Ardealite solid waste resource utilization method

Abstract

The invention relates to the technical field of solid waste treatment, and discloses an ardealite solid waste resource utilization method which comprises the following steps: step 1, crushing an ardealite raw material until the particle size is 50-100 meshes, putting the crushed ardealite raw material into a water washing pool, adding clear water according to a liquid-solid ratio of 3: 1-5: 1, stirring and washing for 30-60 minutes, filtering, and drying a filter cake at 105-120 DEG C until the water content is lower than 10%; 2, the dried ardealite and a modifier accounting for 5%-10% of the mass of the ardealite are evenly mixed and ground in a ball mill for 30-60 minutes, and the modifier is composed of ferrous sulfate and sodium polyacrylate with the mass ratio being 2: 1. According to the ardealite solid waste resource utilization method, through a series of pretreatment steps of magnetic separation, water washing, drying, filtrate treatment and the like, magnetic impurities and water-soluble harmful impurities in ardealite are effectively removed, and useful substances in filtrate are recycled, so that the harm of ardealite to the environment is reduced, and the utilization rate of the ardealite solid waste resources is improved. The cyclic utilization of resources is realized, and the waste discharge is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste treatment, and specifically to a method for the utilization of phosphogypsum solid waste resources. Background Art

[0002] Phosphogypsum is a solid waste residue generated during the production of phosphoric acid by treating phosphate rock with sulfuric acid. Its main component is calcium sulfate, and it also contains undecomposed phosphate rock, phosphoric acid, fluorides, and other impurities. With the rapid development of the phosphate fertilizer industry, the discharge of phosphogypsum is increasing day by day. A large amount of piled phosphogypsum not only occupies a large amount of precious land resources, but also the harmful components contained in it, such as phosphorus and fluorine, may enter the soil and water bodies through rain leaching and other means, posing a serious threat to the ecological environment.

[0003] At present, the treatment and utilization methods of phosphogypsum are limited. The traditional treatment method is mainly open-air stacking, which not only fails to effectively utilize resources but also brings great environmental risks. Some enterprises have tried to use phosphogypsum in the production of building materials, such as gypsum boards and cement retarders. However, due to the influence of impurities in phosphogypsum, the product quality is unstable, and the application range is relatively narrow, making it difficult to be promoted on a large scale. Therefore, developing an efficient, environmentally friendly, and economically feasible method for the utilization of phosphogypsum solid waste resources to achieve the reduction, harmlessness, and resource utilization of phosphogypsum has important practical significance and urgency.

[0004] Therefore, a method for the utilization of phosphogypsum solid waste resources is proposed to solve the above-mentioned problems. Summary of the Invention

[0005] (I) Technical Problems to be Solved

[0006] In view of the deficiencies of the prior art, the present invention provides a method for the utilization of phosphogypsum solid waste resources, which has the advantages of realizing the efficient resource utilization of phosphogypsum, etc., and solves the problems of resource waste, environmental pollution, and unstable product quality existing in the existing phosphogypsum treatment methods.

[0007] (II) Technical Solutions

[0008] To achieve the above-mentioned purpose of realizing the efficient resource utilization of phosphogypsum, the present invention provides the following technical solutions: A method for the utilization of phosphogypsum solid waste resources, comprising the following steps:

[0009] Step 1: Crush the phosphogypsum raw material to a particle size of 50 - 100 mesh, put it into a water washing pool, add clear water according to a liquid-solid ratio of 3:1 - 5:1, stir and wash for 30 - 60 minutes, and after filtration, dry the filter cake at 105 - 120 °C until the moisture content is lower than 10%.

[0010] Step 2: Mix the dried phosphogypsum evenly with a modifier accounting for 5%-10% of its mass, and grind it in a ball mill for 30-60 minutes. The modifier consists of ferrous sulfate and sodium polyacrylate with a mass ratio of 2:1;

[0011] Step 3: Mix the modified phosphogypsum with slag powder accounting for 20%-30% of its mass, fly ash accounting for 10%-15% of its mass, and an activator accounting for 3%-5% of the total mass of the three. Stir in a forced mixer for 10-15 minutes. The activator consists of sodium hydroxide and sodium sulfate with a mass ratio of 1:1;

[0012] Step 4: Mix the prepared building cementitious material with an appropriate amount of water according to a water-binder ratio of 0.4-0.5, stir evenly, pour it into a mold for molding, pre-cure at room temperature for 2-4 hours, then put it into a steam curing box, and cure it for 8-12 hours under the conditions of a temperature of 60-80°C and a relative humidity of 90%-95% to obtain building products.

