Curing and greening method for acidizing high and steep slope

Abstract

The invention provides a curing and regreening method for acidifying a high and steep slope. The curing and regreening method comprises the following steps: preparing a first repairing material and a second repairing material; a fixing net is laid to cover the to-be-repaired position of the acidified high and steep slope, and a to-be-sprayed area is obtained; spraying a first repairing material to the to-be-sprayed area to form a first repairing layer; spraying a second repairing material on the first repairing layer to form a second repairing layer; non-woven fabric is laid on the second repairing layer, so that repairing is completed; the problems that in the prior art, when a traditional method is used for repairing the acidified high and steep slope, the vegetation coverage rate is low, and the maintenance cost is high are solved.

Description

Technical Field

[0001] The invention relates to the technical field of high-steep slope engineering greening, and in particular to a solidification and greening method for acidified high-steep slopes. Background Art

[0002] During the mining process of non-ferrous metal mines, especially when open-pit mining is used, a large number of steep slopes are often generated. The pH value of the steep slopes is less than 4.5, and the slope is between 45° and 75°. These slopes not only have complex geological conditions, but are also affected by acidic mine water seepage and heavy metal pollution, forming a special environment of acidified steep slopes. In this environment, the slopes have extremely low soil pH and high heavy metal content, making it difficult for natural vegetation to grow, which in turn leads to reduced slope stability, increased soil erosion, and even natural disasters such as landslides and collapses, posing a serious threat to the safe operation of mines, the surrounding ecological environment, and the safety of life and property of personnel.

[0003] At present, the industry has tried a variety of methods to repair acidified high and steep slopes in non-ferrous metal mines, including but not limited to spraying greening, vegetation bag greening, imported soil covering greening, and engineering reinforcement greening. However, these traditional methods have encountered a series of problems in practical application, as follows:

[0004] Spraying greening: Spraying a mixture of grass seeds, soil, fertilizer and water onto the slopes through a sprayer to achieve greening. However, on extremely acidic and exposed rock slopes, due to the lack of suitable soil and susceptibility to water damage, the effect is not good, the vegetation coverage is low, and it is difficult to maintain stability, and the subsequent maintenance cost is high.

[0005] Greening with plant bags: greening materials and seeds are placed in bags and fixed on the slopes for greening. However, this method is very expensive to implement on steep slopes, and due to the particularity of the slopes, the plant bags are prone to slipping, and the greening effect is unstable.

[0006] Covering and greening with imported soil: Covering the slope with imported soil to improve soil conditions and plant vegetation. This method is difficult to implement in areas with serious heavy metal pollution because the acquisition and transportation costs of imported soil are high and it is difficult to keep the soil stable on high and steep slopes.

[0007] Engineering reinforcement and greening: The slope is reinforced by engineering means such as anchor rods, hanging nets, concrete, etc., and then greening is carried out. Although it can effectively improve the stability of the slope, the engineering cost is high, the damage to the environment is great, and the greening layer is often thin, the vegetation has poor resistance to adversity, and is easy to degenerate. Summary of the invention

[0008] The main purpose of the present invention is to provide a method for solidifying and regreening acidified steep slopes to solve the problems of low vegetation coverage and high maintenance costs when repairing acidified steep slopes using traditional methods in the prior art.

[0009] In order to achieve the above object, according to one aspect of the present invention, a solidification and greening method for acidification of steep slopes is provided, the solidification and greening method comprising:

[0010] preparing a first repair material and a second repair material;

[0011] Lay fixed nets to cover the acidified high and steep slopes to be repaired and obtain the area to be sprayed;

[0012] Spraying a first repair material onto the area to be sprayed to form a first repair layer;

[0013] spraying a second repair material onto the first repair layer to form a second repair layer;

[0014] Laying nonwoven fabric on the second repair layer to complete the repair;

[0015] Among them, calculated by weight percentage, the first repair material includes 3% to 6% of a first solid waste-based curing agent, 12% to 16% of a first conditioner, 35% to 55% of water, 3% to 6% of a first covering and 22% to 35% of a first waste soil; calculated by weight percentage, the second repair material includes 3% to 6% of a second solid waste-based curing agent, 12% to 16% of a second conditioner, 35% to 55% of water, 2% to 5% of mixed seeds, 3% to 6% of a second covering, and 22% to 35% of a second waste soil; the first covering and the second covering are each independently selected from one or more of sawdust foam, rice husk foam, grass fiber, and mushroom residue.

[0016] Furthermore, the thickness of the first repair layer is 8 cm to 12 cm, and the thickness of the second repair layer is 3 cm to 4 cm.

[0017] Furthermore, after spraying the first repair material, the material is left to stand for 4 hours to 12 hours to form a first repair layer.

[0018] Furthermore, the first waste soil and the second waste soil are both acidified waste soil from metal mining areas with a particle size of ≤5 mm.

[0019] Furthermore, after the step of laying the fixed net, the solidification and greening method further comprises:

[0020] Anchor rods are inserted into the fixed net to enhance the connection strength between the fixed net and the location to be repaired;

[0021] Among them, the anchor rod group includes multiple slope anchor rods and multiple slope top anchor rods. The length of the multiple slope top anchor rods is 50cm~60cm, the distance between each adjacent two slope top anchor rods is 2.5m~3m, the insertion depth of the slope top anchor rod is 35cm~40cm, the length of the slope anchor rod is 35cm~40cm, the insertion depth of the slope anchor rod is 20cm~25cm, and the distance between each adjacent two slope anchor rods is 2.5m~3m.

