Ecological soil prepared from washed quartz sand ore tailing mud and method thereof

Abstract

The invention relates to the technical field of resource utilization of washed quartz sand ore tailing mud, in particular to ecological soil prepared from washed quartz sand ore tailing mud and a method of the ecological soil, the washed quartz sand ore tailing mud is used as a main raw material, coal gangue, a biological matrix and compound microorganism bacteria are mixed to prepare the ecological soil, the leaching rate of heavy metal is low, and the leaching rate is high. According to the present invention, the method has characteristics of simple operation, good stability and good solidification effect, can avoid the secondary pollution of the heavy metal to the environment, can improve the soil attribute of the ecological soil, can improve the quality of the ecological soil, can increase the resource utilization amount of the washed quartz sand ore tailing mud, can enhance the consumption amount, and can reduce the treatment cost and the treatment difficulty of the washed quartz sand ore tailing mud.

Description

Technical Field

[0001] The present invention relates to the technical field of resource utilization of washed quartz sand ore tail mud, and particularly relates to an ecological soil prepared from washed quartz sand ore tail mud and a method thereof. Background Technique

[0002] Before quartz sand is used as raw material for glass sand, it is necessary to wash the quartz sand ore through a washing and beneficiation process to make the purity of the quartz sand reach more than 99% of refined sand. When washing the quartz sand ore, a large amount of tail mud is generated. The washed quartz sand ore tail mud is usually used in the production of building materials. However, with the decrease in the market demand for building materials, the output of the washed quartz sand ore tail mud is far greater than the consumption, resulting in the stockpiling of the washed quartz sand ore tail mud.

[0003] The main components of the washed quartz sand tail mud are SiO 2 , Al 2 O 3 etc., and the content of harmful components is less; however, its soil properties such as bulk density, water retention, air permeability, conductivity, nutrients, content of medium and trace elements, content of microorganisms, content of organic matter, fertility, etc. are poor. Moreover, the washed quartz sand ore tail mud presents a light yellow color after pressure filtration, and the particle size of the tail mud particles is less than 325 mesh (0.045 mm), belonging to silt particles, which are prone to caking. When stockpiling the washed quartz sand ore tail mud, it not only occupies a large amount of land resources but also brings secondary pollution to the environment.

[0004] Therefore, seeking a suitable large-scale consumption way for the washed quartz sand ore tail mud has become the key technology for the sustainable development of the washed quartz sand ore industry and is an urgent technical problem to be solved in the current washed quartz sand ore industry.

[0005] At present, the application of tail mud in the field of artificial soil preparation has been widely studied and certain technologies have been formed. For example, Patent Application No. 202410192075.8 discloses that the tail mud remaining after desalinating sea mud sand and separating out sea sand is pressure-filtered and dehydrated to obtain desalinated tail mud; the desalinated tail mud is crushed and conditioned to obtain tail mud crushed material; dry pig manure is pyrolyzed and cooled in sequence to obtain pig manure biochar; the tail mud crushed material and the pig manure biochar are mixed once to obtain a biochar mixture; the landscaping planting soil and the biochar mixture are mixed twice to obtain conditioned planting soil; the conditioned planting soil is matured to obtain carpet grass planting soil; to activate the microbial community, improve the soil structure, enhance the activity of microorganisms, enrich the microbial community structure and microbial diversity, etc., to meet the normal growth of carpet grass and realize the resource utilization of desalinated tail mud.

[0006] For another example, Patent Application No. 202411507530.5 discloses that mine tailings are pre-screened to obtain mine tailing powder; oyster shells are ground and pre-screened to obtain oyster shell powder. The pre-treated mine tailing powder and oyster shell powder are mixed, stirred, and dried to obtain a material powder; biochar prepared from different types of crop straws is mixed with the material powder to prepare a soil conditioner. Adding harmless mine tailings and biochar can improve the soil structure and texture, and adding oyster shell powder can also improve soil fertility, providing rich nutrients for crop production, promoting crop growth, increasing yields, and having the functions of improving fertilizer utilization rate and soil improvement at the same time.

[0007] However, in the prior art, there is no technical content on how to use the washed quartz sand mine tailings to prepare soil while meeting the requirements of soil properties and reducing the leaching rate of heavy metals (solidification effect), resulting in the lack of technology for resource utilization of washed quartz sand mine tailings to produce artificial soil. Summary of the Invention

[0008] Based on the above technical problems, the present invention provides an ecological soil prepared from washed quartz sand mine tailings and a method thereof.

