achieve the above object, in the first aspect, the present invention provides 3D printed lightweight bricks based on a carbide slag-slag solidified phosphogypsum sludge material. The carbide slag-slag solidified phosphogypsum sludge material used for the 3D printed lightweight porous bricks includes: carbide slag, slag, dredged sludge, phosphogypsum and water; the dosage of the carbide slag is 4% of the mass of the dredged sludge; the dosage of the slag is 10% of the mass of the dredged sludge; the dosage of the phosphogypsum is 5% - 70% of the mass of the dredged sludge, and the water content in the carbide slag-slag solidified phosphogypsum sludge material accounts for 90 - 100% of the dry weight of the dredged sludge.

[0009] By incorporating carbide slag and slag, the present invention can change the environment to alkaline, thereby fixing most of the phosphorus, fluorine and heavy metal ions in phosphogypsum and reducing the leaching rate of impurity ions; there are also gelling substances therein, which can promote the hardening and solidification of sludge. In an alkaline environment, the potential gelling materials in slag and phosphogypsum are activated, thereby enhancing the strength of the solidified soil, and enabling the strength of the solidified soil to meet the engineering requirements. At the same time, the present invention also controls the water content, so that the carbide slag-slag solidified phosphogypsum sludge material can not only meet the requirements of 3D printing, ensure the printing efficiency, but also enable the solidified 3D printed lightweight bricks to have high strength and sound insulation performance. In addition, the present invention can also realize the use of a large amount of phosphogypsum, improving the flexibility of phosphogypsum utilization and the maximum utilization amount of phosphogypsum, and providing an effective way for the efficient treatment and utilization of sludge and phosphogypsum.

[0010] As a preferred embodiment of the present invention, the dosage of the phosphogypsum is 50% - 70% of the mass of the dredged sludge, and the water content in the carbide slag-slag solidified phosphogypsum sludge material accounts for 90% of the dry weight of the dredged sludge. Experimental results show that when the water content accounts for 90% of the dry weight of the dredged sludge, lightweight bricks with good strength and sound insulation performance and convenient for printing can be obtained within a large range of phosphogypsum dosages.

[0011] As a preferred embodiment of the present invention, the dosage of the carbide slag is 4% of the mass of the dredged sludge; the dosage of the slag is 10% of the mass of the dredged sludge; the dosage of the phosphogypsum is 70% of the mass of the dredged sludge, and the water content in the carbide slag-slag solidified phosphogypsum sludge material accounts for 90% of the dry weight of the dredged sludge.

[0012] As a preferred embodiment of the present invention, the water content of the dredged sludge used is 0-50%, that is, the sludge can be used after being dried, or it can be used directly, but it is necessary to ensure that the water content in the final carbide slag-slag solidified phosphogypsum sludge material accounts for 90-100% of the dry weight of the dredged sludge. When preparing the ingredients, first measure the water content in the dredged sludge, and then calculate the amount of water to be added. If the water content in the dredged sludge itself has exceeded the preset value, it is necessary to carry out water treatment first.

[0013] As a preferred embodiment of the present invention, the average particle size of the phosphogypsum is 40μm-200μm, the specific surface area of the slag is 300m 2 / kg, and the average particle size of the carbide slag is 1.89μm.

[0014] The slag used in the present invention refers to blast furnace slag. Slag generally mainly consists of oxides, silicates, sulfides and other metal compounds. The main components of carbide slag are calcium hydroxide (Ca(OH)2) and calcium chloride (CaCl2), and may also contain a small amount of other chlor-alkali compounds and impurities. The main components of phosphogypsum are the same as those of natural gypsum, both being calcium sulfate dihydrate (CaSO4·2H2O).

[0015] The main component of phosphogypsum is calcium sulfate (CaSO4), but it usually also contains a small amount of phosphates, heavy metals and other impurities.

[0016] As a preferred embodiment of the present invention, the 3D printed lightweight bricks are porous bricks with dimensions of 300mm*300mm*100mm, the diameter of a single hole is 12mm, and each brick has a total of 21 holes.

