Method for rapidly improving planting environment of high-sulfur and high-iron coal gangue storage yard in situ

Abstract

The invention belongs to the technical field of mine ecological restoration, and discloses a method for rapidly improving the plant growing environment of a high-sulfur and high-iron coal gangue storage yard in situ, which comprises the following steps: S1, carrying out crushing pretreatment on high-sulfur and high-iron coal gangue on the surface layer of the storage yard to be treated; s2, uniformly mixing the coal gangue with the passivation material and the vegetation improvement material according to a certain mass ratio; and S3, adding a proper amount of water into the mixed coal gangue to keep a certain humidity, and stabilizing and cultivating for a period of time under a normal temperature condition to obtain the coal gangue which has obviously improved vegetation environment and can be directly planted with vegetation. According to the method, the pH value and the oxidation-reduction environment of the coal gangue in the planting layer can be remarkably improved on a high-sulfur and high-iron coal gangue storage yard which is high in acidity, high in iron, manganese and heavy metal concentration and difficult to naturally grow plants, and the content and effectiveness of plant nutrients such as available phosphorus, rapidly available potassium and hydrolytic nitrogen in the coal gangue in the planting layer are remarkably improved; and continuous oxidation of the high-sulfur and high-iron coal gangue for acid production and release of toxic and harmful substances such as iron, manganese, heavy metals and the like can be effectively controlled.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the technical field of mine ecological restoration, and in particular relates to a method for rapidly improving the vegetation environment of a high-sulfur and high-iron coal gangue dump in situ. Background Art

[0002] Gangue is solid waste generated during coal mining. At present, the accumulated gangue in my country has exceeded 7 billion tons. Its storage has caused many serious negative impacts on the surrounding environment, including soil pollution, water pollution and ecological damage. The management of gangue dumps is not only a need to protect the ecological environment, but also an important part of resource reuse and sustainable development. The soil quality in gangue dumps is usually poor. It not only lacks necessary nutrients, but also contains harmful substances such as heavy metals, which makes it difficult for vegetation to grow normally.

[0003] The mainstream restoration measures at present are physical improvement, chemical improvement and biological restoration. Physical improvement mainly covers the surface of coal gangue with soil or organic matter through covering method to reduce soil erosion and weathering; chemical improvement is to use soil conditioners to adjust soil pH and improve the stability of heavy metals; and biological restoration is to introduce pioneer plants with strong tolerance for planting, which can gradually improve soil structure and increase organic matter. However, due to the poor nutrient content of coal gangue matrix, it is difficult for plants to take root. Therefore, the focus of ecological restoration is to enrich the content and effectiveness of nutrients such as nitrogen, phosphorus and potassium in coal gangue, enhance the fertility of the matrix and the content of organic matter, create a good growth environment for plants, and promote the restoration of biodiversity in coal gangue dumps.

[0004] In view of the above analysis, the technical problems that urgently need to be solved in the existing technology are: since the nutrients in the coal gangue matrix are poor, it is difficult for plants to grow. Therefore, the focus of ecological restoration is to enrich the content and effectiveness of nutrients such as nitrogen, phosphorus and potassium in the coal gangue, enhance the fertility of the matrix and the organic matter content, create a good growth environment for plants, and thereby promote the restoration of biodiversity in the coal gangue yard. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a method for rapidly improving the vegetation environment of a high-sulfur and high-iron coal gangue dump in situ, which can significantly improve the pH and redox environment of the planting layer of coal gangue in a high-sulfur and high-iron coal gangue dump with high acidity, high iron, manganese and heavy metal concentrations, and difficult for plants to grow naturally, and significantly improve the content and effectiveness of plant nutrients such as effective phosphorus, quick-acting potassium, and hydrolyzed nitrogen in the planting layer of coal gangue, and can effectively control the continued oxidation of high-sulfur and high-iron coal gangue to produce acid and release toxic and harmful substances such as iron, manganese and heavy metals, and can provide an excellent vegetation environment for soilless rapid ecological restoration and subsequent ecological management of coal gangue dumps. The raw materials used in the present invention are cheap, easy to obtain, and widely sourced, and the operation is simple, the effect is significant, there is no secondary pollution, and the goal of treating waste with waste can be achieved.

