Coal gangue-based porous artificial soil as well as preparation method and application thereof

Abstract

The invention relates to coal gangue-based porous artificial soil as well as a preparation method and application thereof. The method provided by the invention is green and environment-friendly in processing property, free of a heating reaction device, mild in production condition, accurate in process control and suitable for industrial production. The porous planting layer ecological matrix researched and developed by the invention takes the coal gangue as a main raw material, not only provides a reliable new way for comprehensive utilization of the coal gangue, but also can improve soil, replace loess resources and carry out ecological restoration. Meanwhile, the porous planting layer ecological matrix has multiple effects of soil, agglomeration, porosity, water retention and fertilizer conservation are achieved, organic matter, available phosphorus, total nitrogen and quick-acting potassium can meet the requirements for physical and chemical properties of cultivated land soil, and the porous planting layer ecological matrix can replace the soil and can serve as a soil conditioner to improve the soil.

Description

Technical Field

[0001] The present invention belongs to the technical field of comprehensive utilization of coal gangue and ecological restoration, and specifically relates to a preparation technology of coal gangue-based porous artificial soil that can be industrially produced. Background Art

[0002] Coal gangue is a solid waste generated during coal mining and washing. Its main components include carbonaceous shale, argillaceous shale, sandstone, etc., containing a small amount of coal and inorganic minerals. Its chemical composition is complex, usually containing elements such as silicon, aluminum, iron, calcium, magnesium, and a small amount of sulfur, phosphorus, etc.

[0003] As a waste, coal gangue will cause problems of land occupation and environmental pollution. In order to turn waste into treasure, the existing technologies for the application of coal gangue are mainly reflected in the following aspects: as building materials, it can be used to produce building materials such as bricks, cement, and ceramsite; landfill and reclamation, used for landfilling subsidence areas or reclaiming land; chemical raw materials: extracting elements such as aluminum and silicon, or used for producing chemical products.

[0004] In the existing technology, a technology for preparing artificial soil based on coal gangue has emerged for plant cultivation. However, a prominent technical problem of this artificial soil is that it needs to have good air permeability, that is, the formed soil particles should be uniform and moderate, maintaining good air permeability, and there will be no problem of rapid soil loss after watering; furthermore, the process of processing and preparing this artificial soil needs to be under relatively mild conditions. If it needs to go through harsh processing conditions, it will inevitably lead to an increase in cost and is not suitable for industrial production. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the deficiencies of the existing technology and provide a technology for comprehensively utilizing coal gangue under mild conditions and suitable for use as artificial soil.

[0006] To achieve the above object, the present invention provides a preparation method of coal gangue-based porous artificial soil, which includes the following steps:

[0007] Step 1: 100 parts of gangue are crushed to between 13 mm and 50 mm for standby;

[0008] Step 2: Add 2 to 5 parts of slag and 1 to 3 parts of fly ash to the gangue obtained in Step 1, grind it to 120 to 140 meshes, and add 0.5 to 2 parts of a regulator and stir evenly; the regulator is desulfurized gypsum, and the desulfurized gypsum has undergone pre-drying treatment.

[0009] Step 3: Dilute 2.5 to 6 parts of foaming agent and 3.0 to 8 parts of foam stabilizer with water, and then add them to the materials in Step 2 and mix evenly; the foaming agent is selected from alkyl polyglycosides, animal and plant protein products, and polysaccharides, and the proportion of animal and plant protein products and polysaccharides in the foaming agent is 10% to 20%; the foam stabilizer is at least one of the following substances: starch, polytetrafluoroethylene, phosphoric acid esterified starch, starch xanthate, grafted cellulose, carboxymethylated cellulose, hydroxypropylated cellulose;

[0010] Step 4: Dry the evenly mixed slurry to obtain coal gangue-based porous artificial soil.

[0011] Preferably, the animal and plant protein products are at least one of the following substances: soy protein, silk protein, gluten;

[0012] The polysaccharides are at least one of the following substances: pectin, alginate, chitosan.

[0013] Preferably, the pre-drying treatment process of desulfurized gypsum is to dry it at 150 °C for 1 hour and then use it;

[0014] Dilute the foaming agent and foam stabilizer with water by 10 to 25 times and then add them to the materials in Step 2 and mix evenly.