[0017] Furthermore, the preparation method of the carbide slag-slag solidified phosphogypsum sludge material includes:

[0018] Step 1, mix 60 parts by weight of carbide slag and 150 parts by weight of slag evenly;

[0019] Step 2, mix 1500 parts by weight of dredged sludge and 75-1050 parts by weight of phosphogypsum evenly;

[0020] Step 3, mix and stir evenly the two groups of mixed materials obtained in Step 1 and Step 2;

[0021] Step 4: Add water and stir for 5 - 6 minutes to obtain the carbide slag - slag - solidified phosphogypsum sludge material.

[0022] The carbide slag - slag - solidified phosphogypsum sludge material is a new type of material. The carbide slag contains components such as silicate, and these components have cementitious properties, which can promote the cementitious reaction between the sludge and phosphogypsum to form a solid structure. The slag often contains components such as silicate and alumina, which have the properties of a cementing agent and can promote the hardening and solidification of the sludge. The addition of slag can improve the compressive strength, impermeability, and durability of the solidified material. The sludge and phosphogypsum, as the objects to be solidified, provide a certain volume, and at the same time, their particle structure can fill the gaps between the carbide slag and slag to form a uniform solid structure. The sludge and phosphogypsum undergo chemical reactions with the carbide slag and slag during the solidification process to form new solid phases. The cementitious components in the carbide slag and slag may have a mutually enhancing effect with the sludge and phosphogypsum, improving the overall solidification effect. Under the action of the carbide slag and slag, the sludge and phosphogypsum form a uniform and dense structure, which helps to improve the mechanical properties of the solidified material.

[0023] In the second aspect, the present invention provides a 3D - printed lightweight brick partition wall based on the carbide slag - slag - solidified phosphogypsum sludge material, which is obtained by stacking the 3D - printed lightweight bricks described in any one of the above. Using the carbide slag - slag - solidified phosphogypsum sludge material as the 3D - printing material to make the building blocks for the lightweight partition wall is an innovation in technology. The lightweight characteristics of the carbide slag - slag - solidified phosphogypsum sludge material reduce the burden on the partition wall, and at the same time, fully improve the heat insulation and sound insulation performance, which helps to improve the living comfort and energy efficiency.

[0024] In the third aspect, the present invention provides a method for manufacturing a 3D - printed lightweight brick partition wall, including the following steps:

[0025] Step 1: Use CAD software to divide the lightweight brick partition wall into an appropriate number of 3D - printed lightweight bricks, and use 3D slicing software to make it into a 3D model that can be 3D - printed.

[0026] Step 2: Using the carbide slag - slag - solidified phosphogypsum sludge material as the printing raw material, through 3D printing, sequentially produce 3D - printed lightweight bricks one by one, using a special nozzle of the 3D printer.

[0027] Step 3: After the 3D - printed lightweight bricks are printed, perform surface treatment. After removing the printing burrs, perform grinding and polishing, and apply a protective varnish to the exposed surface to obtain the 3D - printed lightweight bricks.

[0028] Step 4: Stack the 3D - printed lightweight bricks on the site in sequence. After applying cement mortar, stack them block by block and layer by layer, using the method of staggered joints up and down.

[0029] Step 5: After the production is completed, water is sprinkled and cured for 7 days, and then cured under outdoor conditions for 28 days to obtain the lightweight brick partition wall.

[0030] Furthermore, the diameter of the printer-specific nozzle is 0.8 cm.

[0031] The application of carbide slag-slag solidified phosphogypsum sludge material in lightweight brick partition walls improves the strength, durability and sound insulation performance of the partition walls, and has the advantages of simple production process and effective reduction of production costs.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention uses carbide slag-slag solidified phosphogypsum sludge as a material for 3D printing, expanding the scope of solid waste utilization and improving the technical level and efficiency of resource utilization; using this material in lightweight partition wall materials has high construction efficiency, and can obtain lightweight, sound-insulating, and environmentally friendly 3D-printed walls that can have the functions of both walls and panels, helping to reduce structural costs, improve the seismic resistance of buildings, fully improve thermal insulation and sound insulation performance, and help improve living comfort and energy efficiency.