[0022] Further, the first solid waste-based curing agent and the second solid waste-based curing agent each include, by weight: 3 to 5 parts of S95 grade slag and 4 to 6 parts of composite alkali;

[0023] The pH value of the composite alkali is 10-12, the particle size of the S95 grade slag is 400-600 meshes, and the 28-day activity index of the S95 grade slag is greater than or equal to 95%. The composite alkali includes 50% to 58.7% of calcium slaked lime and 41.3% to 50% of magnesium slaked lime.

[0024] Furthermore, the first conditioning agent and the second conditioning agent both include biochar, compound organic fertilizer, microbial fertilizer and polyacrylamide;

[0025] The biochar is a product obtained by hydrothermal carbonization of sludge with a moisture content of 80%, a moisture content of 30% to 35%, an organic matter content of 45% to 50%, and a pH of 7.3 to 7.5.

[0026] Among them, the weight ratio of biochar:compound organic fertilizer:microbial fertilizer:polyacrylamide=(0.5~2.5):(1.2~3.5):(1.0~2.5):(25~40).

[0027] Furthermore, in the step of spraying the first repair material and / or the second repair material to the area to be sprayed, the step of spraying the conditioning agent includes:

[0028] At 0.5kg / m 2 -2.5kgm 2 Spray biochar on the area to be sprayed and / or the first restoration layer at a spray rate of 1.2 kg / m 2 -3.5kg / m 2 Spray compound organic fertilizer on the area to be sprayed and / or the first repair layer at a spraying rate of 1.0kg / m 2 -2.5kg / m 2 Spray the microbial fertilizer to the area to be sprayed and / or the first repair layer at a spray rate of 25kg / m 2 -40kg / m 2 Spray polyacrylamide onto the area to be sprayed and / or the first repair layer with a spraying amount of.

[0029] Further, the mixed seeds include: tree seeds, shrub seeds, herb seeds;

[0030] Among them, the weight ratio of tree seeds: shrub seeds: herb seeds = (2-8): (10-20): (25-40).

[0031] In the step of further spraying the second repair material onto the first repair layer, the step of spraying the mixed seed comprises:

[0032] 2g / m 2 ~8g / m 2 Spray tree seeds on the first repair layer at a spray rate of 10g / m 2 ~20g / m 2 Spray the shrub seeds on the first repair layer at a rate of 25g / m 2 ~40g / m 2 Spray herb seeds onto the first repair layer at a spraying rate of;

[0033] Among them, the tree seeds are Robinia pseudoacacia seeds, and the herbaceous seeds are any one or more of white sedge, tall fescue, Croton rot, and wild chrysanthemum.

[0034] Furthermore, the amount of cover used is 1.5 kgm 2 ~3.0kgm 2 and / or,

[0035] The usage of non-woven fabric is 10k / m 2 ~20k / m 2 .

[0036] By applying the technical solution of the present invention, the first solid waste-based curing agent (3% to 6%) and the first conditioning agent (12% to 16%) in the first repair material can effectively solidify and improve acidified soil, enhance the stability of the surface soil, reduce the risk of soil erosion and slope sliding, and provide a solid foundation for subsequent vegetation growth.

[0037] After the first repair layer is formed, the sprayed second repair material (containing 2% to 5% mixed seeds) works together with the first abandoned soil (22% to 35%) and the second conditioner (12% to 16%) to further improve the soil structure and chemical properties, increase the soil pH value, reduce the activity of heavy metals, and create a suitable environment for the germination and growth of tree, shrub and grass seeds.

[0038] The mixed seeds in the second restoration material include seeds of trees, shrubs and herbaceous plants, which can form a plant cover layer in a short period of time. Usually the herbaceous plants begin to grow within 7-15 days, and the coverage can reach more than 60% after 1 month. After 3 months, a stable three-dimensional vegetation structure of trees, shrubs and grasses is formed, which greatly accelerates the ecological recovery of the slope.

[0039] By spraying different restoration materials in layers, a structure of soil consolidation layer and greening layer is formed from bottom to top, imitating the three-dimensional configuration of trees, shrubs and grasses in natural ecosystems. It not only increases the diversity of vegetation and improves the ecological carrying capacity of the slope, but also builds a more stable and lasting vegetation restoration model.

[0040] This solidification and greening method makes full use of the acidified waste soil and solid waste-based solidifiers in metal mining areas, realizes the resource utilization of industrial waste, reduces dependence on foreign soil, reduces restoration costs, and at the same time reduces secondary environmental pollution, reflecting the concept of green mine construction.

[0041] Compared with traditional engineering reinforcement and greening methods, the repair process of the present application is easy to operate and is achieved through net spraying, which reduces a large amount of manual and mechanical uphill operations, reduces construction difficulty and personnel safety risks, and greatly reduces material and construction costs, making slope repair work more economical and feasible; the non-woven fabric covering layer finally laid can effectively reduce the impact of rainwater erosion on newly formed vegetation, while maintaining soil moisture, promoting rapid germination and growth of seeds, and ensuring vegetation survival rate and coverage rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0043] Figure 1 A flow chart of a method for solidifying and regreening an acidified high and steep slope according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0044] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0045] During the mining process of non-ferrous metal mines, especially when open-pit mining is used, a large number of steep slopes are often generated. The pH value of the steep slopes is less than 4.5, and the slope is between 45° and 75°. These slopes not only have complex geological conditions, but are also affected by acidic mine water seepage and heavy metal pollution, forming a special environment of acidified steep slopes. In this environment, due to the extremely low soil pH value and high heavy metal content, it is difficult for natural vegetation to grow, which leads to reduced slope stability, increased soil erosion, and even natural disasters such as landslides and collapses, posing a serious threat to the safe operation of mines, the surrounding ecological environment, and the safety of life and property of personnel.

