Soil structure and method for ecological restoration and application of soil structure and method

Abstract

The invention provides a soil structure for ecological restoration, a method and application thereof. The first soil structure comprises upper-layer soil and lower-layer soil; the upper-layer soil is prepared by mixing fly ash, desulfurized gypsum and first slag according to the volume ratio of (2-3): (1-2): (1-2); the lower-layer soil is prepared by mixing fly ash, desulfurized gypsum, second slag and original soil according to the volume ratio of (2-3): (1-2): (1-2): (3-5); wherein the particle size of the first slag is 40-80 mm; the particle size of the second slag is 3-6mm. According to the method, green, environment-friendly and efficient recycling of the solid waste of the power plant is truly achieved, the limited utilization way of the solid waste of the power plant is expanded, and ecological management of special environments such as Saggoban and strip mines is achieved while the income of the power plant is effectively increased.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection. Specifically, it relates to a soil structure, method and application for ecological restoration. Background Art

[0002] Since the Industrial Revolution, while enjoying the convenience and prosperity brought by industrial development, human society has also faced severe challenges of environmental pollution and resource depletion. With the increasing global emphasis on sustainable development and environmental protection, circular economy has emerged as a new economic model. Circular economy emphasizes the efficient use and recycling of resources to reduce waste and environmental pollution.

[0003] During the coal-fired power generation process in thermal power plants, a large amount of waste (power plant solid waste) will be generated, mainly including fly ash, slag and desulfurized gypsum, which causes a certain amount of pressure on the environment. The power plant solid waste contains harmful substances, which will pollute the soil, water source and atmosphere if not properly treated. Solid waste is actually not "waste", but a kind of resource. Its utilization in the circular economy can not only reduce the accumulation of waste, but also bring double economic and environmental benefits to society. Therefore, how to convert these industrial by-products into environmental protection resources and achieve green transformation has become an important issue in industrial development.

[0004] At present, the methods for treating power plant solid waste are mainly summarized into three types, namely treatment, disposal and reuse. In other words, if it can be treated by reuse, reuse should be the main method. For those that cannot be reused temporarily, necessary measures can be taken for disposal or stacking to solve the problem. The main raw materials for the reuse of power plant solid waste are building materials, road base materials and raw materials for ceramic products. The utilization efficiency and utilization amount are limited, and it is difficult to truly achieve green, environmental protection and efficient utilization.

[0005] Open-pit mining causes relatively serious damage to mountains and vegetation, and the natural habitats of wild animals and plants are damaged. Disasters such as landslides, flash floods, soil erosion and desertification and subsidence accidents occur from time to time. Mine ecological restoration has become an important environmental governance issue. Land desertification is a major problem affecting the sustainable development of mankind. Preventing the expansion of deserts, greening deserts, eliminating sandy lands, and scientifically developing and governing sandy deserts are of great significance to industries such as new energy, agriculture and animal husbandry.

[0006] Therefore, how to develop a solution for ecological restoration of land desertification and open-pit mining areas using power plant solid waste is of great significance. Summary of the Invention

[0007] The main purpose of the present invention is to provide a soil structure, method and application for ecological restoration, so as to improve the problems of serious land desertification and damaged vegetation in open-pit mining areas in the existing technology.

[0008] To achieve the above object, according to the first aspect of the present invention, a first soil structure for ecological restoration is provided. The first soil structure includes upper soil and lower soil;

[0009] The upper soil is made by mixing fly ash, desulfurized gypsum and first slag in a volume ratio of (2 - 3):(1 - 2):(1 - 2);

[0010] The lower soil is made by mixing the fly ash, the desulfurized gypsum, second slag and original soil in a volume ratio of (2 - 3):(1 - 2):(1 - 2):(3 - 5);

[0011] Wherein, the particle size of the first slag is 40 - 80 mm; the particle size of the second slag is 3 - 6 mm.

[0012] Further, the depth ratio of the upper soil to the lower soil is (1 - 2):(10 - 20).

[0013] To achieve the above object, according to the second aspect of the present invention, a second soil structure for ecological restoration is provided. The second soil structure is made by mixing fly ash, desulfurized gypsum, third slag and original soil in a volume ratio of (2 - 3):(1 - 2):(1 - 2):(4 - 6);

[0014] Wherein, the particle size of the third slag is 4 - 6 mm.

[0015] To achieve the above object, according to the third aspect of the present invention, a method for ecological restoration is provided. The method includes:

[0016] Using the soil structure to conduct ecological restoration on the soil to be repaired;

[0017] Wherein, the soil structure includes the above-mentioned first soil structure or the above-mentioned second soil structure.

[0018] Further, the soil to be repaired includes sandy gobi or open-pit mining area; preferably, the sandy gobi is selected from any one of the following: gravelly hard gobi, sandy gobi, fixed desert or mobile desert.

[0019] Further, the method includes: using the first soil structure to conduct ecological restoration on the sandy gobi or using the second soil structure to conduct ecological restoration on the open-pit mining area.

[0020] Further, the method includes: excavating the soil to be repaired to obtain an area to be backfilled; using the soil structure to backfill the area to be backfilled to obtain improved soil; planting plants in the improved soil to obtain vegetation-covered soil;

[0021] Spray the above vegetation-covered soil with water and drip-irrigate the above vegetation-covered soil with nutrient solution to obtain ecologically restored soil.

[0022] Furthermore, the above plants include drought-resistant, acid- and alkali-tolerant perennial varieties; the above drought-resistant, acid- and alkali-tolerant perennial varieties are selected from any one or more of the following: Xanthoceras sorbifolium, Pinus sylvestris var. mongolica, Thymus mongolicus, Glycyrrhiza uralensis, Astragalus adsurgens, Salix psammophila, Hippophae rhamnoides, Prunus armeniaca, Caragana korshinskii, Atriplex canescens, Achnatherum splendens, Salsola collina, Peganum harmala, Astragalus membranaceus, Medicago sativa, Stipa capillata, Tamarix chinensis, Populus euphratica, Hedysarum scoparium, Agriophyllum squarrosum, Sabina vulgaris or Prunus armeniaca var. ansu;

[0023] Preferably, the above plants include arbors, shrubs and herbaceous plants; among them, the above arbors are selected from any one or more of the following: Pinus sylvestris var. mongolica, Tamarix chinensis, Populus euphratica, Xanthoceras sorbifolium or Prunus armeniaca var. ansu; the above shrubs are selected from any one or more of the following: Hippophae rhamnoides, Prunus armeniaca, Caragana korshinskii, Salix psammophila, Sabina vulgaris, Hedysarum scoparium or Atriplex canescens; the above herbaceous plants are selected from any one or more of the following: Astragalus adsurgens, Thymus mongolicus, Glycyrrhiza uralensis, Achnatherum splendens, Salsola collina, Peganum harmala, Astragalus membranaceus, Medicago sativa, Stipa capillata or Agriophyllum squarrosum.

[0024] Furthermore, the depth of the above area to be backfilled ≤ 100 cm; preferably, the pH of the above nutrient solution is 5 - 8 and the conductivity is 0.5 - 2.5.