[0015] Preferably, the slag and fly ash are waste residues generated from industrial production, with a pH less than 8.5, and the heavy metal content meets the requirements of the industrial solid waste for agricultural land risk control in GB15618-2018.

[0016] Preferably, the gangue raw material is gangue tunneling or washed gangue.

[0017] A coal gangue-based porous artificial soil provided by the present invention, which is the coal gangue-based porous artificial soil obtained by using the preparation method of any one of the above.

[0018] Preferably, the conductivity EC = 0.23256 ± 2.52 dS / m; the water-soluble salt content is 1.47 g / kg.

[0019] Preferably, the water retention rate of the coal gangue-based porous artificial soil is 37%, the heat preservation performance is 8.1 °C, the bulk density is 0.43 g / cm 3 , and the soil loss rate is 1.27%.

[0020] Preferably, a foam maintaining agent is used during the planting process. The foam maintaining agent is directly applied to the surface of the artificial soil by spraying, or the soil is plowed in the gap positions among the plants so that the foam maintaining agent is mixed into the artificial soil; the foam maintaining agent is selected from a composition of alkyl polyglycosides, animal and plant protein products, and polysaccharides; the composition is obtained by immersing alkyl polyglycosides and animal and plant protein products in a polysaccharide solution and then drying.

[0021] Preferably, a foaming maintenance agent is applied at 1% to 2% of the weight of the artificial soil every 6 to 8 months.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1. The method provided by the present invention has green and environmental protection process performance, does not involve a heating reaction device, has mild production conditions and precise process control, and is suitable for industrial production.

[0024] 2. The N, P, and K fertilizer effects of the artificial soil prepared by this method can reach the second-level standard of the national soil census, and the electrical conductivity meets the requirements of electrical conductivity in soil reclamation.

[0025] 3. In addition, the product of the present invention has properties such as water retention, fertilizer retention, heat preservation, loose pores, anti-loss, and high germination rate.

[0026] 4. The porous planting layer ecological matrix developed by the present invention is based on coal gangue as the main raw material, which not only provides a reliable new way for the comprehensive utilization of coal gangue, but also can improve the soil, replace the loess resources, and carry out ecological restoration. At the same time, the porous planting layer ecological matrix has many functions of soil, such as aggregation, porous water retention and fertilizer retention, and the organic matter, available phosphorus, total nitrogen, and available potassium can meet the requirements of the physical and chemical properties of cultivated land soil. It can not only replace the soil but also be used as a soil conditioner to improve the soil.

[0027] The action mechanism of the preparation method of the present invention is that alkyl polyglycoside itself is a surfactant and has a basic foaming function. Therefore, it can combine with coal gangue particles to form foam on the surface to form a loose particle state; further, the application of animal and plant protein products can reduce the surface tension of the liquid, thereby forming a stable film on the surface of the foam, which helps to extend the life of the foam, increase the soil looseness, and correspondingly improve the air permeability. Moreover, the viscosity of polysaccharides helps to enhance the structure of the foam and make the foam more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 is a physical diagram of the existing coal gangue raw material (left side) and a physical diagram of the porous artificial soil obtained by processing and preparation (right side);

[0030] Figure 2 is Figure 1 an enlarged view of the physical diagram of the present invention in

[0031] Figure 3 This is a physical picture of different plants grown in the porous artificial soil of the present invention.

[0032] Figure 4 The experimental crop selected is snap beans. After sowing leguminous plants, the growth and development of the plants were observed on the 1st day. Among them, the four soils used from left to right are the soil improved based on Huating gangue in Gansu, the soil improved based on the gangue of the Third Mine in Shuozhou, the flower bed soil in the courtyard of the Xiqu Park in Gujiao, and the soil improved based on the gangue of Xiqu in Gujiao.

[0033] Figure 5 The experimental crop selected is snap beans. After sowing leguminous plants, the growth and development of the plants were observed on the 6th day. Among them, the two soils used from left to right are the soil improved based on the gangue of the Third Mine in Shuozhou, the flower bed soil in the courtyard of the Xiqu Park in Gujiao, and the soil improved based on the gangue of Xiqu in Gujiao.

[0034] Figure 6 The experimental crop selected is snap beans. After sowing leguminous plants, the growth and development of the plants were observed on the 10th day. Among them, the three soils used from left to right are the flower bed soil in the courtyard of the Xiqu Park in Gujiao and the soil improved based on the gangue of Xiqu in Gujiao.

