Spray slope greening method for mine vegetation recovery

Abstract

The invention relates to the technical field of ecological restoration, and discloses a spray slope greening method for mine vegetation restoration, which comprises the following steps: 1) screening and treating mine wastes including tailings and slag; 2) mixing tailings, slag and organic matters to obtain a spray seeding substrate; (3) adding a nano silicon dioxide-based water-retaining agent into the spray-seeding substrate; 4) adding a biodegradable adhesive into the spray seeding matrix, wherein the adhesive is prepared from chitosan and sodium alginate; (5) spray-seeding the mixed material on the slope surface by using spray-seeding equipment; and (6) after spray-seeding is completed, non-woven fabric is covered to protect the spray-seeding matrix, and watering and fertilization maintenance are conducted on the slope surface. The mining wasteland vegetation restoration efficiency and stability are improved, meanwhile, the method adapts to various extreme environment conditions, the construction cost is reduced, and sustainable ecological restoration is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of ecological restoration, in particular to a slope spraying greening method for mine vegetation restoration. Background Art

[0002] With the acceleration of global industrialization and the continuous advancement of mining development, a large number of abandoned mines have gradually formed. These abandoned lands are usually accompanied by severe destruction of vegetation, soil degradation and deterioration of the ecological environment, leading to soil erosion, frequent geological disasters, and loss of regional ecosystem functions. Traditional mine vegetation restoration methods usually rely on simple soil covering or seed sowing. Although they can restore vegetation to a certain extent, they often have problems such as poor results, high costs, low vegetation survival rate and long ecosystem recovery cycle.

[0003] In addition, the environmental conditions of abandoned mine sites are usually harsh, including drought, high temperature, low temperature, acidic soil, steep slopes, etc. These conditions further increase the difficulty of vegetation restoration. Traditional methods usually lack effective technical means when facing these extreme conditions, and it is difficult to ensure the survival and growth of plants, resulting in the failure of vegetation restoration or unsatisfactory results.

[0004] Based on this, there is an urgent need for a technical method that can effectively restore vegetation in abandoned mine sites under complex and extreme environmental conditions. This method should be high in efficiency, low in cost, environmentally friendly and highly adaptable, and be able to achieve rapid and stable vegetation restoration in different mining environments, thereby promoting the sustainable development of the regional ecological environment. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a slope spraying greening method for mine vegetation restoration, which solves the problems of low efficiency and poor stability of vegetation restoration in abandoned mine land under complex and extreme environmental conditions.

[0006] To achieve the above purpose, the present invention is implemented by the following technical scheme: a slope spraying greening method for mine vegetation restoration, comprising the following steps:

[0007] Screening and processing of mine waste, wherein the mine waste includes tailings and slag, the particle size of the tailings is controlled between 0.1 and 2 mm, and the particle size of the slag is controlled between 0.5 and 4 mm;

[0008] The tailings, slag and organic matter are mixed to obtain a spraying matrix, wherein the tailings account for 40-60% of the total matrix, the slag accounts for 20-40% of the total matrix, and the organic matter accounts for 10-20% of the total matrix;

[0009] Adding a nano-silicon dioxide-based water-retaining agent to the spraying matrix, wherein the amount of the water-retaining agent added is 0.1 to 0.5% of the total amount of the matrix;

[0010] Adding a biodegradable adhesive to the spraying matrix, wherein the adhesive is made of chitosan and sodium alginate, wherein the chitosan accounts for 40-60% of the total amount of the adhesive, and the sodium alginate accounts for 30-50% of the total amount of the adhesive;

[0011] Use spraying equipment to spray the above mixed materials onto the slope surface with a spraying thickness of 5 to 10 cm;

[0012] After the spraying is completed, cover the non-woven fabric to protect the spraying matrix, and then sprinkle water and fertilize the slope for maintenance.

[0013] Preferably, the organic matter is humus, compost or a combination thereof, the organic matter is fermented or decomposed, the fermentation time is 20 to 40 days, the fermentation temperature of the compost is 40 to 70°C, the particle size of the humus is 1 to 3 mm, and the particle size of the compost is 0.5 to 2 mm.

[0014] Preferably, microbial agents may be further added to the organic matter before mixing, and the addition ratio of the microbial agents is 1-5% of the total amount of the organic matter.

[0015] Preferably, the biodegradable adhesive is cross-linked by mixing chitosan and sodium alginate solution, and the steps of the cross-linking reaction include:

[0016] Dissolve chitosan in 1-3% dilute acetic acid solution, stir for 30-60 minutes, dissolve at 20-30°C to form a uniform chitosan solution;

[0017] Dissolve sodium alginate in warm water at 40-60°C and stir for 20-40 minutes to form a uniform sodium alginate solution;

[0018] Add the sodium alginate solution dropwise into the chitosan solution at a chitosan to sodium alginate mass ratio of 1:0.5-2, and continue stirring for 30-45 minutes to ensure uniform mixing;

[0019] Add calcium ion solution dropwise into the above mixture, the concentration of calcium ion solution is 0.5-2%, the addition amount is 1-3% of the total amount of the mixture, the reaction time is 15-30 minutes, and the cross-linking temperature is 10-25° C. to form a stable gel structure.