[0046] At present, the industry has tried a variety of methods to repair acidified high and steep slopes in non-ferrous metal mines, including but not limited to spraying greening, vegetation bag greening, imported soil covering greening, and engineering reinforcement greening. However, these traditional methods have encountered a series of problems in practical application, as follows:

[0047] Spraying greening: Spraying a mixture of grass seeds, soil, fertilizer and water onto the slopes through a sprayer to achieve greening. However, on extremely acidic and exposed rock slopes, due to the lack of suitable soil and susceptibility to water damage, the effect is not good, the vegetation coverage is low, and it is difficult to maintain stability, and the subsequent maintenance cost is high.

[0048] Greening with plant bags: greening materials and seeds are placed in bags and fixed on the slopes for greening. However, this method is very expensive to implement on steep slopes, and due to the particularity of the slopes, the plant bags are prone to slipping, and the greening effect is unstable.

[0049] Covering and greening with imported soil: Covering the slope with imported soil to improve soil conditions and plant vegetation. This method is difficult to implement in areas with serious heavy metal pollution because the acquisition and transportation costs of imported soil are high and it is difficult to keep the soil stable on high and steep slopes.

[0050] Engineering reinforcement and greening: The slope is reinforced by engineering means such as anchor rods, hanging nets, concrete, etc., and then greening is carried out. Although it can effectively improve the stability of the slope, the engineering cost is high, the damage to the environment is great, and the greening layer is often thin, the vegetation has poor resistance to adversity, and is easy to degenerate.

[0051] The main purpose of the present invention is to provide a method for solidifying and regreening acidified steep slopes to solve the problems of low vegetation coverage and high maintenance costs when repairing acidified steep slopes using traditional methods in the prior art.

[0052] The solidification and greening method for acidification of steep slopes provided in the present application comprises S1, preparing a first repair material and a second repair material;

[0053] S2. Laying a fixed net to cover the position of the acidified high and steep slope to be repaired and obtain the area to be sprayed;

[0054] S3, spraying the first repair material to the area to be sprayed to form a first repair layer;

[0055] S4, spraying a second repair material onto the first repair layer to form a second repair layer;

[0056] S5. Laying non-woven fabric on the second repair layer to complete the repair;

[0057] Among them, Figure 1As shown, the first repair material includes, by weight percentage, 3% to 6% of a first solid waste-based curing agent, 12% to 16% of a first conditioning agent, 35% to 55% of water, 3% to 6% of a first covering and 22% to 35% of a first waste soil; the second repair material includes, by weight percentage, 3% to 6% of a second solid waste-based curing agent, 12% to 16% of a second conditioning agent, 35% to 55% of water, 2% to 5% of mixed seeds, 3% to 6% of a second covering, and 22% to 35% of a second waste soil; the first covering and the second covering are each independently selected from one or more of sawdust foam, rice husk foam, grass fiber, and mushroom residue.

[0058] The first solid waste-based curing agent (3% to 6%) and the first conditioning agent (12% to 16%) in the first restoration material can effectively solidify and improve acidified soil, enhance the stability of the surface soil, reduce the risk of soil erosion and slope sliding, and provide a solid foundation for subsequent vegetation growth.

[0059] After the first repair layer is formed, the sprayed second repair material (containing 2% to 5% mixed seeds) works together with the first abandoned soil (22% to 35%) and the second conditioner (12% to 16%) to further improve the soil structure and chemical properties, increase the soil pH value, reduce the activity of heavy metals, and create a suitable environment for the germination and growth of tree, shrub and grass seeds.

[0060] The mixed seeds in the second restoration material include seeds of trees, shrubs and herbaceous plants, which can form a plant cover layer in a short period of time. Usually the herbaceous plants begin to grow within 7-15 days, and the coverage can reach more than 60% after 1 month. After 3 months, a stable three-dimensional vegetation structure of trees, shrubs and grasses is formed, which greatly accelerates the ecological recovery of the slope.

[0061] By spraying different restoration materials in layers, a structure of soil consolidation layer and greening layer is formed from bottom to top, imitating the three-dimensional configuration of trees, shrubs and grasses in natural ecosystems. It not only increases the diversity of vegetation and improves the ecological carrying capacity of the slope, but also builds a more stable and lasting vegetation restoration model.

[0062] This solidification and greening method makes full use of the acidified waste soil and solid waste-based solidifiers in metal mining areas, realizes the resource utilization of industrial waste, reduces dependence on foreign soil, reduces restoration costs, and at the same time reduces secondary environmental pollution, reflecting the concept of green mine construction.

[0063] Compared with traditional engineering reinforcement and greening methods, the repair process of the present application is easy to operate and is achieved through net spraying, which reduces a large amount of manual and mechanical uphill operations, reduces construction difficulty and personnel safety risks, and greatly reduces material and construction costs, making slope repair work more economical and feasible; the non-woven fabric covering layer finally laid can effectively reduce the impact of rainwater erosion on newly formed vegetation, while maintaining soil moisture, promoting rapid germination and growth of seeds, and ensuring vegetation survival rate and coverage rate.

[0064] In summary, the method for solidification and regreening of acidified steep slopes provided in this application not only solves the problems of high cost, unstable effect, and high risk of vegetation degradation in traditional solidification and regreening methods, but also has significant environmental and economic benefits. It is an efficient, economical, and environmentally friendly ecological restoration solution suitable for acidified steep slopes in metal mining areas.

[0065] Furthermore, the thickness of the first repair layer is 8 cm to 12 cm, and the thickness of the second repair layer is 3 cm to 4 cm.