[0035] Figure 7 The experimental crop selected is snap beans. After sowing leguminous plants, the growth and development of the plants were observed after one month (i.e., 30 days). Among them, the four soils used from left to right are the soil improved based on Huating gangue in Gansu, the soil improved based on the gangue of the Third Mine in Shuozhou, the soil improved based on the gangue of Xiqu in Gujiao, and the flower bed soil in the courtyard of the Xiqu Park in Gujiao.

[0036] Figure 8 This is a physical picture of the growth in the open air of the compounding of the porous planting layer ecological matrix of the present invention and the loess of Wuminggou.

[0037] Figure 9 This is an existing type of index for the classification of the cultivated land fertility grade in a region.

[0038] Figure 10 This is a physical picture of the application of the coal gangue-based porous artificial soil of the present invention to the water layer for plant growth.

[0039] Figure 11 This is a physical picture of the application of the coal gangue-based porous artificial soil of the present invention to the water layer for plant growth. Observed from the top view, the water layer has been purified and the underwater artificial soil has grown plants.

[0040] Figure 12 This is a physical picture of the application of the coal gangue-based porous artificial soil of the present invention to the water layer for fish farming.

[0041] Figure 13It is a top view of the application of the coal gangue-based porous artificial soil of another group of the present invention to the top of the water layer.

[0042] Figure 14 It is a diagram of the coal gangue-based porous artificial soil soaked in water.

[0043] Figure 15 It is a diagram of the coal gangue-based porous artificial soil soaked in water of another group. Figure 14 The amount of the foaming agent used in Figure 15 the group. Specific embodiments

[0044] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] This embodiment provides a preparation method of a coal gangue-based porous artificial soil, which includes the following steps:

[0046] Step 1: 100 parts of gangue are crushed to between 13 mm and 50 mm for standby;

[0047] Step 2: 3 parts of slag and 2 parts of fly ash are added to the gangue obtained in Step 1, and the mixture is ground to 130 meshes, and 1 part of the regulator is added and stirred evenly; the regulator is desulfurized gypsum, and the desulfurized gypsum has been pretreated by drying; the pretreatment process of the desulfurized gypsum is drying at 150 °C for 1 hour before use;

[0048] Step 3: 3 parts of the foaming agent and 5 parts of the foam stabilizer are diluted with water and then added to the materials in Step 2 and mixed evenly; that is, the foaming agent and the foam stabilizer are diluted 10 times with water and then added to the materials in Step 2 and mixed evenly.

[0049] Among them, the foaming agent is selected from alkyl polyglycoside, soy protein and chitosan of animal and plant protein products, and the proportions of the animal and plant protein products and polysaccharides in the foaming agent are 10% respectively. The foam stabilizer is starch;

[0050] Step 4: The uniformly mixed slurry is dried to obtain the coal gangue-based porous artificial soil.

[0051] The following various experiments are carried out on the coal gangue-based porous artificial soil obtained in this embodiment to verify the relevant properties.

[0052] Experimental Example 1: Appearance observation experiment.

[0053] The porous structure of the coal gangue artificial soil product of the present invention uses coal gangue as the main raw material, and the appearance of the soil product is asFigure 1 The right part and Figure 2 are shown. Compared with the existing coal gangue materials, the corresponding soil obtained by the present invention has formed a planting layer ecological substrate similar to soil with a loose and porous void structure, that is Figure 1 and Figure 2 it can be clearly seen from that the artificial soil particles of coal gangue increase in size, agglomerate tightly, and are loose and porous.

[0054] After being treated by this process, the coal gangue has a high porosity and adsorption capacity. It can effectively improve the air permeability and water retention of the soil, thereby improving the soil structure, having good water absorption and retention, no caking after natural drying, and can be recycled.

[0055] Experimental Example 2: Planting result experiment.

[0056] The above-mentioned plants grow well in the coal gangue artificial soil product prepared by the present invention. The germination situations of different crops are as follows in the table:

[0057] Plant species Survival rate Germination time Wheat 100％ 4 days Wheat (pre-soaked for germination) 100％ 3 days Corn 100％ 4 days Corn (pre-soaked for germination) 100％ 2 days Elymus dahuricus 90％ 4 days Alfalfa 85％ 6 days

[0058] According to the germination situations of planting various crops, the germination situation of the coal gangue artificial soil product prepared by the present invention is better than that of ordinary soil. Figure 3 shows the physical pictures of the coal gangue artificial soil product prepared by the present invention used for planting various different types of plants. For example, for plants such as mint, podocarpus macrophyllus, and coriander, very good plant forms have grown, which are better than the plant forms grown in ordinary soil.

