A multi-purpose artificial soil and its preparation method and application

Abstract

The present invention provides a multi-purpose artificial soil, its preparation method and application, belonging to the technical field of waste resource utilization. The artificial soil, by weight, comprises 1-60 parts of bottom mud, 1-20 parts of bulk solid waste, 1-15 parts of pore-forming agent, 1-10 parts of plasticizer, 0.2-1.3 parts of water-reducing agent and 10-25 parts of water. The preparation method is as follows: collect the sediment between 4-20 cm below the surface layer at the bottom of rivers and lakes as the bottom mud, dry, crush and grind it to a particle size of 0.1-0.5 mm; mix the bottom mud, bulk solid waste, pore-forming agent, plasticizer, water-reducing agent and water in the above proportions evenly; spray water while granulating the obtained mixture in a granulator at a rotational speed of 20-60 m / s, and obtain the product after drying. The obtained artificial soil can be used as a soil improvement material for high-standard farmland and a filling material for field roads, so that the bottom mud of rivers and lakes can be effectively utilized resourcefully. At the same time, it can effectively fix carbon dioxide on a large scale.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste resource utilization, and particularly relates to a multi-purpose artificial soil, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous, rapid and stable development of the economy, the scale of urban sewage treatment has been continuously improved, and the sludge production has increased accordingly. To improve the water environment quality and basically eliminate urban black and smelly water bodies, dredging is one of the key measures. Lake sediment, as a nutrient-rich substance, supports the growth of aquatic plants and animals. However, the increasing pollution has made the sediment a source of eutrophication. Nevertheless, the sediment is rich in total nitrogen, total phosphorus, total potassium and organic matter. From an agronomic perspective, it is more suitable as the main material for improving soil fertility and is an effective way of resource utilization.

[0003] At the same time, the carbon dioxide (CO2) emissions caused by human activities have increased sharply, becoming one of the main reasons for global warming. To alleviate this problem and meet the challenges of climate change, it is crucial to develop and deploy negative emission technologies. One method is to use industrial solid waste for carbon fixation. Industrial solid waste is rich in silicate minerals, and the silicate minerals further react with CO2 in the atmosphere to form stable carbonate minerals, thereby permanently fixing CO2.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-purpose artificial soil, a preparation method thereof, and an application thereof, which can not only effectively utilize the sediment while solving the problem of eutrophication of river channel water bodies, but also use it as a soil improvement material for high-standard farmland and a filling material for field roads. At the same time, by adjusting the artificial soil, the purpose of effectively fixing carbon dioxide on a large scale can be achieved.

[0006] To achieve the above purpose, the present invention specifically adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a multi-purpose artificial soil, which, by weight, comprises 1-60 parts of sediment, 1-20 parts of bulk solid waste, 1-15 parts of pore-forming agent, 1-10 parts of plasticizer, 0.2-1.3 parts of water-reducing agent, and 10-25 parts of water.

[0008] In the second aspect, the present invention also provides a preparation method of the multi-purpose artificial soil, comprising the following steps:

[0009] S1: Collect the sediment between 4-20 cm below the surface layer at the bottom of rivers and lakes as the sediment, and dry, crush and grind the sediment to a particle size of 0.1-0.5 mm;

[0010] S2: Take 1 - 60 parts by weight of the sediment obtained in step S1, 1 - 20 parts of bulk solid waste, 1 - 15 parts of pore former, 1 - 10 parts of plasticizer, 0.2 - 1.3 parts of water - reducing agent, and 10 - 25 parts of water, and mix them evenly;

[0011] S3: Granulate the mixture obtained in step S2 while spraying water in a granulator at a rotational speed of 20 - 60 m / s, and obtain the product after drying.

[0012] In a third aspect, the present invention also provides an application of the multi - purpose artificial soil: Level the surface layer of the farmland to be improved, cover the surface layer of the farmland with the artificial soil and irrigate it, and then rototill the surface layer of the farmland covered with the artificial soil.

[0013] In a fourth aspect, the present invention also provides another application of the multi - purpose artificial soil: After heating and drying the artificial soil, use it as a subgrade material.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) Resource utilization of sediment and bulk solid waste: This method can effectively convert sediment and bulk solid waste into artificial soil with carbon sequestration ability and rich nutrient elements, realizing the efficient utilization of waste resources and reducing environmental pollution.

[0016] (2) Improve soil quality and fertility: The artificial soil prepared in this application is rich in organic matter and nutrient elements, which can improve soil fertility, enhance the nutrient supply for crop growth, and thus increase crop yields.

[0017] (3) Carbon sequestration ability: The artificial soil prepared in this application has the ability to fix carbon dioxide in the air, contributing to addressing climate change.

[0018] (4) Simple operation and low cost: The preparation method is simple and easy to implement, without the need to equip professional equipment and technical personnel, and the operation cost is relatively low, suitable for farmland construction in different regions and conditions.