[0066] The thickness of the first repair layer is designed to be 8cm to 12cm, which can ensure that the first solid waste-based curing agent and the first conditioning agent penetrate deeply into the acidified soil of the slope, effectively neutralize the acidity, passivate heavy metals, and improve the soil structure, thereby forming a solid soil layer. This not only enhances the overall stability of the slope, effectively prevents soil erosion on the slope, but also provides a stable matrix for subsequent vegetation growth.

[0067] The thickness of the second repair layer is designed to be 3cm to 4cm. This layer mainly contains mixed seeds, the second conditioner and the second covering material, which can provide an ideal microenvironment for seed germination and seedling growth. The moderate thickness is conducive to the contact between seeds and soil and promotes germination, but it will not affect the normal development of vegetation roots and their ability to penetrate the soil due to excessive thickness. At the same time, thin layer covering helps reduce water evaporation, maintain soil moisture, and promote rapid growth of vegetation.

[0068] Through layered design, the first repair layer focuses on soil improvement and slope stability. The use of thicker repair materials can achieve the desired effect in one go, reducing the need for repeated construction and effectively controlling costs. The second repair layer focuses on vegetation restoration. The thin layer of coverage not only ensures the rapid growth of vegetation, but also avoids material waste, further reducing repair costs and improving construction efficiency.

[0069] The mixed seeds of trees, shrubs and grasses contained in the second restoration layer can grow rapidly under the protection of the second restoration layer to form plant coverage. The layered design allows plants to take root in soils at different depths, promoting the three-dimensional growth of trees, shrubs and herbs, increasing the diversity of vegetation, and building a more stable and beautiful ecological landscape.

[0070] The first restoration layer deeply improves the soil, and the second restoration layer quickly regreens the soil. The combination of the two not only accelerates the ecological restoration process of the slope, but also enhances the slope's soil and water conservation, carbon sequestration and biodiversity protection functions.

[0071] Furthermore, after spraying the first repair material, the surface is left to stand for 4 hours to 12 hours, and then the second repair material is sprayed.

[0072] The setting of the standing time provides the necessary time window for the first solid waste-based solidifying agent to fully react with the acidic substances and heavy metals in the soil. During the standing period, the first solid waste-based solidifying agent can penetrate deeper into the soil, effectively neutralize the acidity, passivate the heavy metals, and improve the soil structure and properties, thereby creating a more suitable environment for seed germination and plant growth.

[0073] After the first repair layer is left to stand, it can form a relatively stable structure, which helps to improve the erosion resistance of the entire repair layer. Under the action of the first solid waste-based curing agent, the binding force between soil particles increases, reducing the damage to the repair layer caused by rainwater erosion, ensuring that the first repair material can better adhere to the slope, and providing a solid foundation for the subsequent second repair layer.

[0074] By standing still, the moisture in the first repair layer is gradually evenly distributed under the action of the first solid waste-based curing agent, which provides suitable humidity conditions for the germination of seeds in the second repair layer. At the same time, the soil structure improved by the curing agent is looser, which is conducive to the rooting of seeds and the growth of seedlings, and improves the success rate of vegetation establishment.

[0075] Furthermore, the first waste soil and the second waste soil are both acidified waste soil from metal mining areas with a particle size of ≤5 mm.

[0076] Acidified waste soil from metal mines with a particle size of ≤5mm has a high specific surface area, which can promote close contact between soil particles while maintaining sufficient porosity to facilitate water and air penetration. Such soil structure is not only conducive to the uniform distribution of curing agents and conditioners, but also provides a better growth environment for plant roots, enhances the soil's water holding capacity, and reduces water loss.

[0077] Smaller soil particles are conducive to the curing agent to react more quickly and deeply with the acidic substances and heavy metals in the soil, thereby more effectively neutralizing the acid, passivating the heavy metals, and increasing the pH value and biological activity of the soil. The curing agent is more tightly combined with small-sized soil particles, and the curing layer formed is more uniform, which improves the curing agent's use efficiency and the durability of the repair effect.

[0078] Soil particles with a size of ≤5mm can form a relatively stable matrix that is not easily blown away by the wind, nor too large to hinder the growth of plant roots. Using this soil in the first and second restoration layers provides an excellent physical environment for the germination of tree, shrub and grass seeds and the growth of seedlings. At the same time, the optimized soil structure is conducive to the absorption of nutrients and water retention, thereby accelerating the process of vegetation regreening.

[0079] By using the acidified waste soil at the metal mining site, there is no need for additional excavation or transportation of foreign soil, which greatly reduces the cost of restoration. At the same time, by screening out the part with a particle size of ≤5mm, the waste resources are reused, the secondary pollution to the environment is reduced, and the concept of green mine construction and resource recycling is reflected.

[0080] Furthermore, after the step of laying the fixed net, the solidification and greening method further comprises:

[0081] Anchor rods are inserted into the fixed net to enhance the connection strength between the fixed net and the location to be repaired;

[0082] Among them, the anchor rod group includes multiple slope anchor rods and multiple slope top anchor rods. The length of the multiple slope top anchor rods is 50cm~60cm, the distance between each adjacent two slope top anchor rods is 2.5m~3m, the insertion depth of the slope top anchor rod is 35cm~40cm, the length of the slope anchor rod is 35cm~40cm, the insertion depth of the slope anchor rod is 20cm~25cm, and the distance between each adjacent two slope anchor rods is 2.5m~3m.