[0013] Preferably, in Step 1, before water washing, the phosphogypsum raw material is subjected to magnetic separation to remove magnetic impurities therein.

[0014] Preferably, in Step 2, a dispersant accounting for 1%-3% of the mass of phosphogypsum is added during the grinding process of the ball mill. The dispersant is sodium hexametaphosphate; the intermittent grinding method is adopted during the ball mill grinding, and it pauses for 2-3 minutes every 10-15 minutes of grinding.

[0015] Preferably, in Step 1, the filtrate after water washing is treated by evaporation concentration and crystallization processes to recover calcium sulfate and other soluble salt substances in the filtrate.

[0016] Preferably, in Step 3, during the stirring process of the forced mixer, it first stirs at a low speed for 5-8 minutes with the rotation speed controlled at 80-120 revolutions per minute, and then stirs at a high speed for 5-7 minutes with the rotation speed increased to 200-250 revolutions per minute, so that the modified phosphogypsum, slag powder, fly ash and activator are mixed more evenly.

[0017] Preferably, in Step 4, before pouring into the mold for molding, a fiber reinforcing material accounting for 0.5%-1% of the mass of the mixture of the building cementitious material and water is added. The fiber reinforcing material is alkali-resistant glass fiber or polypropylene fiber.

[0018] Preferably, in Step 4, after the steam curing is completed, the building products are placed in an environment with a temperature of 20-25°C and a humidity of 60%-70% for secondary curing for 3-5 days.

[0019] Preferably, in step four, after the building product is demolded, its surface is waterproofed by spraying an organosilicon waterproofing agent or impregnating it with a waterproofing agent, and the dosage of the waterproofing agent is 50-100 grams per square meter of the surface of the building product.

[0020] Preferably, 0.5%-2% of nano-titanium dioxide based on the mass of phosphogypsum is additionally added to the modifier in step two.

[0021] (III) Beneficial effects

[0022] Compared with the prior art, the present invention provides a method for the utilization of phosphogypsum solid waste resources, which has the following beneficial effects:

[0023] 1. In this method for the utilization of phosphogypsum solid waste resources, through a series of pretreatment steps such as magnetic separation, water washing, drying, and filtrate treatment, magnetic impurities and water-soluble harmful impurities in phosphogypsum are effectively removed, useful substances in the filtrate are recovered, which not only reduces the harm of phosphogypsum to the environment but also realizes the recycling of resources and reduces waste emissions; at the same time, converting phosphogypsum into building products significantly reduces the stockpile of phosphogypsum and solves the environmental pollution problem caused by phosphogypsum stockpiling, with significant environmental benefits.

[0024] 2. In this method for the utilization of phosphogypsum solid waste resources, by chemically modifying phosphogypsum to improve its activity, then rationally mixing it with slag powder, fly ash, etc., and activating the reaction through an activator, a building cementitious material with excellent performance is prepared; during the forming and curing processes, fiber reinforcing materials are added and the curing process is optimized, so that the finally obtained building products have good mechanical properties and durability; this not only realizes the resource utilization of phosphogypsum, turning waste into treasure and creating economic benefits, but also provides high-quality building materials for the construction industry, with good market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of the method for the utilization of phosphogypsum solid waste resources of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to 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. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] Example 1

[0028] Please refer to Figure 1 , a method for the utilization of phosphogypsum solid waste resources, including the following steps:

[0029] Step 1: Crush the phosphogypsum raw material to a particle size of 50 - 100 mesh, put it into a water-washing pool, add clear water according to a liquid-solid ratio of 3:1 - 5:1, stir and wash for 30 - 60 minutes, and after filtration, dry the filter cake at 105 - 120 °C until the moisture content is lower than 10%;

[0030] Step 2: Mix the dried phosphogypsum evenly with a modifier accounting for 5% - 10% of its mass, and grind in a ball mill for 30 - 60 minutes. The modifier is composed of ferrous sulfate and sodium polyacrylate with a mass ratio of 2:1;