[0025] Furthermore, after the above plants are planted, spray the above vegetation-covered soil with the above water at night to make the soil humidity 35% - 45%;

[0026] When the above plants successfully recover from transplantation and start to take root, drip-irrigate the above vegetation-covered soil with the above nutrient solution; the frequency of the above drip irrigation is 2 - 3 times / week; among them, the conductivity of the above nutrient solution is 0.5 - 1.0;

[0027] When the above plants start to grow independently, drip-irrigate the above vegetation-covered soil with the above nutrient solution; the frequency of the above drip irrigation is 1 - 2 times / week; among them, the conductivity of the above nutrient solution is 1.0 - 2.5;

[0028] Preferably, use a spray-drip adjustable dripper to adjustably perform the above drip irrigation or the above spraying;

[0029] Preferably, the above spray-drip adjustable dripper is installed on a pipeline, and the above pipeline is selected from φ20 black PE water-saving drip irrigation tape;

[0030] Preferably, the layout of the above pipeline is linear and / or grid-shaped;

[0031] Preferably, the layout of the above pipeline is linear and grid-shaped; the above arbors are planted at the four vertices of the grid, the above shrubs are planted on the four sides of the above grid, and the above herbaceous plants are planted inside the above grid.

[0032] Applying the technical solution of the present invention to hollow out the sandy and waste or open-pit mining area and backfill it with the soil structure of the present invention, and planting plants in the backfilled soil can help to repair the sandy and waste or open-pit mining area.

[0033] The above soil structure is selected from the first soil structure or the second soil structure. Among them, the first soil structure includes upper soil and lower soil; the upper soil is made by mixing fly ash, desulfurized gypsum and the first slag in a volume ratio of (2-3):(1-2):(1-2); the lower soil is made by mixing fly ash, desulfurized gypsum, the second slag and original soil in a volume ratio of (2-3):(1-2):(1-2):(3-5); among them, the particle size of the first slag is 40-80 mm; the particle size of the second slag is 3-6 mm. The second soil structure is made by mixing fly ash, desulfurized gypsum, the third slag and original soil in a volume ratio of (2-3):(1-2):(1-2):(4-6). Among them, the particle size of the third slag is 4-6 mm.

[0034] Using the solid waste from thermal power plants, namely fly ash, desulfurized gypsum and slag, as soil improvement raw materials and mixing them with the original ground can form a surface protection layer in the sandy and waste or open-pit mining area, which plays a role in solidifying the surface. It can not only achieve ecological environment governance but also make full use of waste resources, help to alleviate land desertification and repair the open-pit mining area, and at the same time help to improve the utilization rate of solid waste from thermal power plants, realizing the green and efficient utilization of power plant solid waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0036] Figure 1 Shows a sectional view of soil improvement according to an embodiment of the present invention; among them, 101. Surface layer represents the upper layer of the first soil structure of the present invention; 102. Lower layer represents the lower layer of the first soil structure of the present invention; 103. Excavation layer and 104. Original soil layer to be improved together represent the lower layer of the first soil structure of the present invention; 101. Surface layer, 103. Excavation layer and 104. Original soil layer to be improved together represent the second soil structure of the present invention; 105. Original soil layer represents the original soil layer below the first soil structure or the second soil structure of the present invention.

[0037] Figure 2 Shows a schematic diagram of the laying method of the spray-irrigation and drip-irrigation belt according to an embodiment of the present invention; among them, 201 refers to the spray-irrigation and drip-irrigation belt and 202 refers to the boundary of the area to be improved.

[0038] Figure 3 Shows a schematic diagram of the vegetation planting distribution according to an embodiment of the present invention; wherein, 201 refers to the sprinkler-drip irrigation belt, 202 refers to the boundary of the area to be improved, 203 refers to arbors, 204 refers to shrub A, 205 refers to shrub B, and 206 refers to grass.

[0039] Figure 4 Shows a partial enlargement of the schematic diagram of the vegetation planting distribution according to an embodiment of the present invention; wherein, 203 refers to arbors, 204 refers to shrub A, 205 refers to shrub B, and 206 refers to grass. Detailed implementation manners

[0040] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0041] Term explanation:

[0042] Original soil: refers to the soil of the soil to be repaired.

[0043] Desert, gobi or wasteland: refers to the general term of desert, gobi or wasteland. Among them, the desert includes fixed desert and mobile desert; the gobi includes gravel hard gobi and sandy gobi.

[0044] Nutrient solution: also known as water-soluble fertilizer or liquid fertilizer, which is the raw material for plant growth nutrition supply. It is mainly composed of mineral nutrient elements and water, and contains various nutrient components required for plant growth, such as macronutrients such as nitrogen, phosphorus, potassium, calcium, magnesium and sulfur, and micronutrients such as iron, manganese, boron, zinc and copper.

[0045] EC: represents "Electric Conductivity", that is, electrical conductivity. High electrical conductivity indicates a high concentration of electrolytes in the solution, while low electrical conductivity indicates a low concentration of electrolytes.

[0046] Gravel hard gobi: mainly with soil particle size of 2-20mm, the gravel hard gobi is a desert composed of particulate matters such as gravel, rock and sand. The ground surface presents hard and impenetrable characteristics, usually covered with a large amount of gravel and rock, forming a hard ground surface. This type of desert usually has less wind erosion phenomenon and it is difficult for vegetation to grow.

[0047] Sandy gobi / fixed desert: mainly with soil particle size of 0.5-2mm, the sandy gobi is mainly composed of fine sand and large sand dunes. The ground surface presents a flat or continuous dune shape, and the dunes are in a relatively stable state with less wind and sand. Vegetation is scarce and it is difficult to grow, and the ecological environment is relatively harsh.

[0048] Flowing desert: The soil particle size is mainly 0.05 - 0.5 mm. A flowing desert is a desert composed of a large amount of fine sand or dust. The sand dunes are easily blown and moved by the wind, forming mobile sand dunes. The surface of the flowing desert often shows a bare and vegetation-free state, and the movement of sand dunes will cause environmental problems such as sandstorms.

[0049] Open-pit mining area: It refers to the area where mining activities are carried out on the surface. It has the following characteristics: 1) A large amount of land is mined and damaged, forming a large mining area; 2) The mining area usually presents a vast open-pit mine, and sometimes mining pits hundreds of meters deep are formed; 3) A large amount of waste ore slag and tailings deposits are generated during the mining process, which may affect the surrounding environment and ecosystem; 4) Open-pit mining requires a large amount of mechanical equipment and manpower, and is often a large-scale mining activity.

[0050] As mentioned in the background technology, the current problems of land desertification and open-pit mining areas are becoming increasingly serious. To improve this situation, the inventors in the present invention attempt to use power plant solid wastes (including fly ash, desulfurized gypsum, and slag) to carry out ecological restoration on the sandy and barren areas or open-pit mining areas, and propose a series of protection schemes of the present invention.

