Sand stabilization method of photovoltaic electric field

Abstract

The invention discloses a sand stabilization method of a photovoltaic electric field. The method comprises the following steps: mixing calcium oxide with water, carrying out wet digestion, and grinding to obtain calcium hydroxide; calcium hydroxide is mixed with fine sand, magnesium slag, magnesium sulfate and water to prepare a composite cement-based material, and the composite cement-based material comprises the following components in parts by weight: calcium oxide: fine sand: magnesium slag: magnesium sulfate: water = 1: (0.5-10): (0.1-4): (0.1-3): (0.5-4); mixing the composite cement-based material with desert sand, and feeding the mixture into a granulator to prepare grit; through reasonable formula design and advanced granulation technology, the stability of sandy soil in the desert area can be enhanced, sand erosion can be reduced, the long-term operation stability of the desert photovoltaic electric field can be improved, and the sand stabilizing agent has the advantages of being simple in formula, low in production cost, convenient to construct and the like.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic electric field sand fixation technology, and specifically relates to a method for sand fixation using a photovoltaic electric field. Background Technology

[0002] Photovoltaic power plants are often built in desert or Gobi regions, but shifting sand dunes can easily bury the photovoltaic panel supports, reducing power generation efficiency and accelerating equipment wear. Traditional sand stabilization methods (such as straw checkerboards and chemical spraying) suffer from short lifespan, high cost, and poor ecological compatibility. Composite cement has advantages such as dense solids, high strength, excellent cementitious properties, strong durability, good workability and salt and alkali resistance, rapid curing, and easy maintenance, and is widely used in many fields such as building materials. Composite cement concrete slabs made with calcium oxide as a base material, added with heavy fillers (such as sand and stone) and solid waste (magnesium slag), and assembled into checkerboards, are an ideal alternative to stone checkerboards, straw checkerboards, and other sand stabilization materials.

[0003] In existing technologies, such as patents with application numbers 201710157455.8 and 202110750265.3, magnesium cement is used to make sand-stabilizing boards, which are then directly laid on the sand surface or spliced ​​together to form sand barriers for sand stabilization. However, this method is slow to lay and lacks flexibility, and the sand-stabilizing boards are large in volume, making construction under photovoltaic panels complex. Magnesium oxychloride cement-based sand-stabilizing boards have poor permeability due to their plate-like structure, which is not conducive to the growth of psammophytes. Furthermore, they require a large amount of magnesium cement, resulting in high costs. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems and propose a method for sand fixation using a photovoltaic electric field.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for sand fixation in a photovoltaic electric field, comprising the following steps: Calcium oxide was mixed with water and wet digested, then ground to obtain calcium hydroxide. A composite cement-based material is prepared by mixing calcium hydroxide with fine sand, magnesium slag, magnesium sulfate, and water. The components of the composite cement-based material are proportioned by weight as follows: Calcium oxide : fine sand : magnesium slag : magnesium sulfate : water = 1 : (0.5~10) : (0.1~4) : (0.1~3) : (0.5~4); The composite cement-based material is mixed with desert sand and then fed into a granulator to produce gravel. Gravel is spread on the sand surface of the photovoltaic power plant to complete the sand fixation of the photovoltaic power plant.

[0006] Furthermore, the optimal weight ratio of each component of the composite cement-based material is as follows: Calcium oxide : fine sand : magnesium slag : magnesium sulfate : water = 1 : 2 : 0.6 : 0.3 : 1.75.

[0007] Furthermore, the preparation of the gravel also includes a drying step, in which the gravel is placed in a drying device and dried at 40℃~60℃ for 12~24 hours until it is completely solidified.

[0008] Furthermore, the obtained gravel has a particle size of 2cm to 5cm, is spread by loose spreading and compaction, has a spreading thickness of 3cm to 5cm, and has a gap ratio of ≥30% after spreading.

[0009] Furthermore, the granulator consists of a feeding port, machine body, pressing belt, conveyor belt, and base; The feeding port is fixed to the top of the machine body and is connected to the feeding channel inside the machine body; The main body is fixedly mounted on the upper part of the base, and the base provides support for the main body; The pressing belt is mounted on the discharge side of the machine body, and the pressing belt is connected to the working mechanism inside the machine body for transmission. The conveyor belt is arranged at an angle, with its upper end connected to the lower part of the discharge end of the pressing belt, and the support structure of the conveyor belt is connected to the base.

