Artificial ecological soil based on coal gangue as well as preparation method and application of artificial ecological soil

Abstract

The invention discloses coal gangue-based artificial ecological soil and a preparation method and application thereof, and belongs to the technical field of ecological improvement, the coal gangue-based artificial ecological soil comprises crushed coal gangue and a compound microbial agent, and the compound microbial agent comprises a microbial activating agent and a microbial passivating agent. According to the invention, the coal gangue can be quickly decomposed through the microbial activating agent, useful mineral elements in the coal gangue can be fully activated and analyzed, and the effect of activating a nutrient library in the coal gangue is achieved, so that useful trace elements contained in the coal gangue are effectively released and are easily absorbed by plant growth; meanwhile, harmful heavy metal elements in the coal gangue are passivated through the microbial passivating fungicide, the water-retaining property and the air permeability of the soil are guaranteed by controlling the decomposition particle size proportion of the coal gangue, the soil conditioner can be used for ecological restoration, desert control, agriculture and animal husbandry planting, flower and nursery planting and urban landscaping, the effects of improving the soil and promoting plant growth are achieved, and the soil conditioner is suitable for large-scale popularization and application. The application is wide.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste resource utilization, and specifically relates to an artificial ecological soil based on coal gangue, and a preparation method and application thereof. Background Art

[0002] Gangue is a secondary mineral of coal formed during the coal-forming process, formed by the mixing of ancient soil with coal-forming plants and sedimentation under high temperatures and high pressures over a long period of coal formation. As a by-product of coal, gangue accounts for 10%-20% of coal production and is one of my country's largest industrial solid wastes. my country has a cumulative stockpile of approximately 5 billion tons of gangue, with approximately 500 million tons generated annually. Most of this naturally accumulates near coal mine industrial parks, occupying significant land and polluting the surrounding environment. Furthermore, the presence of residual combustible materials in the gangue can, under certain conditions, spontaneously combust and emit toxic and harmful gases, resulting in a significant waste of resources. The rational disposal of gangue has become a major resource and environmental issue that must be addressed for sustainable economic development in my country.

[0003] Gangue contains a certain proportion of organic matter, a rich variety of heavy metals and trace elements, as well as elements such as carbon, nitrogen, phosphorus, and potassium required for plant growth. Furthermore, the crushed gangue has a variety of particle sizes, relatively large porosity, a certain degree of water retention, and a high effective water utilization rate. These characteristics make it possible to utilize it as a soil resource. However, the organic matter in gangue is primarily carbon, which is highly solidified and difficult to decompose into humic acid-based organic matter that can be absorbed by plants under natural conditions. Furthermore, the inorganic nutrients such as nitrogen, phosphorus, potassium, sulfur, silicon, and calcium within it are highly bound to rock and soil minerals, making them difficult to dissolve and release for plant absorption and utilization, thus increasing the difficulty of ecologically utilising gangue. Summary of the Invention

[0004] The present invention addresses the problem that the organic and inorganic nutrients in coal gangue are highly solidified and difficult to release for plant absorption and utilization, thereby increasing the technical difficulty of the ecological application of coal gangue. The present invention provides an artificial ecological soil based on coal gangue, a preparation method and application thereof, so that the useful trace elements contained in the coal gangue are effectively released and easily absorbed by plant growth. At the same time, the harmful heavy metal elements in the coal gangue are passivated to prevent the heavy metals from being absorbed by plants, thereby recycling the coal gangue. The artificial ecological soil based on coal gangue is mixed and improved with the original soil, and a planting experiment is carried out, achieving the effect of improving the soil and promoting plant growth.

[0005] To solve the above technical problems, the present invention provides an artificial ecological soil based on coal gangue, comprising crushed coal gangue and a composite microbial agent, wherein the composite microbial agent includes a microbial activating agent and a microbial passivating agent, wherein the particle size ratio of the crushed coal gangue is: 40% below 1 mm, 30% 1-2 mm, 20% 2-4 mm, and 10% 4-6 mm, the effective live bacteria concentration of the composite microbial agent is ≥40 billion CFU / mL, the operating environment temperature is 14-35°C, and the attachment time of the composite microbial agent is ≥36 hours.

[0006] Gangue contains over 30 elements, including all the nutrients required for plant growth. These nutrients are primarily in a fixed state, making them inaccessible to plants. Adding microbial activation agents can rapidly decompose the gangue, fully activating and decomposing the useful mineral elements within it. These fixed nutrients are converted into free forms that plants can directly absorb and utilize, thus revitalizing the nutrient reservoir within the gangue.

