Matrix and method for improving soil properties of strip mine desertification waste dump

Abstract

The embodiment of the invention provides a matrix and a method for improving soil properties of a strip mine desertification waste dump. The matrix comprises the following components in parts by weight: 300-700 parts of plant waste, 2-4 parts of a nitrogen source, 1-2 parts of a sugar source, 1-2 parts of a microbial inoculum, 300-700 parts of sandy soil and 4-6 parts of a water-soluble high-molecular polymer. According to the method, local plant waste is fermented, the cyclic economy is met, the adaptability of local plant growth is met, meanwhile, a high polymer material is compounded, and the ecological restoration concept of composite energy conservation, emission reduction and sustainable development is achieved more conveniently, efficiently and economically.

Description

Technical Field

[0001] The present application relates to the technical field of ecological environment restoration in mining areas, and in particular to a substrate and method for improving the soil properties of desertified spoil dumps in open-pit mines. Background Art

[0002] Mining is a production activity that causes serious ecological damage to mining areas, especially open-pit mining. It lasts for a long time, and the newly formed desertified land dump has poor soil structure and weak water and fertilizer retention capacity, resulting in a very long ecological restoration cycle under natural conditions. In the research on soil reconstruction and soil improvement of dumps, the improvement of soil properties is the key work of open-pit ecological restoration. Since the dumps formed by open-pit mining often have imperfect soil structure, no cohesion between sand and soil, and no nutrients required for the growth of plants and soil microorganisms, it is difficult to plant vegetation in such soil environments, resulting in a series of ecological governance problems such as soil erosion, vegetation death, and ecological deterioration.

[0003] Existing research on soil improvement technology in mining areas mainly uses a single measure to improve the soil, such as: further stripping the surface contaminated and nutrient-poor soil by backfilling with imported soil, or changing the soil structure by adding some chemical or microbial materials, or improving the soil structure by planting plants. However, current research has the disadvantages of high improvement cost, low improvement efficiency and unsustainable development. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems in the related art to a certain extent. The present application proposes a matrix and method for improving the soil properties of open-pit mine desertification dumping grounds. The matrix is ​​made by mixing plant waste that cannot be processed locally with nitrogen sources, bacterial agents, sugar sources, and water-soluble high molecular polymers in proportion. The soil properties of open-pit mine desertification dumping grounds are improved by the matrix to form a soil environment suitable for plant growth and capable of locking in water and solidifying fertilizers. The present application ferments local plant waste, which not only meets the circular economy but also meets the adaptability of local plant growth. At the same time, it compounded high molecular materials to realize the concept of ecological restoration of composite energy conservation and emission reduction and sustainable development in a more convenient, efficient, and economical way.

[0005] To achieve the above-mentioned purpose, according to the first aspect of the present application, a matrix for improving the soil properties of an open-pit mine desertification dump is proposed, which comprises, by weight, 300-700 parts of plant waste, 2-4 parts of a nitrogen source, 1-2 parts of a sugar source, 1-2 parts of a bacterial agent, 300-700 parts of sand and 4-6 parts of a water-soluble high molecular polymer.

[0006] In some embodiments, the matrix preparation process comprises:

[0007] After the bacterial agent, the nitrogen source and the sugar source are dissolved in water, the mixed solution is sprayed on the pile of the plant waste to compost and ferment, and water is added and the pile is turned to form a fermentation matrix;

[0008] The fermentation matrix is ​​mixed with water-soluble high molecular polymer and sand.

[0009] In some embodiments, the plant waste includes a mixture of dead branches and / or farm straw crushed to form a particle size not exceeding 5 cm;

[0010] And / or; The cross-section of the pile formed by the plant waste is trapezoidal or triangular, and the height is at least 1.5m.

[0011] In some embodiments, the total nitrogen content of the nitrogen source is ≥ 46.4%;

[0012] And / or; the nitrogen source includes urea, ammonia water, ammonium sulfate, ammonium chloride and ammonium nitrate.