[0020] Preferably, after the cross-linking reaction, nano-silicon dioxide particles or plant fibers are added to the adhesive, wherein the amount of nano-silicon dioxide particles added is 0.1-1% of the total amount of the adhesive, and the amount of plant fibers added is 1-5% of the total amount of the adhesive.

[0021] Preferably, plant seeds are also added to the spraying matrix, and the plant seeds include native grass seeds, shrub seeds or fast-growing tree seeds.

[0022] Preferably, the plant seeds are subjected to germination treatment, including soaking, cold treatment, hormone treatment, stratification treatment and combinations thereof.

[0023] Preferably, the nonwoven fabric is covered immediately after the spraying is completed, and is fixed with steel nails or plastic fixing nails, with the spacing between the fixing points being 50 to 100 cm.

[0024] Preferably, the watering and curing step comprises:

[0025] After the spraying and non-woven covering are completed, the first watering should be carried out immediately, and the watering amount should be set to 2 to 5 liters per square meter;

[0026] In dry seasons or hot weather, increase the frequency of watering to once a day, with a watering amount of 3 to 6 liters per square meter each time to keep the substrate moist; in rainy seasons or high humidity environments, reduce the watering amount to 1 to 2 liters per square meter, or suspend watering according to substrate humidity requirements;

[0027] Watering is carried out by sprinkler irrigation, drip irrigation or infiltration irrigation.

[0028] Preferably, the fertilization and maintenance step comprises:

[0029] At the beginning of watering and maintenance, use quick-acting organic fertilizer for the first fertilization, with the amount of fertilizer being 50 to 100 grams per square meter;

[0030] 2 to 4 weeks after spraying, apply balanced compound fertilizer with NPK ratio of 1 to 2:1:1, and the amount of fertilizer per square meter is 30 to 60 grams;

[0031] Add long-term organic fertilizer or compound fertilizer 6-8 weeks after spraying, and adjust the fertilizer amount to 20-40 grams per square meter;

[0032] Choose to apply fertilizer by spraying, broadcasting or root drench.

[0033] The present invention provides a slope spraying greening method for mine vegetation restoration. It has the following beneficial effects:

[0034] 1. The present invention significantly improves the recovery efficiency of vegetation in abandoned mine land by combining the spraying matrix formed by mixing tailings, slag and organic matter with nano-silicon dioxide-based water-retaining agent and biodegradable adhesive. This matrix can not only provide the nutrients required by plants, but also maintain the stability of the matrix under various extreme environmental conditions, promoting the rapid recovery of vegetation.

[0035] 2. The present invention uses nano-silica-based water-retaining agents to enhance the water-retaining capacity of the substrate, so that it can still effectively retain moisture and reduce water evaporation under harsh conditions such as drought and cold. At the same time, the biodegradable adhesive improves the anti-scouring ability of the substrate, especially in rainy and steep mine slope environments, effectively preventing soil loss and ensuring the stable growth of vegetation.

[0036] 3. The slope spraying greening method of the present invention exhibits strong environmental adaptability through customized matrix formula and innovative material application. Whether in high temperature, low temperature, drought, rainstorm or acidic soil environment, the spraying matrix can maintain good physical and chemical properties to ensure the survival and growth of plants under different environmental conditions.

[0037] 4. The present invention significantly improves the germination rate and initial growth rate of seeds by combining soaking, cold treatment, hormone treatment and stratification treatment for plant seeds. This treatment method is particularly suitable for use under adverse conditions, ensuring that seeds can germinate smoothly and quickly form stable vegetation coverage during the mine vegetation restoration process.

[0038] 5. The spraying matrix and improved materials used in the present invention, such as nano-silicon dioxide and biodegradable adhesives, are environmentally friendly materials and will not cause secondary pollution to the environment. Compared with traditional methods, the present invention not only reduces construction costs, but also reduces damage to the environment, and helps to achieve sustainable development of ecological restoration. DETAILED DESCRIPTION

[0039] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] The present invention provides a slope spraying greening method for mine vegetation restoration, aiming to achieve effective restoration of the ecological environment after mining by rationally utilizing mine waste, adding an ameliorator and suitable plant seeds. The specific implementation of the present invention is described in detail below.

[0041] 1. Screening and treatment of mine waste

[0042] The spray slope greening matrix of the present invention is mainly composed of tailings and slag in mine waste. Tailings are usually the residues after ore mining, and the main components are silicate minerals such as quartz, feldspar, and mica. The particle size of the tailings is controlled between 0.1 and 2 mm, which is achieved through mechanical screening and crushing processes. Slag is a by-product from the smelting process, rich in calcium, silicon, aluminum and other components, and has high alkalinity and water retention. The particle size of the slag is controlled between 0.5 and 4 mm, and is properly crushed and screened.

[0043] In actual operation, tailings and slag are mixed in the following proportions: tailings account for 40-60% of the total matrix, and slag accounts for 20-40% of the total matrix. In order to further improve the fertility and microbial activity of the matrix, 10-20% of organic matter, such as humus or compost, is added. These organic matters are fermented or decomposed for 20-40 days at a temperature of 40-70°C, so that they have good nutrient supply capacity. The particle size of humus is controlled at 1-3mm, and the particle size of compost is controlled at 0.5-2mm.

