Phosphogypsum wallboard and preparation method thereof

Abstract

The invention discloses a phosphogypsum wallboard and a preparation method thereof, and belongs to the technical field of wallboards. The phosphogypsum wallboard is prepared from 70.8 parts of phosphogypsum, 17.7 parts of deaminated manganese slag, 0 to 10 parts of mineral powder, 0 to 2 parts of calcium oxide, 0.6 to 0.8 part of organic modifier and 58 to 60 parts of water. The phosphogypsum and mineral powder are dried and ground into powder; then adding ardealite, mineral powder, deaminated manganese slag and calcium oxide into a container for mixing; adding an organic modifier and water, uniformly stirring to obtain slurry, pouring the slurry into a mold, standing, molding, and demolding; and finally, curing and forming to obtain the phosphogypsum wallboard. On the basis of a multi-source solid waste synergistic utilization theory, deaminated manganese residues and phosphogypsum are synergistically used for preparing the fabricated wallboard, mineral powder with volcanic ash activity and an organic modifier are doped for tempering and modification, the softening coefficient and physical and mechanical properties of the wallboard are improved, the full-solid-waste wallboard with excellent performance is produced, and the resource utilization approach of electrolytic manganese residues and phosphogypsum is widened.

Description

Technical Field

[0001] The invention belongs to the technical field of wallboards, and particularly relates to a phosphogypsum wallboard and a preparation method thereof. Background Art

[0002] Phosphogypsum is an acidic solid waste residue produced during the wet process of phosphoric acid production. Approximately five tons of phosphogypsum are emitted for every ton of phosphoric acid produced. Currently, the comprehensive utilization rate of phosphogypsum is low, and large amounts of phosphogypsum stockpiles pose a potential environmental pollution risk. Building materials are one of the primary areas where phosphogypsum is being utilized, replacing natural gypsum in the production of gypsum wallboard, gypsum bricks, and gypsum blocks. Wallboards, in particular, can be used in standardized prefabricated buildings, offering high construction efficiency and remaining a primary utilization method for phosphogypsum.

[0003] Phosphogypsum, with its lightweight, high-strength, and thermal insulation properties, effectively reduces wall weight when used as a wall material. Its production process is relatively simple and energy-efficient, aligning with the concept of green production. The vigorous development of new wall materials like phosphogypsum not only conserves land and transforms waste into valuable resources, but also helps address the pollution caused by the large-scale accumulation of phosphogypsum. Using phosphogypsum as the primary raw material for prefabricated wallboards, combined with other industrial waste residues as supplementary materials, not only increases the utilization rate of industrial solid waste but also enhances the overall performance of the wallboards.

[0004] However, phosphogypsum is slightly soluble and hygroscopic, and the wallboards used to prepare it have a small softening coefficient. It is prone to mildew in warm and humid climates, has low user acceptance, and is difficult to promote in the market. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a phosphogypsum wallboard and a preparation method thereof, which solve the problems in the prior art.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A phosphogypsum wallboard comprises the following raw materials in parts by weight: 70.8 parts of phosphogypsum, 17.7 parts of deaminated manganese slag, 0-10 parts of mineral powder, 0-2 parts of calcium oxide, 0.6-0.8 parts of an organic modifier and 58-60 parts of water.

[0008] Furthermore, the preparation process of the deaminated manganese slag includes: mixing and stirring electrolytic manganese slag, malonic acid, ascorbic acid and deionized water, filtering the mixed solution, drying and calcining, and finally grinding to obtain the deaminated manganese slag;

[0009] Furthermore, the mass ratio of electrolytic manganese slag, malonic acid, ascorbic acid and deionized water is 25:1.5:3:125.

[0010] Furthermore, the particle size of the deammonified manganese slag after grinding is 60-74 μm.

[0011] Furthermore, the stirring speed is 400 r / min, the stirring time is 45 min, and the calcination temperature is 180°C.

[0012] Furthermore, the organic modifier includes: stearic acid, potassium methyl silicate or liquid paraffin.

[0013] Furthermore, the mass fraction of calcium oxide is 1.5 parts.

