Ecological restoration method for refuse dump constructed by directional pores of coal-based solid waste artificial soil

Abstract

The invention relates to the technical field of coal-based solid waste resource utilization and mining area ecological restoration, in particular to a coal-based solid waste artificial soil directional pore construction waste dump ecological restoration method which comprises the steps that S1, coal-based solid waste is mixed according to a certain mass ratio; s2, mixing organic matters according to a mass ratio; s3, mixing the mixture obtained in the step S2 with the bacterial liquid; s4, compounding the mixture in the step S3 and the mixture in the step S1; s5, the mixture obtained in the step S4 is mixed with aluminum powder and calcium hydroxide; s6, drying after fermentation in S5, and screening the particle size range to obtain a porous medium; s7, holes are punched in the surface of the waste dump, and then the porous media are buried in the holes; s8, the switchgrass and the apocynum venetum are compounded according to the proportion; s9, planting plants in holes in S7 in a hole sowing manner; and S10, monitoring according to a certain period. The coal-based solid waste resource utilization efficiency and the mining area ecological restoration quality are comprehensively improved through coal-based solid waste particle size and mineral component regulation and control, porous medium pore directional construction and soil-vegetation system coupling.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of resource utilization of coal-based solid waste, in particular to a coal-based solid waste artificial soil directional pore construction dump ecological restoration method. BACKGROUND

[0002] Coal gangue, fly ash, gasification slag and desulfurization gypsum and other coal-based industrial solid waste have large annual discharge and wide distribution. If not properly treated, they can cause environmental problems such as water pollution, soil compaction and heavy metal leakage. At the same time, the regional topography of the mining area, especially the dump area, is severely damaged, the soil is poor, the structure is poor, the water retention capacity is weak, and the microbial activity is low, which makes it difficult to reconstruct vegetation and seriously restricts the efficiency of ecological restoration and repair.

[0003] To address the above challenges, many studies have attempted to explore the resource utilization of coal-based solid waste and the ecological restoration technology of mining areas. The current main technical paths include the following three categories: the first category is the guest soil backfilling and vegetation restoration method [1] , which backfills the surface of the dump area with transported loess, cultivated layer nutrient soil or humus soil, and then plants drought-tolerant grass and shrub plants (such as shrubs, sand busters, etc.), hoping to achieve water and soil conservation and ground stabilization through plant coverage. However, this technology mainly focuses on surface improvement and does not reconstruct the structure of the original soil in the mining area from the particle size or soil microstructure dimension; the second category is the composite material covering technology [2] , which uses a composite structure of fiber and water-retaining agent to improve the water retention and vegetation growth rate of the surface layer. Although the ecological blanket has certain water regulation capacity, it is still a physical covering of the surface layer material and has limited effect on the pore reconstruction and structure integration of the underlying solid waste or original soil; the third category is the microbial inoculation and biological conditioning method: this method inoculates rhizobium, nitrogen-fixing bacteria or plant growth-promoting bacteria (such as phosphorus-solubilizing bacteria, AMF bacteria, etc.) [3] to improve microbial activity and plant stress resistance, and to enhance soil fertility and biodiversity. However, most of the inoculation is concentrated in the plant rhizosphere or surface microenvironment, and lacks deep coupling mechanisms with the physical structure of the soil, and the microbial function maintenance time is limited. These methods still have the following common technical problems:

[0004] (1) Structural matching is insufficient: Most methods are surface treatment methods, ignoring the matching between solid waste particle size, distribution and natural soil, and not achieving soil-like structure reconstruction. The material and the original soil may have structural faults, and the stability is poor; (2) Uncontrollable pore system: Whether it is natural fermentation or composite material structure, its pore morphology is formed naturally, lacking engineering means to control pore size, shape and distribution, making it difficult to build a functional and stable pore system; (3) Insufficient biological-structural synergy: Plant configuration and microbial inoculation are mostly independent operations, lacking a "pore-root-microecology" trinity coupling system, and lacking closed-loop support between functional systems, resulting in slow ecological system recovery rate and poor sustainability.

