Greening planting soil prepared by utilizing solid wastes in non-metallic mine industry and preparation method of greening planting soil

Abstract

The invention belongs to the field of non-metallic mine industrial solid waste recycling, ecological restoration and garden gardening agricultural production, and particularly relates to greening planting soil prepared from non-metallic mine industrial solid waste and a preparation method of the greening planting soil. The method comprises the following steps: firstly, screening industrial solid waste meeting requirements as a raw material (base material), then sequentially carrying out color mixing, acid-base adjustment, texture adjustment and nutrient supplementation, supplementing water into the obtained base material subjected to nutrient adjustment, uniformly stirring and mixing, and then granulating; stacking and curing the obtained particles for 1-180 days in a ventilation environment, and performing inspection and acceptance to obtain the green planting soil. By adopting the method disclosed by the invention, the problem of solid waste treatment in the existing non-metal mine industry can be solved, and the required artificial soil can be obtained at the same time.

Description

Technical Field

[0001] This invention belongs to the field of resource utilization, ecological restoration, and horticultural agricultural production of non-metallic mineral industrial solid waste, specifically relating to a greening planting soil prepared from non-metallic mineral industrial solid waste and its preparation method. Background Technology

[0002] With the acceleration of industrialization, the amount of bulk industrial solid waste generated is increasing dramatically. Examples include sludge, tailings powder, and stone powder produced during non-metallic mineral mining; coal gangue from the coal industry; and fly ash from the power industry. The large-scale accumulation of these solid wastes not only occupies valuable land resources but also poses a serious threat to the ecological environment, such as polluting soil, water, and air. Currently, the main methods for treating solid waste from non-metallic mineral industries include building material production, mine backfilling, and tailings dam reclamation. In building material production, although some components of solid waste are used to replace clay, the proportion of solid waste used is decreasing due to overcapacity and stricter building material standards. Mine backfilling, while direct and effective, suffers from high filling costs and transportation difficulties. Tailings dams, by solidifying the tailings and improving the surrounding polluted soil, can absorb tailings, mitigate pollution risks, and promote vegetation restoration, but the relevant technologies still need further improvement.

[0003] In terms of soil utilization, while the current technological system has established a theoretical path for converting solid waste into soil, the main technological paradigm is limited to a single transformation path from solid waste properties to soil properties, and breakthroughs are urgently needed in improving the efficiency and universality of this path. Furthermore, existing artificial soil preparation technologies are insufficient to meet the requirements for greening and planting soil in terms of organic matter content, pH adjustment, nutrient ratio optimization, and heavy metal control, especially in meeting the technical requirements of the main control indicators in "Greening Planting Soil (CJ / T 340-2016)" and the "Soil Environmental Quality Standard for Agricultural Land Soil Pollution Risk Control (GB 15618-2018)". Therefore, developing a greening planting soil and its preparation method that can efficiently utilize non-metallic mineral industrial solid waste, has a short preparation cycle, low cost, and excellent performance is of significant practical importance. Summary of the Invention

[0004] The technical problem this invention aims to solve is to provide a greening planting soil prepared from non-metallic mineral industrial solid waste and its preparation method. This enables the large-scale disposal of non-metallic mineral industrial solid waste while simultaneously producing greening planting soil with properties close to natural soil, thereby turning waste into treasure.