[0014] The above-mentioned method for preparing a phosphogypsum wallboard comprises the following steps:

[0015] S1, drying and grinding phosphogypsum and mineral powder into powder;

[0016] S2, adding phosphogypsum, mineral powder, deaminated manganese slag and calcium oxide into a container and mixing; then adding an organic modifier and water and stirring evenly to obtain a slurry, and pouring the slurry into a mold, allowing it to stand for forming and then demolding;

[0017] S3, after demoulding, the test block is cured and formed to obtain the phosphogypsum wallboard.

[0018] Furthermore, the curing temperature is 20° C., the curing humidity is 90%, and the curing age is 28 days.

[0019] A prefabricated building comprises the above-mentioned phosphogypsum wallboard.

[0020] Beneficial effects of the present invention:

[0021] 1. Based on the theory of synergistic utilization of multi-source solid waste, the present invention synergistically prepares prefabricated wall panels with deammonified manganese slag and phosphogypsum, and adds mineral powder with volcanic ash activity and organic modifiers for tempering and modification, thereby improving the softening coefficient and physical and mechanical properties of the wall panels, producing all-solid waste wall panels with excellent performance, and broadening the resource utilization path of electrolytic manganese slag and phosphogypsum.

[0022] 2. This invention makes full use of the sulfur, calcium and silicon resources in manganese slag to produce low-energy, low-cost, high-performance, and secondary-pollution-free all-solid waste wallboards with good flexural and compressive strength and softening coefficient, effectively solving the problems of slight solubility and softening, moisture absorption and mildew, poor water resistance, and low user acceptance of phosphogypsum wallboards.

[0023] 3. The present invention incorporates appropriate amounts of mineral powder and calcium oxide to create an alkaline environment within the test block, generating CSH gel or ettringite. The CSH tightly encapsulates the gypsum and ettringite, interlocking them within the slurry and improving the mechanical properties of the test block. Organic modifiers are added to coat the surface of the gypsum crystals or fill the pores, forming a hydrophobic film that effectively isolates water molecules from the gypsum and improves the water resistance of the test block. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 The present invention is a flow chart of the preparation method of the phosphogypsum wallboard. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] A phosphogypsum wallboard comprises the following raw materials in parts by weight: 70.8 parts of phosphogypsum, 17.7 parts of deaminated manganese slag, 0-10 parts of mineral powder, 0-2 parts of calcium oxide, 0.6-0.8 parts of an organic modifier, and 58-60 parts of water.

[0028] Wherein, the preparation steps of deammoniation manganese slag include:

[0029] Electrolytic manganese slag, malonic acid, ascorbic acid, and deionized water are poured into a container and mixed, and then stirred in an electric stirring device. After stirring, the mixed solution is filtered, the filter cake is dried, and then calcined in a box-type gradient electric furnace, and ground into a fine powder of 60-74 μm to obtain deaminated manganese slag; wherein the mass ratio of electrolytic manganese slag, malonic acid, ascorbic acid, and deionized water is 25:1.5:3:125;

[0030] The stirring speed of the electric stirring device is 400 r / min, and the stirring time is 45 min; the calcination temperature in the box-type gradient electric furnace is 180° C.

[0031] The mineral powder is of S95 grade, and its main components are CaO, SiO2, Al2O3, and MgO.

[0032] Organic modifiers include: stearic acid, potassium methyl silicate or liquid paraffin;

[0033] like Figure 1 As shown, based on the above raw materials, the preparation steps of the phosphogypsum wallboard include:

[0034] S1, drying the phosphogypsum and mineral powder in a constant temperature drying oven for 8 hours, grinding them into 60-74 μm fine powder using a horizontal ball mill, and setting aside;

[0035] S2, adding phosphogypsum, mineral powder, deaminated manganese slag, and calcium oxide into a container for dry mixing; then adding an organic modifier and water and stirring evenly to obtain a slurry, and pouring the slurry into a mold with a size of 160 mm × 40 mm × 40 mm, allowing it to stand for forming, and then demolding;

[0036] S3, finally placing the demoulding test block in a curing box for curing, and curing and shaping to obtain the phosphogypsum wallboard; wherein the temperature in the curing box is 20° C., the humidity is 90%; and the curing age is 28 days.