[0013] In some embodiments, the sugar source is brown sugar made from sugar cane;

[0014] And / or; the mass ratio of the sugar source to water is 1:12-17.

[0015] In some embodiments, the bacterial agent is a microbial fermentation agent;

[0016] And / or; the sandy soil is the soil source in the desertified soil dump to be improved;

[0017] And / or; the water-soluble high molecular polymer includes polyvinyl alcohol.

[0018] In some embodiments, the composting fermentation process is as follows: turning the pile and replenishing water every 7-8 days to ensure that the moisture content of the pile is 50-60%, the average temperature is higher than 50°C, and the fermentation ends when the central temperature of the pile drops below 35°C.

[0019] According to the second aspect of the present application, a method for improving soil properties in a desertified open-pit mine dump is proposed, comprising the following steps:

[0020] Laying the substrate of any of the above embodiments with a thickness of at least 15 cm on the surface of the spoil dump to form a structural layer, and applying water to the structural layer to make the structural layer completely wet;

[0021] Plant grass seeds on the structural layer and water regularly.

[0022] In some embodiments, the grass seed is alfalfa.

[0023] Compared with the prior art, the present application has the following advantages: the present application adopts a combination of physical and chemical methods, utilizes local plant waste for in-situ open-air fermentation treatment, saves raw material costs and processing costs, and combines polymer solidification materials to form a matrix that can improve the nutrients and soil structure of sandy land in mining areas. The preparation of the matrix is ​​not only low-cost but also sustainable.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0026] Figure 1 It is a flow chart of a method for improving soil properties in a desertified open-pit mine dump in one embodiment of the present application. DETAILED DESCRIPTION

[0027] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0028] This application is improved based on the following related technologies: Mining in mining areas is a production activity that causes extremely serious ecological damage to mining areas, especially open-pit mining. It lasts for a long time, and the soil structure of the newly formed desertified land dump is poor, and the water and fertilizer retention capacity is weak, resulting in a very long ecological restoration cycle under natural conditions. The ecological restoration of mines started late. It was not until the beginning of the 21st century that a large number of scientific researchers carried out research on soil reconstruction and soil improvement in dumps. The improvement of soil properties is the key work of open-pit ecological restoration. Since the dumps formed by open-pit mining often have imperfect soil structure, no cohesion between sand and soil, and no nutrients required for the growth of plants and soil microorganisms, it is difficult to plant vegetation in such soil environments, resulting in a series of ecological governance problems such as soil erosion, vegetation death, and ecological deterioration. At present, in the study of soil improvement in mining areas, my country mainly uses a single measure to improve soil, such as: continuing to strip the surface contaminated and nutrient-poor soil by backfilling with imported soil, or changing the soil structure by adding some chemical and microbial materials, or improving the soil structure by planting plants. Current researches all have drawbacks such as high improvement cost, low improvement efficiency and unsustainable development.

[0029] At present, there are certain constraints on the methods of improving the sandy land in mining areas. For example, the use of physical methods: backfilling with imported soil has disadvantages such as high cost and difficulty in obtaining soil. The use of chemical and microbial materials alone has a long improvement cycle and poor sustainability. If high-temperature fermentation methods are used to produce improved products, the cost of material transportation and processing is high.

[0030] The present application aims to solve at least one of the technical problems in the related art to a certain extent. According to the first aspect of the present application, a matrix for improving the soil properties of an open-pit mine desertification dump is proposed, which comprises, by weight, 300-700 parts of plant waste, 2-4 parts of a nitrogen source, 1-2 parts of a sugar source, 1-2 parts of a bacterial agent, 300-700 parts of sand and 4-6 parts of a water-soluble high molecular polymer.

[0031] The plant waste includes a mixture of dead branches and / or farm straw crushed to form a particle size not exceeding 5 cm; that is, the dead branches and / or farm straw are crushed to form a material with a particle size not exceeding 5 cm, wherein the plant waste is 300-700 parts by weight. In some embodiments, the plant waste is 400-600 parts, for example, in some embodiments, the plant waste is 300 parts, 400 parts, 500 parts, 600 parts, 700 parts, etc.