[0051] In the first typical embodiment of the present invention, a first soil structure for ecological restoration is provided. The first soil structure includes upper soil and lower soil; the upper soil is made by mixing fly ash, desulfurized gypsum, and first slag according to a volume ratio of (2 - 3):(1 - 2):(1 - 2); the lower soil is made by mixing the fly ash, the desulfurized gypsum, second slag, and original soil according to a volume ratio of (2 - 3):(1 - 2):(1 - 2):(3 - 5); wherein, the particle size of the first slag is 40 - 80 mm; the particle size of the second slag is 3 - 6 mm.

[0052] Utilizing the characteristics that fly ash and desulfurized gypsum solidify when encountering water and the first slag has a porous and heavy quality. The upper soil reacts with water and substances in the original soil to form a stable cementitious substance, enhancing the cohesion of the soil and achieving the effect of solidifying the ground surface. The first slag can play a role in blocking and fixing sand and reducing the flow of wind and sand. The lower soil can improve the soil structure, adjust the soil pH value, improve the water absorption and water retention of the soil, increase the compactness and bearing capacity of the sandy land, improve the stability of the soil, and provide some minerals and trace elements necessary for plant growth such as calcium, iron, zinc, copper, aluminum, and silicon, creating good conditions for crop growth.

[0053] In a preferred embodiment of the present invention, the depth ratio of the upper soil to the lower soil is (1 - 2):(10 - 20). At this depth ratio, the original soil structure can be effectively improved, water loss can be reduced, a suitable root environment can be provided for plant growth, and at the same time, the flow of wind and sand can be reduced, and sand can be blocked and fixed, which is economical and efficient.

[0054] In the second typical embodiment of the present invention, a second soil structure for ecological restoration is provided. The second soil structure is made by mixing fly ash, desulfurized gypsum, third slag and original soil according to a volume ratio of (2 - 3):(1 - 2):(1 - 2):(4 - 6); wherein, the particle size of the above-mentioned third slag is 4 - 6 mm. This second soil structure can improve the air permeability and water retention capacity of the soil, optimize the particle size composition of the soil, improve the water, fertilizer, air and heat conditions of the soil, increase the pH value of the soil, and various trace elements such as zinc, copper, molybdenum, boron, etc., as essential elements for plant growth, can supplement soil nutrients, thereby promoting vegetation restoration.

[0055] In the third typical embodiment of the present invention, a method for ecological restoration is provided. The method includes: using the soil structure to carry out ecological restoration on the soil to be repaired; wherein, the above-mentioned soil structure includes the above-mentioned first soil structure or the above-mentioned second soil structure. Using the above-mentioned soil structure to repair the soil to be repaired can efficiently promote the restoration of soil vegetation.

[0056] In a preferred embodiment of the present invention, the soil to be repaired includes sandy gobi or open-pit mining area; in a preferred embodiment of the present invention, the method includes: using the above-mentioned first soil structure to carry out ecological restoration on the above-mentioned sandy gobi or using the above-mentioned second soil structure to carry out ecological restoration on the above-mentioned open-pit mining area.

[0057] Using the first soil structure to repair the sandy gobi can help enhance the cohesion of the soil, reduce the porosity of the sandy gobi soil, and achieve the effect of solidifying the ground surface. Among them, the first slag can play a role in sand blocking and fixing, and reducing the flow of wind and sand.

[0058] Using the second soil structure to repair the open-pit mining area can increase the porosity and permeability of the soil in the open-pit mining area, improve the air permeability and water retention capacity of the soil, optimize the particle size composition of the soil, improve the water, fertilizer, air and heat conditions of the soil, increase the pH value of the soil, and various trace elements such as zinc, copper, molybdenum and boron, etc., as essential elements for plant growth, can supplement soil nutrients, thereby promoting vegetation restoration.

[0059] In a more preferred embodiment of the present invention, the above-mentioned sandy gobi is selected from any one of the following: gravelly hard gobi, sandy gobi, fixed desert or mobile desert. The degree of desertification of gravelly hard gobi, sandy gobi / fixed desert and mobile desert shows an increasing trend. With the increase of the degree of desertification, the proportion of power plant solid waste (fly ash, desulfurized gypsum and slag) in the lower layer soil of the first soil structure increases and the proportion of original soil decreases. The proportion of fly ash and desulfurized gypsum in the upper layer soil and the lower layer soil decreases, and the proportion of slag increases.

[0060] According to different rainfall amounts and soil particle sizes, there are differences in the optimal proportions of the components of the above-mentioned first soil structure.

[0061] In a preferred embodiment of the present invention, the above-mentioned sandy and barren land is gravelly hard gobi, and the above-mentioned upper soil is made by mixing fly ash, desulfurized gypsum, and first slag in a volume ratio of 3:2:1; the above-mentioned lower soil is made by mixing the above-mentioned fly ash, the above-mentioned desulfurized gypsum, second slag, and original soil in a volume ratio of 3:2:1:4.

[0062] In a preferred embodiment of the present invention, the above-mentioned sandy and barren land is sandy gobi or fixed desert, and the above-mentioned upper soil is made by mixing fly ash, desulfurized gypsum, and first slag in a volume ratio of 2:1:(1-2); the above-mentioned lower soil is made by mixing the above-mentioned fly ash, the above-mentioned desulfurized gypsum, second slag, and original soil in a volume ratio of (2-3):(1-2):(1-2):(4-5).

[0063] In a more preferred embodiment of the present invention, the above-mentioned sandy and barren land is sandy gobi or fixed desert.

[0064] When the annual average precipitation of the above-mentioned sandy and barren land > 200 mm, the above-mentioned upper soil is made by mixing fly ash, desulfurized gypsum, and first slag in a volume ratio of 2:1:1; the above-mentioned lower soil is made by mixing the above-mentioned fly ash, the above-mentioned desulfurized gypsum, second slag, and original soil in a volume ratio of 2:1:2:5.

[0065] When the annual average precipitation of the above-mentioned sandy and barren land is 100-200 mm, the above-mentioned upper soil is made by mixing fly ash, desulfurized gypsum, and first slag in a volume ratio of 2:1:2; the above-mentioned lower soil is made by mixing the above-mentioned fly ash, the above-mentioned desulfurized gypsum, second slag, and original soil in a volume ratio of 3:1:2:4.

[0066] When the annual average precipitation of the above-mentioned sandy and barren land < 100 mm, the above-mentioned upper soil is made by mixing fly ash, desulfurized gypsum, and first slag in a volume ratio of 2:1:2; the above-mentioned lower soil is made by mixing the above-mentioned fly ash, the above-mentioned desulfurized gypsum, second slag, and original soil in a volume ratio of 2:2:2:4.

[0067] In a preferred embodiment of the present invention, the above-mentioned sandy and barren land is mobile desert, and the above-mentioned upper soil is made by mixing fly ash, desulfurized gypsum, and first slag in a volume ratio of (2-3):(1-2):(1-2); the above-mentioned lower soil is made by mixing the above-mentioned fly ash, the above-mentioned desulfurized gypsum, second slag, and original soil in a volume ratio of (2-3):(1-2):(1-2):(3-4).

