Artificial soil and preparation method thereof

Abstract

The invention relates to the technical field of ardealite utilization, in particular to artificial soil and a preparation method thereof, and the artificial soil comprises the following raw materials in parts by weight: 15-70 parts of modified ardealite; 0-30 parts of lime; 20 to 35 parts of strong weathered stone; 5-40 parts of humus at the bottom of a lake; the prepared artificial soil has remarkable advantages, key performance such as air permeability and water-retaining property of the soil can be artificially regulated and controlled, growth requirements of different plants can be accurately met, and an ideal matrix is provided for crops; the preparation process is green and environment-friendly, the ardealite and lakebed humus can be effectively utilized, the cyclic utilization of resources is realized, and the environmental pollution is reduced; the preparation period is short, geographical limitation is avoided, a large amount of planting soil can be rapidly provided for projects such as ecological restoration and stony desertification treatment, and improvement of the ecological environment is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of phosphogypsum utilization, in particular to artificial soil and a preparation method thereof. Background Art

[0002] As the soil ecological crisis intensifies, traditional soil remediation methods are unable to meet the demand for rapid improvements in soil quality. Phosphogypsum, a major solid waste from the phosphate fertilizer industry, has long been stored and occupied land. Foreign soil resources are limited and expensive to obtain. Lake bottom humus, while rich in nutrients, is difficult to directly utilize. Artificial soil preparation technology has emerged, using phosphogypsum, lime, foreign soil, and lake bottom humus as core raw materials. Through scientific proportioning and process optimization, this technology combines the cementing properties of phosphogypsum, the physical improvement effects of foreign soil, and the nutrient supply capacity of lake bottom humus. This technology can not only achieve the resource utilization of industrial solid waste and environmental waste, but also quickly construct artificial soil with functions such as water and fertilizer retention. This has opened up a new, green and efficient direction for soil remediation, barren land improvement, and ecological reconstruction.

[0003] At present, we are vigorously promoting the comprehensive utilization of phosphogypsum, promoting the use of phosphogypsum in the field of artificial soil preparation, and actively carrying out the work requirements of demonstrating the use of phosphogypsum in the field of artificial soil preparation and soil improvement, so as to build new arable land.

[0004] Under current circumstances, soil resources are in short supply and increasingly expensive. Regardless of the type of cultivation, soil is still essential. Planting requires suitable soil. While soilless cultivation eliminates the need for ground support, it still requires a solid substrate for cultivation. These substrates still rely on soil as a foundation. Furthermore, with the development of modern agriculture, the advancement of ecological restoration projects, and the growing demand for urban greening, the requirements for soil quality and quantity are constantly increasing. However, natural soil formation takes a long time and is significantly restricted by geographical and environmental factors, making it difficult to meet diverse needs. Artificial soil is needed to address these issues. Summary of the Invention

[0005] The purpose of the present invention is to provide an artificial soil and a method for preparing the same. The aim is to overcome the limitations of natural soil and provide a preparation technology that can flexibly regulate the physical and chemical properties of soil according to actual needs. The present invention uses modified phosphogypsum as a raw material, and lime, strongly weathered fossils, lake bottom humus, etc. as auxiliary materials, and realizes the preparation of artificial soil through a scientific processing flow. During the raw material processing, the raw materials are finely crushed and screened, and in the mixing and blending process, a unique stirring process and proportion formula are adopted to ensure that the various components are evenly distributed; finally, through quality inspection and analysis, the soil's pH, nutrients, heavy metals and other indicators are accurately detected and dynamically adjusted. Compared with traditional soil, the artificial soil prepared by the present invention has significant advantages. First, the key properties of the soil, such as aeration and water retention, can be artificially controlled to accurately adapt to the growth needs of different plants and provide an ideal matrix for crops; second, the preparation process is green and environmentally friendly, and can effectively utilize phosphogypsum and lake bottom humus to achieve resource recycling and reduce environmental pollution; third, the preparation cycle is short and not restricted by geographical location, and can quickly provide a large amount of planting soil for projects such as ecological restoration and desertification control, thereby helping to improve the ecological environment. The artificial soil preparation technology of the present invention provides an innovative solution for the sustainable utilization and diversified needs of soil resources, and has broad application prospects and huge economic and ecological value.