[0044] In addition, before mixing with organic matter, 1 to 5% of microbial agents, such as nitrogen-fixing bacteria, phosphate-solubilizing bacteria, etc., can be further added to enhance the soil improvement performance of the matrix and promote the growth of plant roots.

[0045] 2. Modification of the seeding matrix

[0046] In order to improve the water retention capacity of the spraying matrix, a nano-silicon dioxide-based water-retaining agent is added to the matrix, and the amount of the water-retaining agent added is 0.1-0.5% of the total amount of the matrix. Nano-silicon dioxide particles can significantly improve the water retention capacity of the matrix due to their high specific surface area, and are particularly suitable for use in arid or semi-arid environments.

[0047] A biodegradable adhesive is also added to the matrix, and the adhesive is made of chitosan and sodium alginate. Chitosan is dissolved in a 1-3% dilute acetic acid solution, the stirring time is 30-60 minutes, and the dissolution temperature is 20-30°C. Sodium alginate is dissolved in warm water at 40-60°C, and the stirring time is 20-40 minutes. According to the mass ratio of chitosan to sodium alginate of 1:0.5-2, the sodium alginate solution is added dropwise to the chitosan solution, and stirring is continued for 30-45 minutes to ensure uniform mixing. Calcium ion solution (such as CaCl2) is added dropwise to the mixture, the concentration of the calcium ion solution is 0.5-2%, the addition amount is 1-3% of the total amount of the mixture, the reaction time is 15-30 minutes, and the cross-linking temperature is 10-25°C to form a stable gel structure.

[0048] To further enhance the mechanical strength and degradation performance of the adhesive, 0.1 to 1% of nano-silicon dioxide particles or 1 to 5% of plant fibers may be added after the cross-linking reaction.

[0049] 3. Selection and processing of plant seeds

[0050] Plant seeds are added to the spraying matrix, and the plant seeds include native grass seeds, shrub seeds or fast-growing tree seeds. In order to improve the germination rate of seeds and the recovery effect of vegetation, the seeds are subjected to germination treatment before use. Germination treatment includes soaking, cold treatment, hormone treatment, stratification treatment and a combination thereof.

[0051] The specific operations are as follows:

[0052] Soaking treatment: Soak the seeds in clean water at 20-30℃ for 12-24 hours to promote the seeds to absorb water and swell. For hard seeds, alternately soak them in hot and cold water for 24-48 hours.

[0053] Cold treatment and stratification treatment: Place the soaked seeds in a cold environment of 5-10℃ for 24-72 hours, then mix the seeds with moist sand in a ratio of 1:1-2 and carry out stratification treatment for 1-3 weeks to break the dormancy period of the seeds.

[0054] Hormone treatment: Soak the seeds in 50-100 ppm gibberellin solution or 100-200 ppm indoleacetic acid solution for 6-12 hours to promote seed germination and root development.

[0055] After the seeds have been germinated, they are dried naturally in a cool place and then mixed with the substrate in a mass ratio of 1:1 to 3 to ensure that the seeds are evenly distributed.

[0056] 4. Slope spraying construction

[0057] The prepared spraying matrix is ​​evenly sprayed onto the slope surface through the spraying equipment, and the spraying thickness is 5 to 10 cm. During construction, care should be taken to ensure uniform coverage of the matrix, especially in areas with large slopes, and the spraying angle and pressure should be appropriately adjusted.

[0058] After the spraying is completed, it is immediately covered with a layer of biodegradable non-woven fabric. The material of the non-woven fabric is natural fiber or biodegradable synthetic fiber, with a thickness of 0.2 to 1 mm and a density of 30 to 100 g / m 2 After the non-woven fabric is covered, it is fixed with steel nails or plastic fixing nails, and the spacing between the fixing points is 50 to 100 cm to ensure that the non-woven fabric will not shift or tear in wind and rain.

[0059] 5. Watering maintenance

[0060] After the spraying and non-woven covering are completed, the first watering should be carried out immediately, with a watering amount of 2 to 5 liters per square meter to ensure that the substrate reaches an appropriate wet state. In the subsequent maintenance process, the watering frequency should be adjusted according to the climatic conditions:

[0061] Dry season or hot weather: Increase the frequency of watering to once a day, with each watering amount of 3 to 6 liters per square meter to keep the substrate moist.

[0062] Rainy season or high humidity environment: reduce the amount of watering to 1-2 liters per square meter, or stop watering according to the substrate humidity.

[0063] The watering method is sprinkler irrigation, drip irrigation or seepage irrigation, with the principle of evenly covering the slope surface. Drip irrigation or seepage irrigation is preferred for steep slopes and areas with strong winds.

[0064] 6. Fertilization management

[0065] Fertilization management includes the following steps:

[0066] Initial fertilization: Use quick-acting organic fertilizer for the first fertilization in the initial stage of watering and maintenance. The fertilizer application rate is 50 to 100 grams per square meter to ensure that the fertilizer is quickly absorbed by the substrate.

[0067] Fertilization at the seedling stage: When the plants enter the seedling stage (2 to 4 weeks after spraying), apply a balanced compound fertilizer (NPK ratio of 1:1:1 or 2:1:1) at a rate of 30 to 60 grams per square meter to promote balanced growth of the plants.