[0006] The present invention is achieved by a method for rapidly improving the vegetation environment of a high-sulfur and high-iron coal gangue dump in situ, comprising:

[0007] S1, crushing and pre-treating the high-sulfur and high-iron coal gangue on the surface layer (20-30 cm) of the yard to be treated;

[0008] S2, uniformly mixing the coal gangue, the passivation material and the vegetation improvement material according to a certain mass ratio;

[0009] S3, adding a proper amount of water to the mixed coal gangue to maintain a certain humidity, and stabilizing and cultivating it under normal temperature conditions for a period of time to obtain the coal gangue whose vegetation environment has been significantly improved and on which vegetation can be directly planted.

[0010] Furthermore, the pretreatment of the coal gangue can be performed by using a machine to appropriately crush the coal gangue so that its particle size ranges from 2 mm to 1 cm.

[0011] Furthermore, the passivation materials are limestone and phosphogypsum, the content of CaCO3 in the limestone is 85% to 95%, and the content of CaSO4 in the phosphogypsum is 70% to 80%.

[0012] Furthermore, the passivation materials limestone and phosphogypsum need to be properly crushed by machine and then passed through a 10-25 mesh sieve.

[0013] Furthermore, the addition amount of the passivation material is 3% to 4% (w / w) of the dry weight of the coal gangue as limestone, and 1% to 2% (w / w) of the dry weight of the coal gangue as phosphogypsum.

[0014] Furthermore, the improved materials are brewing sludge and Miscanthus litter.

[0015] Furthermore, the improved materials, brewing sludge and Miscanthus litter, need to be properly crushed by machine and then sieved through a 10-25 mesh screen.

[0016] Furthermore, the addition amount of the improved materials is 2.5% to 7.5% (w / w) of the dry weight of the coal gangue in the case of brewing sludge, and 2.5% to 7.5% (w / w) of the dry weight of the coal gangue in the case of Miscanthus litter.

[0017] Furthermore, a proper amount of water is added to the mixed coal gangue, wherein the amount of deionized water added is 55% to 75% (v / w) of the dry weight of the coal gangue, and water is regularly added to maintain the humidity.

[0018] Furthermore, the mixture is stabilized and cultivated for a period of time under normal temperature conditions, the temperature condition is 20-25° C., and the stabilization and cultivation time is 5-30 days.

[0019] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0020] First, compared with the prior art, the present invention provides a method for rapidly improving the vegetation environment of high-sulfur and high-iron coal gangue dumps in situ. The passivation materials used in the method are all inorganic calcium-rich materials, and the passivation materials are limestone and phosphogypsum. Among the above components, the combined application of limestone and phosphogypsum can effectively improve the pH and redox environment of the planting layer coal gangue, and can also adsorb metal ions such as Fe, Mn, Cu, and Zn, effectively control the continued oxidation of high-sulfur and high-iron coal gangue to produce acid and release toxic and harmful substances such as iron, manganese and heavy metals, and inhibit the release and migration of harmful elements; secondly, the introduction of brewing sludge and Miscanthus litter can significantly increase the content and effectiveness of plant nutrients such as effective phosphorus, quick-acting potassium, and hydrolyzed nitrogen in the planting layer coal gangue, and improve the poor nutritional environment. The reasonable combination of the above components can give full play to multiple functions, thereby quickly improving the vegetation environment of the coal gangue dump, and providing an excellent vegetation environment for the soilless rapid ecological restoration and subsequent ecological management of the coal gangue dump.

[0021] Second, the technical solution of the present invention breaks through the technical limitations of traditional mine ecological restoration methods and realizes an innovative model for the restoration of coal gangue dumps without covering with soil. This soilless restoration method not only simplifies the construction process, but also saves a lot of precious soil and the time, energy and cost of related stripping, loading and unloading, transportation and laying, and greatly shortens the site restoration cycle. Moreover, because the biological toxicity effects of toxic and harmful chemical passivators are not introduced, the normal germination of seeds of subsequently planted vegetation and the normal growth and development of plants can be ensured, thereby quickly restoring the damaged surface ecological vegetation and creating good conditions for subsequent vegetation growth.