[0031] Step 3: Mix the modified phosphogypsum with slag powder accounting for 20% - 30% of its mass, fly ash accounting for 10% - 15% of its mass, and an activator accounting for 3% - 5% of the total mass of the three, and stir in a forced mixer for 10 - 15 minutes. The activator is composed of sodium hydroxide and sodium sulfate with a mass ratio of 1:1;

[0032] Step 4: Mix the prepared building cementitious material with an appropriate amount of water according to a water-binder ratio of 0.4 - 0.5, stir evenly, pour it into a mold for molding, pre-cure at room temperature for 2 - 4 hours, and then put it into a steam curing box. Cure it for 8 - 12 hours under the conditions of a temperature of 60 - 80 °C and a relative humidity of 90% - 95% to obtain building products.

[0033] Specifically, in the pre-treatment of Step 1: Crush the phosphogypsum raw material to 50 - 100 mesh to increase its specific surface area, which is conducive to the dissolution of impurities during subsequent water washing; stir and wash with clear water for 30 - 60 minutes according to a liquid-solid ratio of 3:1 - 5:1, which can effectively remove most of the harmful impurities such as water-soluble phosphorus and fluorine, reducing the harm to products and the environment; filter and dry at 105 - 120 °C until the moisture content is lower than 10%, which is convenient for subsequent processing and storage and avoids the interference of moisture on subsequent processes.

[0034] Chemical modification in Step 2: Mix the dried phosphogypsum with a modifier accounting for 5% - 10% of its mass and composed of ferrous sulfate and sodium polyacrylate with a mass ratio of 2:1, and grind in a ball mill for 30 - 60 minutes, so that the modifier is fully combined with the surface of phosphogypsum particles, changing its surface properties, improving the activity of phosphogypsum, and enhancing the reaction ability and compatibility with other materials.

[0035] Preparation of building cementitious material in Step 3: Mix and stir the modified phosphogypsum with slag powder accounting for 20% - 30% of its mass, fly ash accounting for 10% - 15% of its mass, and an activator accounting for 3% - 5% of the total mass of the three and composed of sodium hydroxide and sodium sulfate with a mass ratio of 1:1; The slag powder and fly ash can improve the performance of the cementitious material, and the activator can stimulate the latent activity of each material, prompting them to react to form a building cementitious material with excellent performance.

[0036] Step 4: Molding and curing: Mix the building cementitious materials and water according to a water-binder ratio of 0.4 - 0.5, stir well and pour into a mold. Pre-cure at room temperature for 2 - 4 hours to initially fix the shape, and then cure in a steam curing box at 60 - 80°C and a relative humidity of 90% - 95% for 8 - 12 hours to accelerate the hydration reaction of the materials, improve the strength, finally obtain building products with stable performance, realize the resource utilization of phosphogypsum, reduce solid waste emissions and environmental pollution, and create economic benefits.

[0037] Example 2

[0038] A method for the utilization of phosphogypsum solid waste resources includes the following steps:

[0039] Step 1: Before washing with water, perform magnetic separation on the phosphogypsum raw material, crush the phosphogypsum raw material to a particle size of 50 mesh, put it into a water-washing tank, add clear water according to a liquid-solid ratio of 3:1, stir and wash for 300 minutes, filter, and dry the filter cake at 105°C until the moisture content is lower than 10%. The filtrate after water washing is treated by evaporation concentration and crystallization processes to recover calcium sulfate and other soluble salt substances in the filtrate.

[0040] Step 2: Mix the dried phosphogypsum evenly with a modifier accounting for 5% of its mass, grind in a ball mill for 30 minutes. The modifier consists of ferrous sulfate and sodium polyacrylate with a mass ratio of 2:1. Add a dispersant accounting for 1% of the phosphogypsum mass during the ball mill grinding process. The dispersant is sodium hexametaphosphate. The ball mill uses an intermittent grinding method, pausing for 2 minutes every 10 minutes of grinding.