[0007] Coal gangue may also contain a variety of heavy metals. Excessive heavy metal elements will pollute the soil environment. By adding microbial passivation agents, free heavy metals can be converted into fixed states, preventing heavy metals from being absorbed by plants and avoiding heavy metals from entering the food chain, thereby purifying coal gangue.

[0008] Through crushing, sorting and proportioning, the gangue raw materials are processed into the particle size composition required for the preparation of artificial soil. The size of the particle size directly affects the speed and effect of the decomposition, activation and passivation of the gangue. The ratio of the particle size composition determines the amount of microbial agent applied. At the same time, a good soil physical structure is obtained by proportioning gangue of different particle sizes, which can make the artificial soil perform well in preventing wind-blown dust, maintaining morphological stability, and improving water retention and air permeability.

[0009] Preferably, the microbial activating agent comprises a mixture of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, potassium-solubilizing bacteria, photosynthetic bacteria, nitrifying bacteria, denitrifying bacteria, and yeast at a volume ratio of 1:1:1:1:1:1:1:1, each with an effective viable bacterial concentration of ≥4×107 CFU / mL. The nitrogen-fixing bacteria are preferably rhizobia or rufipogon nitrogen-fixing bacteria, the phosphate-solubilizing bacteria are preferably Bacillus megaterium, and the potassium-solubilizing bacteria are preferably Bacillus mucilaginosus.

[0010] Adding microbial activation agents to artificial ecological soil based on coal gangue can play many important roles, such as activating soil nutrients, improving soil structure, and promoting plant growth. For example, because the nitrogen content of coal gangue itself is low, adding nitrogen-fixing bacteria can convert nitrogen in the air into ammonia nitrogen or nitrate nitrogen that can be absorbed and utilized by plants, increasing the nitrogen content in the soil, which is especially important for the supply of nitrogen in the early stages of plant growth; nitrogen-fixing bacteria can be autotrophic nitrogen-fixing bacteria or heterotrophic nitrogen-fixing bacteria, among which autotrophic nitrogen-fixing bacteria are preferably rhizobia, and heterotrophic nitrogen-fixing bacteria are preferably round brown nitrogen-fixing bacteria; phosphate-solubilizing bacteria and potassium-solubilizing bacteria can decompose the insoluble phosphorus and potassium minerals in coal gangue, and convert phosphorus and potassium elements from ore state into ionic state that can be absorbed by plants, thereby increasing the effectiveness of phosphorus and potassium in the soil, phosphate-solubilizing bacteria are preferably Bacillus megaterium, and potassium-solubilizing bacteria are preferably Bacillus mucilaginosus; photosynthetic bacteria use light energy for photosynthesis, converting carbon dioxide and water into organic matter, and producing oxygen at the same time, improving the ventilation conditions of the soil where the coal gangue is located, which is beneficial to the growth and activity of other microorganisms and jointly promoting the activation of coal gangue; nitrifying bacteria are a type of chemoautotrophic bacteria, mainly including nitrite bacteria and nitrate bacteria, nitrite bacteria It can oxidize ammonium nitrogen (such as ammonia from fertilizers or microbial nitrogen fixation) into nitrite, and then nitrifying bacteria further oxidizes nitrite into nitric acid. This conversion allows the nitrogen in the soil to exist in the form of nitrate nitrogen, which is more easily absorbed and utilized by plants. Nitrifying bacteria can also regulate soil pH and improve soil ecological structure, thereby driving the prosperity of the entire soil microbial community; in coal gangue ecological soil, when the soil is in a flooded state or a locally hypoxic environment, denitrifying bacteria will play a role, gradually reducing nitrate and eventually generating nitrogen gas, which is very important for maintaining the balance of nitrogen in the soil ecosystem, avoiding excessive accumulation of nitrate nitrogen in the soil, and thus to a certain extent alleviating soil salt damage caused by excessive accumulation of nitrate nitrogen. The nitrogen gas produced by the denitrification process can also regulate soil aeration and water permeability; some metabolites produced by yeast during the fermentation process, such as amino acids, vitamins, etc., can provide nutrition for plants, and its own growth metabolic activities also help to activate coal gangue.

[0011] Preferably, the microbial inactivation agent is composed of Desulfovibrio sulphuridis, Aspergillus niger, Trichoderma sp. and white rot fungi, each with an effective viable bacterial concentration of ≥4×107 CFU / mL, mixed in a volume ratio of 1:1:1:1:1:1:1:1.