[0034] 2. Carbide slag contains silicates and other components with gelling properties, which can promote the gelling reaction between silt and phosphogypsum, forming a solid structure. Slag often contains silicates, alumina and other components with gelling properties, which can promote the hardening and solidification of silt. As the objects of solidification, silt and phosphogypsum provide a certain volume. At the same time, their particle structure can also fill the gaps between the carbide slag and slag, forming a uniform solid structure, improving the overall solidification effect, and helping to enhance the mechanical properties of the cured material.

[0035] 3. The present invention can achieve the use of phosphogypsum in a larger dosage range, improve the flexibility of phosphogypsum utilization and the maximum utilization of phosphogypsum, and provide an effective way for the efficient treatment and utilization of sludge and phosphogypsum. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic structural diagram of the porous bricks printed according to an embodiment of the present invention.

[0037] Figure 2 Schematic diagram of the front and side structures of the masonry wall obtained according to an embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram of the interlocking effect of porous bricks.

[0039] Figure 4 This is a schematic diagram of the interlocking effect of porous bricks.

[0040] Figure 5Is the unconfined compressive strength with different dosages of phosphogypsum.

[0041] In the figure, 1 - porous brick; 2 - cement mortar; 3 - vertical mortar joint. Specific implementation mode

[0042] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0043] Embodiment 1

[0044] The phosphogypsum sludge solidified by carbide slag - slag provided in this embodiment has the following components and parts by weight: 1500 parts of dredged sludge (taken from the Xunsi River in Wuhan, referring to the dried sludge, that is, the water content of the sludge itself is 0%, the same for Embodiments 2 - 4 and will not be repeated), 150 parts of slag (taken from Wuhan Hanguang Iron and Steel Group Co., Ltd.), with a specific surface area of 300m 2 / kg, 150 parts of phosphogypsum (taken from Hubei Huangmailing Phosphochemical Group), with an average particle size of 140μm; 60 parts of carbide slag (taken from Shanxi Ruiheng Chemical Co., Ltd., the sources of the raw materials in the following Embodiments 2 - 4 are the same as those in Embodiment 1 and will not be repeated), with an average particle size of 1.89μm. Add water according to 90% of the water content in the carbide slag - slag solidified phosphogypsum sludge material accounting for the dry weight of the dredged sludge, that is, 1350 parts of water. The bricks used in the lightweight brick partition wall in this embodiment are new lightweight porous bricks obtained by 3D printing the phosphogypsum sludge solidified by carbide slag - slag, with dimensions of 300mm * 300mm * 100mm, and the masonry method is the staggered joint method up and down.

[0045] The construction method of the lightweight brick partition wall in this embodiment is as follows: Prepare the phosphogypsum sludge solidified by carbide slag - slag as the material for 3D printing. Use CAD software to divide the lightweight brick wall into an appropriate number of 3D printed lightweight bricks based on the phosphogypsum sludge material solidified by carbide slag - slag, and use 3D slicing software to prepare it into a 3D model that can be 3D printed. Then, perform 3D printing. Specifically as follows:

[0046] Step 1, mix 60 parts of carbide slag and 150 parts of slag evenly;

[0047] Step 2, mix 1500 parts of dredged sludge and 150 parts of phosphogypsum evenly;

[0048] Step 3, mix the two groups of mixed materials evenly;

[0049] Step 4: Add water to the two groups of mixture and stir for 5 - 6 minutes to obtain the carbide slag - slag - solidified phosphogypsum sludge material;

[0050] Step 5: Through a 3D printing machine, using a 0.8 cm special nozzle for 3D printer, sequentially produce 3D printed block porous bricks based on carbide slag - slag - solidified phosphogypsum sludge, with a single - hole diameter of 12 mm and a total of 21 holes in one brick. Its structure is as Figure 1 shown;