[0005] To address the aforementioned technical problems, this invention provides a method for preparing greening planting soil using solid waste from non-metallic mineral industries, comprising the following steps: 1) Select industrial solid waste that meets the requirements as raw materials; 2) Pretreatment: When the particle size of the raw material is ≤5 mm, it can be used directly as the base material; When the particle size of the raw material is >5 mm, the raw material is crushed, ground, and sieved until the particle size is ≤5 mm to obtain the base material; 3) Color adjustment: Add 1-20% (preferably 1-10%) of fly ash by weight of the base material to the base material obtained in step 2) and stir evenly to change the color of the base material (to make its color darker and closer to the color of natural soil) to obtain the color-adjusted base material; 4) Acid-base adjustment: Divided into the following two methods: Method 1: Add 5-30% (preferably 10-15%) of desulfurized gypsum by weight of the color-adjusted base material to the base material after color adjustment, stir evenly, and let stand for 24-48 hours to obtain the acid-base adjusted base material; Note: The purpose of this step is to release Ca through dissolution. 2+ Directly with alkali-causing ions (CO3) 2- HCO 3- The reaction produces insoluble substances, which quickly fix the alkalinity, achieving "rapid and gentle alkali reduction"; Method 2: First, add 5-30% (preferably 20-30%) of desulfurized gypsum to the color-adjusted base material and stir evenly. Let it stand for 24-48 hours. Then, add 1-5% (preferably 3-5%) of sulfur to the color-adjusted base material and simultaneously inoculate with sulfur-oxidizing bacteria (to further neutralize the alkalinity). Stir evenly and let it stand naturally (in a rainproof and ventilated place) for 6-8 days to obtain the acid-base adjusted base material. Note: Method 2 is suitable for situations requiring long-term, deep alkali reduction; 5) Texture adjustment: Add 4-15% of the weight of the acid-base conditioned base material to the acid-base conditioned base material obtained in step 4) to obtain the texture conditioned base material. Note: The purpose of this step is to adjust the water retention and air permeability to make its texture meet the growth needs of specific plants / crops (i.e., to make its texture reasonable to meet the water retention and air permeability requirements of specific plants / crops). 6) Nutrient supplementation: Nutrients are added to the texture-adjusted base material obtained in step 5) to obtain nutrient-adjusted base material; Note: This step involves supplementing organic matter, macro- and micro-elements, etc., to meet the nutrient requirements of different planting scenarios. 7) Granulation: Add water to the nutrient-adjusted base material obtained in step 6), stir and mix well, and then granulate. 8) Maturation and Cultivation: The particulate matter obtained in step 7) is piled up and matured in a ventilated environment for 1 to 180 days (to make its properties more stable, generally 15 to 60 days).

[0006] Note: During the maturation process, the materials are turned over and the moisture content is controlled regularly to promote uniform maturation.

[0007] An improvement to the method of preparing greening planting soil from non-metallic mineral industrial solid waste of the present invention: In step 1): Industrial solid waste needs to meet the screening value requirements for agricultural land soil pollution risk; In step 3): fly ash needs to meet the screening value requirements for soil pollution risk in agricultural land.

[0008] This means it meets the requirements of the "Soil Environmental Quality Standard for Agricultural Land Soil Pollution Risk Control (GB 15618-2018)". This invention performs component analysis on the screened non-metallic mineral industrial solid waste to ensure safety and determine the ingredient ratio; in the above raw material screening process, non-metallic mineral solid waste that meets pollution standards, is inexpensive, or has treatment needs and potential profits is obtained as raw material.

[0009] As a further improvement to the method of preparing greening planting soil from non-metallic mineral industrial solid waste of the present invention: The non-metallic mineral industrial solid waste includes at least one of the following: washed sand mud, tailings slag / powder, and stone powder.

[0010] As a further improvement to the method of preparing greening planting soil from non-metallic mineral industrial solid waste of the present invention: In step 4) of method two, 100-200 mL of sulfur-oxidizing bacteria solution is inoculated per 100 kg of color-mixed base material, with a sulfur-oxidizing bacteria solution concentration of 10. 8 ~10 9 CFU / mL.

[0011] As a further improvement to the method of preparing greening planting soil from non-metallic mineral industrial solid waste of the present invention: In step 7), add water to control the moisture content to 10%~25%.

[0012] As a further improvement to the method of preparing greening planting soil from non-metallic mineral industrial solid waste of the present invention: In step 8), the pile is turned over once every 6 to 8 days, and the moisture content is adjusted and controlled to be 15% to 20% at the same time.

[0013] As a further improvement to the method of preparing greening planting soil from non-metallic mineral industrial solid waste of the present invention: The screening values ​​for pollution risk in agricultural land soil (pH>7.5) are as follows: cadmium ≤0.6 mg / kg, mercury ≤3.4 mg / kg, arsenic ≤25 mg / kg, lead ≤170 mg / kg, chromium ≤250 mg / kg, copper ≤100 mg / kg, nickel ≤190 mg / kg, and zinc ≤300 mg / kg.

[0014] As a further improvement to the method of preparing greening planting soil from non-metallic mineral industrial solid waste of the present invention, it also includes the following step 9). 9) Inspection and Acceptance: The soil obtained in step 8) is tested for physicochemical properties and ecological safety. Soil that passes the test is named greening planting soil. The physicochemical indicators to be tested include, but are not limited to, soil texture, organic matter content, pH value, salinity, soil infiltration rate, and cation exchange capacity.