[0083] The installation of anchor groups, especially the use of slope anchors and top anchors, significantly enhances the connection strength between the fixed net and the slope. The insertion depth (20cm-25cm) and length (35cm-40cm) of the slope anchors, as well as the insertion depth (35cm-40cm) and length (50cm-60cm) of the top anchors, together build a dense anchoring system that can effectively prevent the sliding of the fixed net and the peeling of the slope surface, significantly improving the anti-slip ability of the slope and reducing the risk of slope collapse and landslides.

[0084] The anchor rod group not only strengthens the connection between the fixed net and the slope, but also supports the solidification and regreening structure. This helps to maintain the long-term stability of the solidification layer and the vegetation layer on the slope, reduces structural damage caused by natural forces (such as wind, rain, etc.), and ensures the durability of the repair project and the long-term effect.

[0085] The presence of anchor rods provides a path and support points for the downward extension of vegetation roots, especially in slope conditions with loose soil structure or exposed rocks. With the guidance of anchor rods, the vegetation roots can take root more deeply inside the slope or in rock crevices, thereby enhancing the fixation ability of vegetation and improving the survival rate and growth of vegetation.

[0086] Under the joint action of the fixed net and the anchor group, the first repair material and the second repair material can be more evenly distributed on the slope, forming a solidified greening layer with moderate thickness and stable structure. This not only improves the conditions of acidified soil and neutralizes the over-acid pH value, but also passivates the heavy metals in the soil through the action of the curing agent and conditioner, reduces the toxicity to vegetation, and promotes the growth of healthy vegetation.

[0087] Further, the first solid waste-based curing agent and the second solid waste-based curing agent each include, by weight: 3 to 5 parts of S95 grade slag and 4 to 6 parts of composite alkali;

[0088] The pH value of the composite alkali is 10-12, the particle size of the S95 grade slag is 400-600 meshes, and the 28-day activity index of the S95 grade slag is greater than or equal to 95%. The composite alkali includes 50% to 58.7% of calcium slaked lime and 41.3% to 50% of magnesium slaked lime.

[0089] The high pH value (10-12) of the compound alkali reacts quickly with the acidic substances in the acidified waste soil, effectively neutralizing the soil acidity and raising the soil pH value to near neutral or slightly alkaline, creating a suitable pH environment for the germination and growth of tree, shrub and grass seeds. At the same time, the combined use of calcium slaked lime and magnesium slaked lime not only improves the neutralization effect, but also supplements the necessary calcium and magnesium elements in the soil, promotes the improvement of soil structure and plant nutrient absorption, and enhances soil fertility.

[0090] The fine particle size (400-600 mesh) of S95 grade slag combines with the second solid waste-based solidifying agent or the composite alkali in the first solid waste-based solidifying agent to form a fine solidification layer, which significantly enhances the bonding force between soil particles and improves the structural stability and anti-erosion ability of the slope soil. The solidified soil layer can effectively block rainwater erosion, reduce soil erosion on the slope, and protect the repair layer from damage.

[0091] Elements such as calcium and magnesium in the composite alkali form insoluble compounds with heavy metals in the soil, which effectively passivates the heavy metals in the soil, reduces the risk of heavy metal toxicity to the environment and organisms, and provides safety guarantees for the ecological restoration of slopes and the construction of green mines.

[0092] The reuse of S95 grade slag as industrial solid waste not only reduces the exploitation of natural resources and the material cost of the repair project, but also promotes the resource utilization of industrial waste, reflecting the concept of circular economy and green development. At the same time, the use of curing agent is controlled at 3% to 6% (based on the mass fraction of soil), which not only ensures the repair effect, but also avoids the waste of materials and cost increase caused by over-curing.

[0093] Furthermore, the first conditioning agent and the second conditioning agent both include biochar, compound organic fertilizer, microbial fertilizer and polyacrylamide;

[0094] The biochar is a product obtained by hydrothermal carbonization of sludge with a moisture content of 80%, a moisture content of 30% to 35%, an organic matter content of 45% to 50%, and a pH of 7.3 to 7.5.

[0095] Weight ratio of biochar:compound organic fertilizer:microbial fertilizer:polyacrylamide=(0.5~2.5):(1.2~3.5):(1.0~2.5):(25~40).

[0096] Furthermore, in the step of spraying the first repair material and / or the second repair material to the area to be sprayed, the step of spraying the conditioning agent includes:

[0097] At 0.5kg / m 2 -2.5kgm 2 Spray biochar on the area to be sprayed and / or the first restoration layer at a spray rate of 1.2 kg / m 2 -3.5kg / m 2 Spray compound organic fertilizer on the area to be sprayed and / or the first repair layer at a spraying rate of 1.0kg / m 2 -2.5kg / m 2 Spray the microbial fertilizer to the area to be sprayed and / or the first repair layer at a spray rate of 25kg / m 2 -40kg / m 2 Spray polyacrylamide onto the area to be sprayed and / or the first repair layer with a spraying amount of.

[0098] As the main component, biochar, with its high organic matter content (45% to 50%) and suitable pH value (7.3 to 7.5), helps to improve the acidic environment of the soil, provide rich organic matter and nutrients, promote soil microbial activity, and enhance soil fertility and structural stability. At the same time, biochar can effectively adsorb and passivate heavy metals, reduce the toxicity of heavy metals in the soil, and create a safe growth environment for vegetation.

[0099] The addition of polyacrylamide significantly enhances the soil's water retention and anti-scouring capabilities, prevents water from evaporating too quickly, keeps the soil moist, and is conducive to seed germination and plant growth. At the same time, it increases the bonding force between soil particles, builds a stable soil structure, effectively reduces the damage to the slope caused by rain erosion and weathering, and improves the long-term stability of the slope.