[0051] Step 6: After the printing of the block porous bricks is completed, perform surface treatment. After removing the printing burrs, carry out grinding and polishing treatment, and apply protective varnish on the exposed surface;

[0052] Step 7: Stack the 3D printed block porous bricks on the site in sequence. After applying cement mortar, stack them block by block and layer by layer, using the method of staggering joints up and down, and finally complete the production of the masonry wall;

[0053] Step 8: After the production is completed, sprinkle water for curing for 7 days, keep the water temperature at 20℃ - 25℃, and then cure under outdoor conditions until 28 days to obtain the said masonry wall.

[0054] The height * width * thickness of the lightweight brick partition wall in this embodiment is 1000 mm * 2400 mm * 300 mm, and its structural schematic diagram is as Figures 2 - 4 shown.

[0055] Example 2

[0056] For the carbide slag - slag - solidified phosphogypsum sludge in this embodiment, its components and parts by weight are: dredged sludge 1500 parts, slag 150 parts, specific surface area of 300 m 2 / kg, phosphogypsum 750 parts, average particle size of 140 μm, carbide slag 60 parts, average particle size of 1.89 μm, and water is added according to 90% of the dry weight of the dredged sludge in the carbide slag - slag - solidified phosphogypsum sludge material. The bricks used for the lightweight brick partition wall in this embodiment are new lightweight porous bricks obtained by 3D printing of carbide slag - slag - solidified phosphogypsum sludge, with dimensions of 300 mm * 300 mm * 100 mm, and the masonry method is staggering joints up and down.

[0057] The construction method of the lightweight brick partition wall in this embodiment is: Prepare carbide slag - slag - solidified phosphogypsum sludge as the material for 3D printing. Using CAD software, divide the lightweight brick wall into an appropriate number of 3D printed lightweight bricks based on carbide slag - slag - solidified phosphogypsum sludge material, and use 3D slicing software to prepare it into a 3D model that can be 3D printed. Then, carry out 3D printing. Specifically as follows:

[0058] Step 1: Mix evenly 60 parts of carbide slag and 150 parts of slag;

[0059] Step 2: Mix 1500 parts of dredged sludge and 750 parts of phosphogypsum evenly.

[0060] Step 3: Mix the two groups of mixtures evenly by stirring.

[0061] Step 4: Add water to the two groups of mixtures and stir for 5 - 6 minutes to obtain the carbide slag - slag - solidified phosphogypsum sludge material.

[0062] Step 5: Through a 3D printing machine, using a 0.8 cm special nozzle for 3D printers, sequentially produce 3D - printed lightweight bricks based on the carbide slag - slag - solidified phosphogypsum sludge material, with a single - hole diameter of 12 mm and a total of 21 holes in one brick. Its structure is as Figure 1 shown;

[0063] Step 6: After the block perforated bricks are printed, conduct surface treatment. After removing the printing burrs, carry out grinding and polishing treatments, and apply a protective varnish to the exposed surface.

[0064] Step 7: Stack the 3D - printed block perforated bricks on the site in sequence. After applying cement mortar, stack them block by block and layer by layer, using the method of staggering joints up and down, and finally complete the production of the masonry wall.

[0065] Step 8: After production, sprinkle water for curing for 7 days, keep the water temperature at 20°C - 25°C, and then cure under outdoor conditions for 28 days to obtain the masonry wall.

[0066] The height * width * thickness of the lightweight brick partition wall in this embodiment is 1000 mm * 2400 mm * 300 mm. Its structural schematic diagram is as Figures 2 - 4 shown.