[0037] The technical solution of the present invention is specifically described below by the following examples; the amounts of raw materials used in Examples 1-7 are shown in Table 1 below:

[0038] Table 1 Raw material addition table of Examples 1-7

[0039]

[0040]

[0041] Example 1

[0042] S1. Preparation of deaminated manganese slag: 25 parts of electrolytic manganese slag, 1.5 parts of malonic acid, 3 parts of ascorbic acid, and 125 parts of deionized water were poured into a container and mixed. After mixing, the mixture was placed in an electric stirring device at 400 r / min and stirred for 45 minutes. After stirring, the mixed solution was filtered, the filter cake was dried, and then calcined in a box-type gradient electric furnace at 180° C. and ground into a fine powder of 60-74 μm for later use.

[0043] S2. Raw material processing: Dry the phosphogypsum in a constant temperature drying oven for 8 hours, grind it into 60-74 μm fine powder using a horizontal ball mill, and set aside;

[0044] S3. Pour 17.7 parts of deaminated manganese slag prepared in S1, 70.8 parts of phosphogypsum prepared in S2, and 1.5 parts of calcium oxide into a container and mix the dry materials. After evenly mixing the dry materials with 58 parts of water, pour the slurry into a mold with a size of 160 mm × 40 mm × 40 mm, let it stand for forming, and then remove the mold.

[0045] S4. Finally, the demoulded test block is placed in a curing box at a temperature of 20°C and a humidity of 90% for curing for 28 days. The phosphogypsum wallboard is obtained after curing and molding.

[0046] Example 2

[0047] S1. Preparation of deaminated manganese slag: 25 parts of electrolytic manganese slag, 1.5 parts of malonic acid, 3 parts of ascorbic acid, and 125 parts of deionized water were poured into a container and mixed. After mixing, the mixture was placed in an electric stirring device at 400 r / min and stirred for 45 minutes. After stirring, the mixed solution was filtered, the filter cake was dried, and then calcined in a box-type gradient electric furnace at 180° C. and ground into a fine powder of 60-74 μm for later use.

[0048] S2. Raw material processing: Dry the phosphogypsum and S95 mineral powder in a constant temperature drying oven for 8 hours, grind them into 60-74 μm fine powder using a horizontal ball mill, and set aside;

[0049] S3. Pour 17.7 parts of the deaminated manganese slag prepared in step S1, 70.8 parts of phosphogypsum prepared in step S2, 5 parts of mineral powder, and 1.5 parts of calcium oxide into a container and mix the dry materials. After evenly mixing the dry materials with 58 parts of water, pour the slurry into a mold with a size of 160 mm × 40 mm × 40 mm, let it stand for molding, and then remove the mold.

[0050] S4. Finally, the demoulded test block is placed in a curing box at a temperature of 20°C and a humidity of 90% for curing for 28 days. The phosphogypsum wallboard is obtained after curing and molding.

[0051] Example 3

[0052] S1. Preparation of deaminated manganese slag: 25 parts of electrolytic manganese slag, 1.5 parts of malonic acid, 3 parts of ascorbic acid, and 125 parts of deionized water were poured into a container and mixed. After mixing, the mixture was placed in an electric stirring device at 400 r / min and stirred for 45 minutes. After stirring, the mixed solution was filtered, the filter cake was dried, and then calcined in a box-type gradient electric furnace at 180° C. and ground into a fine powder of 60-74 μm for later use.

[0053] S2. Raw material processing: Dry the phosphogypsum and S95 mineral powder in a constant temperature drying oven for 8 hours, grind them into 60-74 μm fine powder using a horizontal ball mill, and set aside;

[0054] S3. Pour 17.7 parts of the deaminated manganese slag prepared in step S1, 70.8 parts of phosphogypsum prepared in step S2, and 10 parts of mineral powder into a container and mix the dry materials. After evenly mixing the dry materials with 58 parts of water, pour the slurry into a mold with a size of 160 mm × 40 mm × 40 mm, let it stand for molding, and then remove the mold.

[0055] S4. Finally, the demoulded test block is placed in a curing box at a temperature of 20°C and a humidity of 90% for curing for 28 days. The phosphogypsum wallboard is obtained after curing and molding.