[0006] The scheme of the present invention is: An artificial soil comprising the following raw materials in parts by weight: 15-70 parts of modified phosphogypsum; 0-30 parts of lime; 20-35 parts of strongly weathered fossils; 5 to 40 parts of lake bottom humus.

[0007] As a preferred technical solution, the following raw materials are included in parts by weight: 30-40 parts of modified phosphogypsum; 25-35 parts of strongly weathered fossils; 30 to 40 parts of lake bottom humus are suitable for the cultivation of most general plants, and can take into account soil fertility, air permeability, water and fertilizer retention and other properties.

[0008] As a preferred technical solution, the following raw materials are included in parts by weight: 40-50 parts of modified phosphogypsum; 20-30 parts of strongly weathered fossils; 30 to 40 parts of lake bottom humus increase the acidity of the soil, making it more suitable for the growth of acid-resistant plants that prefer acidic soil environments.

[0009] As a preferred technical solution, the following raw materials are included in parts by weight: 20-30 parts of lime; 15-25 parts of modified phosphogypsum: 25-35 parts of strongly weathered fossils; 20 to 30 parts of lake bottom humus create an alkaline soil environment, which is suitable for the growth of plants that prefer alkaline soil.

[0010] As a preferred technical solution, the following raw materials are included in parts by weight: 10-15 parts of lime; 20-30 parts of modified phosphogypsum; 25-35 parts of strongly weathered fossils; 25 to 35 parts of lake bottom humus can balance the pH of the soil and is suitable for most common plants that do not have high requirements for soil pH.

[0011] As a preferred technical solution, the following raw materials are included in parts by weight: 5-10 parts of lime; 30-40 parts of modified phosphogypsum; 20-30 parts of strongly weathered fossils; 30 to 40 parts of lake bottom humus increase the acidity of the soil and can be used to improve acidic soil to meet the growth needs of acidic plants.

[0012] As a preferred technical solution, 1 to 5 parts of modified biochar are also included.

[0013] The present invention also discloses a method for preparing artificial soil, comprising the following steps: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: weigh 15-70 parts by weight of phosphogypsum, 0-30 parts by weight of lime, 20-35 parts by weight of strongly weathered stone, and 5-40 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

[0014] As a preferred technical solution, in step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; the spacer rods in step 4) are either straw or wood sticks; and the parameters tested in step 5) include alkalinity, moisture content, organic matter content, and nutrient content. If the test results do not meet the expected requirements, adjustments can be made based on the actual situation. For example, if the soil pH is too high, the proportion of phosphogypsum can be increased appropriately; if the soil fertility is insufficient, an appropriate amount of organic fertilizer or chemical fertilizer can be added. The qualified artificial soil will be packaged in plastic bags, woven bags and other packaging materials. After packaging, it should be stored in a dry and ventilated warehouse, away from direct sunlight and rain to prevent the soil from becoming moldy and deteriorating.

[0015] As a preferred technical solution, in the step 3), 1 to 5 parts by weight of modified biochar is added to the mixer; the modified biochar is prepared by soaking the agricultural waste in a 5% potassium hydroxide solution for 12 to 24 hours, separating the solid and liquid, drying at 105°C for 12 hours, and feeding it into a carbonization kiln in an inert atmosphere at a temperature of 600 to 750°C and a heating rate of 5 to 10°C / min. After pyrolysis is completed, water vapor at 200 to 300°C is introduced, with 0.3 kg of water vapor introduced per 1 kg of biochar, followed by washing with 0.1 M hydrochloric acid and deionized water until neutral, and drying at 60°C to obtain the modified biochar.

[0016] Advantages of the present invention: 1. Harmless treatment: Chemical passivation and physical screening technology are used to effectively remove non-target components such as residual fluorine in phosphogypsum.

[0017] 2. Soilization formula: By adding organic matter, mineral amendments, etc., the pH value and nutrient structure of phosphogypsum are regulated to construct a natural soil matrix.

[0018] 3. Structural optimization: simulate the natural soil aggregate structure, enhance water retention and air permeability, and provide a stable carrier for plant growth.