[0015] The ecological safety testing includes the detection of harmful organisms such as pathogens and weed seeds in the soil, as well as heavy metals such as cadmium, chromium, lead, nickel, and mercury.

[0016] The present invention also provides greening planting soil prepared using any of the above methods.

[0017] The method of this invention can not only solve the existing problems of solid waste treatment and disposal in the non-metallic mineral industry, but also obtain the required artificial soil at the same time.

[0018] In this invention: Choose suitable plant varieties and set appropriate soil texture, pH and nutrient levels according to plant growth characteristics.

[0019] The present invention improves soil by reducing alkalinity, adjusting color, improving texture, and supplementing nutrients.

[0020] In actual use, this invention: According to the requirements of the garden landscape design, select suitable garden plants, lay green planting soil in the planting pit, and carry out plant transplanting and maintenance.

[0021] The terrain of the abandoned mining area is reshaped, greening soil is laid or mud is mixed with grass seeds, and then vegetation is restored. In conjunction with the construction of farmland irrigation facilities, the planting soil for greening is evenly spread on the farmland or added in a certain proportion to carry out soil fertilization and moisture retention treatment.

[0022] The physical and chemical properties of the infertile soil were tested. Based on the test results, the planting soil for greening was mixed with the infertile soil in a certain proportion, and subsequent soil improvement measures were carried out.

[0023] Based on the acidification level of the soil to be improved, the steps for reducing the alkalinity of the base soil are reduced according to the degree of acidification, so that the greening planting soil reaches the required alkalinity, and it is mixed with the acidified soil in a certain proportion, and then subsequent soil improvement measures are carried out.

[0024] The organic matter content of the greening planting soil obtained by this invention is 1-3%, and the pH value is 6.5-10.0, which meets the technical requirements of the main control indicators in "Greening Planting Soil (CJ / T 340-2016)". The soil heavy metal content meets the requirements of the agricultural land soil pollution risk screening value. The greening planting soil can be used for landscaping, fruit and vegetable, agricultural product, and Chinese medicinal herb planting, and can also be used for mine reclamation, high-standard farmland construction, basic farmland protection, barren soil remediation, or other plant planting. Compared with the prior art, the present invention has the following technical advantages: 1. Advantages of solid waste disposal: This invention enables large-scale disposal of solid waste from non-metallic mineral industries, providing an effective way to solve the problem of industrial solid waste accumulation. Compared with traditional treatment methods, it greatly improves the utilization efficiency of solid waste and reduces potential harm to the environment.

[0025] 2. Advantages in preparation cost and cycle time: The preparation cycle is relatively short, requiring as little as about one day, and the cost is low. Compared with existing complex artificial soil preparation technologies, it does not require high equipment investment and complex processes, reducing production costs and improving economic efficiency.

[0026] 3. Product performance advantages: The prepared greening planting soil has properties close to natural soil. Its organic matter content, pH value, nutrient ratio and heavy metal content all meet the relevant standards and requirements. It can meet the strict requirements of organic plant production for soil and provide a good growth environment for plants. Compared with artificial soil prepared by existing technologies, it is more conducive to the stable and healthy growth of plants.

[0027] In the process of inventing this invention, the following scheme design was carried out: Orthogonal experimental design: To design a 5-factor, 3-level orthogonal experimental design, L9(3) is required. 4 Orthogonal array (5 factors require either the "quasi-level method" or direct column expansion; here, we directly expand by 1 column, still using L9(3)). 4 (And add a new column corresponding to the 5th factor), the steps are as follows: Step 1: Identify the factors and levels, as shown in Table 1 below: Table 1

[0028] Step 2: Select an orthogonal array and assign factors Select L9(3) 4An orthogonal array (9 trials, 4 columns, 3 levels) is used. Four of the five factors are initially assigned to the four columns. The fifth factor (sulfur powder E) is assigned to an empty column or a new column is added (in practice, L9(3) is still used). 4 ), Column E is filled with 3 horizontal lines.

[0029] Allocation example (columns can be adjusted flexibly; here we select A → column 1, B → column 2, C → column 3, D → column 4, E → "Expanded Columns"): Step 3: Generate the test plan Based on the column-level correspondence of the orthogonal array, 9 groups of experiments were generated, each corresponding to a level combination of 5 factors, as shown in Table 2 below: Table 2

[0030] Core logic: The characteristics of orthogonal arrays are "balanced distribution and neat comparability": Each level of "1", "2", and "3" appears 3 times in each column to ensure that each level of each factor is tested fairly; Any combination of levels in any two columns (such as A1B1, A1B2, etc.) appears exactly once, which can eliminate the interaction interference between factors and cover the main information of 5 factors and 3 levels with the fewest trials (9 trials).