[0012] Microbial passivation agents are a type of special preparation that can reduce the activity and mobility of harmful substances in coal gangue ecological soil through their own metabolic activities. They mainly use the biotransformation and adsorption functions of microorganisms to fix and transform heavy metals and persistent organic pollutants in coal gangue, thereby reducing harm to the surrounding ecological environment and creating a safe environment for plant growth on ecological soil. Among them, Desulfovibrio mainly produces sulfide by reducing sulfate, forming sulfide precipitates with heavy metals, and has a significant passivation effect on heavy metals such as zinc and cadmium commonly found in coal gangue, effectively reducing their migration ability in the soil; Aspergillus niger can secrete a variety of organic acids and enzymes, and the organic acids such as citric acid and oxalic acid produced can react with heavy metals to form complex reactions, reducing the activity of heavy metals. At the same time, Aspergillus niger also has a certain degradation ability for some organic pollutants, and gradually converts complex organic pollutants into simple substances through its own metabolism, reducing the degree of soil pollution; Trichoderma has biological control functions. It can inhibit the growth of pathogens in the soil and participate in the material transformation in coal gangue ecological soil. During its growth, Trichoderma can secrete polysaccharides. These substances can combine with heavy metal ions and play a passivation role. In addition, Trichoderma also has a certain degradation potential for organic pollutants such as polycyclic aromatic hydrocarbons in the soil, which helps to improve the soil environmental quality; the powerful lignin-degrading enzyme system of white rot fungi can oxidize and decompose complex organic pollutants, and can effectively treat petroleum pollutants, pesticide residues and other organic pollutants adsorbed by coal gangue during the accumulation process.

[0013] To solve the above technical problems, the present invention also provides a method for preparing artificial ecological soil based on coal gangue, comprising the following steps: Crushing: The large pieces of coal gangue are crushed by the crushing device to reach the particle size required by the artificial ecological soil, and the coal gangue crushed materials are obtained; Sorting and proportioning: The crushed coal gangue is sorted and proportioned by a sorting and grading device to obtain the basic materials required for preparing artificial ecological soil; the particle size proportion is 40% for particles below 1 mm, 30% for particles 1-2 mm, 20% for particles 2-4 mm, and 10% for particles 4-6 mm; Adding compound microbial agents: Add compound microbial agents to the base material in an amount such that the effective live bacterial concentration of the compound microbial agents is ≥ 40 billion CFU / mL; Curing: After adding the composite microbial agent, it should be piled and cured at 14-35℃ for more than 36 hours to ensure that the microorganisms are fully attached to the base material and start working.

[0014] The application method of the artificial ecological soil based on coal gangue of the present invention is to mix it with the original surface soil of 10 to 15 cm deep in a volume ratio of 1:1 to form planting soil, and then plant crops; or to cover it on the original surface soil with a covering thickness of 20 to 30 cm and directly plant crops.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1) Consistent with the basic components of natural soil: The artificial ecological soil of the present invention is composed of various granular minerals, organic matter, water, air, microorganisms, etc., and can grow plants. The soil density and soil structure are consistent with natural soil. It can be perfectly integrated with the natural surface matrix (including deep underground soil, sandy land, saline-alkali land, desert, etc.), quickly realizes the circulation of organic matter and microorganisms, and is easy to use.

[0016] 2) Nutrient content is several times higher than that of natural soil: The artificial ecological soil of the present invention makes full use of the beneficial components in coal gangue (humic acid, calcium, iron, zinc, selenium, nitrogen, phosphorus, potassium, etc.). After activation treatment, the trace elements that can promote plant growth and basic elements such as nitrogen, phosphorus, and potassium required by plants contained in it are several times higher than those in ordinary soil.

[0017] 3) Better quality and wider application: The artificial ecological soil of the present invention meets the national first-class soil standards, is free of pests and diseases, and is free of weeds. The crops, vegetables, and forage grasses planted in it all meet green and pollution-free standards. It can be widely used in ecological restoration of nature reserves and high-quality agriculture and animal husbandry construction, effectively avoiding the problem of alien species invasion faced by traditional soil restoration. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a technical principle diagram of the artificial ecological soil of the present invention; Figure 2 This is a flow chart for preparing the artificial ecological soil of the present invention; Figure 3 This is the effect diagram of vegetation planting in the first year of application example 2; Figure 4 This is the sunflower planting effect diagram of application example three; Figure 5 This is the greenhouse vegetable planting effect diagram of application example 4; Figure 6 This is a comparison chart of the effects of field planting buckwheat in Application Example 5. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall into the protection scope of the present application.