[0009] The specific technical solution is as follows:

[0010] One of the purposes of the present invention is to provide a method for preparing ecological soil using washed quartz sand mine tailings, including the following steps:

[0011] (1) Naturally air-dry the washed quartz sand mine tailings until the moisture content ≤ 30%, and crush them to 4 - 10 mesh to obtain tailing particles; crush coal gangue to 4 - 10 mesh to obtain coal gangue particles;

[0012] (2) Mix the coal gangue particles, biological matrix, and compound microbial inoculant evenly according to a mass ratio of 1:0.1 - 0.5:0.001 - 0.010, and carry out aging treatment at normal temperature and pressure for 1 - 3 days to obtain a composite material;

[0013] (3) Based on the mass of the coal gangue particles in the composite material, mix the tailing particles and the composite material evenly according to a mass ratio of 1 - 5:1, and carry out aging treatment at normal temperature and pressure for 1 - 3 days to obtain the product.

[0014] Using washed quartz sand mine tailings as the main raw material, supplemented by the incorporation of coal gangue, biological matrix, and compound microorganisms to prepare ecological soil, which has a low leaching rate of heavy metals, excellent stable solidification effect, can avoid secondary pollution of the environment by heavy metals, and can also improve the soil properties of ecological soil, improve the quality of ecological soil, increase the resource utilization amount of washed quartz sand mine tailings, enhance the consumption amount, and reduce the treatment cost and difficulty of washed quartz sand mine tailings.

[0015] Preferably, the biological matrix is a mixture formed by mixing one or several of biological organic fertilizers, humic acids, straws, dead branches, dead leaves, distiller's grains, and humus soils in any mass ratio. For example, the straw can be corn straw, wheat straw, etc. For example, the humus soil is the humus soil formed by the decay of fallen leaves in the forest.

[0016] In order to improve the heavy metal stabilization effect of the ecological soil heap, reduce the heavy metal leaching rate, and at the same time improve the soil properties of the ecological soil and the quality of the ecological soil, preferably, the composite microbial bacteria are mixed by equal mass ratio of growth-promoting and soil-improving microbial bacteria, biocontrol microbial bacteria, and other microbial bacteria; wherein, the other microbial bacteria are mixed by equal mass ratio of sulfur-oxidizing bacteria, Bacillus laterosporus, and Aspergillus niger; the growth-promoting and soil-improving microbial bacteria are one of Bacillus megaterium, Bacillus mucilaginosus, and Paenibacillus gelatinosus; the biocontrol microbial bacteria are one of Bacillus subtilis, Bacillus amyloliquefaciens, and Paenibacillus polymyxa.

[0017] More preferably, the composite microbial bacteria are mixed by equal mass ratio of Bacillus megaterium, Bacillus subtilis, and other microbial bacteria; the other microbial bacteria are mixed by equal mass ratio of sulfur-oxidizing bacteria, Bacillus laterosporus, and Aspergillus niger.

[0018] Preferably, in the step (2), the coal gangue particles, the biological matrix, and the composite microbial inoculant are mixed at a mass ratio of 1:0.2:0.003; and in the step (3), the tail mud particles and the composite material are mixed at a mass ratio of 2:1.

[0019] Preferably, the soil indexes of the washed quartz sand ore tail mud are that the organic matter content is 0, the salt content is 0.21 mS / cm, the bulk density is 0.61 g / m 3 , the infiltration rate is 0 mm / h, the porosity is 8.45%, the aeration degree is 1.089%, and the pH is 7.78.

[0020] Preferably, the mass percentage content of the main components of the washed quartz sand ore tail mud is: SiO 2 85.46%, Al 2 O 3 11.68%, Fe 2 O 3 0.77%, Na 2 O 0.015%, MgO 0.10%, P 2 O 5 0.069%, SO 3 0.020%, Cl 0.0084%, K 2 O 0.82%, CaO 0.19%, TiO 2 0.55%, Cr2 O 3 0.012%, MnO 0.013%, NiO 0.0059%, CuO 0.0058%, As 2 O 3 0.0033%, Rb 2 O 0.0022%, SrO 0.013%, Y 2 O 3 0.0061%, ZrO 2 0.030%, ThO 2 0.0036%, F - 0.2%.

[0021] Preferably, the mass percentage content of the main components of the coal gangue is: SiO 2 49.23%, Al 2 O 3 20.11%, Fe 2 O 3 8.99%, CaO 3.24%, K 2 O 0.10%, MgO 0.96%.