[0005] In recent years, some studies have attempted to pelletize solid waste or introduce some foaming technology to improve porosity, but most still remain at the level of single material modification, failing to achieve the system integration of mineral component synergy, pore structure regulation and ecological coupling.

[0006] REFERENCES:

[0007] [1] Zhang Yufang, Li Xilai, Jin Liqun, et al. Analysis of physicochemical properties of reconstructed soil based on high-cold mine particle organic fertilizer and sheep board manure application [J]. China Soil and Fertilizer, 2023, (07): 129-137.

[0008] [2] Yang Chunyan, Wang Xiaozhan, Shi Changqing, et al. Effects of different material coverings on evaporation characteristics of disturbed interface soil in high-cold mining area [J]. Water and Soil Conservation Research, 2025, 32(02): 198-206.

[0009] [3] Jie Linlin, Bi Yinfeng, Liu Tao. Effects of AMF inoculation on plant-soil nutrient accumulation and colonization of indigenous DSE in eastern grassland open-pit mining area [J]. Journal of Coal, 2024, 49(11): 4603-4616. SUMMARY

[0010] (I) Technical problems solved

[0011] In response to the problems existing in the prior art, such as lack of structural simulation, uncontrollable pores, and fragmentation of biological systems, the present invention provides a method for ecological restoration of spoil dumps by directional pore construction of artificial soil from coal-based solid waste. The method aims to solve the following key technical difficulties: (1) achieving coordinated regulation of the particle size structure and mineral composition of coal-based solid waste to construct a "soil-like" porous medium with both structural stability and ecological adaptability; (2) achieving directional construction of the pore system through the combined mechanism of "microbial connection + foaming pore creation", thus overcoming the problem of uncontrollable pores in traditional composting; (3) synergistically constructing a coupling platform between the prepared porous medium and the grass and shrub system to enhance the coordinated recovery capacity of the physical structure, microecology, and plant functions of the newly constructed soil in the mining area, thereby achieving the goal of systematic and sustainable ecological reconstruction of the mining area.

[0012] (2) Technical solution

[0013] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a method for ecological restoration of spoil dumps by constructing directional pores of artificial soil using coal-based solid waste. The core of the method lies in achieving systematic restoration of newly constructed soil bodies in mining areas by regulating the particle size and mineral composition of multi-source coal-based solid waste, directional pore construction of porous media, and coupling of soil-vegetation systems.

[0014] The technical solution of the present invention has the following steps:

[0015] S1: Gangue, fly ash, fumed slag, and desulfurized gypsum in a mass ratio of (45%–50%): (20%–25%): (20%–30%): (0%–10%) are mixed in a blender for 20–30 minutes. The raw material selection is optimized based on the mineral composition of the original soil so that the overall particle size distribution is close to the sand, silt, and clay ratio of natural loam (the recommended target is 60% ± 10% for sand, 30% ± 10% for silt, and 10% ± 5% for clay);

[0016] S2: sheep manure, straw and bran are mixed in a certain mass ratio of (40%–50%): (20%–30%): (20%–30%), and the C / N ratio is controlled at 20–25;

[0017] S3: mixing the mixture obtained in S2 with a certain amount of fungal and bacterial culture solution, and mixing for a certain period of time using a blender;

[0018] S4: Compounding the mixture obtained in S3 with S1, maintaining the temperature and pH at 55°C-65°C, and the pH at 6.0-6.5;

[0019] S5: mixing the mixture obtained in S4 with a certain amount of aluminum powder and calcium hydroxide, wherein the amount of aluminum powder and calcium hydroxide is 0.1%-0.4% and 0.1%-0.5% of the material respectively, and the moisture content is maintained at 30%-45%;

[0020] S6: Ferment the product of S5 for 20-30 days, and dry the product obtained at 50-60°C for 13-18 hours after the fermentation is completed, while screening a porous medium with a particle size range of 1-15 mm;

[0021] S7: Perform drilling on the surface of the dump of the open-pit coal mine, maintain a hole diameter of 7-9 cm and a depth of 5-8 cm, and the drilling density is 80 / m 2 -100 / m 2 , and then fill the product obtained in S6 into the holes according to an application amount of 50-100 g / hole;