[0020] An artificial ecological soil based on coal gangue, comprising coal gangue crushing products and a composite microbial agent, the composite microbial agent comprising a microbial activation agent and a microbial passivation agent, wherein the particle size ratio of the coal gangue crushing products is: 40% below 1 mm, 30% of 1-2 mm, 20% of 2-4 mm, and 10% of 4-6 mm, the effective viable bacterial concentration of the composite microbial agent is ≥400 billion CFU / mL, the use environment temperature is 14-35℃, and the composite microbial agent adhesion time is ≥36 h, wherein the microbial activation agent is composed of nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, potassium-solubilizing bacteria, photosynthetic bacteria, nitrifying bacteria, denitrifying bacteria and yeast bacteria, each with an effective viable bacterial concentration ≥4×107 CFU / mL, and mixed in a volume ratio of 1:1:1:1:1:1:1; the microbial passivation agent is composed of Desulfovibrio, Aspergillus niger, Trichoderma and white rot fungus, each with an effective viable bacterial concentration ≥4×107 CFU / mL, and mixed in a volume ratio of 1:1:1:1:1:1:1.

[0021] Table 1 Detection results of heavy metal components of the artificial ecological soil based on coal gangue The detection results of the heavy metal components of the artificial ecological soil of the present application are shown in Table 1, and the heavy metal content is lower than the national standard of soil heavy metal content, which proves that the microbial passivation agent can passivate the harmful heavy metal elements in the coal gangue, and the artificial ecological soil of the present application can be used for planting crops.

[0022] The preparation method is shown in Figure 2 and comprises the following steps: (1) crushing: the large pieces of coal gangue are crushed by a crushing device to achieve the required particle size for preparing the artificial soil, forming the basic raw material for preparing the artificial soil, and the crushing process can make the coal gangue raw material quickly reach the required physical form of the artificial soil; (2) Sorting and proportioning: Artificial soils with different functions have different particle size compositions. The crushed coal gangue is sorted and proportioned by a sorting and grading device to obtain the basic materials needed for preparing artificial soil. Raw materials with different particle sizes have different physical properties. For example, particles below 1 mm can achieve good water retention and water content, and at the same time have a large external contact area, which is conducive to the attachment of subsequent microbial agents; 1-4 mm can achieve good water permeability and air permeability, and 4-8 mm can ensure the appropriate looseness of the artificial soil while ensuring sufficient external contact area; 8-12 mm can achieve good sedimentation, and at the same time, the irregular shape can achieve surface stability and dust prevention through interaction; (3) Adding composite microbial agents: According to the physical and chemical properties of coal gangue and the technical requirements of different types of artificial soil product design, the microbial composite agent is evenly added to the coal gangue raw material that meets the design requirements of the artificial soil particle size through the agent adding device. The effective live bacterial concentration of the composite microbial agent is ≥40 billion CFU / mL; (4) Curing: After the addition of the composite microorganisms and composite bacterial agents, they need to be piled and cured at an ambient temperature of 14-35°C for at least 36 hours to ensure that the microorganisms are fully attached to the coal gangue raw materials.

[0023] The present invention can quickly decompose coal gangue through the microbial activation agent, fully activate and analyze the useful mineral elements in the coal gangue, play the role of revitalizing the nutrient reservoir in the coal gangue, effectively release the useful trace elements contained in the coal gangue, and easily be absorbed by plant growth; at the same time, the harmful heavy metal elements in the coal gangue are passivated by the patented microbial passivation agent, and the water retention and air permeability of the soil are guaranteed by controlling the particle size ratio of the coal gangue decomposition. Figure 1 shown.

[0024] Application Example 1: Application of artificial ecological soil based on coal gangue in land reclamation in mining areas Artificial ecological soil was prepared using coal gangue washed in the Suancigou Coal Mine Washing Plant.