[0010] Furthermore, after the spreading is completed, the composite cement-based material undergoes a secondary hydration reaction through periodic wetting treatment.

[0011] Furthermore, the granulator uses mechanical pressure to compress the mixture of composite cement-based material and desert sand into gravel of a predetermined shape.

[0012] Furthermore, the wet digestion of calcium oxide involves mixing calcium oxide with excess water, reacting the mixture, and then grinding it to obtain calcium hydroxide in a soft state.

[0013] Secondly, the present invention provides a composite cement-based desert gravel for sand fixation in photovoltaic electric fields, which is formed by granulation and solidification of composite cement-based materials and desert sand. The composite cement-based material contains calcium hydroxide, fine sand, magnesium slag, and magnesium sulfate, and the calcium hydroxide is obtained by wet digestion of calcium oxide followed by grinding.

[0014] Furthermore, after the gravel was cured for 21 days at 25±2℃ and 35±5% humidity, its compressive strength was not less than 2.19MPa.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: This invention proposes a method for sand fixation in photovoltaic power plants. It utilizes granulation technology to create desert gravel from composite cement-based materials and desert sand, enabling rapid spreading and large-area coverage. It is adaptable to different sandy terrains, allowing for adjustments in particle size and shape. Maintenance costs are low. The method combines sand fixation, water permeability, and plant growth promotion, filling a technological gap in this field. The effectiveness of gravel spreading for sand fixation has been verified in experiments at the Mogao Grottoes. Through rational formula design and advanced granulation technology, this invention enhances the stability of desert soil, reduces wind erosion, and improves the long-term operational stability of desert photovoltaic power plants. It also features a simple formula, efficient solid waste disposal, low production costs, and convenient construction. This invention fully utilizes local natural resources, reducing transportation costs and environmental burden. The production process is simple and efficient, allowing for mass production suitable for large-scale sand fixation projects. The addition of magnesium slag in the formulation facilitates solid waste disposal. It is environmentally friendly and sustainable, using no harmful chemicals and contributing to ecological restoration. It is highly economical, with low raw material costs, a simple production process, and low maintenance requirements. It is easy to promote and apply, possessing significant market potential. Attached Figure Description

[0016] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. In the drawings: Figure 1 This is a schematic diagram of a granulator. In the diagram, 1 is the feed inlet, 2 is the machine body, 3 is the pressing belt, 4 is the conveyor belt, and 5 is the base.

[0017] Figure 2 This is a detailed schematic diagram of the granulator's pressing belt.

[0018] Figure 3 The graphs show the compressive strength test results after 3, 7, and 21 days of curing in Example 1 of this invention.

[0019] Figure 4 The graphs show the compressive strength test results after 3, 7, and 21 days of curing in Example 2 of this invention.

[0020] Figure 5 The graphs show the compressive strength test results after curing for 3, 7, and 21 days in Example 3 of this invention.

[0021] Figure 6 The graphs show the compressive strength test results after 3, 7, and 21 days of curing in Example 4 of this invention.

[0022] Figure 7 Table of XRF component analysis for magnesium slag. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] The present invention will now be described in further detail: A method for sand fixation using a photovoltaic electric field 1. Material composition: The composite cementitious material is composed of the following components: calcium oxide, fine sand, magnesium slag, magnesium sulfate, and water. The weight ratio of each component in the composite cementitious material is: calcium oxide, fine sand, magnesium slag, magnesium sulfate, and water = 1 : (0.5-10) : (0.1-4) : (0.1-3) : (0.5-4). XRF analysis of the magnesium slag composition is as follows... Figure 7 As shown.

[0025] The optimal weight ratio of the components of the composite cement-based material is 1:2:0.6:0.3:1.75.

[0026] 2. Gravel-making process: Step 1: Wet digestion of calcium oxide Calcium oxide (CaO) is mixed with excess water (H2O) and wet digested to obtain soft calcium hydroxide (Ca(OH)2), which is then ground.

[0027] Step 2: Preparation of Composite Cement The calcium hydroxide, fine sand, magnesium slag, magnesium sulfate and water obtained in step one are mixed in a weight ratio of 1:(0.5~10):(0.1~4):(0.1~3):(0.5~4) to form a composite cementitious material.