[0022] S8: Compound the new sand-resistant plants switchgrass and apocynum venetum according to a ratio of 2:1-3:2;

[0023] S9: Seed the mixed seeds after the compounding in S8 into the holes in S7 at a seeding amount of 30-35 seeds / hole;

[0024] S10: Determine the porosity, water retention, soil water content, microbial amount, and plant biomass at regular intervals according to a monitoring period of 180-240 days, and evaluate the effectiveness and sustainability of the system on the structure improvement and ecological function recovery of the new soil body in the mining area.

[0025] The ratio of the coal gangue, fly ash, gasification slag, and desulfurization gypsum in S1 is preferably 47:20:25:8, and the mixing time is 20 minutes. The raw material selection is optimized in combination with the mineral composition of the original soil, so that the overall particle size distribution is close to the sand, powder, and clay ratio of natural soil (recommended target: sand particle 60%, powder particle 30%, clay particle 10%).

[0026] The mass ratio of the sheep manure, straw, and bran in S2 is preferably 45:25:30, and the C / N ratio is controlled to be 25, so as to provide C source and N source for subsequent microbial fermentation;

[0027] The fungi and bacteria in S3 include bacillus megaterium, white rot fungi, and EM bacterial agent. The preferred amount of bacillus megaterium is 0.3% of the organic material, the preferred amount of white rot fungi is 0.4% of the organic material, and the preferred amount of EM bacterial agent is 0.5% of the organic material. The stirring time is 60 minutes.

[0028] The preferred temperature and pH value in S4 are 55°C and 6.3, respectively;

[0029] The amounts of aluminum powder and calcium hydroxide in S5 are 0.2% and 0.2% of the material, respectively, and the moisture content is 45%;

[0030] The fermentation period in S6 is 27 days, the drying temperature is 50°C, the drying time is 16 hours, and the particle size range of the porous medium screening is 1-15mm;

[0031] The preferred pore diameter in S7 is 8cm, the preferred depth is 5cm, and the preferred density is 85 / m 2 , and the preferred application amount is 70g / hole;

[0032] The preferred ratio of switchgrass + agave in S8 is 3:2;

[0033] The preferred sowing amount of mixed seeds in S9 is 30 seeds / hole.

[0034] The monitoring period in S10 is 210 days.

[0035] (III) Beneficial effects

[0036] Compared with the prior art, the present application provides a coal-based solid waste artificial soil directional pore construction dump ecological restoration method, which has the following beneficial effects:

[0037] 1. Breakthrough in soil structure reconstruction bottleneck

[0038] Through the particle size grading coordination regulation and mineral component optimization of multi-source coal-based solid waste (coal gangue, fly ash, gasification slag, desulfurization gypsum) Figure 1-2 ), for the first time, the "macrostructure + microcomponent" double simulation of natural soil is realized: coal gangue (0.1-2mm) as the skeleton material, matching the natural sandy soil particle distribution (main peak 0.2-0.5mm), providing silicon aluminum-based mineral support (SiO2≈25%, Al2O3≈12.6%); gasification slag (0.05-0.5mm) and fly ash (<0.1mm) fill the pores, improve the compactness; desulfurization gypsum (<0.1mm) as a cementing agent to regulate the calcium-sulfur ratio (CaO≈3.3%, SO3≈4.5%). The obtained porous medium has both soil-like skeleton stability and nutrient preservation ability, significantly improving the structural compatibility with the mine soil (the particle size composition of the current coal-based solid waste artificial soil is 52% sand, 26% silt, and 22% clay; the mineral composition is SiO242%, Al2O3 26%, Fe2O3 14%, CaO+MgO 13%, SO3 3%).