[0068] Fertilization in the middle and late stages of plant growth (6 to 8 weeks after spraying), add long-acting organic fertilizer or compound fertilizer according to the growth of vegetation, and adjust the amount of fertilizer to 20 to 40 grams per square meter.

[0069] Fertilization can be done by spraying, broadcasting or root dredging. For steep slopes and areas with a high risk of soil erosion, root dredging or spraying is recommended to reduce fertilizer loss.

[0070] 7. Maintenance monitoring and environmental response

[0071] To ensure the effect of slope spraying, soil moisture sensors are installed during construction and maintenance to monitor the moisture content of the substrate in real time. The humidity should be kept between 40% and 60%. According to the sensor monitoring results, the sprinkler system is automatically adjusted to adapt to weather changes.

[0072] During hot weather, the substrate temperature can be lowered and water evaporation can be reduced by increasing the frequency of watering or adding evaporation inhibitors to the water. At the same time, before low temperatures or frost weather is expected, reduce the frequency of watering and cover the slope with straw or rice husks to prevent frost damage to plants.

[0073] In addition, in order to prevent and control pests and diseases, when pests and diseases are found, they are sprayed in combination with low-toxic biological pesticides or organic fertilizers to ensure the healthy growth of vegetation.

[0074] In order to better understand the present invention, the above method is described in detail below in conjunction with specific embodiments.

[0075] Example 1: Vegetation restoration in arid mining areas

[0076] Step 1: Screening and treatment of mine waste

[0077] Tailings and slag are used as the main matrix materials in abandoned mines in arid areas. The particle size of tailings is controlled between 0.1 and 1.5 mm, and the particle size of slag is controlled between 0.5 and 3 mm. Tailings account for 50% of the total matrix, and slag accounts for 30% of the total matrix. Humus that has been fermented for 40 days is added, and the particle size of humus is 1 to 2 mm, and the addition ratio is 20% of the total matrix.

[0078] Step 2: Modification of the seeding substrate

[0079] A nano-silica-based water-retaining agent was added to the matrix at 0.5% of the total matrix to improve the matrix's water-holding capacity in arid environments. The added biodegradable adhesive was made of chitosan (50% of the total) and sodium alginate (50% of the total), and 1% of nano-silica particles was added to the adhesive to enhance mechanical strength.

[0080] Step 3: Plant seed selection and processing

[0081] Select drought-tolerant native grass and shrub seeds, which are soaked and treated with hormones before use. The soaking time is 24 hours, and the hormone treatment uses a 50ppm gibberellin solution to soak for 12 hours.

[0082] Step 4: Slope spraying

[0083] The prepared spraying matrix is ​​evenly sprayed onto the slope surface through the spraying equipment, with a spraying thickness of 8 cm. After the spraying is completed, the biodegradable non-woven fabric is immediately covered and fixed with steel nails, with a fixed point spacing of 80 cm.

[0084] Step 5: Watering and fertilizing

[0085] After the spraying and non-woven covering are completed, the first watering is carried out immediately, with a watering amount of 3 liters per square meter. Then water once a day in the morning and evening, with each watering amount of 4 liters per square meter. In the early stage of watering maintenance, apply quick-acting organic fertilizer at a fertilizer amount of 60 grams per square meter. Two weeks later, apply compound fertilizer (NPK ratio of 2:1:1) at a fertilizer amount of 40 grams per square meter.

[0086] Example 2: Vegetation restoration in cold mining areas

[0087] Step 1: Screening and treatment of mine waste

[0088] In the mine wasteland in cold areas, tailings and slag are used as matrix materials. The particle size of tailings is controlled between 0.5 and 2 mm, and the particle size of slag is controlled between 1 and 4 mm. Tailings account for 45% of the total matrix, and slag accounts for 40% of the total matrix. Compost that has been fermented at low temperature for 30 days is added, and the particle size of the compost is 0.5 to 1.5 mm, and the addition ratio is 15% of the total matrix.

[0089] Step 2: Modification of the seeding substrate

[0090] 0.3% of nano-silica-based water-retaining agent was added to the matrix to improve water-retaining capacity in cold environments. The biodegradable adhesive was made of chitosan (60% of the total) and sodium alginate (40% of the total), and 2% of plant fiber was added to the adhesive to enhance degradation performance.

[0091] Step 3: Plant seed selection and processing

[0092] Choose cold-resistant shrub seeds and fast-growing tree species, and stratify the seeds before use. Mix the seeds with moist sand in a 1:1 ratio and stratify for 4 weeks.

[0093] Step 4: Slope spraying

[0094] The prepared spraying matrix is ​​evenly sprayed onto the slope surface through the spraying equipment, with a spraying thickness of 7 cm. After the spraying is completed, the biodegradable non-woven fabric is immediately covered and fixed with plastic fixing nails, with a fixed point spacing of 50 cm.

[0095] Step 5: Watering and fertilizing

[0096] After the spraying and non-woven covering are completed, the first watering is carried out immediately, with a watering amount of 5 liters per square meter. During the low temperature period in winter, the frequency of watering is reduced to 2 times a week. In terms of fertilization, quick-acting organic fertilizer is applied in the early stage, with a fertilizer amount of 80 grams per square meter. After four weeks, compound fertilizer (NPK ratio is 1:1:1) is applied, with a fertilizer amount of 50 grams per square meter.