[0031] Subsequently, based on the test results of product performance, indicators, etc., "range analysis" or "variance analysis" can be used to determine the primary and secondary influences of each factor and the optimal combination of levels. Detailed Implementation

[0032] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto: According to the soil pollution risk screening values ​​of agricultural land in the "Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard (GB 15618-2018)", the heavy metal content must meet the following conditions: when pH>7.5, cadmium≤0.6 mg / kg, mercury≤3.4 mg / kg, arsenic≤25 mg / kg, lead≤170 mg / kg, chromium≤250 mg / kg, copper≤100 mg / kg, nickel≤190 mg / kg, and zinc≤300 mg / kg.

[0033] Example 1: Preparation of planting soil for landscaping, comprising the following steps: 1) Raw material selection: Solid waste washing mud from non-metallic mineral industry and fly ash from power industry (as backup coloring material) were collected. Based on the requirements of the agricultural land soil pollution risk screening value in the "Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard (GB 15618-2018)", the soil with cadmium, chromium, lead and other heavy metal content that meets the standards was screened out.

[0034] Note: Non-metallic mineral industrial solid waste washing mud refers to solid waste generated during the mining, crushing, screening, washing and purification of non-metallic minerals (such as quartz sand, feldspar, kaolin, talc, etc.), and belongs to general industrial solid waste.

[0035] 2) Pretreatment: Since the particle size of the non-metallic mineral industrial solid waste washing mud is ≤5 mm, the non-metallic mineral industrial solid waste washing mud that meets the screening conditions in step 1) is directly used as the base material. 3) Color adjustment: Add 5% of the fly ash obtained in step 1) that meets the screening conditions to the base material by mass, and stir evenly for 30 minutes to change the color of the base material from light gray to yellowish-brown close to natural soil, thereby improving the coordination of the garden greening landscape and obtaining the color-adjusted base material.

[0036] 4) Acid-base adjustment: After testing, the pH value of the base material after color adjustment was found to be 9.2 (alkaline). Desulfurized gypsum was added to the base material at 20% of its mass, and stirred evenly for 20 minutes. The calcium in the base material was then utilized. 2+ The alkali-causing ions in the desulfurized gypsum react with the alkali-causing ions to form insoluble substances such as calcium carbonate, achieving rapid alkali reduction. After standing for 24 hours, the pH value dropped to 7.8. Then, sulfur was added at 3% of the weight of the color-adjusted base material, and commercially available sulfur-oxidizing bacteria were inoculated simultaneously (100 mL of bacterial solution was inoculated per 100 kg of color-adjusted base material, with a bacterial concentration of 10). 8 (CFU / mL), and stirred continuously for 5 hours. After being naturally stacked for 7 days, the resulting material was named the acid-base adjusted base material.

[0037] After testing, the pH value of the substrate stabilized at approximately 6.5 to 7.0 after acid-base adjustment, meeting the neutral to slightly acidic environment requirements for the growth of garden plants such as roses and privet.

[0038] Sulfur-oxidizing bacteria can be obtained through conventional commercial means, such as Sulfobacillus thermosulfidooxidans (BMZ122295) from Ningbo Mingzhou Biotechnology Co., Ltd.

[0039] 5) Texture adjustment: Add matrix sand (particle size 0.2~2 mm) to the acid-base adjusted base material and mix evenly to obtain the texture-adjusted base material; the matrix sand accounts for 4% of the mass of the acid-base adjusted base material.

[0040] After texture adjustment, the base material was tested using the ring cutter method and found to have a soil water retention rate of 25% and a porosity of 40%, ensuring that the water retention and air permeability meet the needs of the roots of landscaping plants for respiration and water.

[0041] 6) Nutrient supplementation: According to the growth requirements of garden greening plants (roses, privets), add 15kg of decomposed sheep manure (to provide organic matter, or sheep manure can be used directly), 2kg of nitrogen, phosphorus and potassium compound fertilizer (NPK=15-15-15), and 0.5kg of chelated iron to each ton of texture-adjusted base material, stir well to supplement nutrients, and obtain nutrient-adjusted base material; 7) Granulation: A double-spiral mixing granulator is used to mix the nutrient-adjusted base material obtained in step 6) while spraying clean water (controlling the moisture content to 10%~25%) to produce granular material with a particle size of 3~8 mm, thus avoiding dust during transportation and laying.