[0056] Example 4

[0057] S1. Preparation of deaminated manganese slag: 25 parts of electrolytic manganese slag, 1.5 parts of malonic acid, 3 parts of ascorbic acid, and 125 parts of deionized water were poured into a container and mixed. After mixing, the mixture was placed in an electric stirring device at 400 r / min and stirred for 45 minutes. After stirring, the mixed solution was filtered, the filter cake was dried, and then calcined in a box-type gradient electric furnace at 180° C. and ground into a fine powder of 60-74 μm for later use.

[0058] S2. Raw material processing: Dry the phosphogypsum and S95 mineral powder in a constant temperature drying oven for 8 hours, grind them into 60-74 μm fine powder using a horizontal ball mill, and set aside;

[0059] S3. Pour 17.7 parts of the deaminated manganese slag prepared in step S1, 70.8 parts of phosphogypsum prepared in step S2, 10 parts of mineral powder, and 2 parts of calcium oxide into a container and mix the dry materials. After evenly mixing the dry materials with 58 parts of water, pour the slurry into a mold with a size of 160 mm × 40 mm × 40 mm, let it stand for molding, and then remove the mold.

[0060] S4. Finally, the demoulded test block is placed in a curing box at a temperature of 20°C and a humidity of 90% for curing for 28 days. The phosphogypsum wallboard is obtained after curing and molding.

[0061] Example 5

[0062] S1. Preparation of deaminated manganese slag: 25 parts of electrolytic manganese slag, 1.5 parts of malonic acid, 3 parts of ascorbic acid, and 125 parts of deionized water were poured into a container and mixed. After mixing, the mixture was placed in an electric stirring device at 400 r / min and stirred for 45 minutes. After stirring, the mixed solution was filtered, the filter cake was dried, and then calcined in a box-type gradient electric furnace at 180° C. and ground into a fine powder of 60-74 μm for later use.

[0063] S2. Raw material processing: Dry the phosphogypsum and S95 mineral powder in a constant temperature drying oven for 8 hours, grind them into 60-74 μm fine powder using a horizontal ball mill, and set aside;

[0064] S3. Pour 17.7 parts of the deaminated manganese slag prepared in step S1, 70.8 parts of phosphogypsum prepared in step S2, 10 parts of mineral powder, and 1.5 parts of calcium oxide into a container and mix the dry materials. After evenly mixing the dry materials with 58 parts of water, pour the slurry into a mold with a size of 160 mm × 40 mm × 40 mm, let it stand for molding, and then remove the mold.

[0065] S4. Finally, the demoulded test block is placed in a curing box at a temperature of 20°C and a humidity of 90% for curing for 28 days. The phosphogypsum wallboard is obtained after curing and molding.

[0066] Example 6

[0067] S1. Preparation of deaminated manganese slag: 25 parts of electrolytic manganese slag, 1.5 parts of malonic acid, 3 parts of ascorbic acid, and 125 parts of deionized water were poured into a container and mixed. After mixing, the mixture was placed in an electric stirring device at 400 r / min and stirred for 45 minutes. After stirring, the mixed solution was filtered, the filter cake was dried, and then calcined in a box-type gradient electric furnace at 180° C. and ground into a fine powder of 60-74 μm for later use.

[0068] S2. Raw material processing: Dry the phosphogypsum and S95 mineral powder in a constant temperature drying oven for 8 hours, grind them into 60-74 μm fine powder using a horizontal ball mill, and set aside;

[0069] S3. Pour 17.7 parts of the deaminated manganese slag prepared in step S1, 70.8 parts of phosphogypsum prepared in step S2, 10 parts of mineral powder, and 1.5 parts of calcium oxide into a container and mix the dry materials. After evenly mixing the dry materials with 60 parts of water, pour the slurry into a mold with a size of 160 mm × 40 mm × 40 mm, let it stand for molding, and then remove the mold.

[0070] S4. Finally, the demoulded test block is placed in a curing box at a temperature of 20°C and a humidity of 90% for curing for 28 days. The phosphogypsum wallboard is obtained after curing and molding.

[0071] Example 7

[0072] S1. Preparation of deaminated manganese slag: 25 parts of electrolytic manganese slag, 1.5 parts of malonic acid, 3 parts of ascorbic acid, and 125 parts of deionized water were poured into a container and mixed. After mixing, the mixture was placed in an electric stirring device at 400 r / min and stirred for 45 minutes. After stirring, the mixed solution was filtered, the filter cake was dried, and then calcined in a box-type gradient electric furnace at 180° C. and ground into a fine powder of 60-74 μm for later use.