[0100] The use of compound organic fertilizer and microbial fertilizer supplements the essential nutrients in the soil, such as nitrogen, phosphorus, potassium and trace elements, and promotes the rapid growth and nutrient absorption of plants. Microbial fertilizer can also activate beneficial microorganisms in the soil, promote the reconstruction of the soil ecosystem, enhance the self-repair ability of the slope, and form a stable plant community structure.

[0101] Biochar is derived from the hydrothermal carbonization of sludge with a moisture content of 80%, which realizes the resource utilization of industrial solid waste, reduces secondary pollution to the environment, and reduces the procurement cost of repair materials. The use of compound organic fertilizer and microbial fertilizer also reflects the effective recycling of agricultural waste and biological resources, further optimizing the cost of repair.

[0102] Further, the mixed seeds include: tree seeds, shrub seeds, herb seeds;

[0103] Among them, the weight ratio of tree seeds: shrub seeds: herb seeds = (2-8): (10-20): (25-40).

[0104] The mixed planting of trees, shrubs and herbaceous plants can form a multi-layered vegetation coverage. Trees and shrubs are distributed in the upper and middle parts of the slope, while herbaceous plants are densely distributed in the lower part of the slope and the entire solidified green layer, constructing a three-dimensional biological protection structure, effectively preventing soil erosion and improving the slope's anti-erosion ability.

[0105] The high proportion of herbaceous plant seeds (25-40) accelerated the initial greening process of the slope. Herbs can germinate and grow rapidly within 7-15 days, providing early greening coverage for the slope. Shrub seeds (10-20) and tree seeds (2-8) gradually grew in the following months, forming a stable and ornamental vegetation community, greatly improving the speed and quality of ecological restoration.

[0106] The roots of trees and shrubs penetrate deep into the soil, which can effectively improve soil structure, increase soil stability, and prevent slope sliding and collapse. At the same time, the growth process of trees and shrubs can increase the content of soil organic matter, improve soil fertility, and provide a richer nutritional basis for subsequent plant growth.

[0107] The use of mixed seeds can introduce a variety of plant species, increase the biodiversity of the slope ecosystem, and help build a more complex and stable ecological community. This natural and semi-natural ecological configuration can attract more insects, birds and other organisms, thus forming a healthy ecosystem and enhancing ecological balance and self-recovery capabilities.

[0108] Further, in the step of spraying the second repair material onto the first repair layer, the step of spraying the mixed seeds includes:

[0109] 2g / m 2 ~8g / m 2 Spray tree seeds on the first repair layer at a spray rate of 10g / m 2 ~20g / m 2 Spray the shrub seeds on the first repair layer at a rate of 25g / m 2 ~40g / m 2 Spray herb seeds onto the first repair layer at a spraying rate of;

[0110] Among them, the tree seeds are Robinia pseudoacacia seeds, and the herbaceous seeds are any one or more of white sedge, tall fescue, Croton rot, and wild chrysanthemum.

[0111] Furthermore, the amount of cover used is 1.5 kgm 2 ~3.0kgm 2 and / or,

[0112] The usage of non-woven fabric is 10k / m 2 ~20k / m 2 .

[0113] By setting the spraying rate of tree seeds (such as acacia seeds) to 2g / m 2 ~8g / m 2 The spraying rate for shrub seeds is 10g / m 2 ~20g / m 2 The spraying rate of herbaceous seeds (such as white grass, tall fescue, Crotalaria, wild chrysanthemum, etc.) is 25g / m 2 ~40g / m 2 , a vegetation structure with a three-dimensional configuration of trees, shrubs and grasses from bottom to top was constructed. This configuration not only utilizes the growth characteristics of different plants, but also optimizes the spatial distribution of vegetation communities, promoting the three-dimensional greening of the slope and the overall improvement of its ecological functions.

[0114] Herbaceous plants (such as Crotalaria foetida and tall fescue) have a short growth cycle and require a large spraying volume (25g / m 2 ~40g / m 2 ), can quickly cover the slopes in the early stages of restoration, form a preliminary greening effect, accelerate the process of ecological restoration, and also provide a good shade condition and moisture retention environment for the growth of shrubs and trees.

[0115] Appropriate amount of spraying (10g / m 2 ~20g / m 2 ), forming a dense root network in the middle layer of the slope, enhancing the structural stability of the soil and reducing the impact of rainwater erosion and wind erosion on the slope. A small amount of tree seeds (such as Robinia pseudoacacia) spraying (2g / m 2 ~8g / m 2), a more stable biological protection barrier is built on the upper layer of the slope, further improving the overall anti-erosion ability of the slope.

[0116] In summary, by precisely controlling the spraying amount of tree seeds, shrub seeds and herbaceous seeds, the solidification and regreening method of the present application not only accelerates the three-dimensional greening process of the slope, improves the stability of the soil, and promotes the increase of biodiversity, but also achieves multiple goals such as cost optimization, visual beautification and environmental protection, and provides an efficient, economical, beautiful and environmentally friendly solution for the ecological restoration of acidified steep slopes in metal mining areas.

[0117] Example 1

[0118] A high and steep rock slope acidification test was conducted in a mining area in the south, with a total slope area of ​​500m 2 The overall height of the slope is relatively high, the slope exceeds 60°, the height of the rock slope exceeds 15m, the acidification degree is high, and the pH is 3.5. The management and treatment of this type of slope is particularly important. According to the soil properties of the slope area, blowing is carried out in batches, 5 to 6 times. For local areas with strong acidity, it is planned to blow 7 times to ensure that the acidic soil is fully improved.