[0042] 8) Maturation and Cultivation: The granular material obtained in step 7) is piled up in an open, ventilated area to mature, with a pile height of 1.5 m. The pile is turned over once a week, and the moisture content is adjusted and controlled at 15%~20% during the turning process. The maturation is carried out for 30 days to ensure stable properties.

[0043] 9) Inspection and Acceptance: Step 8) After maturation, the physicochemical indicators of the material were tested. The organic matter content was 2.2%, the pH value was 7.8, the salt content was 0.15%, and the soil infiltration rate was 1.2 mm / min, which met the main control indicators of "Green Planting Soil (CJ / T 340-2016)". The ecological safety test showed that no pathogens were detected, and the heavy metal content met the screening value of GB 15618-2018 standard, so it was judged to be qualified.

[0044] Application of the planting soil obtained in Experiment 1 and Example 1: 1) Site preparation: In urban park and green space areas, clear surface construction waste and weeds, level the land, and divide the area into tree planting areas, shrub planting areas, and lawn planting areas according to design requirements.

[0045] 2) Soil laying: In tree planting areas (such as camphor trees), dig planting pits 1.2 m in diameter and 0.8 m deep, lay 10 cm thick layers of decomposed straw at the bottom, and then fill the pits with prepared planting soil to 2 / 3 of their depth. In shrub planting areas (such as roses), dig planting trenches 0.5 m wide and 0.4 m deep, and fill them with planting soil. In lawn planting areas (such as tall fescue), spread planting soil evenly to a thickness of 15 cm.

[0046] 3) Plant Transplanting and Maintenance: Select robust camphor seedlings (5 cm in diameter at breast height), rose seedlings (30 cm in height), and tall fescue turf, and transplant / lay them in their respective areas. Water thoroughly after transplanting. Maintain regular watering (keeping soil moisture at 18%–22%) and apply conventional fertilizer (apply NPK compound fertilizer every 3 months at a rate of 50 g / m²). 2 After weeding, the survival rate of camphor trees reached over 95% after one year, the roses bloomed abundantly, and the tall fescue lawn coverage reached 98%.

[0047] Example 2: Preparation of planting soil for mine restoration 1) Raw material selection: The pollutant content of non-metallic mineral industrial solid waste washing sand (stone powder) and fly ash produced by coal-fired power plants was tested by a third-party testing agency to ensure that the content of heavy metals such as arsenic, mercury and lead met the requirements of the agricultural land soil pollution risk screening value in the "Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard (GB 15618-2018)".

[0048] 2) Pretreatment: Since the particle size of the non-metallic mineral industrial solid waste washing sand mud (stone powder) is ≤5 mm, the non-metallic mineral industrial solid waste washing sand mud (stone powder) that meets the screening conditions in step 1) is directly used as the base material.

[0049] 3) Color adjustment: Add 1% of the fly ash obtained in step 1) that meets the screening conditions to the base material, stir evenly for 5 minutes, so that the color of the base material changes from dark brown to brownish-brown that is close to natural soil, reducing the visual abruptness of the mining area, and obtain the color-adjusted base material.

[0050] 4) Acid-base adjustment: After testing, the pH value of the base material after color adjustment was 10.5 (strongly alkaline). First, desulfurized gypsum was added to the base material at 30% of its weight, stirred for 20 minutes, and allowed to stand for 48 hours. Afterward, the pH value was measured and found to have decreased to 8.2. Then, sulfur was added at 5% of the base material's weight, and simultaneously, purchased sulfur-oxidizing bacteria (inoculant content 10%) were inoculated. 9(Add 200 mL of CFU / mL for every 100 kg of color-adjusted base material), mix thoroughly for 5 h, and then ventilate and stack for 7 days. The resulting product is named the acid-base adjusted base material.

[0051] After testing, the pH value of the substrate stabilized at 7.2-7.8 after acid-base adjustment, which can meet the growth needs of commonly used plants in mine remediation such as alfalfa and sea buckthorn.

[0052] 5) Texture adjustment: Add matrix sand (particle size 0.5~3 mm) to the acid-base adjusted base material at 15% of the base material mass, mix evenly, and the texture-adjusted base material is obtained. After testing, the water retention rate of the base soil after texture adjustment was 15% and the porosity was 35%, which met the requirements of soil erosion resistance and aeration for plant root growth on mine slopes.