[0025] A 15-cm-thick layer of artificial ecological soil was overlaid on a loess layer in the land reclamation area of ​​the Suancigou Coal Mine of the Inner Mongolia Yitai Group in Zhungeer Banner, Ordos City, Inner Mongolia. This soil was mixed with the 15-cm-thick loess layer at a ratio of 1:1 to form a 30-cm-thick planting soil layer. Sorghum was then cultivated using a sprinkler spraying system. No additional fertilizer or pest control agents were applied. The harvest yielded 800 jin (approximately 100 catties) of sorghum per mu (approximately 1.5 lb) per mu (approximately 1.5 lb) of sorghum, significantly exceeding the yield of 90 jin (approximately 100 catties) per mu (approximately 1.5 lb) of sorghum cultivated on the same land. Table 2 shows the detection results of harmful heavy metals in sorghum. All harmful heavy metals were detected, demonstrating the suitability of the artificial ecological soil for vegetable and grain crops.

[0026] Table 2 Detection results of harmful heavy metal residues in sorghum Application Example 2: Application of Artificial Ecological Soil Based on Coal Gangue in Ecological Restoration of National Nature Reserves Experimental address: Sanjiangyuan Ecological Restoration Demonstration Zone, Beiluhe Permafrost Station, Chinese Academy of Sciences, Zhiduo County, Yushu Tibetan Autonomous Prefecture, Qinghai Province.

[0027] Twenty 1 m × 1 m experimental grids were set up and randomly divided into four groups. 10 wt%, 33 wt%, 50 wt%, and 66 wt% artificial ecological soil were added to the five experimental grids in each group to form a 20 cm thick planting soil layer. The last grid was completely filled with artificial ecological soil to form a 20 cm thick planting soil layer. Each group planted one crop, a total of four crops (respectively, Elymus nutans, Bromus inermis, Lolium perenne, and Oats). The rest were carried out in the same manner. Good vegetation planting results were achieved in the first year, such as Figure 3 shown.

[0028] Application Example 3: Application of artificial ecological soil based on coal gangue in the improvement of severely saline-alkali land In the severe saline-alkali land treatment demonstration area in Shierliancheng Township, Zhungeer Banner, Ordos City, Inner Mongolia Autonomous Region, 10 cm thick artificial ecological soil was laid on the surface and mixed with 15 cm thick saline-alkali soil to form an improved planting soil layer of about 25 cm thick. Sunflowers were planted on an area of ​​about 500 m2. Figure 4 As shown, natural rainfall is used for irrigation during the planting process, and no additional fertilizers or anti-pesticides are applied. During the harvest season, 420 kilograms of sunflowers are harvested per mu. In the same area, sunflowers planted on saline-alkali land will slowly wither and die.

[0029] Artificial ecological soil based on coal gangue contains humic acid, pyrite, organic sulfur, alkali metal compounds, and salts of strong acids and weak bases, which can regulate soil acidity and alkalinity, achieving soil improvement. This case study uses artificial ecological soil to improve saline-alkali land, effectively restoring the local dominant vegetation ecosystem and improving land use efficiency. The specific process involves first determining the degree of salinization of the land to be improved, then identifying the local dominant vegetation species and crop varieties, and finally designing an artificial ecological soil application method based on the characteristics of the saline-alkali land, the growth requirements of vegetation and crops, and other local natural conditions. Compared to other saline-alkali land improvement methods, using artificial ecological soil to restore the soil environment in saline-alkali land takes into account the soil environment requirements for the growth of local dominant species and crops. At the same time, through scientific application methods, it ensures improved water retention and air permeability in the soil environment, effectively controlling recurrent salinization. Using artificial ecological soil to improve saline-alkali land has the advantages of high efficiency and effectiveness.

[0030] Application Example 4: Artificial ecological soil based on coal gangue is used to improve the quality of low-grade land for organic vegetable cultivation In the Pinglu District of Shuozhou City, Shanxi Province, vegetables are planted in greenhouses. A 20 cm thick artificial ecological soil is laid on the surface to form a planting layer. Garland chrysanthemum, lettuce, spinach, radish, and Chinese cabbage are planted. The planting area is 600 m2. During the planting process, drip irrigation is used in the greenhouse. No additional fertilizers or anti-disease and insecticides are applied. All kinds of vegetables are growing well. Figure 5 As shown in Table 3, the detection results of harmful heavy metals in lettuce are shown. It can be seen that all harmful heavy metals in lettuce are detected, which proves that the artificial ecological soil of the present invention can be used for vegetable cultivation.