[0067] Example 3

[0068] For the carbide slag - slag - solidified phosphogypsum sludge in this embodiment, its components and parts by weight are: 1500 parts of dredged sludge, 150 parts of slag, with a specific surface area of 300 m 2 / kg, 1050 parts of phosphogypsum, with an average particle size of 140 μm, 60 parts of carbide slag, with an average particle size of 1.89 μm, and add water according to 90% of the dry weight of the dredged sludge in the water content of the carbide slag - slag - solidified phosphogypsum sludge material. The bricks used for the lightweight brick partition wall in this embodiment are new lightweight perforated bricks 3D - printed from the carbide slag - slag - solidified phosphogypsum sludge, with dimensions of 300 mm * 300 mm * 100 mm, and the masonry method is the staggered - joint method up and down.

[0069] The construction method of the lightweight brick partition wall in this embodiment is as follows: Prepare the phosphogypsum sludge solidified by carbide slag - slag as the material for 3D printing. Using CAD software, divide the lightweight brick wall into an appropriate number of 3D printed lightweight bricks based on the carbide slag - slag solidified phosphogypsum sludge material, and use 3D slicing software to prepare it into a 3D model that can be 3D printed. Then, perform 3D printing. Specifically as follows:

[0070] Step 1: Mix 60 parts of carbide slag and 150 parts of slag evenly;

[0071] Step 2: Mix 1500 parts of dredged sludge and 1050 parts of phosphogypsum evenly;

[0072] Step 3: Stir the two groups of mixtures evenly;

[0073] Step 4: Add water to the two groups of mixtures and stir for 5 - 6 minutes to obtain the carbide slag - slag solidified phosphogypsum sludge material;

[0074] Step 5: Through a 3D printing machine, use a 0.8 cm special nozzle for 3D printers to sequentially produce 3D printed lightweight bricks based on the carbide slag - slag solidified phosphogypsum sludge material. The single - hole diameter is 12 mm, and each brick has 21 holes. Its structure is as Figure 1 shown;

[0075] Step 6: After the block perforated bricks are printed, perform surface treatment. After removing the printing burrs, perform grinding and polishing, and apply a protective varnish to the exposed surface;

[0076] Step 7: Stack the 3D printed block perforated bricks on the site in sequence. After applying cement mortar, stack them block by block and layer by layer, using the method of staggering joints up and down, and finally complete the production of the masonry wall;

[0077] Step 8: After production, sprinkle water for curing for 7 days, keep the water temperature at 20°C - 25°C, and then cure under outdoor conditions for 28 days to obtain the masonry wall.

[0078] The height * width * thickness of the lightweight brick partition wall in this embodiment is 1000 mm * 2400 mm * 300 mm, and its structural schematic diagram is as Figures 2 - 4 shown.

[0079] Example 4

[0080] On the basis of Example 3, change the water content in the carbide slag - slag solidified phosphogypsum sludge to 100% of the dry weight of the dredged sludge to test its fluidity suitable for 3D printing. The carbide slag - slag solidified phosphogypsum sludge in this embodiment has the following components and weight parts: dredged sludge 1500 parts, slag 150 parts, specific surface area of 300 m 2 / kg, 150 parts of phosphogypsum with an average particle size of 140 μm, 60 parts of carbide slag with an average particle size of 1.89 μm, and water is added according to the content of water in the carbide slag-slag solidified phosphogypsum silt being 100% of the dry weight of the dredged silt, that is, 1500 parts of water. The bricks used for the lightweight brick partition wall in this embodiment are new lightweight porous bricks obtained by 3D printing the carbide slag-slag solidified phosphogypsum silt, with dimensions of 300 mm * 300 mm * 100 mm, and the masonry method is the staggered joint method up and down.