[0032] The total nitrogen content in the nitrogen source is ≥46.4%; exemplary nitrogen sources include urea, ammonia water, ammonium sulfate, ammonium chloride and ammonium nitrate, etc., wherein the nitrogen source is 2, 3 or 4 parts by weight. The nitrogen source is an important component of the bacterial agent cells and metabolites. It not only provides nitrogen, but also provides other nutrients required for the growth of microorganisms. In addition, when the sugar source is insufficient during the propagation of the bacterial agent, the nitrogen source can also be used as a supplementary sugar source. In some embodiments, when the weight portion of the nitrogen source is too small, such as less than 2 parts, the activity of the microorganism decreases, resulting in slow fermentation speed, insufficient fermentation of the formed improved matrix, and nutrient imbalance; when the weight portion of the nitrogen source is too large, such as more than 4 parts, nitrogen fertilizer will be wasted, matrix nutrients will be lost, and a large amount of converted nitrite and nitrate will cause matrix acidification.

[0033] Sugar sources include sucrose, lactose, maltose, etc.; an example sugar source is brown sugar made from sugar cane, wherein the sugar source is 1 or 2 parts by weight, etc., and its main function is to activate the bacterial agent and provide nutritional support for the bacterial agent. In some embodiments, when the weight of the sugar source is too small, such as less than 1 part, it affects the activity of microorganisms, resulting in slow fermentation start-up speed and insufficient fermentation; when the weight of the sugar source is too large, such as more than 2 parts, the microorganisms will multiply in large numbers, consume a large amount of oxygen in a short time, cause internal hypoxia during the fermentation process, and form an anaerobic environment.

[0034] The microbial agent is a microbial fermentation agent. In some embodiments, the microbial agent is 1 or 2 parts by weight. After the target microorganisms are propagated through industrial production, they can reproduce rapidly in the soil, improve soil structure, increase soil fertility, and promote the growth and development of crops. In some embodiments, when the weight of the microbial agent is too small, such as less than 1 part, the insufficient microbial agent will reduce the number of effective microorganisms, resulting in insufficient microbial metabolic activity, and the composting temperature is difficult to reach the ideal range, affecting the fermentation efficiency and the inactivation of pathogens; when the weight of the microbial agent is too large, such as more than 2 parts, it will lead to excessive density of microbial populations, intensify competition for resources (such as oxygen and nutrients), and may inhibit the growth of some beneficial microorganisms and over-decompose certain easily degradable substances, which will reduce the overall effect.

[0035] Sand is the soil source in the desertified soil dump to be improved; in some embodiments, the sand is 300-700 parts by weight. In some embodiments, the sand is 400-600 parts, for example, in some embodiments, the sand is 300 parts, 400 parts, 500 parts, 600 parts, 700 parts, etc. The sand in this embodiment satisfies both the circular economy and the adaptability of local plant growth. In some embodiments, when the weight of the sand is too small, such as less than 300 parts, the nutrient concentration of the matrix is ​​high, which may cause the risk of "burning the roots", and when the proportion of the fermentation matrix is ​​too high, the soil structure is too loose, making it difficult for the plant to take root and fall over; when the weight of the sand is too large, such as more than 700 parts, the water retention performance of the matrix is ​​poor, the nutrient content of the matrix is ​​low, and it is impossible to provide a sufficient nutrient environment for the plant.

[0036] The water-soluble polymer includes polyvinyl alcohol. In some embodiments, the water-soluble polymer is 4 parts, 5 parts or 6 parts by weight. Polyvinyl alcohol is a water-soluble polymer made by polymerization of vinyl acetate. It is non-toxic and pollution-free. It can quickly form a film after mixing with water. It has good friction resistance and tensile strength. In some embodiments, when the weight of the water-soluble polymer is too small, such as less than 4 parts, the curing effect on the matrix is ​​not obvious and the water retention effect is poor; when the weight of the water-soluble polymer is too large, such as more than 6 parts, the formed matrix is ​​too compact, the water permeability is reduced, and the growth of plant roots is hindered to a certain extent.