[0059] Experimental Example 3: Component detection experiment.

[0060] Taking the experiment and detection situation of the coal gangue from Xiqu Mine in Gujiao City;

[0061] Using the washed gangue from Xiqu Mine, after sorting to extract high-value pyrite and low-calorie coal, the planting layer ecological substrate (based on Xiqu Mine gangue) is prepared by processing and foaming according to the above preparation method. The full component analysis of the product is shown in the following table.

[0062] Serial number Name Test result Serial number Name Test result 1 <![CDATA[SiO 2 > 62.132 11 <![CDATA[Sodium 2 O]]> 0.114 2 <![CDATA[Al 2 O 3 > 23.880 12 Cl 0.052 3 <![CDATA[Fe 2 O 3 > 6.239 13 SrO 0.030 4 <![CDATA[SO 3 > 2.565 14 <![CDATA[ZrO 2 > 0.029 5 <![CDATA[K 2 O]]> 2.189 15 <![CDATA[WO 3 > 0.025 6 CaO 0.897 16 <![CDATA[Rb 2 O]]> 0.009 7 <![CDATA[TiO 2 > 0.795 17 ZnO 0.008 8 MgO 0.754 18 PbO 0.008 9 <![CDATA[P 2 O 5 > 0.151 19 <![CDATA[Y 2 O 3 > 0.005 10 MnO 0.119 20 Total amount 100.0

[0063] As can be seen from the above table, the main components of the planting layer ecological substrate (coal gangue-based porous artificial soil) are SiO 2 、Al 2 O 3 、Fe 2 O 3 , accounting for 62.132%, 23.880%, and 6.239% of the total amount respectively. Therefore, the planting layer ecological substrate prepared with coal gangue as the raw material contains the same components as the tillage layer soil, and the main components are SiO 2 、Al2 O 3 It contains humic acid and about 30 trace elements such as calcium, iron, zinc, sulfur, phosphorus, and potassium, and all 15 elements required for plant growth to be obtained from the soil are included therein.

[0064] Experimental Example 4: Experiment on salt content.

[0065] Soil water-soluble salt is an important property of saline-alkali soil and is an obstacle factor restricting crop growth. By detecting the soluble salt content of the ecological matrix (coal gangue-based porous artificial soil) in the planting layer, its effects on seed germination and crop growth are analyzed. The laboratory detects the soluble salt content of the ecological matrix in the planting layer according to the conductivity method and the mass method respectively.

[0066] According to "HJ 802-2016 Determination of Soil Conductivity - Electrode Method", the conductivity (EC) of the porous planting layer ecological matrix (coal gangue-based porous artificial soil) of the present invention was measured. EC25 = 0.23256 ± 2.52 dS / m.

[0067] According to "LY / T 1251-1999 Analysis of Water-soluble Salts in Forest Soils", the water-soluble salts of the porous planting layer ecological matrix (coal gangue-based porous artificial soil) of the present invention were measured, and the water-soluble salt content was 1.47 g / kg.

[0068] According to the relationship between the conductivity of the soil saturated leaching solution and the salt content and crop growth shown in the following table, the salt content of the ecological matrix in the planting layer and the plant growth situation are analyzed.

[0069] Relationship between the conductivity of the soil saturated leaching solution and the salt content and crop growth:

[0070]

[0071] Judging from the above two test results, the ecological matrix (coal gangue-based porous artificial soil) prepared with coal gangue as the raw material has a small salt content, and the degree of salinization belongs to non-saline soil, and long-term planting will not cause salinization of the local soil.

[0072] Comparing the salt content with the salinization level given in the soil general survey, the artificial soil of the present invention has a very low salt content, and mixing with loess will not cause changes in the salt content of the loess, and can improve the original saline-alkali soil.

[0073] Experimental Example 5: Analysis of artificial soil pollution.