[0022] The second object of the present invention is to provide the ecological soil prepared by the above method.

[0023] Compared with the prior art, the technical effects of the present invention are reflected in:

[0024] The present invention turns the existing waste resources of washed quartz sand mine tailings and coal gangue into valuable resources, enabling the medium and trace elements beneficial to plant growth in the coal gangue to be compounded into the washed quartz sand mine tailings, improving the soil properties of the washed quartz sand mine tailings. Combined with the selection of biological matrix and compound microbial agents, the nutrients in the ecological soil are rationally matched, and the stabilization and solidification effect of heavy metals in the ecological soil can be enhanced, the leaching rate of heavy metals can be reduced, the consumption of washed quartz sand mine tailings can be increased, and the treatment cost and difficulty of washed quartz sand mine tailings can be reduced.

[0025] The process flow of the present invention is simple and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order for those skilled in the art to fully understand the technical solution of the present invention, the following description is made on the provided drawings in combination with the content of the technical solution.

[0027] Figure 1 It is the process flow chart of the present invention.

[0028] Figure 2 It is the morphology photo of the washed quartz sand mine tailings after being pressed and formed into blocks.

[0029] Figure 3 Photo of the ecological soil prepared for this invention

[0030] Figure 4 is the inspection report of the sample prepared by using humus soil as the biological matrix addition for this invention. Detailed implementation manners

[0031] For the convenience of those skilled in the art to correctly understand this invention, so that those skilled in the art can fully understand the technical content of this invention, the technical solution of this invention will be further elaborated below in combination with specific implementation manners and drawings. However, this elaboration does not limit the scope of protection required by this invention. Those skilled in the art's scope of protection of this invention cannot be limited only to the following elaboration content. Any equivalent replacement or change made by those skilled in the art or those familiar with the technology in the art based on the technical solution and inventive concept of this invention should be covered within the scope of protection of this invention.

[0032] As Figure 1 shown, in some embodiments, a method for preparing ecological soil by using washed quartz sand mine tailings includes the following steps:

[0033] (1) Naturally air-dry the washed quartz sand mine tailings until the moisture content ≤ 30%, for example: 10%, 15%, 20%, 30%, etc., and crush them to 4 - 10 mesh to obtain tailing particles; crush coal gangue to 4 - 10 mesh to obtain coal gangue particles;

[0034] (2) Mix the coal gangue particles, biological matrix, and composite microbial inoculant evenly according to a mass ratio of 1:0.1 - 0.5:0.001 - 0.010, for example: 1:0.1:0.003, 1:0.2:0.003, 1:0.15:0.003, etc., and carry out aging treatment at normal temperature and pressure for 1 - 3 d, for example: 1 d, 2 d, 3 d, etc., to obtain a composite material;

[0035] (3) Based on the mass of the coal gangue particles in the composite material, mix the tailing particles and the composite material evenly according to a mass ratio of 1 - 5:1, for example: 1:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 5:1, etc., and carry out aging treatment at normal temperature and pressure for 1 - 3 d, for example: 1 d, 2 d, 3 d, etc., to obtain the product.

[0036] Using the tail mud with poor soil properties as raw materials, through the mixed aging of coal gangue, biological matrix, and composite microorganisms, the decay-ripening is achieved, making the nutrients in the coal gangue, biological matrix, and composite microorganisms evenly mixed. Then, the tail mud particles are added and mixed evenly for aging. The mixing ratio of each raw material is strictly controlled to improve the soil properties of the obtained ecological soil. Moreover, combined with the addition of composite microorganisms, the leaching rate of heavy metals is reduced, and the stable solidification effect of heavy metals in the ecological soil is improved.

[0037] In some embodiments of the present invention, the biological matrix is a mixture formed by mixing one or several of biological organic fertilizer, humic acid, straw, dead branches, dead leaves, distiller's grains, and humus soil in any mass ratio. It can supplement organic matter and enhance the soil properties of the ecological soil prepared with tail mud as the main raw material.

[0038] In some embodiments of the present invention, the composite microbial bacteria are formed by mixing growth-promoting and soil-improving microbial bacteria, biocontrol microbial bacteria, and other microbial bacteria in an equal mass ratio; among them, the other microbial bacteria are formed by mixing sulfur-oxidizing bacteria, Bacillus laterosporus, and Aspergillus niger in an equal mass ratio; the growth-promoting and soil-improving microbial bacteria are one of Bacillus mucilaginosus, Paenibacillus mucilaginosus, and Bacillus megaterium; the biocontrol microbial bacteria are one of Bacillus megaterium, Bacillus mucilaginosus, and Paenibacillus mucilaginosus. This will help reduce the leaching rate of heavy metals and enhance the stable solidification effect of heavy metals in the ecological soil.