[0019] 4. Scenario Adaptation: Develop customized soil improvement solutions for different scenarios, including damaged land reclamation, mine ecological restoration, landscaping, and desertification control.

[0020] Excellent effects of the present invention: The artificial soil and its preparation method described in this invention aim to promote ecological civilization, improve the ecological environment, promote and steadily expand agricultural production space, and achieve sustainable development. They utilize a comprehensive approach tailored to local conditions, organically combining biological, engineering, and technical measures. Tests have shown positive results during planting, reducing the use of red soil when restoring pits and depressions to agricultural land. This approach not only addresses the comprehensive utilization of phosphogypsum for the company itself and Kaiyuan City, but also improves the regional environment, increases the value of regional land use, and reduces soil resource utilization.

[0021] Social benefits: The implementation of this invention is conducive to the safe production of enterprises, the sustainable development of the local economy and ecology, and the maximum benefits to society and enterprises. First, the project uses harmless treatment of modified phosphogypsum, strongly weathered fossils, and lake bottom humus as artificial soil preparation materials to fully solve the phosphogypsum storage problem of phosphorus chemical enterprises, and promote the coordinated and synchronous sustainable development of local social economy, enterprise development and ecological restoration. Secondly, the promotion and application of this technology can effectively solve the problem of non-point source pollution of the regional ecological environment, and can play a positive role in improving the regional environmental quality. By formulating enterprise standards, local standards and industry standards, it can effectively guide the healthy and sustainable development of phosphorus chemical enterprises, play a guiding and demonstration role, and develop a circular economy.

[0022] Ecological benefits: After the implementation of this invention, the soil structure of the project area will be basically controlled. By changing the microtopography, increasing ground vegetation, and improving soil properties, soil infiltration can be increased and soil erosion can be reduced. It will produce obvious water and soil conservation benefits, prevent losses caused by the reduction of land area and the decline of land quality, and improve the original soil structure and ecological environment of the reclaimed area to a certain extent.

[0023] Economic benefits: Engaging in seedling cultivation and tending can reduce the employment pressure of surplus labor in rural areas, solve the employment problem of part of the local labor force within a period of time, increase the income of local residents, and at the same time can be linked with other industries.

[0024] 1. By using artificial soil, we can achieve source control, unified planning, and overall arrangement, control or reduce unnecessary damage to land resources, achieve unified planning of land reclamation and production construction, and combine prevention with reclamation.

[0025] 2. Adapt to local conditions and prioritize agricultural use. Reclamation planning for damaged land should be coordinated with the overall land use plan. The purpose of reclamation should be determined based on economic rationality, local natural conditions, and the current state of resource damage, with priority given to agricultural land.

[0026] 3. Ensure the sustainable use of land resources. Reclamation planning should be rationally laid out, scientifically planned, focused on efficiency, and utilize advanced technologies to maximize the comprehensive functions and benefits of land, unify social, economic, and ecological benefits, and ensure the sustainable use of land resources.

[0027] 4. Protect and improve the ecological environment. During the project construction process, the original ecological environment will be protected as much as possible. At the same time, reclamation planning will be combined with ecological protection to restore the original ecological environment, and reasonable and effective measures will be taken to improve the original ecological environment in the project area.

[0028] 5. Artificial soil preparation technology breaks through the limitations of slow natural soil formation and uncontrollable properties through human intervention, and prepares planting soil that meets diverse needs.

[0029] 6. This technology uses modified phosphogypsum as raw material, lime, strongly weathered fossils, lake bottom humus and other auxiliary materials to enhance soil fertility and water and fertilizer retention capacity, while adding lime and other additives as needed to adjust soil pH and nutrients.

[0030] 7. The artificial soil prepared by this technology can flexibly control its physical and chemical properties, making it suitable for fields such as crop cultivation, garden landscape construction, and ecological restoration. It can also efficiently utilize phosphogypsum, lake bottom humus, etc., achieving resource recycling and environmental protection. It is not restricted by region or climate, and has a short preparation cycle, providing an innovative and efficient solution for the sustainable use of soil resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] 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. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0033] In order to make up for the above deficiencies, the present invention provides an artificial soil and a preparation method thereof to solve the problems in the above background technology.