[0053] 6) Nutrient supplementation: To meet the needs of mine restoration plants for tolerance to poor soil and nitrogen fixation, 20 kg of rice straw, 1 kg of superphosphate, 0.3 kg of potassium sulfate, and 0.2 kg of borax were added to each ton of texture-adjusted substrate and thoroughly mixed to obtain the nutrient-adjusted substrate.

[0054] 7) Granulation: A roller mill granulator is used to add the base material after the texture has been adjusted, and water is sprayed while rolling (the moisture content is controlled at 12%-18%) to make granules with a diameter of 5-10 mm, which enhances the compressive strength of the granules and prevents collapse during slope paving.

[0055] 8) Maturation and Cultivation: The granular material obtained in step 7) is piled up in a well-ventilated area to mature, with a pile height of 2 m. It can be covered with a breathable shade net. The pile is turned over once every 5 days, and the moisture content is adjusted and controlled at 12%~18% during turning. The maturation period is 60 days. During this period, the pH value of the material can be tested.

[0056] 9) Inspection and Acceptance: Step 8) After maturation, the physicochemical indicators of the material were tested. The organic matter content was 1.8%, the pH value was 7.5, the salt content was 0.12%, and the soil infiltration rate was 0.9 mm / min, which met the CJ / T 340-2016 standard. The ecological safety test showed that the heavy metal content, pathogens, and weed seeds all met the standards and were deemed qualified.

[0057] Application of the planting soil obtained in Experiment 2 and Example 2 1) Mine terrain preparation: The abandoned slope of the mine (30° slope) was repaired, loose rocks and dangerous rocks were removed, and the slope was fixed with anchor bolts and wire mesh to prevent landslides. Horizontal planting strips 0.8 m wide and 0.5 m deep were excavated every 5 m on the slope, and a 5 cm thick layer of crushed stone was laid at the bottom (to enhance drainage).

[0058] 2) Soil laying: Fill the prepared greening planting soil into the horizontal planting strip to a thickness of 0.4 m. At the same time, use a hydroseeding machine to spread the greening planting soil (mixed with grass seeds: alfalfa and sea buckthorn seeds, seed rate 20 g / m²) in other areas of the slope. 2 Spraying coverage, with a spraying thickness of 5-8 cm.

[0059] 3) Vegetation restoration and monitoring: After hydroseeding, non-woven fabric was used to cover the soil to retain moisture, and watering was carried out regularly (a drip irrigation system was used on the slopes to maintain a soil moisture content of 15%-20%). One month later, the alfalfa germination rate reached 85%, and three months later, the sea buckthorn seedlings were about 20 cm tall. Six months later, the soil organic matter content was 1.6%, the soil erosion on the slopes was reduced by 90% compared with before restoration, and the vegetation coverage rate reached 80%, achieving the initial goal of mine ecological restoration.

[0060] Example 3: Preparation of planting soil for high-standard farmland construction: 1) Raw material selection: When collecting non-metallic mineral tailings and power plant fly ash, the content of heavy metals (cadmium, chromium, lead, etc.) must meet the requirements of the agricultural land soil pollution risk screening value in the "Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard (GB 15618-2018)".

[0061] 2) Pretreatment: Since the particle size of non-metallic mineral tailings is ≤5 mm, non-metallic mineral tailings that meet the screening conditions in step 1) are directly used as base material. 3) Color adjustment: Add 10% of the fly ash obtained in step 1) that meets the screening conditions to the base material, stir for 25 minutes to make the base material color light yellow, close to the natural soil color of farmland, and reduce the impact on crop photosynthesis, to obtain the color-adjusted base material.

[0062] 4) Acid-base adjustment: After testing, the pH value of the color-adjusted base material was found to be 8.8 (weakly alkaline). Desulfurized gypsum was added to the color-adjusted base material at 10% of its mass, stirred for 1 hour, and allowed to stand for 24 hours. The pH value then dropped to 7.5. The resulting material was named the acid-base adjusted base material.

[0063] Because high-standard farmland requires neutral soil for growing wheat and corn, there is no need to add sulfur, and the pH value meets the needs of crop growth.

[0064] 5) Texture adjustment: Add matrix sand (particle size 0.1~1mm) to the acid-base adjusted base material at 6% of the base material mass, mix evenly, and the texture-adjusted base material is obtained. After testing, the soil moisture retention rate of the substrate after texture adjustment was 30% and the porosity was 45%, which meets the requirements of wheat and corn for soil water retention, fertilizer retention and air permeability.