[0039] In some embodiments of the present invention, the composite microbial bacteria are formed by mixing Bacillus megaterium, Bacillus subtilis, and other microbial bacteria in an equal mass ratio; the other microbial bacteria are formed by mixing sulfur-oxidizing bacteria, Bacillus laterosporus, and Aspergillus niger in an equal mass ratio. It can enhance the solidification effect on heavy metals.

[0040] In some embodiments of the present invention, in step (2), the coal gangue particles, biological matrix, and composite microbial inoculant are mixed in a mass ratio of 1:0.2:0.003; and in step (3), the tail mud particles and the composite material are mixed in a mass ratio of 2:1. This helps reduce the salt content of the ecological soil.

[0041] In order to better verify the technical effects of the present invention, the researchers of the present invention carried out the following experimental studies:

[0042] Take the washed quartz sand ore tail mud and detect its main components and mass percentages. The results are: SiO 2 85.46%, Al 2 O 3 11.68%, Fe 2 O 3 0.77%, Na 2O 0.015%, MgO 0.10%, P 2 O 5 0.069%, SO 3 0.020%, Cl 0.0084%, K 2 O 0.82%, CaO 0.19%, TiO 2 0.55%, Cr 2 O 3 0.012%, MnO 0.013%, NiO 0.0059%, CuO 0.0058%, As 2 O 3 0.0033%, Rb 2 O 0.0022%, SrO 0.013%, Y 2 O 3 0.0061%, ZrO 2 0.030%, ThO 2 0.0036%, F - 0.2%; It can be seen that the main components of this tail mud are SiO 2 、Al 2 O 3 、Fe 2 O 3 ,Among them, the content of SiO 2 is as high as over 85%, and the contents of heavy metals such as Cr and As are relatively low, so the impact of heavy metals on the soil environment is small. The soil property indexes such as pH, organic matter, salt content, soil bulk density, soil infiltration rate, porosity, and soil aeration degree of the washed quartz sand ore tail mud are detected, and the results are shown in Table 1 below:

[0043] Table 1

[0044]

[0045] It can be seen that the washed quartz sand ore tail mud tends to be neutral, and indexes such as organic matter content and soil infiltration rate cannot meet the requirements of standards such as the "Quality Control Standards for Land Reclamation" (TD / T 1036 - 2013) and the "Greening Planting Soil" (CJ / T 340 - 2016). Therefore, the washed quartz sand ore tail mud cannot be directly used as soil and needs to be modified.

[0046] Coal gangue is an industrial by - product produced during coal mining. After detection, the mass percentage content of its main components is: SiO 2 49.23%, Al 2 O 3 20.11%, Fe 2 O 3 8.99%, CaO 3.24%, K 2O 0.10%, MgO 0.96%; in addition, it also contains trace elements such as B, Mn, Cu, Co, etc. Therefore, coal gangue can supplement medium and trace elements to the soil and improve the coordination properties of the soil.

[0047] In view of the above, the researcher used coal gangue and washed quartz sand mine tailings as the main raw materials to prepare ecological soil, so as to broaden the scope of resource utilization of washed quartz sand mine tailings, increase the consumption of washed quartz sand mine tailings, reduce the stockpile, and reduce environmental pollution.

[0048] Experiment 1: Study on the soil properties of the mixture formed by coal gangue particles and tailings particles.

[0049] The washed quartz sand mine tailings were naturally air-dried to a moisture content of 30%, and crushed to a particle size between 4 and 10 mesh to obtain tailings particles; the coal gangue particles were crushed to a particle size between 4 and 10 mesh to obtain coal gangue particles; the tailings particles and coal gangue particles were mixed into a mixture according to the mass ratio shown in Table 2 below, and the soil properties of the mixture were detected with reference to CJ / T 340-2016. The results are shown in Table 2 below:

[0050] Table 2

[0051]

[0052] It can be seen from Table 2 that different mass ratios of tailings particles to coal gangue particles will cause changes in the soil properties of the mixture formed by tailings particles and coal gangue particles. Generally speaking, as the mass ratio of tailings particles to coal gangue particles increases, the soil properties become worse; but as the amount of tailings particles increases, the salt content in the obtained mixture gradually decreases; therefore, the mass ratio of tailings particles to coal gangue particles should be appropriately controlled to ensure better soil property indicators when the obtained mixture is used as ecological soil.