[0037] The matrix preparation process of the present application includes: dissolving the bacterial agent, nitrogen source and sugar source in water to form a mixed solution, wherein the mass ratio of the sugar source to water is 1:12-17, and the mass ratio of the sugar source to water in the example is 1:(12, 13, 14, 15, 16 or 17), and spraying the mixed solution on the pile of plant waste, wherein the cross-section of the pile formed by the plant waste is a trapezoid or a triangle, and the height is at least 1.5m. The pile is covered with a plastic film for composting and fermentation, and water is added and turned during the composting and fermentation process to form a fermentation matrix. For example, the pile is turned and watered once every 7-8 days to ensure that the water content of the pile is 50-60%, the average temperature is higher than 50°C, and the fermentation ends when the center temperature of the pile drops below 35°C. The matrix generated by fermentation is mixed with a water-soluble high molecular polymer and sand to obtain the matrix for improving the soil properties of the open-pit mine desertification dump in the embodiment of the present application.

[0038] According to the second aspect of the present application, a method for improving the soil properties of an open-pit mine desertification dump is proposed. Figure 1 As shown, the following steps are included:

[0039] S1: laying the substrate in any of the above embodiments with a thickness of at least 15 cm on the surface of the spoil dump to form a structural layer, and applying water to the structural layer to make the structural layer completely wet;

[0040] S2: Plant grass seeds on the structural layer and add water regularly. The grass seeds are alfalfa.

[0041] In S1, the surface of the soil dump is paved with the matrix in any of the above embodiments to form a structural layer, wherein the thickness of the structural layer is not less than 15 cm; wherein the root system of the grass seeds requires sufficient soil depth to grow and expand. If the structural layer is too thin, the root system of the grass seeds cannot penetrate into the soil, resulting in poor root development, affecting the stability and growth rate of the grass seeds; at the same time, if the structural layer is too thin, the water and nutrients in the soil cannot be fully supplied, affecting the survival rate of the grass seeds.

[0042] In this step, water is applied to the structural layer to make the structural layer completely moist, so as to ensure that there is enough water stored in the structural layer. The grass seed roots are mainly distributed in the structural layer and have natural water-seeking and water storage functions. Applying water to the structural layer to make the structural layer completely moist can achieve a basic balance of humidity between the upper and lower structural layers, ensure that the grass seed roots can fully absorb water, maintain the normal growth and health of the plant, prevent long-term surface watering from causing root problems such as empty roots, flying roots, incomplete roots, and rotten roots, and avoid the formation of a layer of water film or water stains on the surface of the structural layer, resulting in obstruction of air circulation. Long-term water retention may cause salinization of the structural layer, which is not conducive to the growth of grass seeds.

[0043] In S2, grass seeds are planted on the structural layer and water is added regularly. The grass seeds are alfalfa, which has a strong adaptability to the environment and can grow in drought, saline-alkali land and barren land, and can even survive at low temperatures of minus 25 degrees Celsius. Its roots have rhizobia that can fix nitrogen and increase the nitrogen content of the soil, so it can grow well in poor soil.

[0044] In addition, alfalfa has a developed root system that can penetrate deep into the soil and absorb more water and nutrients. Through nitrogen fixation, it stores nitrogen elements in the soil, which can be gradually released in the subsequent growth cycle to provide sufficient nutrition for plants. This nitrogen fixation property allows alfalfa to significantly reduce the amount of fertilizer applied when planting other crops after rotation, thereby protecting the ecological environment and improving the fertility of the soil. The developed root system of alfalfa can fix the soil, reduce soil erosion and soil and water loss. Its deep root system and rich root structure help to maintain the stability of the soil and prevent land desertification and soil and water loss. Finally, the roots of alfalfa can go deep into the ground for more than 6 to 9 meters, absorbing and retaining a large amount of natural nutrients and minerals, such as calcium, potassium, magnesium and other essential elements for the human body. These minerals not only provide a comprehensive health care effect for the human body, but also effectively balance the pH in the soil and improve the soil structure. Therefore, this application selects alfalfa, whose root system and above-ground parts provide a rich food source for the beneficial microorganisms in the soil, promote soil biodiversity, and further improve the soil structure.