[0034] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.

[0035] Example 1 A method for preparing artificial soil comprises the following steps: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: Weigh 15 parts by weight of phosphogypsum, 20 parts by weight of highly weathered stone, and 5 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

[0036] In the step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; and the items tested in the step 5) include alkalinity, water content, organic matter content, and nutrient content.

[0037] Example 2 A method for preparing artificial soil comprises the following steps: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: weigh 70 parts by weight of phosphogypsum, 30 parts by weight of lime, 35 parts by weight of strongly weathered stone, and 40 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

[0038] In the step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; and the items tested in the step 5) include alkalinity, water content, organic matter content, and nutrient content.

[0039] Example 3 A method for preparing artificial soil comprises the following steps: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: Weigh 70 parts by weight of phosphogypsum, 25 parts by weight of highly weathered stone, and 5 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

[0040] In the step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; and the items tested in the step 5) include alkalinity, water content, organic matter content, and nutrient content.

[0041] Example 4 A method for preparing artificial soil comprises the following steps: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: Weigh 35 parts by weight of phosphogypsum, 30 parts by weight of highly weathered stone, and 35 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

[0042] In the step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; and the items tested in the step 5) include alkalinity, water content, organic matter content, and nutrient content.

[0043] Example 5 A method for preparing artificial soil comprises the following steps: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: Weigh 45 parts by weight of phosphogypsum, 25 parts by weight of highly weathered stone, and 35 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

[0044] In the step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; and the items tested in the step 5) include alkalinity, water content, organic matter content, and nutrient content.

[0045] Example 6 The present invention also discloses a method for preparing artificial soil, comprising the following steps: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: weigh 20 parts by weight of phosphogypsum, 25 parts by weight of lime, 30 parts by weight of strongly weathered stone, and 25 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

[0046] In the step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; and the items tested in the step 5) include alkalinity, water content, organic matter content, and nutrient content.

[0047] Example 7 A method for preparing artificial soil comprises the following steps: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: weigh 25 parts by weight of phosphogypsum, 12 parts by weight of lime, 30 parts by weight of strongly weathered stone, 1 part by weight of modified biochar, and 30 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

[0048] In the step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; and the items tested in the step 5) include alkalinity, water content, organic matter content, and nutrient content.

[0049] The modified biochar preparation method comprises the following steps: immersing agricultural waste in a 5% potassium hydroxide solution for 12 to 24 hours, separating the solid and liquid, drying at 105° C. for 12 hours, feeding the biochar into a carbonization kiln under an inert atmosphere, at a temperature of 600 to 750° C., and at a heating rate of 5 to 10° C. / min; introducing water vapor at 200 to 300° C. after pyrolysis is completed, introducing 0.3 kg of water vapor per kg of biochar, and then washing the biochar with 0.1 M hydrochloric acid and deionized water until neutral, and drying the biochar at 60° C. to obtain the modified biochar.

[0050] Example 8 A method for preparing artificial soil comprises the following steps: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: weigh 35 parts by weight of phosphogypsum, 8 parts by weight of lime, 25 parts by weight of strongly weathered stone, and 35 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

[0051] In the step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; and the items tested in the step 5) include alkalinity, water content, organic matter content, and nutrient content.

[0052] Example 9 A method for preparing artificial soil comprises the following steps: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: weigh 30 parts by weight of phosphogypsum, 15 parts by weight of lime, 28 parts by weight of strongly weathered stone, 5 parts by weight of modified biochar, and 26 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

[0053] In the step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; and the items tested in the step 5) include alkalinity, water content, organic matter content, and nutrient content.

[0054] The modified biochar preparation method comprises the following steps: immersing agricultural waste in a 5% potassium hydroxide solution for 12 to 24 hours, separating the solid and liquid, drying at 105° C. for 12 hours, feeding the biochar into a carbonization kiln under an inert atmosphere, at a temperature of 600 to 750° C., and at a heating rate of 5 to 10° C. / min; introducing water vapor at 200 to 300° C. after pyrolysis is completed, introducing 0.3 kg of water vapor per kg of biochar, and then washing the biochar with 0.1 M hydrochloric acid and deionized water until neutral, and drying the biochar at 60° C. to obtain the modified biochar.