[0039] 2. Directional construction of porous medium pores

[0040] The fusion of microbial network connection (EPS and hyphae) and chemical foaming pore formation (aluminum powder-calcium hydroxide reaction) breaks through the uncontrollable limitations of traditional pores. In terms of biological synergy, EPS and hyphae build a stable connection network between solid waste particles; in terms of chemical pore formation, aluminum water reacts under alkaline conditions to release H2, forming in-situ multi-level pores (10-1000μm); in terms of hydraulic control, the pore structure is directional induced by the water content (30%-45%). Figure 3 ), transforming from low-water-content, high-density micropores to high-water-content, uniform macropores, and ultimately increasing the porosity to 25%–30%, forming a “quasi-aggregate medium” that mimics the fractal structure of soil.

[0041] 3. Coupling repair system integration

[0042] A three-dimensional coupling system of "porous medium improvement + herbaceous cover + root system integration" was constructed to systematically improve the physical structure and ecological function of the newly constructed soil in the mining area, and the vegetation coverage increased by 5.8-7.4 times ( Figure 4 ) to achieve comprehensive restoration and sustainable reconstruction of the mining area ecosystem.

[0043] Based on soil-like structure simulation and porous media pore construction, this technology is deeply integrated with the ecological vegetation system. By introducing ecological restoration herbaceous plants (panicum virgatum and rhubarb), the three-dimensional cross-linking of the root systems of the two plants is utilized. Through the solid three-dimensional root structure, the nutrients and places required for life activities of microorganisms are provided, and a functional closed-loop ecological restoration platform is constructed. It has significant advantages such as strong sustainability, high systematicity, and wide adaptability, and can achieve sustainable improvement of the ecological functions of the newly constructed soil in the mining area in multiple dimensions. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a flow chart of the artificial soil preparation and repair process according to the present invention;

[0045] Figure 2 To invent a histogram of particle size gradation effects of multi-source solid waste;

[0046] Figure 3 This is a bar chart of the ratio of multi-source solid waste to minerals in the present invention;

[0047] Figure 4 This is a diagram of the directional pore structure of coal-based solid waste according to the present invention;

[0048] Figure 5 Aerial photos comparing the new structure soil in the mining area before and after improvement (left: before improvement, right: after improvement). DETAILED DESCRIPTION

[0049] Clearly and completely, the technical solutions in the patent embodiments of the present application will be described below in combination with the drawings in the patent embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the patent of the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the patent of the present application.

[0050] Embodiment 1:

[0051] S1: mix coal gangue, fly ash, gasification slag and desulfurization gypsum according to 45±0.5%:30±0.1%:20±0.1%:5±0.1%, and mix for 20±0.1 minutes using a stirrer;

[0052] S2: mix sheep manure, straw and bran according to 40±0.5%:30±0.1%:30±0.1%, and control C / N at 23±0.2;

[0053] S3: mix the mixture obtained in S2 with Bacillus megaterium, white rot fungus and EM bacterial agent culture solution, the dosage of Bacillus megaterium is 0.2% of the organic material, the dosage of white rot fungus is 0.5% of the organic material, and the dosage of EM bacterial agent is 0.4% of the organic material, and mix for 55±1 minutes using a stirrer;

[0054] S4: compound the mixture obtained in S3 with the mixture obtained in S1, and keep the temperature at 60±1℃ and the pH at 6.2±0.05;

[0055] S5: mix the mixture obtained in S4 with aluminum powder at a material weight ratio of 0.3±0.01% and calcium hydroxide at a material weight ratio of 0.2±0.01%, and control the moisture content of the mixture at 40±0.5%;

[0056] S6: ferment the product of S5 for 25±0.5 days, and after the fermentation is completed, dry the obtained product at 50±0.5℃ for 15±0.5 hours, and at the same time, screen the porous medium with a particle size ranging from 1mm to 15mm;

[0057] S7: punch holes on the surface of the open-pit coal mine dump, keep the hole diameter at 7cm and the depth at 6cm, and the punching density at 80 / m 2 , and then bury the product obtained in S6 in the holes at an application amount of 50g / hole;

[0058] S8: compound the new sand-resistant plant switchgrass+apocynum according to a ratio of 2:1;

[0059] S9: adopt a seeding amount of 30±1 seeds / hole, and seed in the holes in S7 in a hill-planting manner;

[0060] S10: According to a cycle of 180±2 days, the indicators of porosity, water retention, soil water content, microbial biomass, and plant biomass are monitored to evaluate the effectiveness and sustainability of the system in improving the structure of new construction soil in the mining area and restoring ecological functions.