[0022] This technical solution optimizes the restoration process, ensuring that vegetation can resume normal growth in a relatively short period of time, effectively improving restoration efficiency. At the same time, it eliminates the need for large-scale soil covering operations, significantly saving soil stripping, loading and unloading, transportation and laying, and labor costs, providing a solid guarantee for the overall economic benefits of the project.

[0023] The present invention is not limited to the restoration of coal gangue dumps, but also broadens the scope of resource utilization of industrial solid waste. The use of bulk inorganic or organic industrial solid wastes such as phosphogypsum and brewing sludge not only reduces the cost of solid waste management and restoration, but also realizes the green development concept of treating waste with waste and turning waste into treasure, bringing considerable commercial value and expected benefits to enterprises.

[0024] At present, there is limited systematic research in the field of using brewing sludge to repair coal gangue and other solid wastes at home and abroad. The technical solution of the present invention fills this gap. Its innovation and practicality provide valuable reference and demonstration effects for related fields, promote the development of environmental protection repair technology, and also contribute new ideas to the realization of circular economy and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of a method for rapidly improving the vegetation environment of a high-sulfur and high-iron coal gangue dump in situ provided by an embodiment of the present invention;

[0026] Figure 2 It is a bar graph of the pH change of coal gangue after adding the passivation improvement material provided by the embodiment of the present invention;

[0027] Figure 3 It is a bar chart showing the change of Eh of coal gangue after adding the passivation improvement material provided by the embodiment of the present invention;

[0028] Figure 4 It is a bar chart showing the change of hydrolyzed nitrogen in coal gangue after adding the passivation improvement material provided by the embodiment of the present invention;

[0029] Figure 5 It is a bar chart showing the change of available potassium in coal gangue after adding the passivation improvement material provided by the embodiment of the present invention;

[0030] Figure 6 It is a bar chart showing the change of available phosphorus in coal gangue after adding the passivation improvement material provided by the embodiment of the present invention;

[0031] Figure 7 It is a bar chart showing the change of organic matter in coal gangue after adding the passivation improvement material provided by the embodiment of the present invention;

[0032] Figure 8 This is a diagram showing the effect of planting Miscanthus sinensis on coal gangue after adding passivation improvement materials for five months as provided in the application example of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] like Figure 1 As shown, the method for in-situ rapid improvement of the vegetation environment of a high-sulfur and high-iron coal gangue dump provided by an embodiment of the present invention includes:

[0035] S1, crushing and pre-treating the high-sulfur and high-iron coal gangue on the surface layer (20-30 cm) of the yard to be treated;

[0036] S2, uniformly mixing the coal gangue, the passivation material and the vegetation improvement material according to a certain mass ratio;

[0037] S3, adding a proper amount of water to the mixed coal gangue to maintain a certain humidity, and stabilizing and cultivating it under normal temperature conditions for a period of time to obtain the coal gangue whose vegetation environment has been significantly improved and on which vegetation can be directly planted.

[0038] As solid waste generated during coal mining and washing, coal gangue usually contains high sulfur and iron components, which can easily cause acid mine drainage (AMD) and heavy metal pollution. In an embodiment of the present invention, the high-sulfur and high-iron coal gangue on the surface layer (20 to 30 cm) of the yard is first crushed to increase its specific surface area, improve the mixing uniformity of subsequent passivation materials and vegetation improvement materials, and promote chemical and biological reactions. This pretreatment process can effectively reduce the physical hardness of coal gangue, making it more suitable as a vegetation matrix, while improving the pore structure, which is conducive to the penetration and retention of water and nutrients.

[0039] In order to reduce the environmental hazards of high-sulfur and high-iron coal gangue, this method uses passivation materials (such as alkaline mineral powder, biochar, calcium-magnesium compounds, etc.) and vegetation improvement materials (such as organic fertilizer, humic acid, biological inoculants, etc.) to mix evenly in a certain mass ratio. Passivation materials reduce the risk of dissolution of acidic pollutants by neutralizing sulfate and stabilizing iron ions, while inhibiting the activity of heavy metals and improving their ecological safety. Vegetation improvement materials provide necessary nutrients and organic matter, improve soil microbial communities, and promote the transformation of coal gangue into a matrix suitable for plant growth.