[0074] Heavy metals and organic pollutants were measured according to "Soil Environmental Quality Risk Control Standards for Agricultural Land" (GB 15618-2018), and the test results are shown in the following table:

[0075]

[0076]

[0077] It can be seen from the detection results that the monitoring indicators of heavy metals and organic pollution in the foamed soil are all less than the risk screening value standards in the "Soil Environmental Quality - Risk Control Standards for Soil Pollution of Agricultural Land (Trial)" (GB 15618-2018); from the perspective of pollution, the foamed soil can be used as soil for growing crops.

[0078] Experimental Example 6: Comparative effect experiment.

[0079] The ecological matrix of the planting layer in this embodiment, namely the coal gangue-based porous artificial soil product (using Gansu Huating gangue, Shuozhou No. 3 Mine gangue, and Xiqu Mine gangue as raw materials respectively), selected French beans as the experimental crop. After sowing leguminous plants, the growth and development of the plants were observed on the 1st, 6th, 10th, and 30th days. During the test period, a comparative test was started between the porous planting layer ecological matrix and the local soil, and the test effects of the porous planting layer ecological matrix (coal gangue-based porous artificial soil) during the 30-day sowing period are as follows:

[0080] On the 1st day, the growth conditions of the porous artificial soil obtained from different coal gangues: The first two pictures from left to right are the porous planting layer ecological matrix of coal gangue from different provinces (Gansu Huating gangue and Shuozhou No. 3 Mine gangue respectively), and the two groups of improved soils on the left were pre-planted with plants; the last two pictures are the local garden soil and the porous planting layer ecological matrix of Xiqu coal gangue, showing the planting soil conditions with synchronous planting and the same soil layer thickness. It can be seen from the pictures that since the two groups of improved soils on the left were pre-planted with plants, the growth of this coal gangue soil is good and the roots are developed, indicating that the porous artificial soils formed from coal gangue in different regions are all suitable for plant planting. The two pictures on the right are the physical pictures on the first day of planting, and no germination has occurred yet.

[0081] On the 6th day, a comparison was made between the germination of the porous artificial soil formed from the coal gangue of the present invention and the local garden soil. Figure 6 It can be seen that the porous planting layer ecological matrix (porous artificial soil formed from coal gangue) germinates earlier than the local garden soil and has well-developed roots. From the growth conditions, it can be seen that the growth of the porous planting layer ecological matrix is excellent.

[0082] On the 10th day, the improved soils of the planting soil (coal gangue) in other places (planted earlier) grew vigorously, the local garden soil began to germinate and the roots were visible, while the porous planting layer ecological matrix of Xiqu coal gangue in this project had grown many leaves and was in good growth condition.

[0083] After a long time (one month, i.e., 30 days), the local garden soil gradually withered, while the porous planting layer ecological matrix remained in good growth; this shows that the porous artificial soil formed from the coal gangue of the present invention has strong durability and is suitable for long-term planting.

[0084] Experimental Example 7: Experiment on the compound planting situation.

[0085] The growth situation outdoors of the porous planting layer ecological substrate (porous artificial soil formed from coal gangue) of the present invention compounded with ordinary loess is as follows:

[0086] As Figure 8 shown, for the porous artificial soil formed from coal gangue with the coal gangue of Xiqu Mine as the main raw material, the germination rate is nearly 98%, and the germination is fast and the growth is excellent.

[0087] Test Example 8: Analysis of the fertilizer efficiency detection situation.

[0088]

[0089] According to the detection results, the relevant indicators of the porous planting layer ecological substrate (porous artificial soil formed from coal gangue) of the present invention meet the relevant indicator requirements in Table 4 of the national standard NY / T 309-1999 for the classification of cultivated land types and cultivated land fertility grades in the loess plateau area. Specifically, as shown in the Figure 9 table data below.

[0090] In summary: The porous planting layer ecological substrate developed in the present invention is based on coal gangue as the main raw material, which not only provides a reliable new way for the comprehensive utilization of coal gangue, but also can improve the soil, replace the loess resources for ecological restoration. At the same time, the porous planting layer ecological substrate has many functions of soil, such as aggregation, porous water retention and fertilizer retention, and the organic matter, available phosphorus, total nitrogen and available potassium can meet the requirements of the physical and chemical properties of cultivated land soil. It can not only replace the soil but also be used as a soil conditioner to improve the soil.

[0091] Experimental Example 9: Physical property indexes and product performance indexes of artificial soil. The soil in the table is the soil of an ordinary garden, and the gangue powder is pure gangue powder directly applied without adding modifiers and other substances. The product refers to the porous artificial soil formed from coal gangue prepared in the present invention.