[0061] The unit area improvement cost under this example is 3800 yuan / ha, and its main innovation is high water content (40%) and micropore dominance, which enhances water holding capacity and is suitable for moderately saline and alkaline mining areas.

[0062] Example 2:

[0063] S1: Mix coal gangue, fly ash, gasification slag, and desulfurization gypsum in the proportions of 47±0.5%:20±0.1%:25±0.1%:8±0.1%, and mix for 20±0.1 minutes using a mixer, as shown in Figure 2 The particle size composition of the current coal-based solid waste artificial soil is 52% sand, 26% silt, and 22% clay, as shown in Figure 3 The mineral composition of the current coal-based solid waste artificial soil is SiO242%, Al2O326%, Fe2O314%, CaO+MgO 13%, and SO3 3%, which is closest to soil in terms of particle size and mineral composition;

[0064] S2: Mix sheep manure, straw, and bran in the proportions of 45±0.5%:25±0.1%:30±0.1% and control the C / N ratio at 25±0.1;

[0065] S3: Mix the mixture obtained in S2 with Bacillus megaterium, white rot fungi, and EM bacterial culture solution. The dosage of Bacillus megaterium is 0.3% of the organic material, the dosage of white rot fungi is 0.4% of the organic material, and the dosage of EM bacterial agent is 0.5% of the organic material. Mix for 60±1 minutes using a mixer;

[0066] S4: Compound the mixture obtained in S3 with the mixture obtained in S1, and maintain the temperature at 55±1°C and the pH at 6.3±0.05;

[0067] S5: Mix the mixture obtained in S4 with 0.2±0.01% aluminum powder and 0.2±0.01% calcium hydroxide based on the weight of the material, and control the water content of the mixture at 45%±0.5;

[0068] S6: Ferment the product of S5 for 27±0.5 days, and then dry the obtained product at 50±0.5°C for 16±0.5 hours. Meanwhile, screen the porous medium with a particle size range of 1mm-15mm, as shown in Figure 4 As can be seen, the porosity of the final artificial soil increases from 12.6% to 29.3%;

[0069] S7: Drilling holes on the surface of the open-pit coal mine dump, maintaining a hole diameter of 8±0.1 cm and a depth of 5±0.1 cm, and a drilling density of 85±1 / m 2 , and then filling the product obtained in S6 into the holes at an application amount of 70±1 g / hole;

[0070] S8: Using a new type of sand-resistant plant, switchgrass + apocynum, in a ratio of 3:2 for compounding;

[0071] S9: Using a seeding amount of 30±1 seeds / hole, and sowing in the holes of S7 in a hill planting manner;

[0072] S10: Monitoring the indicators of porosity, water retention, soil moisture content, microbial biomass, and plant biomass at a period of 210±1 days, to evaluate the effectiveness and sustainability of the system in improving the structure of the new soil body and restoring the ecological function of the mining area.

[0073] The unit area improvement cost under this embodiment is 3200 yuan / ha, and the main innovation point is the optimization of calcium-sulfur ratio (8% desulfurization gypsum), large-pore dominance, and suitability for generally degraded mining areas.

[0074] Example 3:

[0075] S1: Mixing coal gangue, fly ash, gasification slag, and desulfurization gypsum at a ratio of 49±0.5%:21±0.1%:28±0.1%:2±0.1%, and mixing for 20±0.1 minutes using a mixer;

[0076] S2: Mixing sheep manure, straw, and bran at a ratio of 47±0.5%:23±0.1%:30±0.1%, and controlling the C / N ratio at 24±0.1;

[0077] S3: Mixing the mixture obtained in S2 with Bacillus megaterium, white rot fungus, and EM bacterial culture solution; the use amount of Bacillus megaterium is 0.2% of the organic material, the use amount of white rot fungus is 0.5% of the organic material, and the use amount of EM bacterial agent is 0.4% of the organic material, and mixing for 65±1 minutes using a mixer;