[0028] Step 3: Gravel Formation Process The moistened composite cementitious material mixed in step two is fed into the granulator. The granulator consists of a feeding port 1, a machine body 2, a pressing belt 3, a conveyor belt 4, and a base 5. (See attached image) Figure 1 ; The feeding port 1 is fixed to the top of the machine body 2, and the feeding port 1 is connected to the feeding channel inside the machine body 2; The body 2 is fixedly installed on the upper part of the base 5, and the base 5 provides support for the body 2. The pressing belt 3 is assembled on the discharge side of the machine body 2, and the pressing belt 3 is connected to the working mechanism inside the machine body 2. The conveyor belt 4 is arranged at an angle, and the upper end of the conveyor belt 4 is connected to the lower part of the discharge end of the pressing belt 3. The support structure of the conveyor belt 4 is connected to the base 5.

[0029] like Figure 1 and Figure 2 The pressing belt provides sufficient machine pressure to compress the composite cement from step two into oval-shaped blocks of varying sizes, which are then transported out via conveyor belt. The operation of the granulator and the working principle of the briquetting machine are based on the mechanical force used to compress the raw materials, reducing their volume, increasing their density, and forming them into a specific shape.

[0030] Inside the granulator, after the raw material enters the pressing chamber, the pressing belt applies pressure hydraulically or mechanically, compressing the material into the mold. The shape of the mold determines the shape of the finished product, such as oval, square, round, or a specific pattern. Under high pressure, the particles or fibers inside the raw material interlock, forming a blocky finished product with a certain strength and density. This process typically involves physical changes, such as friction and interlocking between particles, and chemical changes, such as the carbonization of calcium ions and the formation of Mg... 2+ It forms a double salt with Ca(OH)₂ or promotes the formation of Mg-OH gel. At this point, the granulator's pressing belt can be changed to obtain materials of different sizes, depending on the required particle size. Generally, the particle size should be adjusted according to the actual application requirements, with diameters typically between 2cm and 5cm.

[0031] Step 4: Storage and Use After the gravel particles are formed in the granulator, they still contain a certain amount of moisture and need to be dried to solidify. The granulated gravel particles are then fed into a drying device, where the temperature is controlled between 40°C and 60°C to ensure rapid evaporation of moisture while preventing damage to the composite cement from high temperatures. The drying process typically lasts 12 to 24 hours, ensuring that each gravel particle reaches the required hardness and stability.

[0032] Completely dried gravel particles should be stored in a dry, well-ventilated environment to prevent moisture or weathering. Ultimately, the resulting gravel particles can be used in projects such as desert photovoltaic power plants, forming a fixed layer by spreading the gravel to effectively reduce wind and sand erosion and provide excellent protection.

[0033] 3. Application method: Gravel is laid on the sand surface under the photovoltaic panel using a "loose-compacted" method, with a thickness of 3-5cm and a gravel gap ratio of ≥30%. The sand is then regularly moistened by a spray system to promote the secondary hydration reaction of the composite cement and enhance the consolidation strength.

[0034] The sand-fixing method of this invention uses composite cement-based materials and desert fine sand to produce gravel through a granulator, which has many unique advantages and characteristics, as follows: Resource Utilization: This method fully utilizes existing fine sand and composite cementitious materials in the desert, maximizing the use of local natural resources and significantly reducing dependence on external materials, effectively lowering transportation costs and environmental burden. Desert fine sand can be obtained locally, avoiding excessive extraction of external resources. Composite cementitious materials are low-cost, environmentally friendly, and highly weather-resistant. The addition of magnesium slag to its formula not only enhances the material's performance but also helps to absorb solid waste to a certain extent, achieving resource recycling and making it more suitable for use in extreme desert environments. When mixed with desert fine sand, it significantly enhances the cohesiveness of the gravel and its resistance to wind and sand erosion.

[0035] The production process is simple and efficient: Production is carried out using a granulator, making the entire process convenient and highly efficient. The mixture, under the action of the disc granulator, can quickly form oval-shaped gravel, enabling large-scale production and fully meeting the needs of large-scale desert sand fixation projects. The resulting oval-shaped gravel particles can be easily solidified after drying. The solidification process is very simple to control, requiring no overly complex equipment or technology, which greatly reduces the difficulty and cost of production.