[0097] Example 3: Vegetation restoration in rainy mining areas

[0098] Step 1: Screening and treatment of mine waste

[0099] In the mine wasteland in rainy areas, choose tailings and slag with larger particle size. The particle size of tailings is controlled between 1 and 2 mm, and the particle size of slag is controlled between 2 and 4 mm. Tailings account for 40% of the total matrix, and slag accounts for 40% of the total matrix. Add compost that has been fermented at high temperature for 20 days, the particle size of the compost is 0.5 to 2 mm, and the addition ratio is 20% of the total matrix.

[0100] Step 2: Modification of the seeding substrate

[0101] 0.2% of nano-silica-based water-retaining agent was added to the matrix to maintain moderate water-retaining capacity in rainy environments. The biodegradable adhesive was made of chitosan (55% of the total) and sodium alginate (45% of the total), and 1.5% of nano-silica particles were added to the adhesive to enhance structural stability.

[0102] Step 3: Plant seed selection and processing

[0103] Select native grass and shrub seeds with strong waterlogging resistance, and the seeds are cold treated and hormone treated before use. The cold treatment time is 48 hours, and the hormone treatment uses 100ppm gibberellin solution to soak for 8 hours.

[0104] Step 4: Slope spraying

[0105] The prepared spraying matrix is ​​evenly sprayed onto the slope surface through the spraying equipment, with a spraying thickness of 6 cm. After the spraying is completed, the biodegradable non-woven fabric is immediately covered and fixed with plastic fixing nails, with a fixed point spacing of 100 cm.

[0106] Step 5: Watering and fertilizing

[0107] After the spraying and non-woven covering are completed, the first watering is carried out immediately, with a watering rate of 2 liters per square meter. During the rainy season, the watering rate is reduced or suspended depending on the weather conditions. For the initial fertilization, use quick-acting organic fertilizers at a rate of 70 grams per square meter. After two weeks, apply compound fertilizers (NPK ratio of 1:1:1) at a rate of 40 grams per square meter.

[0108] Example 4: Vegetation restoration in high-altitude mining areas

[0109] Step 1: Screening and treatment of mine waste

[0110] Tailings and slag are used as the main matrix materials in abandoned mines in high altitude areas. The particle size of tailings is controlled between 0.5 and 1.5 mm, and the particle size of slag is controlled between 1 and 3 mm. Tailings account for 55% of the total matrix, and slag accounts for 30% of the total matrix. Humus that has been fermented for 30 days is added, and the particle size of humus is 1 to 2 mm, and the addition ratio is 15% of the total matrix.

[0111] Step 2: Modification of the seeding substrate

[0112] 0.4% of nano-silica-based water-retaining agent was added to the matrix to adapt to the dry environment of high altitude areas. The biodegradable adhesive was made of chitosan (60% of the total amount) and sodium alginate (40% of the total amount), and 3% of plant fiber was added to the adhesive to enhance the degradation performance.

[0113] Step 3: Plant seed selection and processing

[0114] Choose cold-resistant and drought-resistant native grass and shrub seeds, which are stratified and germinated before use. The germination time is 3 weeks.

[0115] Step 4: Slope spraying

[0116] The prepared spraying matrix is ​​evenly sprayed onto the slope surface through the spraying equipment, with a spraying thickness of 8 cm. After the spraying is completed, the biodegradable non-woven fabric is immediately covered and fixed with steel nails, with a fixed point spacing of 50 cm.

[0117] Step 5: Watering and fertilizing

[0118] After the spraying and non-woven covering are completed, the first watering is carried out immediately, with a watering amount of 4 liters per square meter. Then water once every two days, with each watering amount of 3 liters per square meter. In the early stage of watering maintenance, apply quick-acting organic fertilizer at a fertilizer amount of 50 grams per square meter. After three weeks, apply compound fertilizer (NPK ratio of 2:1:1) at a fertilizer amount of 30 grams per square meter.

[0119] Example 5: Vegetation restoration in acidic soil mining areas

[0120] Step 1: Screening and treatment of mine waste

[0121] Tailings and slag are used as the main matrix materials in the abandoned land of acidic soil mining areas. The particle size of tailings is controlled between 0.5 and 2 mm, and the particle size of slag is controlled between 1 and 4 mm. Tailings account for 50% of the total matrix, and slag accounts for 30% of the total matrix. Compost that has been fermented for 20 days is added, and the particle size of compost is 0.5 to 2 mm, and the addition ratio is 20% of the total matrix. In order to neutralize the acidic soil, additional lime is added, and the addition amount is 2% of the total matrix.

[0122] Step 2: Modification of the seeding substrate

[0123] 0.3% of nano-silica-based water-retaining agent was added to the matrix to ensure moisture retention in acidic environments. The biodegradable adhesive was made of chitosan (60% of the total) and sodium alginate (40% of the total), and 1% of nano-silica particles was added to the adhesive to enhance acid resistance.

[0124] Step 3: Plant seed selection and processing

[0125] Choose acid-resistant native grass and shrub seeds. The seeds should be treated with hormones before use and soaked in 100ppm indoleacetic acid solution for 8 hours.