[0078] S4: Compounding the mixture obtained in S3 with the mixture obtained in S1, and maintaining the temperature at 60±1℃ and the pH at 6.5±0.05;

[0079] S5: Mixing the mixture obtained in S4 with aluminum powder at a material weight ratio of 0.3±0.01%, and with calcium hydroxide at a material weight ratio of 0.5±0.01%, and controlling the moisture content of the mixture at 43±0.5%;

[0080] S6: The product of S5 is subjected to fermentation for 30±0.5 days, and the resulting product is dried at 50±0.5°C for 18±0.5 hours after the fermentation is completed, while screening a porous medium with a particle size range of 1mm-15mm;

[0081] S7: Holes are punched on the surface of the dump of the open-pit coal mine, with a hole diameter of 9±0.1cm and a depth of 8±0.1cm, and a punching density of 80±1 / m 2 , and the product obtained in S6 is buried in the holes at an application amount of 100±1g / hole;

[0082] S8: A new sand-resistant plant, switchgrass, is compounded with hemp in a ratio of 2:1;

[0083] S9: The seeding amount is 30±1 seeds / hole, and the holes in S7 are seeded in a hill-planting manner;

[0084] S10: The indicators of porosity, water retention, soil moisture content, microbial biomass, and plant biomass are monitored at a period of 240±2 days, and the effectiveness and sustainability of the system in improving the structure of the new soil body in the mining area and restoring the ecological function are evaluated. Figure 5 It can be seen that the vegetation coverage increases significantly by 7.4 times under this embodiment.

[0085] The unit area improvement cost under this embodiment is 4100 yuan / ha, which is mainly due to the high skeleton content (49% of coal gangue), strong wind erosion resistance, and suitability for severe arid areas.

[0086] Example 4:

[0087] S1: The purchased soil is passed through a 1cm sieve to remove stones and impurities, and only natural soil is used without adding microorganisms and chemical foaming agents;

[0088] S2: Holes are punched on the surface of the dump of the open-pit coal mine, with a hole diameter of 9±0.1cm and a depth of 8±0.1cm, and a punching density of 80±1 / m 2 , and the sieved soil is buried in the holes at an application amount of 100±1g / hole;

[0089] S3: A new sand-resistant plant, switchgrass, is compounded with hemp in a ratio of 2:1;

[0090] S4: The seeding amount is 35±1 seeds / hole, and the holes in S2 are seeded in a hill-planting manner;

[0091] S5: The indicators of porosity, water retention, soil moisture content, microbial biomass, and plant biomass are monitored at a period of 240±2 days, and the effectiveness and sustainability of the system in improving the structure of the new soil body in the mining area and restoring the ecological function are evaluated.

[0092] Using natural soil for backfilling, construction of non-porous structure, and soil transportation cost is extremely high, and the unit area improvement cost is 8000-12000 yuan / hm2.

[0093] Compared with the traditional method, the present technology constructs the pore structure through the double mechanism of "microbial bonding + chemical foaming", and the pore structure is constructed directionally by adjusting the amount of water and foaming agent. The traditional method relies on natural accumulation, and the pores are randomly distributed, so the air guiding and water holding functions are unbalanced. In terms of ecological restoration efficiency, the coverage and biomass of the switchgrass + rubus suavissimus suter + shrub symbiotic system are much higher than those of the traditional single grass species. In terms of economy, the transportation cost of the traditional guest soil method is extremely high, the solid waste resourceization reduces the raw material cost, and the mine area can be used locally.

[0094] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application in any way. Those skilled in the art understand that the technical solution can be modified and replaced without departing from the spirit and principles of the present application, and these modifications and replacements will also fall within the protection scope defined by the claims.