[0053] Experiment 2: Study on the influence of different raw material mass ratios on the soil properties of ecological soil.

[0054] The tailings particles, coal gangue particles, and biological matrix (the crushed product of corn straw crushed through a 10-mesh sieve) were taken according to the mass ratio shown in Table 3 below; first, the coal gangue particles and the biological matrix were mixed and stacked for aging treatment for 3 days under normal temperature and pressure to obtain a composite material; then the composite material and the tailings particles were mixed evenly and stacked for aging treatment for 3 days under normal temperature and pressure to obtain ecological soil. And the soil property indicators of the obtained ecological soil were detected. The results are shown in Table 3 below:

[0055] Table 3

[0056]

[0057] As can be seen from Table 3, with the increase in the dosage of the biological matrix, the soil properties of the obtained ecological soil have been improved. When the dosage of the biological matrix remains unchanged and the mass ratio of tail mud particles to coal gangue particles increases, the soil property indexes of the ecological soil generally become worse and the salt content also shows an obvious downward trend. However, in order to improve the soil properties of tail mud, the dosage of coal gangue cannot be too low. Therefore, the mass ratio of tail mud particles to coal gangue particles should be appropriately controlled to ensure that the soil property indexes of the obtained mixture as ecological soil are relatively good; and to ensure a large consumption of the washed quartz sand mine tail mud.

[0058] Experiment 3: Study on the influence of adding composite microorganisms on the soil properties of ecological soil.

[0059] On the basis of Experiment 2, the test group with tail mud particles: coal gangue particles: biological matrix = 100:50:5 was taken as a sample, and the heavy metal indexes were analyzed in accordance with CJ / T 340-2016 "Greening Planting Soil". The results are shown in Table 4 below:

[0060] Table 4 (unit: mg / kg)

[0061]

[0062] On this basis, composite microbial agent A, composite microbial agent B, and composite microbial agent C were respectively prepared. Among them, composite microbial agent A is composed of Bacillus megaterium as a growth-promoting and soil-improving microbial agent, Bacillus subtilis as a biocontrol microbial agent and other microbial agents mixed in equal mass ratio; the other microbial agents are Thiobacillus thiooxidans, Bacillus laterosporus, and Aspergillus niger mixed in equal mass ratio. Composite microbial agent B is composed of Paenibacillus mucilaginosus as a growth-promoting and soil-improving microbial agent, Paenibacillus polymyxa as a biocontrol microbial agent and other microbial agents mixed in equal mass ratio, and the others are the same as composite microbial agent A. Composite microbial agent C is composed of Bacillus mucilaginosus as a growth-promoting and soil-improving microbial agent, Bacillus amyloliquefaciens as a biocontrol microbial agent and other microbial agents mixed in equal mass ratio, and the others are the same as composite microbial agent A.

[0063] Take composite microbial agent A, composite microbial agent B, and composite microbial agent C respectively according to the mass ratio of tail mud particles: coal gangue particles: biological matrix: composite microbial agent of 100:50:5:0.15. First, mix the coal gangue particles with the biological matrix and the composite microbial agent, stack and age them at normal temperature and pressure for 3 days to obtain a composite material; then mix the composite material with the tail mud particles evenly and stack and age them at normal temperature and pressure for 3 days to obtain the ecological soil. And the heavy metal content of the obtained ecological soil was detected, and the results are shown in Table 5 below; at the same time, the soil properties of the obtained ecological soil were detected, and the results are shown in Table 6 below.

[0064] Table 5 (unit: mg / kg)

[0065]

[0066] Table 6

[0067]

[0068] It can be seen from Table 3, Table 4, Table 5 and Table 6 that adding the compound microbial inoculant will help to enhance the stabilization and solidification of heavy metals, reduce the leaching rate of heavy metals, and at the same time help to improve the soil properties of ecological soil and improve the quality of ecological soil. Different types of compound microbial inoculants will have different effects on the quality of ecological soil. In this invention, it is preferable to select compound microbial inoculant A.

[0069] Test 4: Sample preparation and submission for inspection test.