[0092]

[0093] It can be seen from the above table data that the water retention rate of the product of the present invention is 37%, the heat preservation performance is 8.1, the loose density is 0.43, and the soil loss rate is 1.27. These data are significantly better than those of the existing ordinary soil, which shows that the product of the present invention is very suitable for plant planting.

[0094] Experimental Example 10: Performance indicators of the soil in the control examples. The product refers to the porous artificial soil formed from coal gangue base prepared by the present invention. The difference between Control Example 1 and the product is that no animal and plant protein products are used in the foaming agent, while the difference between Control Example 2 and the product is that no polysaccharides are used in the foaming agent.

[0095] From the data in the table, it can be seen that when animal and plant protein products or polysaccharides are not applicable, the performance of the obtained soil decreases. This is mainly because the application of animal and plant protein products can reduce the surface tension of the liquid, and the viscosity of polysaccharides helps to enhance the structure of the foam, making the foam more stable; when these two substances are not used, the performance of the corresponding soil products also decreases.

[0096]

[0097] Example 11:

[0098] In this example, the coal gangue-based porous artificial soil is applied underwater and then used for the cultivation of underwater plants. The coal gangue-based porous artificial soil forms a layered isolation underwater and forms a sponge-like structure.

[0099] As Figures 10 to 15 shown, when the coal gangue-based porous artificial soil is applied underwater, it forms two natural upper and lower layers, and the decomposition is obvious, forming a sponge-like structure. When touched, this artificial soil has a certain elasticity and is immiscible with water. Figure 14 and Figure 15 are two sponge-like structures taken out after soaking in water for a period of time. It can be seen that they form an integral structure as a whole, and the surface properties are single and uniform, forming a relatively large pore distribution structure, which can be used to adsorb and purify pollutants in water.

[0100] Figure 14 In the group of Figure 15 the content of the foam stabilizer in the artificial soil used is higher than that in the group of Figure 14 By using different amounts of foam stabilizer, soil structures with different surface pores are obtained, and the pores after soaking in water in Figure 15 are significantly larger than those in

[0101] The sponge structure forms a natural integrated state and will not float, disperse, or dissolve in water, which is significantly different from traditional soil. Additionally, the existing coal gangue-based porous artificial soil obtained by the prior art does not form a similar sponge structure due to the different binder materials used in its preparation method, and it does not form a uniform integrated structure.

[0102] As Figures 11 to 13 shown, after a period of time, it can be seen that the upper water layer has been purified, indicating that the pores inside this sponge structure have an adsorption effect, purifying the upper water, and aquatic plants have grown on the soil.

[0103] As Figure 12 shown, after the coal gangue-based porous artificial soil is applied underwater, the purified water can be used for the normal growth of fish, that is, for fish farming.

[0104] Experimental Example 11:

[0105] During the planting process, a foam stabilizer is used. The foam stabilizer is directly applied to the surface of the artificial soil by spraying, or the soil is plowed in the gaps between plants so that the foam stabilizer is mixed into the artificial soil.

[0106] The foam stabilizer is selected as a composition of alkyl polyglycoside, animal and plant protein products, and polysaccharides; this composition is obtained by immersing alkyl polyglycoside and animal and plant protein products in a polysaccharide solution and then drying. When the product soil is used for a period of time, due to problems such as soil compaction, the heat preservation performance and bulk density of the soil will inevitably change. In order to maintain the self-performance of the soil or delay the decline of this performance of the soil, the foaming agent can be continuously applied during the process of using the soil for planting, so that foam can be continuously and slowly formed, thereby maintaining the inherent performance of the soil and making the use effect of the soil better.

[0107]

[0108] The preparation method of the foaming sustainer is as follows: dissolve polysaccharides such as chitosan in water or organic solvents, then immerse alkyl polyglycosides and solid products of animal and plant proteins (preferably granular solids) into the chitosan solution and quickly fish them out, and then dry them. In this way, encapsulated particles with chitosan coated on the surface are formed. When applied to the soil, the three substances are combined together, which is not only convenient for application, but also the combined action of the three substances is faster, avoiding the problems of single application. In addition, chitosan itself has a slow-release function, that is, after gradual molecular degradation, the internal alkyl polyglycosides and solid products of animal and plant proteins leak out, and foam bubbles are gradually formed in the soil, so as to maintain a high air permeability in the soil and correspondingly maintain the soil performance. The function of the gradual release of the chitosan membrane to leak out the internal foaming substances makes the application effect more lasting. The dosage ratio of the substances in the prepared foaming sustainer is the same as the dosage ratio of the three in the above preparation method.