[0055] Experimental Case Yunnan Yuntianhua Red Phosphorus Chemical Co., Ltd. commissioned Yunnan Geological Engineering Survey and Design Institute Co., Ltd. to design the project based on standards and specifications such as the "Land Reclamation Quality Control Standard" (TD / T1036-2013), the "Soil Environmental Quality Agricultural Soil Pollution Risk Control Standard (Trial)" (GB15618-2018), and the "Technical Specifications for the Use of Phosphogypsum Mixed with Yilong Lake Bottom Humus for Forest and Green Space Restoration" (Q / HLGS 01-2024). Construction will be carried out according to the procedures of terrain preparation, soil reconstruction, and soil fertility cultivation. The planned implementation area of ​​the project is 193 mu. From August to October 2024, terrain preparation will be completed using modified phosphogypsum as the filling material. In November 2024, the planting soil will be reconstructed by mixing modified phosphogypsum, highly weathered fossils, and lake bottom humus as raw materials. In November 2024, the soil fertility cultivation stage will begin, and potato planting will be trialed.

[0056] The demonstration project is located in the Yushaqing phosphogypsum reservoir area. The land rights belong to Yunnan Yuntianhua Red Phosphorus Chemical Co., Ltd. The land used for this project is the company's own mining land and does not occupy permanent basic farmland or various protected areas. The land area used for this project is 12.8906hm 2 The scope of responsibility is consistent with the project area, which is 12.8906hm2. 2 .

[0057] Test location and time: The test site is Yusa Village, Lebaidao Sub-district, Kaiyuan City, Honghe Prefecture, with coordinates N23°46′44″, E103°17′14″ and an altitude of 1,270 meters. The climate is characterized by a dry, hot valley climate with an average annual temperature of 20-24°C and little precipitation.

[0058] Experimental time: Sowing from November 8 to 20, 2024, harvesting from April 13 to 15, 2025, with a total growing period of 140 days.

[0059] Test soil: The test soil for this experimental demonstration is the artificial soil prepared by the present invention (modified phosphogypsum: strongly weathered fossil: lake bottom humus = 7:2.5:0.5), with a pH value of 7.0-7.5, medium fertility, and good irrigation conditions for the test plot.

[0060] Test demonstration layout: The total area is 193 mu, divided into two areas A and B. The yield measurement this time is for area A.

[0061] Cultivation and management: The main cultivation measures and field management are carried out in accordance with local production standards. Details are as follows: Test variety: Lishu No. 6.

[0062] Planting specifications: row spacing 30cm×80cm, 2800 plants per mu.

[0063] Fertilization: The whole process is mechanized, with mulching and drip irrigation; the base fertilizer is diammonium phosphate (N-P2O5-K2O=18-46-0) 80kg / mu, and the topdressing is potassium dihydrogen phosphate (N-P2O5-K2O=0-52-34) 16kg / mu (mother liquor, applied once every 15 days), and no pesticides or other fertilizers are used.

[0064] Sample point arrangement and area: The yield measurement method was adopted in this study. Due to the uniformity of the land, the samples were randomly selected at a ratio of 5%, with a total of 10 sampling points, each with a radius of 100m. 2 .

[0065] Measurement indicators and analysis: 1. Agronomic traits: germination rate, plant height, and commercial potato rate (the proportion of tubers ≥50g).

[0066] 2. Economic traits indicators: weight of commercial potato tuber, sample yield, yield per mu calculation formula: yield (kg / mu) = actual yield of sample (kg) / plot area (150m 2 )×667m 2 .

[0067] 3. Fertilizer partial productivity: This refers to the ratio of crop yield under a specific fertilizer application to the fertilizer application rate. It is an important indicator reflecting the combined effects of local soil nutrient levels and fertilizer application rates. Calculation formula: Fertilizer partial productivity (kg / kg) = Economic crop yield per unit area (kg) / Nutrient (N+P2O5+K2O) input per unit area (kg).