[0045] To facilitate further understanding of the present application, the scheme of the present application is further described below in conjunction with embodiments. Those skilled in the art will understand that only some embodiments are described in the present application, and any other suitable specific embodiments are within the scope of the present application.

[0046] The urea in each embodiment of the present application is a high-purity urea nitrogen fertilizer with a total nitrogen content of ≥46.4%; the brown sugar is pure sugarcane brown sugar; and the bacterial agent is a microbial fermentation bacterial agent produced by Henan Hebi Hesheng Biological Company.

[0047] Example 1

[0048] This embodiment provides a method for improving the soil properties of an open-pit mine desertification dump, and the specific steps and methods are as follows:

[0049] Dissolve 2 parts of bacterial agent, 4 parts of urea and 2 parts of brown sugar in water to form a mixture, in which the mass ratio of brown sugar to water is 1:15. Spray the mixture on 700 parts of plant waste to form a pile with a trapezoidal cross-section and a pile height of 1.5m.

[0050] The pile is covered with plastic film for composting fermentation. During the composting fermentation process, water is added and the pile is turned to form a fermentation matrix. For example, the pile is turned and water is added once every 7 days to ensure that the moisture content of the pile is 60% and the average temperature is 55° C. The fermentation ends when the central temperature of the pile drops below 35° C. The matrix generated by fermentation is mixed with 4 parts of polyvinyl alcohol and 300 parts of sand from the open-pit mine sand dump to be improved to obtain a matrix for improving the soil properties of the open-pit mine sand dump.

[0051] The improved substrate is laid on the surface of the soil dump with a thickness of 15 cm to form a structural layer, and water is applied to the structural layer to make the entire structural layer moist; grass seeds are planted on the structural layer, and water is added regularly, for example, once every 2-3 days.

[0052] Example 2

[0053] Compared with Example 1, this example has the following differences: 700 parts of sand, 300 parts of plant waste, 2 parts of urea, 1 part of brown sugar, 1 part of bacterial agent, and 4 parts of polyvinyl alcohol.

[0054] Example 3

[0055] Compared with Example 1, this example has the following differences: 300 parts of sand, 700 parts of plant waste, 4 parts of urea, 2 parts of brown sugar, 2 parts of bacterial agent, and 6 parts of polyvinyl alcohol.

[0056] Example 4

[0057] Compared with Example 1, this example has the following differences: 700 parts of sand, 300 parts of plant waste, 2 parts of urea, 1 part of brown sugar, 1 part of bacterial agent, and 6 parts of polyvinyl alcohol.

[0058] Comparative Example 1

[0059] This comparative example is different from Example 1 in that the improved matrix includes 1000 parts of sand and 4 parts of polyvinyl alcohol.

[0060] This comparative example is different from Example 1 in that the improved substrate includes 1000 parts of sand.

[0061] Experimental example

[0062] The improved substrates in the embodiments and comparative examples were tested for soil quality, including available nutrients, pH, bulk density, total porosity and saturated hydraulic conductivity, and the results are shown in Table 1. The improved substrates in the embodiments and comparative examples were laid on the surface of the dump to form a structural layer, and alfalfa was planted, and the planting management and plant growth were tested, and the results are shown in Table 2.

[0063] Table 1 Soil quality test results of improved matrix

[0064] Treatment Group Quick-acting nutrients (nitrogen, phosphorus and potassium mg / kg) pH <![CDATA[Unit weight (g / m 3 )]]> Total porosity Saturated hydraulic conductivity (mm / min) Example 1 703 7.8 1.03 66％ 1.55 Example 2 330 7.7 1.42 63％ 1.5 Example 3 752 7.3 0.95 63％ 1.2 Example 4 373 7.4 1.44 55％ 1.1 Comparative Example 1 214 8.0 1.62 46％ 1.45 Comparative Example 2 227 8.1 1.6 51％ 2.45