Claims

1. A method for ecological restoration of a coal-based solid waste dump using directional pores in artificial soil, characterized by: The steps are as follows: S1: Gangue, fly ash, fumed slag, and desulfurized gypsum in a mass ratio of (45%–50%): (20%–25%): (20%–30%): (0%–10%) are mixed in a mixer for 20–30 minutes. The raw material selection is optimized based on the mineral composition of the original soil so that the overall particle size distribution is close to the sand, powder, and clay ratio of natural loam. S2: sheep manure, straw and bran are mixed in a certain mass ratio of (40%–50%): (20%–30%): (20%–30%), and the C / N ratio is controlled at 20–25; S3: mixing the mixture obtained in S2 with fungal and bacterial culture solutions, wherein the fungi and bacteria include Bacillus megaterium, white rot fungi, and EM microbial agent, and mixing for 50-80 minutes using a blender; S4: Compounding the mixture obtained in S3 with S1, while maintaining the temperature at 55°C-65°C and the pH value between 6.0-6.5; S5: The mixture obtained in S4 is mixed with 0.1%-0.4% of aluminum powder and 0.1%-0.5% of calcium hydroxide based on the material, while maintaining the moisture content; S6: fermenting the product of S5 for 20-30 days, drying the resulting product after the fermentation, and screening the porous media with a particle size range of 1-15 mm; S7: drilling holes on the surface of the open-pit coal mine dump, and then filling the holes with the product obtained in S6 at an application rate of 50g-100g / hole; S8: Use the new sand-resistant plant Panicum virgatum + Apocynum venetum in a ratio of 2:1 to 3:2; S9: Plant the mixed seeds prepared in S8 in the holes of S7 at a sowing rate of 30 to 35 seeds per hole. S10: Based on a monitoring cycle of 180-240 days, regularly measure porosity, water retention, soil moisture content, microbial biomass, and plant biomass to evaluate the effectiveness and sustainability of the system in improving the structure of the newly constructed soil and restoring its ecological functions in the mining area.

2. The method for ecological restoration of a spoil dump using directional pore construction of coal-based solid waste artificial soil according to claim 1, characterized in that: The overall particle size distribution in S1 is close to that of natural loam, with sand particles accounting for 60%±10%, silt particles accounting for 30%±10%, and clay particles accounting for 10%±5%.

3. The method for ecological restoration of a spoil dump using directional pore construction of coal-based solid waste artificial soil according to claim 1, characterized in that: In the S1, the coal gangue is classified into a particle size of 0.1-2 mm, the gasified slag is classified into a particle size of 0.05-0.5 mm, the fly ash is classified into a particle size of 10-30 μm, and the desulfurized gypsum is classified into a particle size of 40-60 μm.

4. The method for ecological restoration of a spoil dump using directional pore construction of coal-based solid waste artificial soil according to claim 1, characterized in that: The fungi and bacteria in S3 include Bacillus megaterium, white rot fungi and EM microbial agent. The dosage of Bacillus megaterium is 0.2%-0.5% of the organic material, the dosage of white rot fungi is 0.2%-0.6% of the organic material, and the dosage of EM microbial agent is 0.3%-0.6% of the organic material.

5. The method for ecological restoration of a spoil dump using directional pore construction of coal-based solid waste artificial soil according to claim 1, characterized in that: The moisture content in the S5 is maintained at 30%-45%.

6. The method for ecological restoration of a spoil dump according to claim 1, characterized in that: In the step S6, the drying temperature is 50° C. to 60° C., the drying time is 13 hours to 18 hours, and the porous medium with a particle size range of 1-15 mm is screened at the same time.

7. The method for ecological restoration of a spoil dump according to claim 1, characterized in that: The S7 has a pore diameter of 7cm-9cm, a depth of 5cm-8cm, and a punching density of 80 per m 2 -100 pieces / m 2 The application amount of porous medium is 50g-100g / hole.

8. The method for ecological restoration of a spoil dump according to claim 1, characterized in that: The mass compounding ratio of switchgrass and apocynum venetum seeds in S8 is 2:1 to 3:

2.

9. The method for ecological restoration of a spoil dump using directional pore construction of coal-based solid waste artificial soil according to claim 1, characterized in that: The timing in S10 is set to an interval of 30 days.

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