[0081] The construction method of the lightweight brick partition wall in this embodiment is as follows: Prepare the carbide slag-slag solidified phosphogypsum silt as the material for 3D printing. Using CAD software, divide the lightweight brick wall into an appropriate number of 3D printed lightweight bricks based on the carbide slag-slag solidified phosphogypsum silt material, and use 3D slicing software to prepare it into a 3D model that can be 3D printed. Then, perform 3D printing. Specifically as follows:

[0082] Step 1, Mix 60 parts of carbide slag and 150 parts of slag evenly;

[0083] Step 2, Mix 1500 parts of dredged silt and 150 parts of phosphogypsum evenly;

[0084] Step 3, Mix the two groups of mixtures evenly by stirring;

[0085] Step 4, Add 1500 parts of water to the two groups of mixtures and stir for 5 - 6 minutes to obtain the carbide slag-slag solidified phosphogypsum silt material;

[0086] Step 5, Through a 3D printing machine, use a 0.8 cm 3D printer special nozzle to sequentially produce 3D printed lightweight bricks based on the carbide slag-slag solidified phosphogypsum silt material, with a single hole diameter of 12 mm, and a total of 21 holes in one brick. Its structure is as Figure 1 shown;

[0087] Step 6, After the printing of the block porous bricks is completed, perform surface treatment. After removing the printing burrs, perform grinding and polishing treatments, and apply a protective varnish to the exposed surface;

[0088] Step 7, Stack the 3D printed block porous bricks on the site in sequence. After applying cement mortar, stack them block by block and layer by layer, using the staggered joint masonry method up and down, and finally complete the production of the masonry wall;

[0089] Step 8, After the production is completed, sprinkle water for curing for 7 days, keep the water temperature at 20°C - 25°C, and then cure under outdoor conditions for 28 days to obtain the masonry wall.

[0090] The height * width * thickness of the lightweight brick partition wall in this embodiment = 2400 mm * 300 mm * 1000 mm, and its structural schematic diagram is as Figures 2 - 4as shown

[0091] Table 1 Formulation Composition of Examples 1 - 4

[0092]

[0093] Among them, the moisture content in Table 1 refers to the percentage of the water content in the carbide slag - slag solidified phosphogypsum silt material to the dry weight of the dredged silt.

[0094] Test Example 1

[0095] The flow value and 28 - day unconfined compressive strength of the carbide slag - slag solidified phosphogypsum silt materials prepared in Examples 1 - 4 were tested.

[0096] 1) The steps for testing the flow value are as follows:

[0097] Step 1: Place a cylindrical slump test cylinder with a diameter and height of 8 cm on a flat rectangular plexiglass plate. Wipe the dust on the inner wall of the slump cylinder and the surface of the plexiglass plate with a damp cloth, which also serves to slightly moisten them.

[0098] Step 2: Fill the slump cylinder with the freshly and evenly stirred silt fluid soil (the mixture obtained in Step 4), and scrape the surface of the cylinder flat with a scraper. Wipe off the spillage on the cylinder wall and the plexiglass plate surface, then quickly lift the slump cylinder, and measure the maximum diameter and the minimum diameter of the spread silt fluid soil. The average value of the two is the flow value of the fluid soil.

[0099] Step 3: During the test, in order to avoid the influence of the thixotropic effect, the slump cylinder needs to be lifted as soon as possible, and the lifting time should be within 10 seconds. The entire test process should be completed within 1 minute.

[0100] 2) The steps for testing the 28 - day unconfined compressive strength are as follows:

[0101] Step 1: First, fill the cylindrical mold with a diameter of 39.1 mm and a height of 80 mm with the silt fluid soil in three layers. Each layer needs to be vibrated sufficiently to expel the air inside, and then the next layer is filled until it is full. Three parallel samples need to be made for the solidified silt of each mixture ratio. Then place the specimens loaded into the mold in a constant temperature and humidity curing box at 20°C and humidity > 95% for curing;

[0102] Step 2: The unconfined compressive strength test is carried out with reference to the "Standard for Geotechnical Test Methods". The equipment used is the YYW - 2 type electric strain - controlled unconfined pressure instrument produced by Nanjing Ningxi Soil Instrument Co., Ltd. Before the test, apply a layer of vaseline to both ends of the specimen, and control the axial strain rate to 1 mm / min. Three parallel samples are measured for each group of tests for comparison and verification, and the strength result takes its average value.