[0068] In a more preferred embodiment of the present invention, the above-mentioned sandy and desertified land is mobile desert; when the annual average precipitation of the above-mentioned sandy and desertified land > 200 mm, the above-mentioned upper soil is made of fly ash, desulfurized gypsum and first slag mixed according to a volume ratio of 2:1:2; the above-mentioned lower soil is made of the above-mentioned fly ash, the above-mentioned desulfurized gypsum, second slag and original soil mixed according to a volume ratio of 2:2:2:4.

[0069] When the annual average precipitation of the above-mentioned sandy and desertified land is 100 - 200 mm, the above-mentioned upper soil is made of fly ash, desulfurized gypsum and first slag mixed according to a volume ratio of 3:2:2; the above-mentioned lower soil is made of the above-mentioned fly ash, the above-mentioned desulfurized gypsum, second slag and original soil mixed according to a volume ratio of 2:2:2:4.

[0070] When the annual average precipitation of the above-mentioned sandy and desertified land < 100 mm, the above-mentioned upper soil is made of fly ash, desulfurized gypsum and first slag mixed according to a volume ratio of 3:2:2; the above-mentioned lower soil is made of the above-mentioned fly ash, the above-mentioned desulfurized gypsum, second slag and original soil mixed according to a volume ratio of 3:2:2:3.

[0071] In a preferred embodiment of the present invention, the above method includes: excavating the above-mentioned soil to be repaired to obtain an area to be backfilled; backfilling the area to be backfilled with the above-mentioned soil structure to obtain improved soil; planting plants in the above-mentioned improved soil to obtain vegetation-covered soil; spraying water on the above-mentioned vegetation-covered soil and drip-irrigating the above-mentioned vegetation-covered soil with nutrient solution to obtain ecologically repaired soil.

[0072] Plants help to prevent wind and fix sand, reduce the wind speed and wind force on the ground surface, reduce solar radiation, reduce the evaporation of surface water, increase the soil moisture content, increase soil organic matter and soil microorganisms. In a preferred embodiment of the present invention, the above-mentioned plants include drought-resistant and acid-base-tolerant perennial varieties; the above-mentioned drought-resistant and acid-base-tolerant perennial varieties are selected from any one or more of the following: Xanthoceras sorbifolium, Pinus sylvestris var. mongolica, Thymus mongolicus, Glycyrrhiza uralensis, Astragalus adsurgens, Salix psammophila, Hippophae rhamnoides, Caragana korshinskii, Atriplex canescens, Achnatherum splendens, Salsola collina, Peganum harmala, Astragalus membranaceus, Medicago sativa, Stipa capillata, Tamarix chinensis, Populus euphratica, Hedysarum scoparium, Agriophyllum squarrosum, Sabina vulgaris or Prunus armeniaca var. ansu.

[0073] Combined planting of plants according to the principle of "trees, shrubs and herbs" helps to form an integrated vegetation cover in three-dimensional space, with better effects of wind prevention, sand fixation and soil and water conservation, and greatly improves the comprehensive survival rate of the vegetation. In a more preferred embodiment of the present invention, the above-mentioned plants include trees, shrubs and herbs; among them, the above-mentioned trees are selected from any one or more of the following: Pinus sylvestris var. mongolica, Tamarix ramosissima, Populus euphratica, Xanthoceras sorbifolium or Prunus mongolica; the above-mentioned shrubs are selected from any one or more of the following: Hippophae rhamnoides, Caragana korshinskii, Salix psammophila, Sabina vulgaris, Hedysarum scoparium or Atriplex canescens; the above-mentioned herbaceous plants are selected from any one or more of the following: Astragalus adsurgens, Thymus mongolicus, Glycyrrhiza uralensis, Achnatherum splendens, Salsola collina, Peganum harmala, Astragalus membranaceus, Medicago sativa, Stipa capillata or Agriophyllum squarrosum. Using the above-mentioned plants helps with wind prevention, sand fixation and vegetation cover in sandy deserts and is conducive to ecological restoration and soil and water conservation in open-pit mining areas.

[0074] The depth of the area to be backfilled may affect soil air permeability, water absorption and water retention, the fixing effect and survival rate of plants, and the difficulty and cost of soil improvement and ecological restoration projects. In a preferred embodiment of the present invention, the depth of the area to be backfilled is 70 - 100 cm.

[0075] In a preferred embodiment of the present invention, the pH of the above-mentioned nutrient solution is 5 - 8 and the conductivity is 0.5 - 2.5. Using the above-mentioned nutrient solution helps the growth of plants, thus further contributing to vegetation cover and realizing the treatment and restoration of sandy deserts and open-pit mining areas.

[0076] In a preferred embodiment of the present invention, after the above-mentioned plants are planted, the above-mentioned vegetation-covered soil is sprayed with the above-mentioned water at night to make the soil humidity 35% - 45%;

[0077] When the above-mentioned plants have successfully survived the slow seedling stage and start to take root, the above-mentioned vegetation-covered soil is drip-irrigated with the above-mentioned nutrient solution; the frequency of the above-mentioned drip irrigation is 2 - 3 times / week; among them, the conductivity of the above-mentioned nutrient solution is 0.5 - 1.0;

[0078] When the above-mentioned plants start to grow independently, the above-mentioned vegetation-covered soil is drip-irrigated with the above-mentioned nutrient solution; the frequency of the above-mentioned drip irrigation is 1 - 2 times / week; among them, the conductivity of the above-mentioned nutrient solution is 1.0 - 2.5.

[0079] The watering range of spraying is large and the water consumption is much. Spraying with water can help with soil moistening, the formation of a surface protection layer and the water supply for newly planted vegetation. The irrigation range of drip irrigation is small, water-saving and highly targeted. Drip irrigation with a nutrient solution can provide water and nutrient elements for plant growth, promote the rapid growth of plants, prepare for vegetation restoration, and contribute to the ecological restoration and treatment of sandy deserts and open-pit mining areas.

[0080] In a preferred embodiment of the present invention, the above-mentioned drip irrigation or the above-mentioned spraying is adjusted by a spray-drip adjustable dripper; preferably, the above-mentioned spray-drip adjustable dripper is installed on a pipeline, and the above-mentioned pipeline is selected from a φ20 black PE water-saving drip irrigation tape; preferably, the above-mentioned pipeline is arranged linearly and / or in a grid pattern; preferably, the above-mentioned pipeline is arranged linearly and in a grid pattern; the above-mentioned arbors are planted at the four vertices of the grid, the above-mentioned shrubs are planted on the four sides of the above-mentioned grid, and the above-mentioned herbs are planted within the above-mentioned grid. The above-mentioned arrangement, water drip irrigation tape and dripper have beneficial effects such as dual use of spraying and dripping, high adaptability to plant irrigation, water saving and energy saving, and high vegetation survival rate.

[0081] In a preferred embodiment of the present invention, the above-mentioned drip irrigation and the above-mentioned spraying are arranged linearly and in a grid pattern; the above-mentioned arbors are planted at the four vertices of the above-mentioned grid, the above-mentioned shrubs are planted on the four sides of the above-mentioned grid, and the above-mentioned herbs are planted within the above-mentioned grid. The above-mentioned combined planting method of "trees, shrubs and herbs" has beneficial effects such as mutual protection of different types of plants, stable positions, not being easily blown or buried by wind and sand, overall wind prevention and sand fixation, and reduction of surface evaporation.