[0040] Add an appropriate amount of water to the mixed coal gangue to keep it at a certain humidity to activate microbial activity and promote the physical and chemical stabilization process. Stable cultivation under normal temperature conditions allows the passivation reaction, redox reaction and microbial decomposition process to be gradually completed, ensuring that the pH of the planting matrix is ​​moderate, the bioavailability of heavy metals is reduced, and a more stable aggregate structure is formed to improve water and fertilizer retention capacity. In addition, the biodegradation and mineral reaction at this stage help to further improve soil activity and enhance the adaptability of plant roots.

[0041] After stable cultivation, the vegetation environment of coal gangue has been significantly improved, the pH tends to be neutral, the heavy metal activity is greatly reduced, the nutrient content is increased, the agglomeration structure is optimized, and it is suitable for plant root growth. At this time, coal gangue can be directly used for vegetation planting, reducing the cost of soil covering or foreign soil landfill in traditional restoration methods, and improving the ecological restoration efficiency of mining wasteland. This method not only shortens the restoration cycle, but also reduces the cost of environmental governance, and realizes the ecologically friendly utilization of high-sulfur and high-iron coal gangue yards.

[0042] The pretreatment of coal gangue can be done by using machines to properly crush the coal gangue to a particle size range of 2mm to 1cm.

[0043] The passivation materials are limestone and phosphogypsum, the content of CaCO3 in the limestone is 85% to 95%, and the content of CaSO4 in the phosphogypsum is 70% to 80%.

[0044] The passivation materials limestone and phosphogypsum need to be properly crushed by machine and then passed through a 10-25 mesh sieve.

[0045] The addition amount of the passivating material is 3% to 4% (w / w) of the dry weight of the gangue for limestone, and 1% to 2% (w / w) of the dry weight of the gangue for phosphogypsum.

[0046] The improved materials are winemaking sludge and Miscanthus litter.

[0047] The improved materials, brewing sludge and Miscanthus litter, need to be properly crushed by machine and then passed through a 10-25 mesh sieve.

[0048] The amount of improved materials added is 2.5% to 7.5% (w / w) of the dry weight of coal gangue for brewing sludge and 2.5% to 7.5% (w / w) of the dry weight of coal gangue for Miscanthus litter.

[0049] Add a proper amount of water to the mixed coal gangue, the amount of deionized water added is 55% to 75% (v / w) of the dry weight of the coal gangue, and regularly add water to maintain this humidity.

[0050] Stabilize and cultivate for a period of time under normal temperature conditions, the temperature condition is 20-25°C, and the stabilization and cultivation time is 5-30 days.

[0051] Embodiment 1:

[0052] The surface gangue of the gangue dump was collected and brought back to the laboratory. After removing plant residues and soil particles, it was naturally air-dried and passed through a 6mm sieve for later use. 100g of gangue was put into a 250mL beaker, and 3% (w / w) limestone, 2% (w / w) phosphogypsum, 7.5% (w / w) brewing sludge and 2.5% (w / w) Miscanthus litter were added and mixed evenly. 60% deionized water (v / w) was added to keep the gangue at this humidity and stably incubated in a (25±1)℃ constant temperature incubator for 5, 10, 15 and 30 days respectively. Samples were taken for analysis, and the samples were naturally air-dried, ground and sieved.

[0053] Embodiment 2:

[0054] The surface gangue of the gangue dump was collected and brought back to the laboratory. After removing plant residues and soil particles, it was naturally air-dried and passed through a 6mm sieve for later use. 100g of gangue was put into a 250mL beaker, and 3% (w / w) limestone, 2% (w / w) phosphogypsum, 5% (w / w) brewing sludge and 5% (w / w) Miscanthus litter were added and mixed evenly. 60% deionized water (v / w) was added to keep the gangue at this humidity. After stable cultivation in a (25±1)℃ constant temperature incubator for 5, 10, 15 and 30 days, samples were taken for analysis, and the samples were naturally air-dried, ground and sieved.