[0036] Environmental Protection and Sustainability: Composite cement itself is an environmentally friendly material. The raw materials and processes used in its preparation have minimal environmental impact, fully aligning with the principles of green building and sustainable development. This sand-fixing method does not use any harmful chemicals, thus preventing secondary pollution of the ecological environment. Furthermore, it possesses ecological restoration capabilities. In addition to effectively preventing wind and sand erosion, the laid gravel layer creates favorable conditions for desert ecological restoration, helping to curb desertification and promoting the restoration and improvement of the ecological environment in desert regions.

[0037] Economic viability: The raw material costs of composite cement-based sand and desert sand are relatively low, and the production process is simple, requiring no large amount of high-end equipment, which can significantly reduce the treatment costs of desert sand fixation projects. For large-scale sand fixation projects in desert areas, this method undoubtedly provides a cost-effective solution. Due to the high durability of composite cement-based sand and gravel, the maintenance requirements of the sand fixation layer are low, thereby reducing the costs and labor costs of long-term maintenance.

[0038] Easy to promote and apply: The disc granulator can quickly and efficiently prepare gravel from large quantities of desert sand and composite cement-based materials, making it ideal for large-scale sand fixation projects. With its simple and low-cost production method, this method has a promising market prospect for widespread application in desert areas. Besides its use in sand fixation for photovoltaic power plants, gravel prepared from composite cement-based materials and desert sand can also be widely used in other sand fixation and windbreak / sand resistance applications, such as wind farms and desert tourist area protection, demonstrating broad application potential.

[0039] The present invention will be further described in detail below with reference to the embodiments: Example 1 A method for sand fixation in a photovoltaic electric field involves preparing a composite cement-based material. This material comprises calcium oxide, fine sand, magnesium slag, magnesium sulfate, and water in a weight ratio of 1:0.5:0.6:0.3:1.5. The mixture is stirred thoroughly and poured into a cylindrical mold with a diameter of 5 mm and a height of 100 mm. After molding for 24 hours, the mold is removed, and the samples are cured in an environment of 25±2℃ and 35±5% humidity for 3, 7, and 21 days, respectively. The compressive strengths tested are 0.354, 1.52, and 2.27 MPa, respectively.

[0040] The steps for preparing composite cement-based sand-fixing gravel are as follows: Calcium oxide (CaO) is mixed with excess water (H2O) and wet digested to obtain soft calcium hydroxide (Ca(OH)2), which is then ground. The calcium hydroxide, fine sand, magnesium slag, magnesium sulfate, and water obtained from S1 were mixed in a weight ratio of 1:0.5:0.6:0.3:1.5 to form a composite cement-based material. The well-mixed, moistened composite cementitious material is fed into a granulator. The completely dried gravel particles are then spread and compacted onto the sand surface beneath the photovoltaic panels.

[0041] Example 2 A method for sand fixation in a photovoltaic electric field involves preparing a composite cement-based material comprising calcium oxide, fine sand, magnesium slag, magnesium sulfate, and water in a weight ratio of 1:1.3:0.6:0.3:1.5. The mixture is stirred thoroughly and poured into a cylindrical mold with a diameter of 5 mm and a height of 100 mm. After molding for 24 hours, the mold is removed, and the samples are cured in an environment of 25±2℃ and 35±5% humidity for 3, 7, and 21 days, respectively. The compressive strengths tested are 0.91, 2.13, and 2.62 MPa, respectively.

[0042] The steps for preparing composite cement-based sand-fixing gravel are as follows: Calcium oxide (CaO) is mixed with excess water (H2O) and wet digested to obtain soft calcium hydroxide (Ca(OH)2), which is then ground. The obtained calcium hydroxide, fine sand, magnesium slag, magnesium sulfate and water are mixed in a weight ratio of 1:1.3:0.6:0.3:1.5 to form a composite cement-based material; The well-mixed, moistened composite cementitious material is fed into a granulator. The completely dried gravel particles are then spread and compacted onto the sand surface beneath the photovoltaic panels.