[0068] 4. Safety indicators: Heavy metals (cadmium, mercury, arsenic, lead, chromium), fluorine, pesticide residues, etc. are tested by the Mengzi Customs Comprehensive Technology Center. Among them, heavy metals are tested according to Method 1 of GB 5009.268-2016 "National Food Safety Standard - Determination of Multiple Elements in Foods"; fluorine is tested according to Method 3 of GB / T 5009.18-2003 "Determination of Fluoride in Foods"; pesticide residues are tested according to Part 1, Method 2 of NY / T 761-2008 "Determination of Organophosphorus, Organochlorine, Pyrethroid and Carbamate Pesticide Residues in Vegetables and Fruits".

[0069] Analysis of main agronomic traits of potato: As shown in Table 1, the potato germination rate in this experimental demonstration reached 92.6%, the average plant height was 52.8 cm, reaching the average level of the southwest region, and the commercial potato rate reached 82.3%, which was 37.17%-64.6% higher than the average level of the southwest region.

[0070] Analysis of potato economic traits: As can be seen from Table 2, the average weight of commercial potatoes in this experimental demonstration is 150g, which is three times the commercial potato standard (≥50g), and the yield is 2008.4kg / mu, both reaching the upper level of the average level in the southwest region.

[0071] Analysis of partial productivity of potato fertilizers: According to the experimental demonstration, 80 kg / mu of diammonium phosphate (N-P2O5-K2O=18-46-0) was applied as base fertilizer for potatoes, and 16 kg / mu of potassium dihydrogen phosphate (N-P2O5-K2O=0-52-34) was used as topdressing. The calculated pure N dosage was 9 kg / mu, P2O5 dosage was 45.12 kg / mu, and K2O dosage was 5.44 kg / mu. The total nutrient input (N+P2O5+K2O) per mu was 59.57 kg, and the fertilizer partial productivity was 2008.4 / 59.57=33.72 kg / kg, which was at a relatively high level.

[0072] Potato agricultural product safety analysis: The heavy metal safety of agricultural products was determined in accordance with GB2672-2022 "National Food Safety Standard Limits of Contaminants in Food". The results showed that heavy metals cadmium and arsenic were detected in potato agricultural products, with detection values ​​of 15.2% and 4.28% of the standard limits, respectively. No heavy metals mercury, chromium and lead were detected. The overall result was qualified.

[0073] The fluoride safety of agricultural products was determined by referring to GB5749-2022 "Sanitary Standards for Drinking Water". The results showed that the detection value was 30% of the standard limit, and the overall result was qualified.

[0074] In this test demonstration, no pesticide residues such as triazophos and chlorpyrifos were detected in potato agricultural products, and the overall result was qualified. The purpose of this yield measurement is to verify the effectiveness and safety of potato planting in improved soil through field trials and test data, and to provide support for promoting the soil utilization of phosphogypsum.

[0075] in conclusion: 1. In the pilot demonstration of this project, the potato plant height, commercial potato weight, and average yield per mu generally reached the upper level of the average level in the southwest region. The fertilizer-based productivity was also at a relatively high level, indicating that the artificial soil prepared by modified phosphogypsum can ensure the normal growth of potatoes and the productivity level is also at a relatively high level.

[0076] 2. Through the analysis of heavy metal, fluorine and major pesticide residue indicators in potatoes, the output of this experimental demonstration was far below the relevant limit requirements of the national food safety standards. The overall result was qualified, indicating that potato agricultural products grown in artificial soil prepared by modified phosphogypsum are safe.

[0077] 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. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. An artificial soil, characterized in that The invention comprises the following raw materials in parts by weight: 15-70 parts of modified phosphogypsum; 0-30 parts of lime; 20-35 parts of strongly weathered fossils; 5 to 40 parts of lake bottom humus.

2. The artificial soil according to claim 1, wherein: The invention comprises the following raw materials in parts by weight: 30-40 parts of modified phosphogypsum; 25-35 parts of strongly weathered fossils; 30-40 parts of lake bottom humus.

3. The artificial soil according to claim 1, wherein: The invention comprises the following raw materials in parts by weight: 40-50 parts of modified phosphogypsum; 20-30 parts of strongly weathered fossils; 30-40 parts of lake bottom humus.