[0055] Embodiment 3:

[0056] The surface gangue of the gangue dump was collected and brought back to the laboratory. After removing plant residues and soil particles, it was naturally air-dried and passed through a 6mm sieve for use. 100g of gangue was placed in a 250mL beaker, and 3% (w / w) limestone, 2% (w / w) phosphogypsum, 2.5% (w / w) brewing sludge and 7.5% (w / w) Miscanthus litter were added and mixed evenly. 60% deionized water (v / w) was added to keep the gangue at this humidity and stably incubated in a (25±1)℃ constant temperature incubator for 5, 10, 15 and 30 days respectively. Samples were taken for analysis, and the samples were naturally air-dried, ground and sieved.

[0057] Embodiment 4:

[0058] The surface gangue of the gangue dump was collected and brought back to the laboratory. After removing plant residues and soil particles, it was naturally air-dried and passed through a 6mm sieve for later use. 100g of gangue was put into a 250mL beaker, and 4% (w / w) limestone, 1% (w / w) phosphogypsum, 7.5% (w / w) brewing sludge and 2.5% (w / w) Miscanthus litter were added and mixed evenly. Then 60% deionized water (v / w) was added to keep the gangue at this humidity and stably cultured in a (25±1)℃ constant temperature incubator for 5, 10, 15 and 30 days respectively. Samples were taken for analysis, and the samples were naturally air-dried, ground and sieved.

[0059] Embodiment 5:

[0060] The surface gangue of the gangue dump was collected and brought back to the laboratory. After removing plant residues and soil particles, it was naturally air-dried and passed through a 6mm sieve for later use. 100g of gangue was put into a 250mL beaker, and 4% (w / w) limestone, 1% (w / w) phosphogypsum, 5% (w / w) brewing sludge and 5% (w / w) Miscanthus litter were added and mixed evenly. Then 60% deionized water (v / w) was added to keep the gangue at this humidity and incubated stably in a (25±1)℃ constant temperature incubator for 5, 10, 15 and 30 days respectively. Samples were taken for analysis, and the samples were naturally air-dried, ground and sieved.

[0061] Embodiment 6:

[0062] The surface gangue of the gangue dump was collected and brought back to the laboratory. After removing plant residues and soil particles, it was naturally air-dried and passed through a 6 mm sieve for later use. 100 g of gangue was placed in a 250 mL beaker, and 4% (w / w) limestone, 1% (w / w) phosphogypsum, 2.5% (w / w) brewing sludge and 7.5% (w / w) Miscanthus litter were added and mixed evenly. Then 60% deionized water (v / w) was added to keep the gangue at this humidity and stably cultured in a (25±1)°C constant temperature incubator for 5, 10, 15 and 30 days respectively. Samples were taken for analysis, and the samples were naturally air-dried, ground and sieved.

[0063] Figures 2-3It shows that the pH of coal gangue increased significantly and Eh decreased significantly after adding passivation improvement materials. Compared with the control, the pH increased by 1.64 to 1.90 times and Eh decreased by 18.67 to 54.56 times after passivation for 30 days. Figures 4 to 7 It shows that the nutrient contents of hydrolyzed nitrogen, available potassium, effective phosphorus and organic matter in the gangue increased significantly after the addition of passivation improvement materials. After 30 days of passivation, the hydrolyzed nitrogen increased by 20.00-47.37 times, the available potassium increased by 2.25-24.05 times, the effective phosphorus increased by 25.81-39.06 times, and the organic matter increased by 2.04-4.33 times. The present invention can significantly increase the nitrogen, phosphorus, available potassium and organic matter content of the gangue matrix, increase the pH of the gangue, reduce Eh, effectively improve the pH value and redox environment of the gangue, and realize the rapid improvement of the vegetation environment of the gangue.

[0064] Application Example 1: Improving the vegetation environment of high-sulfur and high-iron coal gangue using the passivation improved material of the present invention

[0065] (1) Experimental conditions and materials

[0066] Source of coal gangue: mined from an abandoned coal mine dump, with a sulfur content of 3.8%, an iron content of 12.5%, and a pH of 2.5.

[0067] Passivation materials: 3% (w / w) limestone, 2% (w / w) phosphogypsum.