[0070] According to the sample preparation method in Test 3, a test sample for submission is prepared by taking the mass ratio of tail mud particles: coal gangue particles: biological matrix (humus soil): compound microbial inoculant B as 100:40:5:0.30. The test results are shown in Figure 4. It can be seen from the test results that in this invention, humus soil is used as the biological matrix, and compound microbial inoculant B is added to prepare ecological soil. The soil properties of this ecological soil are relatively good and the quality is excellent. Moreover, the detectable content of heavy metals is low, which can reduce the migration rate of heavy metals.

[0071] For other matters not covered in this invention, reference can be made to the prior art or the common general knowledge well-known to those skilled in the art, and they can be realized by conventional technical means. For example: the mixing method of compound microbial inoculants, the operation method of aging treatment in a normal temperature and pressure environment for stacking, etc.

Claims

1. A method for preparing ecological soil using washed quartz sand mine tailings, characterized in that: The following steps are involved: (1) naturally air-drying the washed quartz sand ore tailings to a moisture content of ≤30%, crushing them to 4-10 meshes to obtain tailings particles; crushing the coal gangue to 4-10 meshes to obtain coal gangue particles; (2) mixing the coal gangue particles, the biological matrix and the composite microbial agent in a mass ratio of 1:0.1-0.5:0.001-0.010, and aging the mixture at room temperature and pressure for 1-3 days to obtain a composite material; (3) The composite material is calculated based on the mass of the coal gangue particles. The tailings particles and the composite material are evenly mixed in a mass ratio of 1-5:1, and aged at room temperature and pressure for 1-3 days to obtain the composite material.

2. The method for preparing ecological soil by using washed quartz sand mine tailings as claimed in claim 1, characterized in that: The biological matrix is ​​a mixture of one or more of biological organic fertilizer, humic acid, straw, dead branches, dead leaves, wine lees and humus soil in any mass ratio.

3. The method for preparing ecological soil by using washed quartz sand mine tailings as claimed in claim 1, characterized in that: The composite microorganism is formed by mixing growth-promoting and soil-improving microorganisms, biocontrol microorganisms, and other microorganisms in equal mass ratios; wherein the other microorganisms are sulfur-oxidizing bacteria, Bacillus laterosporus, and Aspergillus niger in equal mass ratios; the growth-promoting and soil-improving microorganism is one of Bacillus megaterium, Bacillus mucilaginosus, and Bacillus mucilaginosus; the biocontrol microorganism is one of Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus polymyxa.

4. The method for preparing ecological soil by using washed quartz sand tailings as claimed in claim 1 or 3, characterized in that: The composite microorganism is formed by mixing Bacillus megaterium, Bacillus subtilis and other microorganisms in equal mass ratio; the other microorganisms are formed by mixing sulfur-oxidizing bacteria, Bacillus laterosporus and Aspergillus niger in equal mass ratio.

5. The method for preparing ecological soil by using washed quartz sand tailings as claimed in claim 1, characterized in that: In the step (2), the gangue particles are mixed with the biological matrix and the composite microbial agent in a mass ratio of 1:0.2:0.003; and in the step (3), the tailings particles are mixed with the composite material in a mass ratio of 2:

1.

6. The method for preparing ecological soil by using washed quartz sand tailings as claimed in claim 1, characterized in that: The soil indicators of the washed quartz sand mine tailings are organic matter content of 0, salt content of 0.21mS / cm, and bulk density of 0.61g / m 3 , infiltration rate is 0mm / h, porosity is 8.45%, aeration is 1.089%, and pH is 7.

78.

7. The method for preparing ecological soil by using washed quartz sand tailings as claimed in claim 1 or 6, characterized in that: The main components of the washed quartz sand tailings are as follows: SiO2 85.46%, Al2O3 11.68%, Fe2O3 0.77%, Na2O 0.015%, MgO 0.10%, P2O5 0.069%, SO3 0.020%, Cl 0.0084%, K2O 0.82%, CaO0.19%, TiO2 0.55%, Cr2O3 0.012%, MnO 0.013%, NiO 0.0059%, CuO 0.0058%, As2O3 0.0033%, Rb2O 0.0022%, SrO 0.013%, Y2O3 0.0061%, ZrO2 0.030%, ThO2 0.0036%, F - 0.2%.

8. The method for preparing ecological soil by using washed quartz sand mine tailings as claimed in claim 1, characterized in that: The main components of the coal gangue are as follows: SiO2 49.23%, Al2O3 20.11%, Fe2O3 8.99%, CaO 3.24%, K2O 0.10%, and MgO 0.96%.

9. Ecological soil prepared according to the method according to any one of claims 1 to 8.

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