[0103] Table 2 Performance test results of phosphogypsum sludge solidified by carbide slag-slag in Examples 1 to 4

[0104] Serial number Flow value (mm) Unconfined compressive strength at 28 days (MPa) Example 1 150 mm 1.747 Example 2 85 mm 1.848 Example 3 80 mm 2.431 Example 4 190 mm 1.577

[0105] The flowability of Example 4 is 190 mm, a 27% increase compared to Example 1. This is because increasing the water content leads to an increase in the flowability, while decreasing the water content of the phosphogypsum sludge material decreases the flowability. Excessively high water content increases the flowability of the phosphogypsum sludge material, but reduces its strength. Excessively low water content can improve its strength, but it can also result in excessively low flowability, making it difficult to print. Therefore, the present invention controls the water content of the carbide slag-slag solidified phosphogypsum sludge material to 90-100%, preferably 90%, of the dry weight of the dredged sludge. Under these conditions, a wide range of phosphogypsum content can be achieved while maintaining high printing efficiency, demonstrating the practicality and universality of the present formulation. The optimal 28-day unconfined compressive strength is achieved when the dredged sludge has a water content of 90% and a phosphogypsum content of 70% by weight. It can be seen that the present invention can obtain materials with relatively excellent strength by adding only a small amount of carbide slag and slag under high dredged sludge and phosphogypsum dosage, thereby significantly improving the secondary utilization rate of solid waste.

[0106] As shown in Table 1, the carbide slag-slag solidified phosphogypsum sludge materials prepared in Examples 1 to 3 have good fluidity and are suitable for 3D printing. Their 28d unconfined compressive strength meets the strength requirements for lightweight partition walls.

[0107] like Figure 5 (pg in the figure represents phosphogypsum) is the unconfined compressive strength of the phosphogypsum sludge material solidified by carbide slag-slag obtained with different phosphogypsum contents (relative to the mass content of the dredged sludge, the other components are the same as in Example 1). It can be seen that with the increase of the phosphogypsum content, the unconfined compressive strength basically shows a gradual increasing trend.

[0108] The sound insulation performance test method involves testing two adjacent rooms with a lightweight brick partition wall made from 300mm-thick calcium carbide slag-slag-solidified phosphogypsum sludge. A standard sound source is installed in one of the rooms. A low-frequency signal generator generates a standard, constant-amplitude 600Hz audio signal, which is amplified by a power amplifier and converted to 600Hz sound through a speaker. The amplifier's output power is adjusted to ensure the sound pressure in the room exceeds 115dB. A sound pressure meter is used on both sides of the partition wall between the room and the adjacent room to record the sound pressure (in decibels). According to the "Residential Design Code" (GB50096-1999), the weighted sound insulation value of airborne sound between partition walls and floor slabs in bedrooms and living rooms should be greater than or equal to 40dB. The sound insulation performance of the masonry material is then determined, and corresponding conclusions drawn.

[0109] Table 3 Performance test results of lightweight brick partition walls obtained in Examples 1 to 4

[0110] Serial number Block printing efficiency Sound insulation performance (weighted sound insulation value under the condition of 600 Hz) Example 1 57 minutes / block 62 dB Example 2 61 minutes / block 62 dB Example 3 62 minutes / block 66 dB Example 4 50 minutes / block 60 dB

[0111] Performance tests of the lightweight brick partition walls obtained from carbide slag-slag solidified phosphogypsum sludge materials in Examples 1 to 4 showed that the sound insulation performance of the 3D-printed lightweight brick partition walls based on carbide slag-slag solidified phosphogypsum sludge materials meets and exceeds the "Residential Design Code" (GB50096-1999) standard for airborne sound insulation between partition walls and floor slabs in bedrooms and living rooms (halls) of residential buildings, which requires a weighted sound insulation value of greater than or equal to 40dB. Compared with traditional prefabrication processes, the efficiency of single-block construction is shortened by 70%-80%; production time is reduced by 60%-80%. The blocks are directly printed and formed, without the need for formwork and supporting materials. There is no mud, sand, bricks, or dust on site, which reduces construction noise pollution and the amount of waste generated.