[0068] Vegetation improvement materials: 7.5% (w / w) brewing sludge, 2.5% (w / w) Miscanthus litter.

[0069] Moisture Control: 60% moisture content.

[0070] (2) Operation steps

[0071] 1. Crushing pretreatment: crush the surface 30cm of coal gangue to a particle size of less than 6mm to increase the reaction rate of the material.

[0072] 2. Even mixing: Evenly mix according to the mass ratio of 100:5:10 (coal gangue: passivation material: vegetation improvement material).

[0073] 3. Moisture control: Add appropriate amount of water to maintain the moisture content at 60% to promote chemical and biological reactions.

[0074] 4. Stable cultivation: Stack at room temperature for 15 days, stir every 4 days to allow it to fully react and mature.

[0075] (3) Experimental results

[0076] After 15 days, the pH value of coal gangue increased from 2.5 to 7.2, and the acidity was significantly reduced.

[0077] Soluble iron levels were reduced by 96% and sulfate by 50%.

[0078] The soil organic matter content increased by 2 times and the microbial activity was enhanced.

[0079] In the test planting of Miscanthus, the germination rate reached 98% within 15 days and it grew well.

[0080] Application Example 2: Improving the vegetation environment of high-sulfur and high-iron coal gangue using the passivation improved material of the present invention

[0081] (1) Experimental conditions and materials

[0082] Source of coal gangue: mined from an abandoned coal mine dump, with a sulfur content of 3.8%, an iron content of 12.5%, and a pH of 2.5.

[0083] Passivation materials: 3% (w / w) limestone, 2% (w / w) phosphogypsum.

[0084] Vegetation improvement materials: 5% (w / w) brewing sludge, 5% (w / w) Miscanthus litter.

[0085] Moisture Control: 60% moisture content.

[0086] (2) Operation steps

[0087] 1. Crushing pretreatment: crush the surface 30cm of coal gangue to a particle size of less than 6mm to increase the reaction rate of the material.

[0088] 2. Even mixing: Evenly mix according to the mass ratio of 100:5:10 (coal gangue: passivation material: vegetation improvement material).

[0089] 3. Moisture control: Add appropriate amount of water to maintain the moisture content at 60% to promote chemical and biological reactions.

[0090] 4. Stable cultivation: Stack at room temperature for 15 days, stir every 4 days to allow it to fully react and mature.

[0091] (3) Experimental results

[0092] After 15 days, the pH value of coal gangue increased from 2.5 to 7.2, and the acidity decreased significantly.

[0093] Soluble iron ion content was reduced by 90% and sulfate was reduced by 58%.

[0094] The soil organic matter content increased by 2 times and the microbial activity was enhanced.

[0095] In the test planting of Miscanthus, the germination rate reached 98% within 15 days and it grew well.

[0096] Application Example 3: Improving the vegetation environment of high-sulfur and high-iron coal gangue using the passivation improved material of the present invention

[0097] (1) Experimental conditions and materials

[0098] Source of coal gangue: mined from an abandoned coal mine dump, with a sulfur content of 3.8%, an iron content of 12.5%, and a pH of 2.5.

[0099] Passivation materials: 3% (w / w) limestone, 2% (w / w) phosphogypsum.

[0100] Vegetation improvement materials: 2.5% (w / w) brewing sludge, 7.5% (w / w) Miscanthus litter.

[0101] Moisture Control: 60% moisture content.

[0102] (2) Operation steps

[0103] 1. Crushing pretreatment: crush the surface 30cm of coal gangue to a particle size of less than 6mm to increase the reaction rate of the material.

[0104] 2. Even mixing: Evenly mix according to the mass ratio of 100:5:10 (coal gangue: passivation material: vegetation improvement material).

[0105] 3. Moisture control: Add appropriate amount of water to maintain the moisture content at 60% to promote chemical and biological reactions.

[0106] 4. Stable cultivation: Stack at room temperature for 15 days, stir every 4 days to allow it to fully react and mature.

[0107] (3) Experimental results

[0108] After 15 days, the pH value of coal gangue increased from 2.5 to 7.0, and the acidity decreased significantly.