4. The artificial soil according to claim 1, wherein: The invention comprises the following raw materials in parts by weight: 20-30 parts of lime; 15-25 parts of modified phosphogypsum: 25-35 parts of strongly weathered fossils; 20 to 30 parts of lake bottom humus.

5. The artificial soil according to claim 1, wherein: The invention comprises the following raw materials in parts by weight: 10-15 parts of lime; 20-30 parts of modified phosphogypsum; 25-35 parts of strongly weathered fossils; 25-35 parts of lake bottom humus.

6. The artificial soil according to claim 1, wherein: The invention comprises the following raw materials in parts by weight: 5-10 parts of lime; 30-40 parts of modified phosphogypsum; 20-30 parts of strongly weathered fossils; 30-40 parts of lake bottom humus.

7. The artificial soil according to claim 1, wherein: It also includes 1 to 5 parts of modified biochar.

8. A method for preparing artificial soil according to any one of claims 1 to 7, characterized in that: The following steps are involved: 1) Modification of phosphogypsum: the collected phosphogypsum is aired to reduce the moisture content to less than 15%, then crushed, passed through an 80-100 mesh sieve, and added with a first modifier in a mass ratio of phosphogypsum to modifier one of 1:0.03-0.

05. After mixing and stirring, the mixture is reacted for 1-2 hours and aged for 35-40 hours to obtain a first phosphogypsum. The first phosphogypsum is mixed with a second modifier in a mass ratio of 1:0.01-0.02 and aged for 25-30 hours until the pH reaches 6.5-7.5 to obtain a second phosphogypsum. The second phosphogypsum is then uniformly mixed with a third modifier in a mass ratio of 1:0.05-0.1 and aged for 7-14 days to obtain a modified phosphogypsum. 2) Processing: Quicklime powder is passed through a 60-80 mesh sieve and set aside. The weathered fossils are crushed to a particle size of ≤5 mm. After crushing, they are rinsed with clean water and dried to form the weathered fossil powder. The lake bottom humus is excavated and air-dried to a moisture content of 30-40%. It is then screened to remove debris and set aside. 3) Mixing and stirring: weigh 15-70 parts by weight of phosphogypsum, 0-30 parts by weight of lime, 20-35 parts by weight of strongly weathered stone, and 5-40 parts by weight of lake bottom humus; pour the weighed materials into a blender and stir at a speed of 100-150 rpm for 15-20 minutes; 4) Stacking and fermentation: The mixed materials are piled into strips 1-1.5 meters high, 2-3 meters wide, and 0.1-10 meters long. During the stacking process, a spacer rod is inserted every 0.5 meters and removed after the stacking is completed to form a ventilation hole. After the stacking is completed, the pile is covered with plastic film to maintain the temperature and humidity inside the pile at 50-65°C and 30-40% to accelerate the fermentation process. During the fermentation process, the pile is turned every 3-5 days. Fermentation is complete when the temperature of the pile begins to drop, the color of the material becomes darker, the texture becomes loose, and there is no obvious odor. The fermentation time is 20-30 days. 5) Testing and adjustment: After fermentation is completed, the prepared artificial soil is tested and packaged after passing the inspection.

9. The method for preparing artificial soil according to claim 8, wherein: In the step 1), the first modifier is calcium oxide, the second modifier is silicate, and the third modifier is humic acid; the isolation rod in the step 4) is straw or a wooden stick; and the items tested in the step 5) include alkalinity, water content, organic matter content, and nutrient content.

10. The method for preparing artificial soil according to claim 8, wherein: In step 3), 1 to 5 parts by weight of modified biochar is added to the mixer; the modified biochar is prepared by soaking agricultural waste in a 5% potassium hydroxide solution for 12 to 24 hours, separating the solid and liquid, drying at 105°C for 12 hours, and feeding the waste into a carbonization kiln under an inert atmosphere at a temperature of 600 to 750°C and a heating rate of 5 to 10°C / min. After pyrolysis is completed, water vapor at 200 to 300°C is introduced, with 0.3 kg of water vapor introduced per kg of biochar, followed by washing with 0.1 M hydrochloric acid and deionized water until neutral, and drying at 60°C to obtain the modified biochar.

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