[0126] Step 4: Slope spraying

[0127] The prepared spraying matrix is ​​evenly sprayed onto the slope surface through the spraying equipment, with a spraying thickness of 6 cm. After the spraying is completed, the biodegradable non-woven fabric is immediately covered and fixed with steel nails, with a fixed point spacing of 100 cm.

[0128] Step 5: Watering and fertilizing

[0129] After the spraying and non-woven covering are completed, the first watering is carried out immediately, with a watering amount of 3 liters per square meter. The watering frequency is then adjusted according to the pH value of the substrate, and water is applied once a day. At the beginning of the watering maintenance, alkaline quick-acting organic fertilizer is applied at a fertilizer amount of 60 grams per square meter. After two weeks, compound fertilizer (NPK ratio is 1:1:1) is applied at a fertilizer amount of 40 grams per square meter.

[0130] Test experiment 1: Plant growth experiment

[0131] Objective: To evaluate the germination rate, survival rate and growth rate of plants under different embodiments (drought, cold, rainy, high altitude, acidic soil conditions) and determine the effectiveness of each embodiment under different environmental conditions.

[0132] Experimental steps:

[0133] 1. Preparation of spraying substrate:

[0134] According to the conditions of each experimental group, the spraying matrix was prepared according to the recipe in Examples 1-5.

[0135] The prepared substrate is mixed with corresponding plant seeds according to the proportions in the examples.

[0136] 2. Experimental site preparation:

[0137] Abandoned mine sites representing different environmental conditions were selected for the experiments.

[0138] Experimental groups and control groups were arranged under each environmental condition (the control group adopted direct sowing).

[0139] 3. Slope spraying construction:

[0140] Use spraying equipment to evenly spray the mixed matrix on the slope of the experimental site with a spraying thickness of 7-10 cm.

[0141] After the spraying is completed, the biodegradable non-woven fabric is immediately covered and fixed according to the requirements of the embodiment.

[0142] 4. Watering and fertilization management:

[0143] According to the watering and fertilizing management methods in the embodiment, each experimental group was regularly maintained.

[0144] 5. Data Collection:

[0145] The germination rate, survival rate, plant height and vegetation coverage of plants were recorded at the 2nd, 4th, 8th and 12th week after spraying.

[0146] The experimental results are shown in Table 1:

[0147] Table 1 Plant growth experimental results under different environmental conditions

[0148]

[0149]

[0150] From the data in Table 1, we can draw the following conclusions:

[0151] 1. Significant improvement in plant germination rate and survival rate:

[0152] The embodiments of the present invention all showed high germination rate and survival rate under various extreme environmental conditions such as drought, cold, rainy, high altitude, acidic soil, etc. For example, under drought conditions, the germination rate reached 70% within 12 weeks and the survival rate reached 61%, which were significantly higher than the germination rate of 42% and the survival rate of 36% in the control group.

[0153] This improvement is mainly attributed to the nano-silica-based water-retaining agent and biodegradable adhesive used in the present invention. Nano-silica has an extremely high specific surface area and water absorption, which enables the matrix to retain sufficient moisture under extreme drought conditions to ensure the germination of plant seeds and the growth of seedlings. The biodegradable adhesive (a combination of chitosan and sodium alginate) not only improves the stability of the matrix and prevents soil erosion, but also provides a more favorable growth environment for plant roots.

[0154] 2. Optimization of plant growth rate:

[0155] The data show that the various embodiments of the present invention are superior to the control group in terms of plant growth rate. The plant height under rainy conditions reached 11.3 cm in 12 weeks, while the control group was only 7.0 cm. This shows that the method of the present invention can reduce the pressure of excessive water on the plant root system while ensuring water supply, thereby promoting the rapid growth of plants.

[0156] This is due to the specially designed spraying matrix formula of the present invention, in which an appropriate amount of slag and tailings are added, which provide rich minerals and improve the fertility of the soil. At the same time, by optimizing the fermentation process of organic matter (such as the precise control of fermentation time and temperature in the embodiment), the nutrient supply of the matrix is ​​more stable, which is suitable for supporting plant growth for a long time.

[0157] 3. Increase of vegetation coverage:

[0158] In all experimental groups, the vegetation coverage rate was significantly higher than that of the control group. For example, under acidic soil conditions, the vegetation coverage rate reached 54% after 12 weeks, which was 23 percentage points higher than the 31% of the control group. This shows that the slope spraying greening method of the present invention can more effectively restore the vegetation coverage of the mine wasteland and improve the ecological environment.

[0159] The realization of this effect mainly depends on the selection and pretreatment of plant seeds. The germination treatment used in the present invention (such as a combination of soaking, cold treatment, hormone treatment, and stratification treatment) significantly improves the germination rate and vitality of seeds, allowing more seeds to germinate and grow rapidly under harsh soil conditions.

[0160] 4. Extensive environmental adaptability:

[0161] The various embodiments of the present invention all show good adaptability under five different environmental conditions: drought, cold, rainy, high altitude, and acidic soil. This shows that the slope spraying greening method of the present invention has a high degree of environmental adaptability, and can flexibly adjust technical parameters and material ratios according to different mine ecological restoration needs to ensure the success rate of vegetation restoration.