[0109] Soluble iron ion content was reduced by 98% and sulfate was reduced by 62%.

[0110] The soil organic matter content increased by 3 times and the microbial activity was enhanced.

[0111] In the test planting of Miscanthus, the germination rate reached 98% within 15 days and it grew well.

[0112] Application Example 4: Improving the vegetation environment of high-sulfur and high-iron coal gangue using the passivation improved material of the present invention

[0113] (1) Experimental conditions and materials

[0114] Source of coal gangue: mined from an abandoned coal mine dump, with a sulfur content of 3.8%, an iron content of 12.5%, and a pH of 2.5.

[0115] Passivation materials: 4% (w / w) limestone, 1% (w / w) phosphogypsum.

[0116] Vegetation improvement materials: 2.5% (w / w) brewing sludge, 7.5% (w / w) Miscanthus litter.

[0117] Moisture Control: 60% moisture content.

[0118] (2) Operation steps

[0119] 1. Crushing pretreatment: crush the surface 30cm of coal gangue to a particle size of less than 6mm to increase the reaction rate of the material.

[0120] 2. Even mixing: Evenly mix according to the mass ratio of 100:5:10 (coal gangue: passivation material: vegetation improvement material).

[0121] 3. Moisture control: Add appropriate amount of water to maintain the moisture content at 60% to promote chemical and biological reactions.

[0122] 4. Stable cultivation: Stack at room temperature for 15 days, stir every 4 days to allow it to fully react and mature.

[0123] (3) Experimental results

[0124] After 15 days, the pH value of coal gangue increased from 2.5 to 7.3, and the acidity was significantly reduced.

[0125] Soluble iron ion content was reduced by 98% and sulfate was reduced by 61%.

[0126] The soil organic matter content increased by 2.8 times and the microbial activity was enhanced.

[0127] In the test planting of Miscanthus, the germination rate reached 98% within 15 days and it grew well.

[0128] Application Example 5: Improving the vegetation environment of high-sulfur and high-iron coal gangue using the passivation improved material of the present invention

[0129] (1) Experimental conditions and materials

[0130] Source of coal gangue: mined from an abandoned coal mine dump, with a sulfur content of 3.8%, an iron content of 12.5%, and a pH of 2.5.

[0131] Passivation materials: 4% (w / w) limestone, 1% (w / w) phosphogypsum.

[0132] Vegetation improvement materials: 2.5% (w / w) brewing sludge, 7.5% (w / w) Miscanthus litter.

[0133] Moisture Control: 60% moisture content.

[0134] (2) Operation steps

[0135] 1. Crushing pretreatment: crush the surface 30cm of coal gangue to a particle size of less than 6mm to increase the reaction rate of the material.

[0136] 2. Even mixing: Evenly mix according to the mass ratio of 100:5:10 (coal gangue: passivation material: vegetation improvement material).

[0137] 3. Moisture control: Add appropriate amount of water to maintain the moisture content at 60% to promote chemical and biological reactions.

[0138] 4. Stable cultivation: Stack at room temperature for 15 days, stir every 4 days to allow it to fully react and mature.

[0139] (3) Experimental results

[0140] After 15 days, the pH value of coal gangue increased from 2.5 to 7.1, and the acidity was significantly reduced.

[0141] Soluble iron ion content was reduced by 98% and sulfate was reduced by 58%.

[0142] The soil organic matter content increased by 2 times and the microbial activity was enhanced.

[0143] In the test planting of Miscanthus, the germination rate reached 98% within 15 days and it grew well.

[0144] Application Example 6: Improving the vegetation environment of high-sulfur and high-iron coal gangue using the passivation improved material of the present invention

[0145] (1) Experimental conditions and materials

[0146] Source of coal gangue: mined from an abandoned coal mine dump, with a sulfur content of 3.8%, an iron content of 12.5%, and a pH of 2.5.

[0147] Passivation materials: 4% (w / w) limestone, 1% (w / w) phosphogypsum.

[0148] Vegetation improvement materials: 2.5% (w / w) brewing sludge, 7.5% (w / w) Miscanthus litter.

[0149] Moisture Control: 60% moisture content.