[0043] Example 3 A method for sand fixation in a photovoltaic electric field involves preparing a composite cement-based material, comprising calcium oxide, fine sand, magnesium slag, magnesium sulfate, and water in a weight ratio of 1:2:0.6:0.3:1.75. The mixture is stirred thoroughly and poured into a cylindrical mold with a diameter of 5 mm and a height of 100 mm. After molding for 24 hours, the mold is removed, and the samples are cured in an environment of 25±2℃ and 35±5% humidity for 3, 7, and 21 days, respectively. The compressive strengths tested are 1.62, 2.43, and 3.41 MPa, respectively.

[0044] The steps for preparing composite cement-based sand-fixing gravel are as follows: Calcium oxide (CaO) is mixed with excess water (H2O) and wet digested to obtain soft calcium hydroxide (Ca(OH)2), which is then ground. The obtained calcium hydroxide, fine sand, magnesium slag, magnesium sulfate and water were mixed in a weight ratio of 1:2:0.6:0.3:1.75 to form a composite cement-based material; The well-mixed, moistened composite cementitious material is fed into a granulator. The completely dried gravel particles are then spread and compacted onto the sand surface beneath the photovoltaic panels.

[0045] Example 4 A method for sand fixation in a photovoltaic electric field involves preparing a composite cement-based material comprising calcium oxide, fine sand, magnesium slag, magnesium sulfate, and water in a weight ratio of 1:0.75:0.6:0.3:1.5. The mixture is stirred thoroughly and poured into a cylindrical mold with a diameter of 5 mm and a height of 100 mm. After molding for 24 hours, the mold is removed, and the samples are cured in an environment of 25±2℃ and 35±5% humidity for 3, 7, and 21 days, respectively. The compressive strengths tested are 0.41, 1.04, and 2.19 MPa, respectively.

[0046] The steps for preparing composite cement-based sand-fixing gravel are as follows: Calcium oxide (CaO) is mixed with excess water (H2O) and wet digested to obtain soft calcium hydroxide (Ca(OH)2), which is then ground. The obtained calcium hydroxide, fine sand, magnesium slag, magnesium sulfate and water were mixed in a weight ratio of 1:0.75:0.6:0.3:1.5 to form a composite cement-based material; The well-mixed, moistened composite cementitious material is fed into a granulator. The completely dried gravel particles are then spread and compacted onto the sand surface beneath the photovoltaic panels.

[0047] Examples 1-4 were all made into identical cement products, and performance tests were conducted to compare their basic properties, as shown in Table 1 below.

[0048] Table 1: Comparison of compressive strength of cement products prepared in Examples 1-4 under different curing times

[0049] The following conclusions can be drawn from Table 1: Overall trend: The intensity of the formulation in all embodiments generally increased with curing time (3 days < 7 days < 21 days), with most samples reaching the highest peak at 21 days; like Figure 3 The proportions for Example 1: 3 days: Peak stress is about 0.35 MPa, peak strain is about 0.035, low stiffness, and obvious brittleness.

[0050] 7 days: peak pressure ≈ 1.52 MPa, peak strain ≈ 0.052, stiffness and strength are significantly improved.

[0051] 21 days: peak pressure ≈ 2.27 MPa, peak strain ≈ 0.055, strength continues to increase, and there is a small amount of plasticity before fracture.

[0052] like Figure 4 The proportions for Example 2 are as follows: 3 days: Peak value ≈ 0.901 MPa, with good toughness / ductility.

[0053] 7 days: peak pressure ≈ 2.13 MPa, peak strain ≈ 0.04–0.05, rapid intensity increase.

[0054] 21 days: peak pressure ≈ 2.62 MPa, peak strain ≈ 0.06, reaching the highest strength in 21 days.

[0055] like Figure 5 The proportions in Example 3: 3 days: Peak value ≈ 1.62 MPa, high early strength, indicating good early hydration / densification.

[0056] 7 days: Peak pressure ≈ 2.43 MPa. The peak pressure appears at a relatively small strain, indicating high rigidity.

[0057] 21 days: Although the early strength is low, it increases linearly with strain to ≈3.41MPa (maximum strain ≈0.09), indicating that the later strength and ductility are both good.

[0058] like Figure 6The proportions in Example 4: 3 days: Peak pressure ≈ 0.41 MPa, low intensity.

[0059] 7 days: Peak pressure ≈ 0.9–1.04 MPa, intensity increased.

[0060] 21 days: peak pressure ≈ 2.19 MPa, peak strain ≈ 0.07, balancing strength and ductility.