[0073] S2. Raw material processing: Dry the phosphogypsum and S95 mineral powder in a constant temperature drying oven for 8 hours, grind them into 60-74 μm fine powder using a horizontal ball mill, and set aside;

[0074] S3. Pour 17.7 parts of the deaminated manganese slag prepared in step S1, 70.8 parts of phosphogypsum prepared in step S2, 10 parts of mineral powder, and 1.5 parts of calcium oxide into a container and mix the dry materials. After uniformly mixing 60 parts of water and 0.6 parts of stearic acid, mix the dry materials and the aqueous solution evenly, and then pour them into a mold with a size of 160 mm × 40 mm × 40 mm, let it stand for molding, and then remove the mold.

[0075] S4. Finally, the demoulded test block is placed in a curing box at a temperature of 20°C and a humidity of 90% for curing for 28 days. The phosphogypsum wallboard is obtained after curing and molding.

[0076] Example 8

[0077] The only difference between Example 8 and Example 7 is that 0.6 parts of stearic acid in Example 7 is replaced by 0.6 parts of potassium methyl silicate, and the rest is consistent with Example 7.

[0078] Example 9

[0079] The difference between Example 9 and Example 7 is that 0.6 parts of stearic acid in Example 9 is replaced by 0.8 parts of liquid paraffin, and the rest are consistent with Example 7.

[0080] Performance testing

[0081] 1. Flexural strength: The flexural strength was measured in accordance with the "Determination of Mechanical Properties of Building Gypsum" (GB / T17669.3-1999). Test specimens with a size of 160 mm × 40 mm × 40 mm were prepared. The compressive strength of the phosphogypsum wallboards of Examples 1-7 and Comparative Examples 1-2 was tested using a pressure testing machine. The results are shown in Table 2.

[0082] 2. Compressive strength: The compressive strength was measured in accordance with the "Determination of Mechanical Properties of Building Gypsum" (GB / T17669.3-1999). Test specimens with a size of 160 mm × 40 mm × 40 mm were prepared. The compressive strength of the phosphogypsum wallboard Examples 1-9 was tested using a pressure testing machine. The results are shown in Table 2.

[0083] 3. Softening Coefficient: Compressive strength was measured in accordance with "Determination of Mechanical Properties of Building Gypsum" (GB / T17669.3-1999). Test specimens measuring 160 mm × 40 mm × 40 mm were prepared and divided into two groups. One group was dried in a 50°C oven to constant weight. The compressive strength of Examples 1-9 of the phosphogypsum wallboards was tested using a pressure testing machine. The results are shown in Table 2. The other group was immersed in water at (20±3)°C for 24 hours. After wiping the surface water with a towel, the compressive strength of Examples 1-9 of the phosphogypsum wallboards was tested using a pressure testing machine. The results are shown in Table 2.

[0084] Table 2 Comparison of performance of phosphogypsum wallboard products prepared in different embodiments

[0085] Sample number Flexural strength / MPa Compressive strength / MPa Softening coefficient Example 1 2.54 6.61 0.37 Example 2 3.38 11.75 0.43 Example 3 2.67 6.35 0.51 Example 4 3.69 10.04 0.61 Example 5 3.77 12.30 0.69 Example 6 3.76 11.73 0.70 Example 7 3.95 10.74 0.85 Example 8 2.38 5.24 0.76 Example 9 3.59 10.64 0.62

[0086] Table 2 shows that, based on Examples 1, 2, and 5, the flexural and compressive strengths and softening coefficients of the test blocks are positively correlated with the amount of mineral powder added. While Example 1 did not include mineral powder, the addition of an appropriate amount of mineral powder significantly improved the flexural and compressive strengths and softening coefficients of the test blocks. The strength of the test blocks in Example 5 met the compressive strength requirements of "Lightweight Partition Boards for Buildings" (GB / T 23451-2023).