[0150] (2) Operation steps

[0151] 1. Crushing pretreatment: crush the surface 30cm of coal gangue to a particle size of less than 6mm to increase the reaction rate of the material.

[0152] 2. Even mixing: Evenly mix according to the mass ratio of 100:5:10 (coal gangue: passivation material: vegetation improvement material).

[0153] 3. Moisture control: Add appropriate amount of water to maintain the moisture content at 60% to promote chemical and biological reactions.

[0154] 4. Stable cultivation: Stack at room temperature for 15 days, stir every 4 days to allow it to fully react and mature.

[0155] (3) Experimental results

[0156] After 15 days, the pH value of coal gangue increased from 2.5 to 7.2, and the acidity decreased significantly.

[0157] Soluble iron content was reduced by 95% and sulfate by 62%.

[0158] The soil organic matter content increased by 3.1 times and the microbial activity was enhanced.

[0159] In the test planting of Miscanthus, the germination rate reached 98% within 15 days and it grew well.

[0160] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0161] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for rapidly improving the vegetation environment of a high-sulfur and high-iron coal gangue dump in situ, characterized in that: include: S1, crushing and pre-treating the high-sulfur and high-iron coal gangue on the surface of the yard to be treated; S2, uniformly mixing the coal gangue, the passivation material and the vegetation improvement material according to a certain mass ratio; S3, adding a proper amount of water to the mixed coal gangue to maintain a certain humidity, and stabilizing and cultivating it under normal temperature conditions for a period of time to obtain the coal gangue whose vegetation environment has been significantly improved and on which vegetation can be directly planted.

2. The method for in-situ rapid improvement of the vegetation environment of a high-sulfur and high-iron coal gangue dump site according to claim 1, characterized in that: The pretreatment of coal gangue can be done by using machines to properly crush the coal gangue to a particle size range of 2mm to 1cm.

3. The method for in-situ rapid improvement of the vegetation environment of a high-sulfur and high-iron coal gangue dump site as claimed in claim 1, characterized in that: The passivation materials are limestone and phosphogypsum, the content of CaCO3 in the limestone is 85% to 95%, and the content of CaSO4 in the phosphogypsum is 70% to 80%.

4. The method for in-situ rapid improvement of the vegetation environment of a high-sulfur and high-iron coal gangue dump site according to claim 1, characterized in that: The passivation materials limestone and phosphogypsum need to be properly crushed by machine and then passed through a 10-25 mesh sieve.

5. The method for in-situ rapid improvement of vegetation environment of high-sulfur and high-iron coal gangue dump as claimed in claim 1, characterized in that: The amount of passivation material added is 3% to 4% of the dry weight of coal gangue for limestone and 1% to 2% of the dry weight of coal gangue for phosphogypsum.

6. The method for in-situ rapid improvement of vegetation environment of high-sulfur and high-iron coal gangue dump as claimed in claim 1, characterized in that: The improved materials are winemaking sludge and Miscanthus litter.

7. The method for in-situ rapid improvement of vegetation environment of high-sulfur and high-iron coal gangue dump as claimed in claim 1, characterized in that: The improved materials, brewing sludge and Miscanthus litter, need to be properly crushed by machine and then passed through a 10-25 mesh sieve.

8. The method for in-situ rapid improvement of the vegetation environment of a high-sulfur and high-iron coal gangue dump as claimed in claim 1, characterized in that: The amount of improved materials added is 2.5% to 7.5% of the dry weight of coal gangue for brewing sludge and 2.5% to 7.5% of the dry weight of coal gangue for Miscanthus litter.

9. The method for in-situ rapid improvement of vegetation environment of high-sulfur and high-iron coal gangue dumpsite according to claim 1, characterized in that: Add an appropriate amount of water to the mixed coal gangue, the amount of deionized water added is 55% to 75% of the dry weight of the coal gangue, and water is regularly added to maintain this humidity.

10. The method for rapidly improving the vegetation environment of a high-sulfur and high-iron coal gangue dumpsite according to claim 1, characterized in that: Stabilize and cultivate for a period of time under normal temperature conditions, the temperature condition is 20-25°C, and the stabilization and cultivation time is 5-30 days.

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