[0112] In summary, the present invention uses carbide slag-slag solidified phosphogypsum sludge as a 3D printing material to produce lightweight partition wall blocks. Through material properties and experimental research, the fluidity is adapted to the 3D printing nozzle and affects its printing speed, thereby improving the efficiency of engineering construction and better solving practical problems.

[0113] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A 3D printed lightweight brick based on carbide slag-slag solidified phosphogypsum sludge material, characterized in that, The carbide slag-slag solidified phosphogypsum sludge material used in the 3D printed lightweight bricks is prepared from carbide slag, slag, dredged sludge, phosphogypsum and water; the dosage of the carbide slag is 4% of the mass of the dredged sludge; the dosage of the slag is 10% of the mass of the dredged sludge; the dosage of the phosphogypsum is 70% of the mass of the dredged sludge, and the water content in the carbide slag-slag solidified phosphogypsum sludge material accounts for 90-100% of the dry weight of the dredged sludge; The average particle size of the phosphogypsum is 40 μm to 200 μm, the specific surface area of the slag is 300 m 2 / kg, and the average particle size of the carbide slag is 1.89 μm.

2. The 3D printed lightweight brick based on the carbide slag-slag solidified phosphogypsum sludge material according to claim 1, wherein The water content in the carbide slag-slag solidified phosphogypsum sludge material accounts for 90% of the dry weight of the dredged sludge.

3. The 3D printed lightweight brick based on the carbide slag-slag solidified phosphogypsum sludge material according to claim 1, characterized in that, The water content of the dredged sludge is 0-50%.

4. The 3D printed lightweight brick based on the carbide slag-slag solidified phosphogypsum sludge material according to any one of claims 1-3, characterized in that, The 3D printed lightweight bricks are porous bricks with dimensions of 300mm * 300mm * 100mm, the diameter of a single hole is 12mm, and each brick has a total of 21 holes.

5. The 3D printed lightweight brick based on the carbide slag-slag solidified phosphogypsum sludge material according to any one of claims 1-3, characterized in that, The carbide slag-slag solidified phosphogypsum sludge material is prepared by the following method: Step 1, mix 60 parts by weight of carbide slag and 150 parts by weight of slag evenly; Step 2, mix 1500 parts by weight of dredged sludge and 1050 parts by weight of phosphogypsum evenly; Step 3, mix and stir evenly the two groups of mixed materials obtained in Step 1 and Step 2; Step 4, add water and stir for 5-6 minutes to obtain the carbide slag-slag solidified phosphogypsum sludge material.

6. A 3D printed lightweight brick partition wall made of carbide slag-slag solidified phosphogypsum sludge material, characterized in that, Stacked by the 3D printed lightweight bricks described in any one of claims 1-5.

7. The manufacturing method of the 3D printed lightweight brick partition wall according to claim 6, characterized in that, Including the following steps: Step 1, use CAD software to divide the lightweight brick partition wall into an appropriate number of 3D printed lightweight bricks, and use 3D slicing software to make it into a 3D model that can be 3D printed; Step 2, use the carbide slag-slag solidified phosphogypsum sludge material as the printing raw material, and through 3D printing, produce 3D printed lightweight bricks one by one in sequence, using a special printer nozzle; Step 3, after the 3D printed lightweight bricks are printed, perform surface treatment. After removing the printing burrs, perform grinding and polishing treatment, and apply a protective varnish to the exposed surface to obtain the 3D printed lightweight bricks; Step 4, stack the 3D printed lightweight bricks on the site in sequence. After applying cement mortar, stack them block by block and layer by layer, using the method of staggering joints up and down; Step 5, after production, sprinkle water and cure for 7 days, and then cure under outdoor conditions until 28 days to obtain the lightweight brick partition wall.

8. The manufacturing method of the 3D printed lightweight brick partition wall according to claim 7, characterized in that, The diameter of the special printer nozzle is 0.8 cm.

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