[0065] Table 2 Planting management situation and plant growth results

[0066] Treatment Group Water replenishment Germination rate Growth time Example 1 Once every 2 days 90％ 60 days (end of experiment) Example 2 Once every 2 days 77％ 60 days (end of experiment) Example 3 Once every 3-4 days 79％ 60 days (end of experiment) Example 4 Once every 3-4 days 75％ 60 days (end of experiment) Comparative Example 1 Once every 2-3 days 72％ 25 days Comparative Example 2 Once a day 70％ 25 days

[0067] As shown in Table 1 and Table 2, by comparing Example 1 with Comparative Example 2, the nutrient content of the improved substrate in the present embodiment is significantly increased, according to the calculation formula (703-227) / 227=2.10, the nutrient content available for plant absorption increases by 210%. By comparing Example 1 with Example 2, the germination rate of alfalfa is 90%-77%=13% according to the calculation formula, and the germination rate of alfalfa increases by 13%, and the germination rate reaches 90%. By comparing Example 1 with Example 3, the germination rate of alfalfa increases by 11%, that is, the film-like structure formed by the excessively high polyvinyl alcohol content can limit the growth of plant roots. By comparing Example 1 with Comparative Example 2, it can be seen that water is saved by more than 50%, and after alfalfa grows for 25 days, it dies due to insufficient nutrients. By comparing Example 1-4 with Comparative Example 1-2, it can be seen that the result is that alfalfa directly planted on sandy soil under the same conditions cannot survive, and the effect of locking water and consolidating fertilizer can be well played by adding polyvinyl alcohol, reducing water loss, and improving plant growth ability to a certain extent.

[0068] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0069] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0070] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0071] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A substrate for improving the soil properties of an open-pit mine desertification dump, characterized in that: The invention comprises, by weight, 300-700 parts of plant waste, 2-4 parts of nitrogen source, 1-2 parts of sugar source, 1-2 parts of bacterial agent, 300-700 parts of sand and 4-6 parts of water-soluble high molecular polymer.

2. The matrix according to claim 1, characterized in that The matrix preparation process comprises: After the bacterial agent, the nitrogen source and the sugar source are dissolved in water, the mixed solution is sprayed on the pile of the plant waste to compost and ferment, and water is added and the pile is turned to form a fermentation matrix; The fermentation matrix is ​​mixed with water-soluble high molecular polymer and sand.

3. The matrix according to claim 2, characterized in that The plant waste includes a mixture of dead branches and / or farm straw crushed to form a particle size not exceeding 5 cm; And / or; The cross-section of the pile formed by the plant waste is trapezoidal or triangular, and the height is at least 1.5m.

4. The matrix according to any one of claims 1 to 3, characterized in that The total nitrogen content of the nitrogen source is ≥46.4%; And / or; the nitrogen source includes urea, ammonia water, ammonium sulfate, ammonium chloride and ammonium nitrate.

5. The matrix according to any one of claims 1 to 3, characterized in that The sugar source is brown sugar made from sugar cane; And / or; the mass ratio of the sugar source to water is 1:12-17.

6. The matrix according to any one of claims 1 to 3, characterized in that The bacterial agent is a microbial fermentation bacterial agent; And / or; the sandy soil is the soil source in the desertified soil dump to be improved; And / or; the water-soluble high molecular polymer includes polyvinyl alcohol.

7. The matrix according to claim 2, characterized in that The compost fermentation process is as follows: turning the pile and replenishing water every 7-8 days to ensure that the moisture content of the pile is 50-60%, the average temperature is higher than 50°C, and the fermentation ends when the central temperature of the pile drops below 35°C.

8. A method for improving soil properties of open-pit mine desertification dump, characterized in that: The steps include: Laying a substrate according to any one of claims 1 to 7 with a thickness of at least 15 cm on the surface of a spoil dump to form a structural layer, and applying water to the structural layer to make the structural layer completely wet; Plant grass seeds on the structural layer and water regularly.

9. The method according to claim 8, characterized in that The grass seeds are alfalfa.

Images