[0082] The following further describes the present invention in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present invention.

[0083] The main raw material sources in the following embodiments are as follows:

[0084] Fly ash from a coal-fired power plant, from Yangluo Power Plant of Huaneng Wuhan Power Generation Co., Ltd.

[0085] Desulfurized gypsum from a coal-fired power plant, from Yangluo Power Plant of Huaneng Wuhan Power Generation Co., Ltd.

[0086] Cinder from a coal-fired power plant, from Yangluo Power Plant of Huaneng Wuhan Power Generation Co., Ltd.

[0087] Nutrient solution, using Hoagland general formula nutrient solution, from Hunan Hoagland Biotechnology Co., Ltd., standard Hoagland formula (general type);

[0088] Nutrient solution system, the water and fertilizer integration machine is selected from Beijing Aotuo Zhicheng Technology Development Co., Ltd., AUTO-C5;

[0089] The spray / drip irrigation pipe is selected from Netafim, a customized product. Plant species are purchased locally and self-bred.

[0090] Example 1

[0091] It was implemented in the southern new energy base of Kubuqi Desert, Ordos City, Inner Mongolia Autonomous Region in 2023, and the operation is as follows:

[0092] (1) The target area is located in the Kubuqi Desert, which is a fixed desert with an altitude of about 800 - 2200 meters. The landform is aeolian landform, mainly composed of mobile sand, semi-fixed sand and dune chains, mostly undulating dunes; the soil type is mainly aeolian soil; it has a temperate continental monsoon climate, in the mid-temperate arid and semi-arid regions, with high temperatures, large temperature differences between day and night, dry climate, an average annual temperature of 8.1 °C, extreme temperatures of 39.6 °C / -33.8 °C, an average annual precipitation of 179.9 mm, and most of the precipitation is concentrated in summer, and the precipitation from June to August accounts for 60 - 70% of the annual total.

[0093] (2) It is determined that the area requiring ecological restoration and treatment is the sandy, gobi and barren area. Different soil improvement raw materials are used for soil improvement in the upper and lower layers. Among them: the lower-layer soil improvement raw materials are fly ash, desulfurized gypsum, small-sized slag (particle size of 3 mm) and original soil, mixed in a volume ratio of 3:1:2:4; the upper layer, that is, the surface layer, is prepared with fly ash, desulfurized gypsum and large-sized slag (particle size of 40 mm) in a volume ratio of 2:1:2. The improvement depth of the lower layer is 90 cm, and the thickness of the surface layer is 5 cm. The Hoagland general nutrient solution formula is selected, the pH of the nutrient solution is 6, the EC is 0.5 in the initial stage and 1.0 in the later stage. The drip irrigation layout form is mainly grid-shaped and supplemented by linear. Pinus sylvestris var. mongolica, Caragana korshinskii, Sabina vulgaris and Peganum harmala are planted respectively to form the final professional plan.

[0094] (3) According to the determined plan, calculate the dosage of each component according to the formula VX = S × H × RX, where VX is the volume of component X in the soil improvement raw material, X is a certain component in the power plant solid waste or the original soil, S is the area to be improved in the region, H is the improvement depth, and RX is the formula proportion of component X in the soil improvement raw material: A total of 1500 m of test plots are selected for this experiment 2 , with 500 m for experimental group 1, control group 1 and control group 2 respectively 2 , for experimental group 1, it is calculated that 135 m of fly ash in the lower layer 3 , 45 m of desulfurized gypsum 3 , 90 m of 3 mm small-sized slag 3 , 180 m of original soil 3 , 10 m of fly ash in the upper layer 3 , 5 m of desulfurized gypsum 3 , 10 m of 40 mm large-sized slag 3 are used to prepare the soil improvement raw material.

[0095] (4) Then, 270 m of the original soil in the area of experimental group 1 is dug out 3 , and after leveling, 135 m of fly ash 3 , 45 m of desulfurized gypsum 3 , 90 m of 3 mm small-sized slag 3Mix evenly and lay it on the ground as the raw material for subsoil improvement. Use a rotary tiller to conduct uniform and comprehensive deep plowing and mixing according to the designed improvement depth of 90 cm (the total volume of the original soil in the mixture is 180 m 3 ), and then backfill and level the upper soil improvement raw material in the experimental group 1 area, with a thickness of about 5 cm, as Figure 1 shown.

[0096] (5) After the implementation of soil improvement, experimental group 1 and the control groups (including control group 1 and control group 2) respectively adopt black PE water-saving drip irrigation tapes with spray-drip adjustable drippers and lay them linearly and in a grid pattern at an equal distance of 1.5 m. The specific laying form is as Figure 2 shown. The nutrient solution is uniformly supplied by a centralized integrated water and fertilizer machine, and the two systems of experimental group 1 and the control groups are independent.

[0097] (6) Next, plant Pinus sylvestris var. mongolica (tree), Caragana korshinskii (shrub), Sabina vulgaris (shrub), and Peganum harmala (herb) evenly in the target area according to the plan. Experimental group 1 is planted according to the combination principle of "trees, shrubs, and herbs" in accordance with Figure 3 and Figure 4 . Pinus sylvestris var. mongolica is planted at the four vertex positions, Caragana korshinskii is planted along the short side, Sabina vulgaris is planted along the long side, and Peganum harmala is planted in the grid.

[0098] (7) After the vegetation is planted, the control groups and experimental group 1 use the nutrient solution drip irrigation / sprinkling system to conduct high-pressure clear water spraying through the constant-pressure variable-frequency water pump supporting the integrated water and fertilizer machine at night to ensure that the soil humidity is 40±5%. After 7 days, the vegetation adapts to the new environment, successfully slows down seedlings and starts to take root, and then conducts drip irrigation twice a week with a low-concentration nutrient solution with an EC of 0.5 prepared by the integrated water and fertilizer machine. When the plants start to grow independently, conduct drip irrigation once a week with a nutrient solution with an EC (electrical conductivity, used to measure the content of dissolved minerals - salts in the nutrient solution) of 1.0 concentration prepared by the water and fertilizer machine. After an 8-month operation test of the ecological restoration and treatment method, respectively count the water consumption, vegetation survival rate, soil humidity, and surface wind and sand conditions of experimental group 1 and the control groups, as shown in Table 1 below.

[0099] Control group 1 conducts original soil excavation and backfilling, and the rest is the same as experimental group 1.

[0100] Control group 2 randomly disperses and plants the same amount of Pinus sylvestris var. mongolica, Caragana korshinskii, Sabina vulgaris, and Peganum harmala, and the rest is the same as experimental group 1.

[0101] The differences between Experimental Group 2 and Experimental Group 1 are as follows: The upper-layer soil of Experimental Group 2 is made by mixing fly ash, desulfurized gypsum, and large-sized slag (40 mm) in a volume ratio of 2:1:1. The lower-layer soil is made by mixing the above fly ash, the above desulfurized gypsum, small-sized slag (3 mm), and original soil in a volume ratio of 2:2:1:5.