[0087] It can be seen from Examples 3, 4, and 5 that when preparing phosphogypsum wallboards, if too much calcium oxide is added (Example 4), the flexural strength, compressive strength, and softening coefficient of the prepared phosphogypsum wallboard are lower than those of the flexural strength, compressive strength, and softening coefficient of the phosphogypsum wallboard added with an appropriate amount of calcium oxide (Example 5). Among them, the flexural strength, compressive strength, and softening coefficient of the phosphogypsum wallboard prepared without adding calcium oxide (Example 3) are the lowest compared to the flexural strength, compressive strength, and softening coefficient of the phosphogypsum wallboard added with calcium oxide (Examples 4 and 5). This shows that the addition of calcium oxide provides an alkaline environment for the test block, allowing the mineral powder to react with the phosphogypsum in the presence of an alkaline activator to produce calcium aluminate and hydrated calcium silicate, which can effectively improve the performance of the phosphogypsum test block. However, too much calcium oxide can easily lead to microcracks and pores inside and on the surface of the test block; in a water-immersed environment, water molecules can easily damage the hardened body, resulting in poor performance.

[0088] As can be seen from Examples 5 and 6, the water-cement ratio has little effect on the flexural and compressive strengths and softening coefficients of the test blocks. However, insufficient water usage can easily lead to increased slurry consistency, increased stirring resistance, and difficulty in casting.

[0089] As shown in Examples 7-9, stearic acid, liquid paraffin, and potassium methyl silicate were used to organically modify phosphogypsum test blocks. Stearic acid exhibited the best effect on increasing the compressive softening coefficient of the test blocks and the lowest effect on reducing mechanical properties. The stearic acid-doped test blocks met the requirements of the "Lightweight Partition Panels for Buildings" (GB / T23451-2023) standard, exhibiting superior performance and facilitating factory production and promotion.

[0090] As shown in Examples 6 and 7, the flexural and compressive strengths and softening coefficients of the phosphogypsum wallboard prepared without an organic modifier (Example 6) were the lowest compared to those prepared with an organic modifier (Example 7). This indicates that the addition of an organic modifier forms a more complete hydrophobic film on the gypsum surface, effectively reducing water ingress and the likelihood of gypsum dissolution. Furthermore, the organic modifier fills the internal pores of the test block, thereby improving its structural stability.

[0091] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0092] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A phosphogypsum wallboard, characterized in that: The method comprises the following raw materials in parts by mass: 70.8 parts of phosphogypsum, 17.7 parts of deaminated manganese slag, 0-10 parts of mineral powder, 0-2 parts of calcium oxide, 0.6-0.8 parts of organic modifier and 58-60 parts of water.

2. The phosphogypsum wallboard according to claim 1, characterized in that: The preparation process of deaminated manganese slag includes: mixing and stirring electrolytic manganese slag, malonic acid, ascorbic acid and deionized water, then filtering the mixed solution, drying and calcining, and finally grinding to obtain deaminated manganese slag.

3. The phosphogypsum wallboard according to claim 2, characterized in that: The mass ratio of electrolytic manganese slag, malonic acid, ascorbic acid and deionized water is 25:1.5:3:

125.

4. The phosphogypsum wallboard according to claim 2, characterized in that: The particle size of the deammonified manganese slag after grinding is 60-74 μm.

5. The phosphogypsum wallboard according to claim 2, characterized in that: The stirring speed is 400 r / min, the stirring time is 45 min, and the calcination temperature is 180° C.

6. The phosphogypsum wallboard according to claim 1, characterized in that: The organic modifier includes: stearic acid, potassium methyl silicate or liquid paraffin.

7. The phosphogypsum wallboard according to claim 1, characterized in that: The mass fraction of the calcium oxide is 1.5 parts.

8. The method for preparing a phosphogypsum wallboard according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, drying and grinding phosphogypsum and mineral powder into powder; S2, adding phosphogypsum, mineral powder, deaminated manganese slag and calcium oxide into a container and mixing; then adding an organic modifier and water and stirring evenly to obtain a slurry, and pouring the slurry into a mold, allowing it to stand for forming and then demolding; S3, after demoulding, the test block is cured and formed to obtain the phosphogypsum wallboard.

9. The method for preparing a phosphogypsum wallboard according to claim 8, characterized in that: The curing temperature is 20° C., the curing humidity is 90%, and the curing age is 28 days.

10. An assembled building, characterized in that: The invention comprises a phosphogypsum wallboard according to any one of claims 1 to 7.

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