[0031] Table 3 Detection results of harmful heavy metal residues in lettuce Application Example 5: Artificial ecological soil based on coal gangue is used for desertification control and crop planting In the Maowusu Desert Control Demonstration Area in Yulin City, Shaanxi Province, field planting was carried out. A 15 cm thick artificial ecological soil was laid on the surface and mixed with a 15 cm thick original sandy soil to form an improved planting soil layer of about 30 cm thick. Buckwheat was planted in an area of ​​600 m2. Natural rainfall irrigation was used during the planting process. No additional fertilizers or anti-disease and insecticides were applied. Buckwheat grew well in the experimental area improved with artificial ecological soil, while the buckwheat plants in the control area with original sandy soil were sparse and short. Figure 6 shown.

[0032] As can be seen from the above application examples, the coal gangue-based artificial ecological soil of the present invention can be used for ecological restoration, desertification control, agricultural and animal husbandry planting, flower nursery planting and urban greening, and has a wide range of uses. In addition, heavy metals are passivated, and no harmful heavy metal residues are left in the crops grown.

[0033] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the scope of protection of the present invention.

Claims

1. An artificial ecological soil based on coal gangue, comprising crushed coal gangue, characterized in that: It also includes a composite microbial agent, which includes a microbial activating agent and a microbial passivating agent. The particle size ratio of the coal gangue crushed material is: 40% of the particle size below 1 mm, 30% of the particle size of 1-2 mm, 20% of the particle size of 2-4 mm, and 10% of the particle size of 4-6 mm. The effective live bacteria concentration of the composite microbial agent is ≥40 billion CFU / mL, the operating environment temperature is 14-35°C, and the attachment time of the composite microbial agent is ≥36 h.

2. The artificial ecological soil based on coal gangue according to claim 1, characterized in that: The microbial activation agent has an effective live bacterial concentration of each bacterium ≥ 4×10 7 The nitrogen-fixing bacteria, phosphate-solubilizing bacteria, potassium-solubilizing bacteria, photosynthetic bacteria, nitrifying bacteria, denitrifying bacteria and yeast were mixed in a volume ratio of 1:1:1:1:1:1:1:

1.

3. The artificial ecological soil based on coal gangue according to claim 2, characterized in that: The nitrogen-fixing bacteria are rhizobia or round brown nitrogen-fixing bacteria, the phosphate-solubilizing bacteria are Bacillus megaterium, and the potassium-solubilizing bacteria are Bacillus mucilaginosus.

4. The artificial ecological soil based on coal gangue according to claim 1, characterized in that: The microbial inactivation agent has an effective live bacterial concentration of each bacterium ≥ 4×10 7 The CFU / mL of Desulfovibrio sulphuri, Aspergillus niger, Trichoderma and white rot fungi were mixed in a volume ratio of 1:1:1:1:1:1:1:

1.

5. A method for preparing artificial ecological soil based on coal gangue, characterized in that: The following steps are involved: Crushing: The large pieces of coal gangue are crushed by the crushing device to obtain coal gangue crushed materials; Sorting and proportioning: The crushed coal gangue is sorted and proportioned by a sorting and grading device to obtain the basic materials required for preparing artificial ecological soil; the particle size proportion is 40% for particles below 1 mm, 30% for particles 1-2 mm, 20% for particles 2-4 mm, and 10% for particles 4-6 mm; Adding compound microbial agents: Add compound microbial agents to the base material in an amount such that the effective live bacterial concentration of the compound microbial agents is ≥ 40 billion CFU / mL; Maintenance: After adding the compound microbial agent, pile and maintain at 14-35℃ for more than 36 hours.

6. The preparation method according to claim 5, characterized in that: The composite microbial agent includes a microbial activating agent and a microbial inactivating agent, wherein the microbial activating agent is composed of each bacterium with an effective live bacterial concentration of ≥4×10 7 CFU / mL of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, potassium-solubilizing bacteria, photosynthetic bacteria, nitrifying bacteria, denitrifying bacteria and yeast are mixed in a volume ratio of 1:1:1:1:1:1:1; the microbial inactivation agent has an effective viable bacterial concentration of each bacteria ≥4×10 7 The CFU / mL of Desulfovibrio sulphuri, Aspergillus niger, Trichoderma and white rot fungi were mixed in a volume ratio of 1:1:1:1:1:1:1:

1.

7. The use of the artificial ecological soil based on coal gangue according to any one of claims 1 to 4, characterized in that: The artificial ecological soil is mixed with the original surface soil at a depth of 10 to 15 cm in a volume ratio of 1:1 and then crops are planted.

8. The use of the artificial ecological soil based on coal gangue according to any one of claims 1 to 4, characterized in that: The artificial ecological soil is covered on the surface original soil with a covering thickness of 20 to 30 cm, and crops are planted directly on the artificial ecological soil.

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