[0102] The differences between Experimental Group 3 and Experimental Group 1 are as follows: The upper-layer soil of Experimental Group 3 is made by mixing fly ash, desulfurized gypsum, and large-sized slag (40 mm) in a volume ratio of 4:2:3. The lower-layer soil is made by mixing the above fly ash, the above desulfurized gypsum, small-sized slag (3 mm), and original soil in a volume ratio of 5:3:3:9.

[0103] Table 1 Result Statistics and Comparison

[0104] / Water consumption / ton Vegetation survival rate Soil humidity Surface windblown sand Experimental group 1 280 72％ 36％ Wind force 6.4, less windblown sand Experimental group 2 293 64％ 30％ Wind force 6.8, less windblown sand Experimental group 3 288 69％ 32％ Wind force 6.5, less windblown sand Control group 1 325 46％ 21％ Wind force 7.6, more windblown sand Control group 2 300 58％ 28％ Wind force 6.9, less windblown sand

[0105] Note: The water consumption is read through a water meter, the vegetation survival rate is calculated by counting the planted quantity and the final survived quantity, the soil humidity is read using a portable soil humidity detector, and the surface wind and sand are monitored and obtained through an integrated outdoor weather station.

[0106] As can be seen from Table 1, compared with Control Group 1, Experimental Group saves about 9% - 13.8% of water, the soil humidity is 9% - 15% higher, the vegetation survival rate is higher, reaching over 64%, the surface wind force is reduced by 11% - 16%, and there is relatively less wind and sand. The experiment shows that using the technical solution described in the present invention for desertified and barren soil restoration and ecological governance can significantly reduce the water consumption per unit area, save water and energy, is beneficial to improving soil humidity, air permeability, and water retention capacity, increase the survival rate of plants, reduce the surface wind force and the flow of wind and sand, and the effect in desertified and barren area ecological restoration and governance is significantly better than the conventional scheme.

[0107] Example 2

[0108] It was implemented in the New Energy Empirical Base in Jiayuguan, Gansu in 2023. The target area is located in Plot 1 of the New Energy Empirical Base in Jiayuguan, Gansu, a gobi desert. The soil is mainly composed of particulate matter such as gravel, rock, and sand, belonging to gravelly hard gobi, and the annual average precipitation is about 85 mm.

[0109] The upper-layer soil of the experimental group is made by mixing fly ash, desulfurized gypsum, and large-sized slag (40 mm) in a volume ratio of 3:2:1. The lower-layer soil is made by mixing the above fly ash, the above desulfurized gypsum, small-sized slag (5 mm), and original soil in a volume ratio of 3:2:1:4. The depth of the upper-layer soil is 10 cm, and the depth of the lower-layer soil is 90 cm. The control group carried out original soil excavation and backfilling.

[0110] The pH of the nutrient solution is 5. When the plant has successfully acclimatized and starts to root, the drip irrigation frequency is 2 times / week, and the EC of the nutrient solution is 1. When the plant starts to grow independently, the drip irrigation frequency is 1 time / week, and the EC of the nutrient solution is 2.5.

[0111] The remaining steps of this example are the same as those of Experimental Group 1 in Example 1, and the experimental results are shown in Table 2.

[0112] Table 2 Statistical Comparison of Results

[0113] / Water consumption / ton Vegetation survival rate Soil humidity Surface windblown sand Experimental group 315 62％ 35％ Wind force 6.6, less windblown sand Control group 340 42％ 20％ Wind force 7.6, more windblown sand

[0114] Example 3

[0115] It was implemented in the new energy demonstration base in Jiayuguan, Gansu in 2023. The target area is located in Plot 2 of the new energy demonstration base in Jiayuguan, Gansu, a gobi desert. The soil particle size is mainly 0.5 - 1 mm. The surface mainly shows fine sand and flat or continuous dune forms. The dunes are in a relatively stable state, belonging to sandy gobi, and the annual average precipitation is about 90 mm.

[0116] In Experimental Group 1, the upper-layer soil is made by mixing fly ash, desulfurized gypsum, and large-sized slag (particle size 60 mm) in a volume ratio of 2:1:1. The lower-layer soil is made by mixing the above fly ash, the above desulfurized gypsum, small-sized slag (particle size 6 mm), and original soil in a volume ratio of 3:1:1:5. The depth of the upper-layer soil is 5 cm, and the depth of the lower-layer soil is 50 cm.

[0117] In Experimental Group 2, the upper-layer soil is made by mixing fly ash, desulfurized gypsum, and large-sized slag (particle size 60 mm) in a volume ratio of 2:1:2. The lower-layer soil is made by mixing the above fly ash, the above desulfurized gypsum, small-sized slag (particle size 6 mm), and original soil in a volume ratio of 2:2:2:4. The depth of the upper-layer soil is 5 cm, and the depth of the lower-layer soil is 50 cm.

[0118] In Experimental Group 3, the upper-layer soil is made by mixing fly ash, desulfurized gypsum, and large-sized slag (particle size 60 mm) in a volume ratio of 4:2:3. The lower-layer soil is made by mixing the above fly ash, the above desulfurized gypsum, small-sized slag (particle size 6 mm), and original soil in a volume ratio of 5:3:3:9. The depth of the upper-layer soil is 5 cm, and the depth of the lower-layer soil is 50 cm.

[0119] The pH of the nutrient solution is 8. When the plant has successfully acclimatized and starts to root, the drip irrigation frequency is 3 times / week, and the EC of the nutrient solution is 0.8. When the plant starts to grow independently, the drip irrigation frequency is 1 time / week, and the EC of the nutrient solution is 1.5.

[0120] The control group carried out excavation and backfilling of the original soil.

[0121] The remaining steps of this embodiment are the same as those of Experimental Group 1 in Embodiment 1, and the experimental results are shown in Table 3.

[0122] Table 3 Result Statistics and Comparison

[0123] / Water consumption / ton Vegetation survival rate Soil humidity Surface windblown sand Experimental group 1 318 64％ 35％ Wind force 6.5, less windblown sand Experimental group 2 316 68％ 38％ Wind force 6.3, less windblown sand Experimental group 3 320 61％ 36％ Wind force 6.8, less windblown sand Control group 338 43％ 23％ Wind force 7.6, more windblown sand

[0124] Embodiment 4

[0125] In 2024, it was implemented in the demonstration area of the Xinjiang Hotan Photovoltaic New Energy Large Base. The target area is located in the Taklimakan Desert. The ground soil is all desert composed of a large amount of fine sand or dust. The sand dunes are continuous and form flowing sand dunes under the wind, belonging to a mobile desert, with an average annual precipitation of about 120 mm.

[0126] The upper-layer soil of Experimental Group 1 is made by mixing fly ash, desulfurized gypsum, and large-sized slag (particle size of 80 mm) in a volume ratio of 2:1:1. The lower-layer soil is made by mixing the above fly ash, the above desulfurized gypsum, small-sized slag (particle size of 6 mm), and original soil in a volume ratio of 3:1:1:3. The depth of the upper-layer soil is 6 cm, and the depth of the lower-layer soil is 40 cm.