[0061] Overall conclusion: The formulation in Example 3 showed high strength in both the early and late stages (high peak values ​​at 7 and 21 days), making it suitable for applications requiring high strength. The formulation of Example 2 showed moderate strength compared to that of Example 4, with the formulation of Example 2 being slightly better at 21 days. The formulation in Example 1 has the lowest overall strength, making it suitable for scenarios with low strength requirements or those requiring higher porosity.

[0062] Many embodiments and applications beyond the examples provided will be apparent to those skilled in the art upon reading the foregoing description. Therefore, the scope of this teaching should not be determined by reference to the foregoing description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

[0063] The above content provides a further detailed description of the present invention. It should not be construed that the specific embodiments of the present invention are limited to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the defined protection scope of the present invention.

Claims

1. A method for sand fixation using a photovoltaic electric field, characterized in that, Includes the following steps: Calcium oxide was mixed with water and wet digested, then ground to obtain calcium hydroxide. The calcium hydroxide is mixed with fine sand, magnesium slag, magnesium sulfate, and water to prepare a composite cement-based material. The components of the composite cement-based material are proportioned by weight as follows: Calcium oxide : fine sand : magnesium slag : magnesium sulfate : water = 1 : (0.5~10) : (0.1~4) : (0.1~3) : (0.5~4); The composite cement-based material is mixed with desert sand and then fed into a granulator to produce gravel. The gravel is spread on the sand surface of the photovoltaic field to complete the sand fixation of the photovoltaic field.

2. The method for sand fixation in a photovoltaic electric field according to claim 1, characterized in that, The optimal weight ratio of each component of the composite cementitious material is as follows: Calcium oxide : fine sand : magnesium slag : magnesium sulfate : water = 1 : 2 : 0.6 : 0.3 : 1.

75.

3. The method for sand fixation in a photovoltaic electric field according to claim 1, characterized in that, The preparation of the sand and gravel also includes a drying step, in which the sand and gravel are placed in a drying device and dried at 40℃~60℃ for 12~24 hours until completely solidified.

4. The method for sand fixation in a photovoltaic electric field according to claim 1, characterized in that, The obtained gravel has a particle size of 2cm to 5cm, and the gravel is spread by loose spreading and compaction, with a spreading thickness of 3cm to 5cm, and the gap ratio of the gravel after spreading is ≥30%.

5. A method for sand fixation in a photovoltaic electric field according to claim 1, characterized in that, The granulator consists of a feeding port (1), a machine body (2), a pressing belt (3), a conveyor belt (4), and a base (5); The feeding port (1) is fixed to the top of the machine body (2), and the feeding port (1) is connected to the feeding channel inside the machine body (2); The body (2) is fixedly installed on the upper part of the base (5), and the base (5) provides support for the body (2); The pressing belt (3) is assembled on the discharge side of the machine body (2), and the pressing belt (3) is connected to the working mechanism inside the machine body (2) in a transmission connection. The conveyor belt (4) is arranged at an angle, and the upper end of the conveyor belt (4) is connected to the lower part of the discharge end of the pressing belt (3), and the support structure of the conveyor belt (4) is connected to the base (5).

6. The method for sand fixation in a photovoltaic electric field according to claim 1, characterized in that, After spreading, the composite cementitious material undergoes a secondary hydration reaction through periodic wetting treatment.

7. A method for sand fixation in a photovoltaic electric field according to claim 1, characterized in that, The granulator uses mechanical pressure to compress a mixture of composite cement-based material and desert sand into gravel of a predetermined shape.

8. A method for sand fixation in a photovoltaic electric field according to claim 1, characterized in that, The wet digestion of calcium oxide involves mixing calcium oxide with excess water, reacting the mixture, and then grinding it to obtain calcium hydroxide in a soft state.

9. A composite cement-based desert gravel for sand fixation in photovoltaic power plants, characterized in that, It is formed by granulation and solidification of composite cement-based materials and desert sand; The composite cement-based material comprises calcium hydroxide, fine sand, magnesium slag, and magnesium sulfate, and the calcium hydroxide is obtained by wet digestion of calcium oxide followed by grinding.

10. A composite cement-based desert gravel for sand fixation in photovoltaic power plants according to claim 9, characterized in that, After being cured for 21 days at 25±2℃ and 35±5% humidity, the compressive strength of the gravel is not less than 2.19MPa.

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