[0119] The method for repairing the slope is as follows:

[0120] Slope cleaning: clean up debris (pumice, loose layers, plants, garbage) on acidified steep slopes, keep them basically flat, ensure the safety and stability of the slopes, and build intercepting drainage ditches;

[0121] Lay galvanized wire mesh (fixed mesh). The mesh is 18# galvanized wire mesh (chain link fence) with a mesh size of 5cm×5cm. When laying the mesh, extend the mesh 1m to the top of the slope, and insert anchor rods at intervals of 2.5m. After the top of the slope is fixed, lay the fixed mesh from top to bottom. There are many fixed nets, and the surroundings of the multiple fixed nets are parallelly overlapped with adjacent fixed nets, that is, after the first fixed net is fixed, the width of the overlap between the second fixed net and the first fixed net is greater than or equal to 10cm along the width direction of the slope, and the two adjacent fixed nets are tied tightly with wires. Along the extension direction of the slope, the width of the overlap between the second fixed net and the first fixed net is greater than or equal to 15cm. On the top of the slope, a slope top anchor rod is inserted every 2.5m to fix the fixed net on one side of the slope top, and on the slope surface, a slope surface anchor rod is inserted every 2.5m to fix the fixed net on the slope surface, wherein the slope top anchor rod and the slope surface anchor rod are both made of φ14mm threaded steel, the slope surface anchor rod is 35cm long, the slope surface anchor rod is driven into the slope body 20cm, and 15cm is exposed; the slope top anchor rod is 50cm long, the slope top anchor rod is driven into the slope body 35cm, and 15cm is exposed.

[0122] The metal mine acid waste soil is sieved through a 5mm sieve for later use. The amount used is 0.15m 3 / m 2 ;

[0123] Select a first solid waste-based curing agent composed of 4 parts of S95-grade slag powder and 6 parts of composite alkali, with the first solid waste-based curing agent having a mixing mass ratio of 6% (calculated by the mass fraction of the waste soil);

[0124] Put the prepared metal mine acidified waste soil and the first solid waste-based solidifying agent into the tank of the vehicle-mounted sprayer and add 55% water;

[0125] Add biochar and mix thoroughly. The amount of biochar used is 1.5 kg / m 2 , compound organic fertilizer is 2.5Kg / m 2 , microbial fertilizer 1.2g / m 2 , polyacrylamide is 35g / m 2 ;

[0126] Blowing and greening: Based on the slope netting, use the vehicle-mounted sprayer to blow and attach respectively, add water to the mixed substrate and spray it evenly from top to bottom on the slope, and try to ensure that the spray port is vertical to the slope;

[0127] First, spray the first repair material on the area to be repaired, with an average thickness of about 10 cm on the slope; then spray the second repair material, with an average thickness of about 4 cm on the slope. The two layers are cured and sprayed 5-7 times, with a total thickness of about 14 cm.

[0128] Among them, without affecting the stability of the slope, the trees are selected as Robinia seeds, the shrubs are selected as Rhus chinensis and Sophora japonica, and the herbs are selected as Bahia grass, Fescue arundinacea, Croton dahliae, and Chrysanthemum indica. The amount of spraying on the slope is: 2g / m2 of tree seeds 2 , shrub seeds 12g / m 2 , Herbal seeds 30g / m 2 ;

[0129] Finally, cover with non-woven fabric for maintenance. After all the above are completed, cover with non-woven fabric immediately to prevent compression of plant buds. Use 12g / m 2 Non-woven fabric. Be careful when covering, and use soil or wire to tie the edges tightly. The overlapping width between two adjacent non-woven fabrics is 10cm to prevent them from being blown away by the wind. At the same time, do a good job of maintenance for a period of time.

[0130] Mining area 500m 2 Half a year after the slope solidification and regreening experiment, the results showed that the slope vegetation coverage rate reached more than 90%, trees, shrubs and grasses were arranged in a three-dimensional manner and grew vigorously, the acidification and heavy metal pollutants in the slope soil were effectively controlled, and a satisfactory verification and restoration effect was achieved.

[0131] Example 2

[0132] The same points as in Example 1 are not described in detail, except that:

[0133] On the top of the slope, a slope top anchor rod is inserted every 3m, and on the slope surface, a slope surface anchor rod is inserted every 3m to fix the fixed net on the slope surface. The slope surface anchor rod is 40cm long, 25cm into the slope, and 15cm exposed; the slope top anchor rod is 60cm long, 40cm into the slope, and 10cm exposed;

[0134] The first solid waste-based curing agent is mixed at a mass ratio of 5% (calculated based on the mass fraction of the waste soil);

[0135] Put the prepared metal mine acidified waste soil and the first solid waste-based solidifying agent into the tank of the vehicle-mounted sprayer and add 50% water;

[0136] The amount of biochar used is 2.5Kg / m 2 , compound organic fertilizer is 3Kg / m 2 , microbial fertilizer 2.5g / m 2 , polyacrylamide is 40g / m 2 ;

[0137] Slope spraying amount: 4g / m2 of tree seeds 2 , shrub seeds 15g / m 2 , Herbal seeds 35g / m 2 .

[0138] Example 3

[0139] The same points as in Example 1 are not described in detail, except that:

[0140] The amount of biochar used is 1Kg / m 2 , compound organic fertilizer is 3.3Kg / m 2 , microbial fertilizer 2g / m 2 , polyacrylamide is 35g / m 2 ;

[0141] The amount of spraying on the slope is: 6g / m2 of tree seeds 2 , shrub seeds 18g / m 2 , Herbal seeds 30g / m 2 .