[0041] Step 3: Mix the modified phosphogypsum with 20% of slag powder, 10% of fly ash, and 3% of an activator accounting for the total mass of the three in a forced mixer and stir for 10 minutes. The activator consists of sodium hydroxide and sodium sulfate with a mass ratio of 1:1. During the stirring process of the forced mixer, first stir at a low speed for 5 minutes with a rotation speed controlled at 80 revolutions per minute, and then stir at a high speed for 5 minutes with the rotation speed increased to 200 revolutions per minute to make the modified phosphogypsum, slag powder, fly ash, and activator mix more evenly.

[0042] Step 4: Before pouring into the mold for molding, add a fiber reinforcing material accounting for 0.5% of the mass of the mixture of building cementitious materials and water. The fiber reinforcing material is alkali-resistant glass fiber. Mix the prepared building cementitious materials and appropriate water evenly according to a water-binder ratio of 0.4 - 0.5 and pour into the mold for molding. Pre-cure at room temperature for 2 hours, then put it into a steam curing box and cure at a temperature of 60°C and a relative humidity of 90% for 8 hours to obtain building products. After the steam curing is completed, place the building products in an environment with a temperature of 20°C and a humidity of 60% for secondary curing for 3 days.

[0043] Specifically, through the fine operation of each step, the resource utilization of phosphogypsum solid waste has been comprehensively realized; magnetic separation is used to remove magnetic impurities, providing a purer raw material for subsequent treatment; crushing, washing, drying, and filtrate treatment effectively purify phosphogypsum and recover resources; chemical modification enhances the activity of phosphogypsum; a high-performance building cementitious material is prepared by reasonably proportioning slag powder, fly ash, and activator; fiber reinforcing materials are added, and the forming and curing processes are optimized to finally obtain high-quality building products; the entire process not only solves the environmental problems caused by phosphogypsum stacking but also creates significant economic benefits and has good prospects for popularization and application.

[0044] Example 3

[0045] A method for the resource utilization of phosphogypsum solid waste includes the following steps:

[0046] Step 1: Before washing, magnetic separation is carried out on the phosphogypsum raw material. A belt magnetic separator can be used for magnetic separation, which can effectively adsorb magnetic impurities in the phosphogypsum raw material, such as ferromagnetic particles, to remove the magnetic impurities therein. The phosphogypsum raw material is crushed to a particle size of 100 mesh, put into a washing pool, and stirred and washed for 60 minutes with clear water added according to a liquid-solid ratio of 5:1. After filtration, the filter cake is dried at 120°C until the moisture content is lower than 10%. The filtrate after washing is treated by evaporation concentration and crystallization processes to recover calcium sulfate and other soluble salt substances in the filtrate.

[0047] Step 2: The dried phosphogypsum is mixed evenly with a modifier accounting for 10% of its mass and ground in a ball mill for 60 minutes. The modifier is composed of ferrous sulfate and sodium polyacrylate with a mass ratio of 2:1. A dispersant accounting for 3% of the mass of phosphogypsum is added during the ball mill grinding process, and the dispersant is sodium hexametaphosphate. The ball mill grinding adopts an intermittent grinding method, pausing for 3 minutes every 15 minutes of grinding.

[0048] Step 3: The modified phosphogypsum is mixed with 30% of its mass of slag powder, 15% of fly ash, and an activator accounting for -5% of the total mass of the three in a forced mixer and stirred for 15 minutes. The activator is composed of sodium hydroxide and sodium sulfate with a mass ratio of 1:1. During the stirring process of the forced mixer, it is first stirred at a low speed for 8 minutes with a rotation speed controlled at 120 revolutions per minute, and then stirred at a high speed for 7 minutes with the rotation speed increased to 250 revolutions per minute, so that the modified phosphogypsum, slag powder, fly ash, and activator are mixed more evenly.

[0049] Step 4: Before pouring into the mold for forming, add 1% by mass of fiber reinforcing material based on the mixture of building cementitious material and water. The fiber reinforcing material is polypropylene fiber. Mix the prepared building cementitious material with appropriate water according to a water-binder ratio of 0.5 and stir evenly, then pour it into the mold for forming. Cure it at room temperature for 4 hours, and then put it into a steam curing chamber and cure it for 12 hours under the conditions of a temperature of 80°C and a relative humidity of 95% to obtain a building product. After the steam curing is completed, place the building product in an environment with a temperature of 25°C and a humidity of 70% for secondary curing for 5 days.