[0065] 6) Nutrient supplementation: Based on the nutrient requirements of wheat and corn during their growth cycles, add 25 kg of well-rotted cow manure (organic matter content ≥30%), 3 kg of urea, 2 kg of diammonium phosphate, 1 kg of potassium chloride, and 0.1 kg of zinc sulfate (to prevent zinc deficiency in wheat) to each ton of texture-adjusted substrate. Mix thoroughly to ensure nutrient balance. This yields the nutrient-adjusted substrate.

[0066] 7) Granulation: A disc granulator is selected. The nutrient-adjusted base material is added to the disc, the disc is tilted at 30°, and water is sprayed while rotating (the moisture content is controlled at 18%~22%) to produce granules with a diameter of 2~5 mm, which is convenient for mechanized laying and subsequent cultivation.

[0067] 8) Maturation and Cultivation: The granular material obtained in step 7) is ventilated and piled up to a height of 1.2 m. The pile is turned over once every 10 days, and the moisture content is adjusted and controlled to be 10%~15% while turning the pile. The material is matured for 15 days (due to the tight planting cycle in farmland, the maturity time is shortened, and the material properties are tested to ensure stability during the period).

[0068] 9) Inspection and Acceptance: Step 8) After maturation, the physicochemical indicators of the material were tested. The organic matter content was 2.5%, the pH value was 7.2, the salt content was 0.10%, and the cation exchange capacity was 15 cmol / kg, which met the requirements of CJ / T 340-2016 and high-standard farmland soil quality. The ecological safety test showed that the heavy metals, pathogens, and weed seeds all met the standards and were deemed qualified.

[0069] Application of the planting soil obtained in Experiment 3 and Example 3: 1) Farmland irrigation facilities: Irrigation and drainage channels were built in high-standard farmland areas, and drip irrigation systems were installed to ensure uniform irrigation and smooth drainage. At the same time, the land was leveled and divided into plots (each plot is 1 mu in area, 50 m long and 13.3 m wide).

[0070] 2) Soil laying and fertilization: The prepared planting soil is evenly spread on the farmland to a thickness of 20cm, and then tilled to a depth of 25cm using a rotary tiller to fully mix the planting soil with the original soil layer. After spreading, 50 kg of decomposed straw is spread per acre, and the soil is tilled again to improve the soil organic matter content and aggregate structure.

[0071] 3) Crop planting and management: Wheat is planted in autumn at a seeding rate of 15 kg / mu, using a seeder for row sowing with a row spacing of 20 cm. During the growing season, irrigation is provided through a drip irrigation system (with key irrigation during the jointing and grain-filling stages). Nitrogen fertilizer is applied according to the wheat's growth stages (10 kg / mu of urea during the greening stage). The following summer, the wheat is harvested, yielding 550 kg / mu. Subsequently, corn is planted at a seeding rate of 2 kg / mu. With proper fertilization and pest and disease control during the growing season, the autumn corn yield reaches 600 kg / mu, achieving the high-yield target for high-standard farmland.

[0072] Comparative Example 1, relative to Example 1: While keeping the dosage unchanged, desulfurized gypsum, sulfur, and sulfur-oxidizing bacteria were added together and stirred for 5 hours. The rest was the same as in Example 1.

[0073] In Comparative Experiment 1, the greening planting soil obtained from Comparative Example 1 was applied as described in Experiment 1. The results showed that after one year, the survival rate of camphor trees was approximately 82%, and the coverage rate of tall fescue lawn was less than 90%.

[0074] Comparative Example 2, relative to Example 1: The amount of sulfur used was changed from 3% as described in Example 1 to 5%, while the rest remained the same as in Example 1.

[0075] In comparative experiment 2, the greening planting soil obtained from comparative example 2 was applied as described in experiment 1. The results showed that after 1 year, the survival rate of camphor trees was about 80%, and the coverage rate of tall fescue lawn reached about 85%.

[0076] Comparative Example 3, relative to Example 1: The method was changed to first adjust the acid and base, then adjust the color, and the rest was the same as in Example 1.

[0077] In comparative experiment 3, the greening planting soil obtained from comparative example 3 was applied as described in experiment 1. The results showed that after 1 year, the survival rate of camphor trees was about 87%, and the coverage rate of tall fescue lawn reached about 92%.