[0109] Preferably, the foaming sustainer is applied at 1% to 2% of the weight of the artificial soil every 6 to 8 months.

[0110] Obviously, the above embodiments are only examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made on the basis of the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for preparing coal gangue-based porous artificial soil, characterized in that: The following steps are included: Step 1: 100 parts of gangue are crushed to a size between 13 mm and 50 mm for later use; Step 2: Add 2 to 5 parts of slag and 1 to 3 parts of fly ash to the gangue obtained in step 1, grind to 120 mesh to 140 mesh, add 0.5 to 2 parts of a regulator and stir evenly; the regulator is desulfurized gypsum, and the desulfurized gypsum has been pre-treated by drying; Step 3: dilute 2.5 to 6 parts of a foaming agent and 3.0 to 8 parts of a foam stabilizer with water, add the mixture to the materials in step 2 and mix evenly; the foaming agent is selected from alkyl glycoside, animal and plant protein products and polysaccharides, the weight proportion of the animal and plant protein products and polysaccharides in the foaming agent is 10% to 20%, and the rest of the foaming agent is alkyl glycoside; the foam stabilizer is at least one of the following substances: starch, polytetrafluoroethylene, phosphated starch, starch xanthate, grafted cellulose, carboxymethylated cellulose, hydroxypropylated cellulose; Step 4: Drying the uniformly mixed slurry to obtain the gangue-based porous artificial soil.

2. The method for preparing the gangue-based porous artificial soil according to claim 1, characterized in that: The animal or plant protein product is at least one of the following substances: soy protein, silk protein, gluten; The polysaccharide is at least one of the following substances: pectin, alginate, and chitosan.

3. The method for preparing the gangue-based porous artificial soil according to claim 1, characterized in that: The drying pretreatment process of desulfurized gypsum is to dry it at 150℃ for 1 hour before use; Dilute the foaming agent and foam stabilizer with water by 10 to 25 times, then add to the materials in step 2 and mix evenly.

4. The method for preparing the gangue-based porous artificial soil according to claim 1, characterized in that: Slag and fly ash are waste residues produced by industrial production with a pH value of less than 8.5 and heavy metal content that meets the requirements of agricultural land risk classification and control in GB 15618-2018, which are industrial solid wastes.

5. The method for preparing the gangue-based porous artificial soil according to claim 1, characterized in that: The gangue raw material is gangue excavation or washed gangue; In step 4: the uniformly mixed slurry is dried and then crushed to obtain the gangue-based porous artificial soil.

6. A coal gangue-based porous artificial soil, characterized in that: The gangue-based porous artificial soil is obtained by the preparation method according to any one of claims 1 to 5.

7. The gangue-based porous artificial soil according to claim 6, characterized in that: Electrical conductivity EC = 0.23256 ± 2.52 dS / m; water-soluble salt content is 1.47 g / kg; the water retention rate of the gangue-based porous artificial soil is 37%, the thermal insulation performance is 8.1 °C, and the loose density is 0.43 g / cm 3 , soil loss rate is 1.27%.

8. The use of the gangue-based porous artificial soil for plant planting according to claim 6, characterized in that: The gangue-based porous artificial soil is applied underwater and then used for planting underwater plants. The gangue-based porous artificial soil is isolated in layers underwater and formed into a sponge structure.

9. The use of the gangue-based porous artificial soil as claimed in claim 7 or 8 for plant planting, characterized in that: The foaming agent is used during the planting process. The foaming agent is directly applied to the surface of the artificial soil in a spraying manner, or the soil is tilled at the gap position between the plants so that the foaming agent is mixed into the artificial soil.

10. The use according to claim 9, characterized in that: The foaming agent is a composition of alkyl glycoside, animal and plant protein products and polysaccharides; the composition is obtained by immersing alkyl glycoside and animal and plant protein products in a polysaccharide solution and then drying; 1% to 2% of the weight of the artificial soil foaming agent is applied every 6-8 months.

Images