[0050] Specifically, in the pretreatment of Step 1:

[0051] Magnetic separation: Use a belt magnetic separator to adsorb and remove magnetic impurities such as ferromagnetic particles to provide a purer raw material for subsequent processing and avoid the influence of magnetic impurities on subsequent processes and product quality;

[0052] Crushing: Crush the phosphogypsum to 100 mesh to increase the specific surface area, which is beneficial to the dissolution of impurities during water washing, improve the water washing efficiency, and also create good conditions for subsequent material mixing and reaction;

[0053] Water washing: Add clear water according to a liquid-solid ratio of 5:1 and stir and wash for 60 minutes to fully dissolve and remove harmful impurities such as water-soluble phosphorus and fluorine in the phosphogypsum, reduce the harm to the environment, and improve the quality of the phosphogypsum;

[0054] Drying: Dry the filter cake at 120°C until the moisture content is lower than 10% to facilitate storage, transportation, and subsequent processing, prevent moisture from interfering with subsequent processes, and ensure the quality stability of the product;

[0055] Filtrate treatment: Recover calcium sulfate and other soluble salts in the filtrate through evaporation concentration and crystallization processes to achieve resource recycling, reduce production costs, and reduce waste emissions.

[0056] Specifically, in Step 2 of chemical modification: Mix a specific proportion of modifier (the mass ratio of ferrous sulfate and sodium polyacrylate is 2:1) accounting for 10% by mass with the phosphogypsum to change the surface properties of the phosphogypsum and enhance its activity and reaction ability.

[0057] Ball mill grinding: Grind for 60 minutes to fully combine the modifier with the phosphogypsum, add 3% sodium hexametaphosphate dispersant to prevent material agglomeration, improve the grinding efficiency and uniformity; intermittent grinding (pause for 3 minutes every 15 minutes of grinding) to avoid local overheating, ensure the performance of the modifier, and ensure the modification effect.

[0058] Specifically, Step 3 of preparing the building cementitious material

[0059] Material measurement and primary mixing: Mix the materials in proportion (30% slag powder, 15% fly ash, and 5% activator based on the total mass of the modified phosphogypsum), and stir at a low speed for 8 minutes to initially mix evenly, laying a foundation for the subsequent action of the activator.

[0060] Activator addition and high-speed stirring: After adding the activator (sodium hydroxide and sodium sulfate with a mass ratio of 1:1), stir at a high speed for 7 minutes to activate the latent activity of phosphogypsum, slag powder, and fly ash, promote chemical reactions, and form a building cementitious material with excellent performance to meet the requirements of building use.

[0061] Specifically, in step four, forming and curing

[0062] Addition of fiber-reinforcing material: Add 1% polypropylene fiber based on the mass of the mixture, which can effectively enhance the crack resistance and tensile strength of building products, significantly improve the mechanical properties and durability of building products, and extend the service life.

[0063] Forming operation: Pour it into the mold and vibrate to discharge air bubbles, making the material fill densely, ensuring the forming quality and appearance flatness of building products, and improving the product quality and aesthetics.

[0064] Curing process: Pre-cure at room temperature for 4 hours to initially harden and fix the shape, steam cure (at 80°C, relative humidity 95%, for 12 hours) to accelerate the hydration reaction and increase the strength, and secondary cure (at 25°C, humidity 70%, for 5 days) to optimize the internal microstructure, further improve the late strength and durability, and make the building products reach the best performance state.

[0065] In summary, the method for the utilization of phosphogypsum solid waste effectively removes magnetic impurities and water-soluble harmful impurities in phosphogypsum through a series of pretreatment steps such as magnetic separation, water washing, drying, and filtrate treatment, recovers useful substances in the filtrate, reduces the environmental harm of phosphogypsum, realizes the recycling of resources, and reduces waste emissions; at the same time, converts phosphogypsum into building products, greatly reducing the stockpile of phosphogypsum and solving the environmental pollution problem caused by phosphogypsum stockpiling, with significant environmental benefits.