[0162] It is particularly noteworthy that under high altitude and acidic soil conditions, the use of a specific combination of slag and tailings, combined with lime neutralization treatment, not only effectively improved the physical and chemical properties of the soil, but also significantly improved the growth rate and health level of plants. This further highlights the practicality and innovation of the invention in diverse environments.

[0163] Test experiment 2: Soil water retention capacity experiment

[0164] Purpose: To test the water retention capacity of the spraying substrate in different embodiments, especially in arid and rainy environments, and to evaluate the effectiveness of the water retaining agent and the water retention performance of the substrate.

[0165] Experimental steps:

[0166] 1. Matrix preparation:

[0167] According to the conditions of each experimental group, the spraying matrix was prepared according to the formula in Examples 1-5, and the water retention capacity was enhanced using a nano-silicon dioxide-based water-retaining agent.

[0168] The control group used a substrate with the same formulation but without the addition of water retaining agent.

[0169] 2. Experimental site preparation:

[0170] Different environmental conditions such as drought and rain were simulated in the laboratory, and experimental and control groups were set up.

[0171] Each set of experiments was carried out under the same temperature and humidity conditions to ensure the controllability of the experimental conditions and the reliability of the data.

[0172] 3. Water retention capacity test:

[0173] Initial moisture content determination: All substrates were soaked at the same time and fully absorbed water, then drained for 24 hours to allow the substrates to reach saturated moisture. The initial moisture content was measured using a soil moisture sensor.

[0174] Evaporation rate determination: An evaporation experiment was conducted at a constant ambient temperature (such as 25°C), and the water content of the substrate was measured at different time points (0 h, 24 h, 48 h, 72 h and 1 week later) to evaluate the water evaporation rate.

[0175] Rainfall simulation: For the rainy condition group, a continuous rainfall test was conducted using a simulated rainfall device to measure the water retention capacity and water discharge of the substrate.

[0176] 4. Data Collection:

[0177] The water content of each experimental group at different time points was recorded, and the water retention rate (percentage compared with the initial water content) was calculated.

[0178] The experimental results are shown in Table 2:

[0179] Table 2 Experimental results of substrate water retention capacity under different environmental conditions

[0180]

[0181] From the data in Table 2, we can draw the following conclusions:

[0182] 1. Significant improvement in water retention capacity:

[0183] The experimental results showed that in all experimental groups, the initial moisture content of the spraying matrix remained at 100%, and the moisture content after 24 hours, 48 ​​hours, 72 hours and 1 week was significantly higher than that of the control group. For example, under drought conditions, the moisture content after 24 hours was 84%, while the control group was only 72%. Similar trends were reflected in cold, rainy, high-altitude and acidic soil conditions. This phenomenon shows that nano-silica-based water-retaining agents can significantly enhance the water-retaining capacity of the matrix.

[0184] The present invention introduces nano-silicon dioxide-based water-retaining agents into the spraying matrix, effectively utilizing its extremely high specific surface area and water absorption, and forms a soil structure that can retain moisture for a long time. This structure can reduce the rapid evaporation of water under drought conditions and prevent excessive water loss in rainy environments, thereby ensuring that plants can obtain a stable water supply under various environmental conditions.

[0185] 2. Effective control of evaporation rate:

[0186] The data showed that the evaporation rate of the experimental group under drought conditions was significantly lower than that of the control group. After 72 hours, the moisture content of the drought experimental group remained at 63%, while the moisture content of the control group had dropped to 48%. This shows that the application of nano-silica-based water-retaining agents can significantly slow down the evaporation process of water, thereby prolonging the retention time of water in the matrix.

[0187] This effect is particularly evident under cold and high altitude conditions. The water content of the experimental group under cold conditions was still as high as 55% after one week, while the water content of the experimental group under high altitude conditions was 54% after one week, both significantly higher than the 37% of the control group. This shows that the present invention, by using nano-silica-based water-retaining agents, is not only suitable for arid environments, but can also effectively control water loss under low temperature conditions, ensuring the survival and growth of vegetation under harsh conditions.

[0188] 3. Water management in rainy environments:

[0189] Under rainy conditions, the water content of the experimental group after 72 hours was 67%, while the control group was only 48%. This shows that the nano-silica-based water retainer can not only play a role in water retention under drought conditions, but also help the substrate manage excess water under rainy conditions, keeping the water at a moderate level and avoiding damage to plant roots due to excessive moisture.

[0190] The experimental results in a rainy environment further verified the innovation of the present invention, that is, through the rational application of the water retaining agent, the substrate can still maintain a stable moisture content in an extremely humid environment, thereby providing a good environment for the root growth of the plant.

[0191] 4. Adaptability under different environmental conditions:

[0192] The data of each experimental group showed that the nano-silica-based water retaining agent exhibited excellent water retention performance under different environmental conditions. For example, under acidic soil conditions, the water content of the experimental group after one week was 53%, which was higher than 37% of the control group. This result shows that the water retaining agent of the present invention can not only adapt to extreme climate conditions such as drought, high altitude, and cold, but also maintain stable water management performance in special soil environments such as acidic soil.