[0078] Finally, it should be noted that the above examples are merely some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing greening planting soil using non-metallic mineral industrial solid waste, characterized in that... Includes the following steps: 1) Select industrial solid waste that meets the requirements as raw materials; 2) Pretreatment: When the particle size of the raw material is ≤5 mm, it can be used directly as the base material; When the particle size of the raw material is >5 mm, the raw material is crushed, ground, and sieved until the particle size is ≤5 mm to obtain the base material; 3) Color adjustment: Add 1-20% fly ash by weight of the base material to the base material obtained in step 2) and stir evenly to change the color of the base material, thus obtaining the color-adjusted base material; 4) Acid-base adjustment: Divided into the following two methods: Method 1: Add 5-30% by weight of desulfurized gypsum to the color-adjusted base material, stir evenly, and let stand for 24-48 hours to obtain the acid-base adjusted base material. Method 2: First, add 5-30% of desulfurized gypsum by weight of the color-adjusted base material and stir evenly. Let it stand for 24-48 hours. Then, add 1-5% of sulfur by weight of the color-adjusted base material and simultaneously inoculate with sulfur-oxidizing bacteria. Stir evenly and let it stand naturally for 6-8 days to obtain the acid-base adjusted base material. 5) Texture adjustment: Add 4-15% of the weight of the acid-base conditioned base material to the acid-base conditioned base material obtained in step 4) to obtain the texture conditioned base material. 6) Nutrient supplementation: Nutrients are added to the texture-adjusted base material obtained in step 5) to obtain nutrient-adjusted base material; 7) Granulation: Add water to the nutrient-adjusted base material obtained in step 6), stir and mix well, and then granulate. 8) Maturation and Cultivation: The particulate matter obtained in step 7) is piled up and matured in a ventilated environment for 1 to 180 days.

2. The method for preparing greening planting soil from non-metallic mineral industrial solid waste according to claim 1, characterized in that: In step 1): Industrial solid waste needs to meet the screening value requirements for agricultural land soil pollution risk; In step 3): fly ash needs to meet the screening value requirements for soil pollution risk in agricultural land.

3. The method for preparing greening planting soil from non-metallic mineral industrial solid waste according to claim 2, characterized in that: The non-metallic mineral industrial solid waste includes at least one of the following: washed sand mud, tailings slag / powder, and stone powder.

4. The method for preparing greening planting soil from non-metallic mineral industrial solid waste according to claim 3, characterized in that: In step 4) of method two, 100-200 mL of sulfur-oxidizing bacteria solution is inoculated per 100 kg of color-mixed base material, with a sulfur-oxidizing bacteria solution concentration of 10. 8 ~10 9 CFU / mL.

5. The method for preparing greening planting soil from non-metallic mineral industrial solid waste according to claim 4, characterized in that: In step 7), add water to control the moisture content to 10%~25%.

6. The method for preparing greening planting soil from non-metallic mineral industrial solid waste according to claim 5, characterized in that: In step 8), the pile is turned over every 5 to 10 days, and the moisture content is adjusted to 10% to 20% at the same time.

7. The method for preparing greening planting soil from non-metallic mineral industrial solid waste according to any one of claims 1 to 6, characterized in that: The screening values ​​for soil pollution risks in agricultural land are as follows: cadmium ≤ 0.6 mg / kg, mercury ≤ 3.4 mg / kg, arsenic ≤ 25 mg / kg, lead ≤ 170 mg / kg, chromium ≤ 250 mg / kg, copper ≤ 100 mg / kg, nickel ≤ 190 mg / kg, and zinc ≤ 300 mg / kg.

8. The method for preparing greening planting soil from non-metallic mineral industrial solid waste according to any one of claims 1 to 7, characterized in that... It also includes the following step 9); 9) Inspection and Acceptance: The soil obtained in step 8) is tested for physicochemical properties and ecological safety. Soil that passes the test is named greening planting soil.

9. The method for preparing greening planting soil from non-metallic mineral industrial solid waste according to claim 8, characterized in that: The physicochemical indicators to be tested include, but are not limited to, soil texture, organic matter content, pH value, salinity, soil infiltration rate, and cation exchange capacity. The ecological safety testing includes the detection of harmful organisms such as pathogens and weed seeds in the soil, as well as heavy metals such as cadmium, chromium, lead, nickel, and mercury.

10. Green planting soil prepared by any one of claims 1 to 9.

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