[0127] The soil of Experimental Group 2 is made by mixing fly ash, desulfurized gypsum, and large-sized slag (particle size of 80 mm) in a volume ratio of 3:2:2. The lower-layer soil is made by mixing the above fly ash, the above desulfurized gypsum, small-sized slag (particle size of 6 mm), and original soil in a volume ratio of 2:2:2:4. The depth of the upper-layer soil is 6 cm, and the depth of the lower-layer soil is 40 cm.

[0128] The soil of Experimental Group 3 is made by mixing fly ash, desulfurized gypsum, and large-sized slag (particle size of 80 mm) in a volume ratio of 5:3:3. The lower-layer soil is made by mixing the above fly ash, the above desulfurized gypsum, small-sized slag (particle size of 6 mm), and original soil in a volume ratio of 5:3:3:7. The depth of the upper-layer soil is 6 cm, and the depth of the lower-layer soil is 40 cm.

[0129] The control group carried out original soil excavation and backfilling.

[0130] The remaining steps of this embodiment are the same as those of Experimental Group 1 in Embodiment 1, and the experimental results are shown in Table 4.

[0131] Table 4 Result Statistics and Comparison

[0132] / Water consumption / ton Vegetation survival rate Soil humidity Surface windblown sand Experimental group 1 336 55％ 36％ Wind force 6.5, less windblown sand Experimental group 2 332 58％ 38％ Wind force 6.4, less windblown sand Experimental group 3 340 49％ 35％ Wind force 6.8, less windblown sand Control group 368 32％ 20％ Wind force 7.8, more windblown sand

[0133] Embodiment 5

[0134] (1) The target area is the open-pit mining area in Yiminhe Town, Hailar District, Hulunbuir City, Inner Mongolia Autonomous Region. It is located in the middle of the Hulunbuir Grassland. The terrain is basin-shaped, with an altitude of about 660 - 800 meters. It has a subarctic continental climate, characterized by strong and frequent monsoons, severe and long winters, and short summers. The average annual temperature is -2.4°C, the average temperature in January is -25.2°C, and the extreme minimum temperature is -46.6°C; the average temperature in July is 29.7°C, and the extreme maximum temperature is 40.1°C. The average annual growth period is 85 days, the average annual frost-free period is 90 days, the longest is 110 days, and the shortest is 80 days. The duration above 0°C is 120 days (generally from the end of May to the beginning of September). The average annual precipitation is 315.7 mm, and the rainfall is concentrated from July to September every year, with the most in August.

[0135] (2) It is determined that the area requiring ecological restoration and treatment is the open-pit mining area. The soil improvement raw materials need to be prepared by mixing fly ash, desulfurized gypsum, small-sized (5 mm) slag, and original soil in a ratio of 2:2:2:4. According to a modification depth of 90 cm, the Hoagland general nutrient solution formula is selected, the pH of the nutrient solution is 5.8, the EC is 0.5 initially and 1.0 later. The drip irrigation layout form is mainly linear and supplemented by grid type. Pinus sylvestris var. mongolica, Armeniaca sibirica, Hippohae rhamnoides, and Medicago sativa are planted to form the final professional plan.

[0136] (3) According to the determined plan, according to V X =S×H×R X , in the formula, V X is the volume of component X in the soil improvement raw materials, X is a certain component in the power plant solid waste or the original soil, S is the area to be improved in the region, H is the improvement depth, and R X is the formula proportion of component X in the soil improvement raw materials. Calculate the dosage of each component: In this experiment, a test plot of 1500 m 2 is selected, with 500 m 2 for experimental group 1, control group 1, and control group 2 respectively. It is calculated that 90 m 3 of fly ash, 90 m 3 of desulfurized gypsum, 90 m 3 of 5 mm small-sized slag, and 180 m 3 of original soil are used to prepare the soil improvement raw materials.

[0137] (4) Then, 270 m 3 of the original soil in the area of experimental group 1 is dug out, and after leveling, 90 m 3 of fly ash, 90 m 3 of desulfurized gypsum, and 90 m 3 of 5 mm small-sized slag are evenly mixed as the soil improvement raw materials and laid on the ground. According to the designed improvement depth of 90 cm, a rotary tiller is used for uniform and comprehensive deep plowing and mixing, and leveling, as shown in Figure 1 (there is no surface coverage in the open-pit mining area).

[0138] (5) After the implementation of soil improvement is completed, Experimental Group 1 and the control groups (including Control Group 1 and Control Group 2) respectively adopt, in the same manner, black PE water-saving drip irrigation tapes with spray-drip adjustable drippers, and are laid linearly and in a grid pattern at an equal distance of 2 meters. The specific laying form is as Figure 2 shown. Nutrient solution is uniformly supplied by a centralized integrated water and fertilizer machine. The two systems of Experimental Group 1 and the control groups are independent.

[0139] (6) Next, Pinus sylvestris var. mongolica, Armeniaca sibirica, Hippophae rhamnoides, and Medicago sativa are evenly planted in the target area according to the plan. Experimental Group 1 is planted according to the combination principle of "trees, shrubs, and grasses" in accordance with Figure 3 and Figure 4 . Pinus sylvestris var. mongolica is planted at the four vertex positions, Armeniaca sibirica is planted along the short side, Hippophae rhamnoides is planted along the long side, and Medicago sativa is planted within the grid.

[0140] (7) After the vegetation is planted, the control groups and Experimental Group 1 use the nutrient solution drip irrigation / sprinkling system to conduct high-pressure clear water sprinkling through the constant pressure variable frequency water pump supporting the integrated water and fertilizer machine at night to ensure that the soil humidity is 40 ± 5%. After the vegetation is planted, the control groups and Experimental Group 1 use the nutrient solution drip irrigation / sprinkling system to conduct high-pressure clear water sprinkling through the constant pressure variable frequency water pump supporting the integrated water and fertilizer machine at night to ensure that the soil humidity is 40 ± 5%. After 5 days, the vegetation adapts to the new environment, the seedling recovery is successful and starts to take root, and then low-concentration nutrient solution with an EC of 0.5 is prepared by the integrated water and fertilizer machine for drip irrigation twice a week. The planted vegetation survives the fittest and starts to grow independently. Nutrient solution with an EC of 1.0 concentration is prepared by the water fertilizer machine for drip irrigation once a week. After an 8-month operation test of the ecological restoration and treatment method, the water consumption, vegetation survival rate, soil humidity, and surface wind and sand conditions of Experimental Group 1 and the control groups are respectively counted, as shown in Table 5 below.

[0141] Control Group 1 conducts original soil excavation and backfilling, and the rest is the same as Experimental Group 1.

[0142] Control Group 2 randomly disperses the same amount of Pinus sylvestris var. mongolica, Caragana korshinskii, Sabina vulgaris, and Peganum harmala, and the rest is the same as Experimental Group 1.

[0143] The difference between Experimental Group 2 and Experimental Group 1 is that the soil of Experimental Group 2 is made by mixing fly ash, desulfurized gypsum, small particle size slag (4 mm), and original soil in a volume ratio of 3:1:1:6.