[0142] Table 1: Comparison with existing high and steep slope reinforcement and greening methods:

[0143]

[0144] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0145] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0146] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0147] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0148] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0149] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for solidification and greening of acidified high and steep slopes, characterized in that: The curing and greening method comprises: preparing a first repair material and a second repair material; Laying a fixed net to cover the position to be repaired of the acidified high and steep slope to obtain an area to be sprayed; Spraying the first repair material onto the area to be sprayed to form a first repair layer; spraying the second repair material onto the first repair layer to form a second repair layer; Laying non-woven fabric on the second repair layer to complete the repair; Among them, calculated by weight percentage, the first repair material includes 3% to 6% of a first solid waste-based curing agent, 12% to 16% of a first conditioner, 35% to 55% of water, 3% to 6% of a first covering and 22% to 35% of a first waste soil; calculated by weight percentage, the second repair material includes 3% to 6% of a second solid waste-based curing agent, 12% to 16% of a second conditioner, 35% to 55% of water, 2% to 5% of mixed seeds, 3% to 6% of a second covering, and 22% to 35% of a second waste soil; the first covering and the second covering are each independently selected from one or more of sawdust foam, rice husk foam, grass fiber, and mushroom residue.

2. The method for solidification and greening of acidified high and steep slopes according to claim 1, characterized in that: The thickness of the first repair layer is 8 cm to 12 cm, and the thickness of the second repair layer is 3 cm to 4 cm.

3. The method for solidification and greening of acidified high and steep slopes according to claim 1 or 2, characterized in that: After spraying the first repair material, let it stand for 4 hours to 12 hours, and then spray the second repair material.

4. The method for solidification and greening of acidified high and steep slopes according to claim 1, characterized in that: The first abandoned soil and the second abandoned soil are both acidified abandoned soil from metal mining areas with a particle size of ≤5 mm.

5. The method for solidification and greening of acidified high and steep slopes according to claim 1, characterized in that: After the step of laying the fixed net, the curing and greening method further comprises: Inserting an anchor rod group on the fixing net to enhance the connection strength between the fixing net and the position to be repaired; Among them, the anchor rod group includes multiple slope surface anchor rods and multiple slope top anchor rods, the lengths of the multiple slope top anchor rods are 50cm~60cm, the distance between each adjacent two slope top anchor rods is 2.5m~3m, the insertion depth of the slope top anchor rod is 35cm~40cm, the length of the slope surface anchor rod is 35cm~40cm, the insertion depth of the slope surface anchor rod is 20cm~25cm, and the distance between each adjacent two slope surface anchor rods is 2.5m~3m.

6. The method for solidification and greening of acidified high and steep slopes according to claim 1 or 2, characterized in that: In parts by weight, the first solid waste-based curing agent and the second solid waste-based curing agent both include: 3 to 5 parts of S95 grade slag and 4 to 6 parts of composite alkali; Among them, the pH value of the composite alkali is 10-12, the particle size of the S95 grade slag is 400-600 mesh, and the 28-day activity index of the S95 grade slag is greater than or equal to 95%, and the composite alkali includes 50% to 58.7% of calcium slaked lime and 41.3% to 50% of magnesium slaked lime.

7. The method for solidification and greening of acidified high and steep slopes according to claim 1 or 2, characterized in that: The first conditioning agent and the second conditioning agent both include biochar, compound organic fertilizer, microbial fertilizer and polyacrylamide; The biochar is a product obtained by hydrothermal carbonization of sludge with a moisture content of 80%, the moisture content of the biochar is 30% to 35%, the organic matter content is 45% to 50%, and the pH is 7.3 to 7.5; Weight ratio of the biochar: the composite organic fertilizer: the microbial fertilizer: polyacrylamide = (0.5-2.5): (1.2～3.5):(1.0～2.5):(25～40)。 8. The method for solidification and greening of acidified high and steep slopes according to claim 7, characterized in that: In the step of spraying the first repair material and / or the second repair material onto the area to be sprayed, the step of spraying the conditioning agent comprises: At 0.5kg / m 2 -2.5kgm 2 The biochar is sprayed on the area to be sprayed and / or the first repair layer at a spraying rate of 1.2 kg / m 2 -3.5kg / m 2 The composite organic fertilizer is sprayed on the area to be sprayed and / or the first repair layer at a spraying rate of 1.0 kg / m 2 -2.5kg / m 2 The microbial fertilizer is sprayed on the area to be sprayed and / or the first repair layer at a spraying rate of 25kg / m 2 -40kg / m 2 The polyacrylamide is sprayed onto the area to be sprayed and / or the first repair layer in a spraying amount.

9. The method for solidification and greening of acidified high and steep slopes according to claim 1, characterized in that: The mixed seeds include: Tree seeds, shrub seeds, herb seeds; Among them, the weight ratio of the tree seeds: the shrub seeds: the herb seeds = (2-8): (10-20): (25～40)。 10. The method for solidification and greening of acidified high and steep slopes according to claim 9, characterized in that: In the step of spraying the second repair material onto the first repair layer, the step of spraying the mixed seeds comprises: 2g / m 2 ~8g / m 2 The tree seeds are sprayed onto the first repair layer at a spraying rate of 10 g / m 2 ~20g / m 2 The shrub seeds are sprayed onto the first repair layer at a spray rate of 25 g / m 2 ~40g / m 2 spraying the herb seeds onto the first repair layer in a spraying amount of Wherein, the tree seeds are Robinia pseudoacacia seeds, and the herbaceous seeds are any one or more of Scutellaria baicalensis, Fescue arundinacea, Croton rotundus, and Chrysanthemum indica.

11. The method for solidification and greening of acidified high and steep slopes according to claim 1 or 2, characterized in that: The usage of the covering is 1.5 kgm 2 ~3.0kgm 2 and / or, The usage of the nonwoven fabric is 10k / m 2 ~20k / m 2 .

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