[0193] In addition, the experimental data also showed that the water content of each experimental group after one week was more than 15% higher than that of the control group. This result further verified the high efficiency and wide applicability of the water retaining agent in the spraying matrix of the present invention, indicating that the present invention can provide strong support for vegetation restoration under different environmental conditions.

[0194] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for spraying slope greening for mine vegetation restoration, characterized in that: The following steps are involved: Screening and processing of mine waste, wherein the mine waste includes tailings and slag, the particle size of the tailings is controlled between 0.1 and 2 mm, and the particle size of the slag is controlled between 0.5 and 4 mm; The tailings, slag and organic matter are mixed to obtain a spraying matrix, wherein the tailings account for 40-60% of the total matrix, the slag accounts for 20-40% of the total matrix, and the organic matter accounts for 10-20% of the total matrix; Adding a nano-silicon dioxide-based water-retaining agent to the spraying matrix, wherein the amount of the water-retaining agent added is 0.1 to 0.5% of the total amount of the matrix; Adding a biodegradable adhesive to the spraying matrix, wherein the adhesive is made of chitosan and sodium alginate, wherein the chitosan accounts for 40-60% of the total amount of the adhesive, and the sodium alginate accounts for 30-50% of the total amount of the adhesive; Use spraying equipment to spray the above mixed materials onto the slope surface with a spraying thickness of 5 to 10 cm; After the spraying is completed, cover the non-woven fabric to protect the spraying matrix, and then sprinkle water and fertilize the slope for maintenance.

2. The method for spraying slope greening for mine vegetation restoration according to claim 1, characterized in that: The organic matter is humus, compost or a combination thereof. The organic matter is fermented or decomposed. The fermentation time is 20 to 40 days. The fermentation temperature of the compost is 40 to 70° C. The particle size of the humus is 1 to 3 mm, and the particle size of the compost is 0.5 to 2 mm.

3. The method for spraying slope greening for mine vegetation restoration according to claim 2, characterized in that: The organic matter may be further added with microbial agents before mixing, and the addition ratio of the microbial agents is 1-5% of the total amount of the organic matter.

4. The method for spraying slope greening for mine vegetation restoration according to claim 1, characterized in that: The biodegradable adhesive is cross-linked by mixing chitosan and sodium alginate solution, and the steps of the cross-linking reaction include: Dissolve chitosan in 1-3% dilute acetic acid solution, stir for 30-60 minutes, dissolve at 20-30°C to form a uniform chitosan solution; Dissolve sodium alginate in warm water at 40-60°C and stir for 20-40 minutes to form a uniform sodium alginate solution; Add the sodium alginate solution dropwise into the chitosan solution at a chitosan to sodium alginate mass ratio of 1:0.5-2, and continue stirring for 30-45 minutes to ensure uniform mixing; Add calcium ion solution dropwise into the above mixture, the concentration of calcium ion solution is 0.5-2%, the addition amount is 1-3% of the total amount of the mixture, the reaction time is 15-30 minutes, and the cross-linking temperature is 10-25° C. to form a stable gel structure.

5. The method for spraying slope greening for mine vegetation restoration according to claim 4, characterized in that: After the cross-linking reaction, nano silicon dioxide particles or plant fibers are added to the adhesive, wherein the amount of the nano silicon dioxide particles added is 0.1-1% of the total amount of the adhesive, and the amount of the plant fibers added is 1-5% of the total amount of the adhesive.

6. The method for spraying slope greening for mine vegetation restoration according to claim 1, characterized in that: Plant seeds are also added into the spraying matrix, and the plant seeds include native grass seeds, shrub seeds or fast-growing tree seeds.

7. The method for spraying slope greening for mine vegetation restoration according to claim 6, characterized in that: The plant seeds are subjected to germination treatments including soaking, cold treatment, hormone treatment, stratification treatment and combinations thereof.

8. The method for spraying slope greening for mine vegetation restoration according to claim 1, characterized in that: The nonwoven fabric is covered immediately after the spraying is completed and fixed with steel nails or plastic fixing nails, and the spacing between the fixing points is 50 to 100 cm.

9. The method for spraying slope greening for mine vegetation restoration according to claim 1, characterized in that: The watering curing step comprises: After the spraying and non-woven covering are completed, the first watering should be carried out immediately, and the watering amount should be set to 2 to 5 liters per square meter; In dry seasons or hot weather, increase the frequency of watering to once a day, with a watering amount of 3 to 6 liters per square meter each time to keep the substrate moist; in rainy seasons or high humidity environments, reduce the watering amount to 1 to 2 liters per square meter, or suspend watering according to substrate humidity requirements; Watering is carried out by sprinkler irrigation, drip irrigation or infiltration irrigation.

10. The method for spraying slope greening for mine vegetation restoration according to claim 1, characterized in that: The fertilization and maintenance steps include: At the beginning of watering and maintenance, use quick-acting organic fertilizer for the first fertilization, with the amount of fertilizer being 50 to 100 grams per square meter; 2 to 4 weeks after spraying, apply balanced compound fertilizer with NPK ratio of 1 to 2:1:1, and the amount of fertilizer per square meter is 30 to 60 grams; Add long-term organic fertilizer or compound fertilizer 6-8 weeks after spraying, and adjust the fertilizer amount to 20-40 grams per square meter; Choose to apply fertilizer by spraying, broadcasting or root drench.

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