[0144] The difference between Experimental Group 3 and Experimental Group 1 is that the soil of Experimental Group 3 is made by mixing fly ash, desulfurized gypsum, small particle size slag (6 mm), and original soil in a volume ratio of 5:3:3:9.

[0145] Table 5 Result Statistical Comparison

[0146]

[0147]

[0148] Note: The water consumption is read through a water meter, the survival rate of vegetation is calculated by counting the planting quantity and the final survival quantity, the soil humidity is read by using a portable soil humidity detector, and the surface wind sand is monitored and obtained through an integrated outdoor weather station.

[0149] As can be seen from Table 5, compared with Control Group 1, Experimental Group 1 saves about 14.4% - 20% of water, the soil humidity is 10% - 16% higher, the survival rate of vegetation is higher, reaching more than 68%, the surface wind force is reduced by about 13% - 17%, and there is relatively less wind sand and dust. The experiment shows that by adopting the technical solution described in the present invention for soil restoration and ecological governance in open-pit mine mining areas, the water consumption per unit area is significantly reduced, the soil humidity, air permeability and water retention capacity are significantly improved, the survival rate of plants increases by about 20%, the surface wind force and dust flow are reduced, and the effect in soil restoration and ecological governance in open-pit mine mining areas is significantly better than the conventional scheme, and the ecological reconstruction and soil and water conservation effects are remarkable.

[0150] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: The present invention uses the slag, desulfurized gypsum and fly ash generated during the operation of a thermal power plant to be laid on the original ground according to different proportion formulas according to the different conditions of land such as desert-governable or open-pit mine mining areas, and a centralized water and fertilizer integration machine supplies nutrient solution, and resistant plants or crops are planted on the restored land of desert-governable or open-pit mines, so as to realize the restoration of desert-governable and open-pit mine mining areas.

[0151] This method uses the solid waste of the thermal power plant to react with water and substances in the original soil to form stable cementitious substances, enhancing the cohesion of the soil and achieving the effect of solidifying the ground surface. The large-particle slag can play a role in sand blocking and fixing and reducing the flow of wind sand, truly realizing the green, environmental protection and high-efficiency resource utilization of the power plant solid waste, reducing costs and increasing efficiency; expanding the limited utilization ways of the power plant solid waste and enhancing the benefits of the power plant. This method is simple and easy to operate, water-saving and energy-saving, low-cost, and has a wide application prospect.

[0152] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A first soil structure for ecological restoration, characterized in that: The first soil structure includes an upper soil layer and a lower soil layer; The upper soil layer is made by mixing fly ash, desulfurized gypsum and first slag in a volume ratio of (2-3): (1-2): (1-2); The lower soil layer is composed of the fly ash, the desulfurized gypsum, the second slag and the original soil according to (2-3): (1-2): (1-2):(3-5) in a volume ratio; Wherein, the particle size of the first slag is 40-80 mm; the particle size of the second slag is 3-6 mm.

2. The first soil structure according to claim 1, characterized in that: The depth ratio of the upper soil layer to the lower soil layer is (1-2):(10-20).

3. A second soil structure for ecological restoration, characterized in that: The second soil structure is made by mixing fly ash, desulfurized gypsum, third slag and raw soil in a volume ratio of (2-3): (1-2): (1-2): (4-6); Wherein, the particle size of the third slag is 4 to 6 mm.

4. A method for ecological restoration, characterized in that: The method comprises: Use soil structure to carry out ecological restoration of the soil to be restored; Wherein, the soil structure comprises the first soil structure described in claim 1 or 2 or the second soil structure described in claim 3.

5. The method according to claim 4, characterized in that The soil to be remediated includes sand wasteland or open-pit mining areas; Preferably, the sandy desert is selected from any one of the following: gravelly hard Gobi, sandy Gobi, fixed desert or mobile desert.

6. The method according to claim 5, characterized in that The method comprises: using the first soil structure to carry out ecological restoration of the Shago wasteland or using the second soil structure to carry out ecological restoration of the open-pit mining area.

7. The method according to claim 6, characterized in that The method comprises: Excavating the soil to be repaired to obtain an area to be backfilled; Backfilling the area to be backfilled using the soil structure to obtain improved soil; Planting plants in the improved soil to obtain vegetation-covered soil; Ecologically restored soil is obtained by spraying the vegetation-covered soil with water and drip-irrigating the vegetation-covered soil with nutrient solution.

8. The method according to claim 7, characterized in that The plants include drought-resistant and acid- and alkali-tolerant perennial varieties; The drought-resistant and acid-alkali-resistant perennial varieties are selected from any one or more of the following: Xanthoceras sorbifolia, Pinus sylvestris, Pepper, Licorice, Astragalus, Salix psammophila, Hippophae rhamnoides, Prunus armeniaca, Caragana microphylla, Atriplex quadrangularis, Achnatherum splendens, Salsola, Peganum harmala, Astragalus, Alfalfa, Stipa granatum, Salix psammophila, Populus euphratica, Smilax glabra, Sago serrata, Ceropegia serrata, or Prunus armeniaca; Preferably, the plants include trees, shrubs and herbaceous plants; Wherein, the tree is selected from any one or more of the following: Pinus sylvestris var. mongolica, Salix babylonica, Populus euphratica, Xanthoceras sorbifolia or Prunus armeniaca; The shrub is selected from any one or more of the following: sea buckthorn, apricot, caragana, salix psammophila, juniper, calamus, or Atriplex quadrangularis; The herbaceous plants are selected from any one or more of the following: Astragalus membranaceus, Peppermint, Licorice, Achnatherum splendens, Salsola, Peganum harmala, Astragalus, Alfalfa, Stipa or Sago.

9. The method according to claim 8, characterized in that The depth of the area to be backfilled is ≤100 cm; Preferably, the pH of the nutrient solution is 5-8 and the conductivity is 0.5-2.

5.

10. The method according to claim 9, characterized in that After the plants are planted, the water is used to spray the soil covered with vegetation at night to make the soil moisture reach 35% to 45%; When the plant seedlings have been successfully grown and started to take root, the nutrient solution is used to drip irrigate the soil covered with vegetation; the frequency of the drip irrigation is 2 to 3 times per week; wherein the conductivity of the nutrient solution is 0.5 to 1.0; When the plants begin to grow autonomously, the nutrient solution is used to drip irrigate the vegetation-covered soil; the frequency of the drip irrigation is 1 to 2 times per week; wherein the conductivity of the nutrient solution is 1.0 to 2.5; Preferably, the drip irrigation or the spraying is carried out in an adjustable manner using a spray-drip adjustable dripper; Preferably, the spray-drip adjustable dripper is installed on a pipe, and the pipe is selected from a φ20 black PE water-saving drip irrigation tape; Preferably, the pipelines are arranged in a linear and / or grid pattern; Preferably, the pipelines are arranged in a linear and grid pattern; the trees are planted at the four vertices of the grid, the shrubs are planted at the four sides of the grid, and the grasses are planted within the grid.

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