[0066] Moreover, chemically modify phosphogypsum to improve its activity, then rationally mix it with slag powder, fly ash, etc., and stimulate the reaction through an activator to prepare a building cementitious material with excellent performance; during the forming and curing process, add fiber-reinforcing materials and optimize the curing process to make the final building products have good mechanical properties and durability; this not only realizes the resource utilization of phosphogypsum, turns waste into treasure, creates economic benefits, but also provides high-quality building materials for the construction industry, with good market application prospects.

[0067] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0068] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for the utilization of phosphogypsum solid waste resources, characterized in that , including the following steps: Step 1: Crush the phosphogypsum raw material to a particle size of 50 - 100 mesh, put it into a water-washing tank, add clear water according to a liquid-solid ratio of 3:1 - 5:1, stir and wash for 30 - 60 minutes, and after filtration, dry the filter cake at 105 - 120 °C until the moisture content is lower than 10%; Step 2: Mix the dried phosphogypsum evenly with a modifier accounting for 5% - 10% of its mass, and grind in a ball mill for 30 - 60 minutes. The modifier is composed of ferrous sulfate and sodium polyacrylate with a mass ratio of 2:1; Step 3: Mix the modified phosphogypsum with slag powder accounting for 20% - 30% of its mass, fly ash accounting for 10% - 15% of its mass, and an activator accounting for 3% - 5% of the total mass of the three in a forced mixer and stir for 10 - 15 minutes. The activator is composed of sodium hydroxide and sodium sulfate with a mass ratio of 1:1; Step 4: Mix the prepared building cementitious material with an appropriate amount of water according to a water-binder ratio of 0.4 - 0.5, stir evenly, pour it into a mold for molding, pre-cure at room temperature for 2 - 4 hours, then put it into a steam curing box, and cure for 8 - 12 hours under the conditions of a temperature of 60 - 80 °C and a relative humidity of 90% - 95% to obtain building products.

2. The method for utilizing phosphogypsum solid waste resources according to claim 1, wherein: In Step 1, before water washing, the phosphogypsum raw material is subjected to magnetic separation to remove magnetic impurities therein.

3. A method for utilizing phosphogypsum solid waste resources according to claim 1, characterized in that: In Step 2, during the grinding process of the ball mill, a dispersant accounting for 1% - 3% of the mass of phosphogypsum is added. The dispersant is sodium hexametaphosphate; the ball mill uses an intermittent grinding method, pausing for 2 - 3 minutes every 10 - 15 minutes of grinding.

4. A method for utilizing phosphogypsum solid waste resources according to claim 1, characterized in that: In Step 1, the filtrate after water washing is treated by evaporation concentration and crystallization processes to recover calcium sulfate and other soluble salts in the filtrate.

5. A method for utilizing phosphogypsum solid waste resources according to claim 1, characterized in that: In Step 3, during the stirring process of the forced mixer, it is first stirred at a low speed for 5 - 8 minutes with a rotation speed controlled at 80 - 120 revolutions per minute, and then stirred at a high speed for 5 - 7 minutes with the rotation speed increased to 200 - 250 revolutions per minute, so that the modified phosphogypsum, slag powder, fly ash and activator are mixed more evenly.

6. A method for utilizing phosphogypsum solid waste resources according to claim 1, characterized in that: In Step 4, before pouring into the mold for molding, a fiber reinforcing material accounting for 0.5% - 1% of the mass of the mixture of the building cementitious material and water is added. The fiber reinforcing material is alkali-resistant glass fiber or polypropylene fiber.

7. A method for utilizing phosphogypsum solid waste resources according to claim 1, characterized in that: In Step 4, after the steam curing is completed, the building products are placed in an environment with a temperature of 20 - 25 °C and a humidity of 60% - 70% for secondary curing for 3 - 5 days.

8. A method for utilizing phosphogypsum solid waste resources according to claim 1, characterized in that: In Step 4, after the building products are demolded, their surfaces are subjected to waterproof treatment, which can be carried out by spraying an organosilicon waterproof agent or impregnating a waterproof agent. The dosage of the waterproof agent is 50 - 100 grams per square meter of the surface of the building products.

9. A method for utilizing phosphogypsum solid waste resources according to claim 1, characterized in that: In the modifier in Step 2, an additional 0.5% - 2% of the mass of phosphogypsum of nano-titanium dioxide is added.

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