[0019] (5) Multi - functional application: This artificial technical soil can not only be used for farmland construction to improve fertility and soil quality, but also can be applied to field road engineering, meeting the construction requirements of high - standard farmland, and having broad application prospects and market potential. Specific embodiments

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. 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.

[0021] For the parts where the proportional relationship of substances is not marked in the embodiments, it should be understood that they can be matched in any proportion. For the parts where the proportional unit of substances is not marked, it should be understood as the relationship of mass ratio.

[0022] A multi-purpose artificial soil according to an embodiment of the present invention, by weight, comprises 1-60 parts of bottom sediment, 1-20 parts of bulk solid waste, 1-15 parts of pore-forming agent, 1-10 parts of plasticizer, 0.2-1.3 parts of water-reducing agent, and 10-25 parts of water.

[0023] The physical and chemical properties of the bottom sediment are similar to those of terrestrial soil and contain various nutrient elements required for plant growth. Applying such nutrient element-rich bottom sediment-based artificial soil to farmland can not only improve soil fertility (such as accelerating the mineralization of organic matter and maintaining the supply of phosphorus for a long time), but also improve soil properties (such as reducing density, increasing soil cation exchange capacity, aggregation degree, and porosity), and can increase the yield of crops.

[0024] A preparation method of the multi-purpose artificial soil according to an embodiment of the present invention comprises the following steps:

[0025] S1: Collect the sediment between 4-20 cm below the surface layer at the bottom of rivers and lakes as the bottom sediment, and dry, crush, and grind the bottom sediment to a particle size of 0.1-0.5 mm.

[0026] The sediment between 4-20 cm below the surface layer at the bottom of rivers and lakes has richer organic matter and nutrient elements such as nitrogen, phosphorus, and potassium. Moreover, its particle size can meet the requirement of 0.1-0.5 mm after simple crushing and screening.

[0027] If the particle size is greater than 0.5 mm, the functions of organic matter and other nutrient components cannot be fully exerted. If it is less than 0.1 mm, it will hinder the exposure of silicate and other active sites during subsequent mixing with other components, especially bulk solid waste, thereby affecting the carbon sequestration effect.

[0028] S2: Take 1-60 parts of the bottom sediment obtained in step S1, 1-20 parts of bulk solid waste, 1-15 parts of pore-forming agent, 1-10 parts of plasticizer, 0.2-1.3 parts of water-reducing agent, and 10-25 parts of water according to weight, and mix them evenly.

[0029] In some alternative embodiments, the bulk solid waste includes one or more of magnesium slag, mica slag, coal gangue or fly ash with a particle size of 1-2 mm. In some more preferred embodiments, the bulk solid waste includes coal gangue with a particle size of 1-2 mm.

[0030] These bulk solid wastes contain a considerable amount of silicate. By combining the sediment with different particle sizes and the remaining components to prepare artificial soil, while effectively increasing the nutrient elements of the artificial soil, the geochemical principle can also be used to fix carbon dioxide through the weathering of silicate solid waste. First, carbon dioxide reacts with silicate to form bicarbonate (HCO3 - ): SiO4 2- + CO2 + H2O → H2SiO4 + HCO3 - , and further, the calcium ions in the artificial soil and the original soil can be used to generate calcium carbonate precipitation for the permanent and stable fixation of carbon dioxide: Ca 2+ + 2HCO3 - = CaCO3 + CO2 + H2O. The large-scale use of this artificial soil will effectively fix CO2 in the atmosphere.

[0031] In some alternative embodiments, the pore-forming agent includes one or more of graphite, coal powder, PMMA microspheres, starch, organic fibers or rice husk powder. In some more preferred embodiments, the pore-forming agent is starch.

[0032] In some alternative embodiments, the plasticizer includes one or more of calcined kaolin, bentonite or black mud. In some more preferred embodiments, the plasticizer is calcined kaolin.

[0033] In some alternative embodiments, the water-reducing agent includes one or more of lignosulfonates, naphthalene-based superplasticizers, melamine-based superplasticizers or amino sulfonate-based superplasticizers. In some more preferred embodiments, the water-reducing agent is lignosulfonates.

[0034] In some preferred embodiments, the particle size of the pore-forming agent is 0.1-1 mm, the particle size of the plasticizer is 0.1-1 mm, and the particle size of the water-reducing agent is 0.1-1 mm.

[0035] S3: Granulate the mixed product described in step S2 in a granulator while spraying water at a rotation speed of 20-60 m / s, and obtain the product after drying.

[0036] In some preferred embodiments, the particle size after granulation is 1-2 mm.

[0037] Application of the multi-purpose artificial soil according to an embodiment of the present invention: Level the surface layer of the field to be improved, cover the surface layer of the field with the artificial soil and irrigate it, and rototill the surface layer of the field covered with the artificial soil.

[0038] In some preferred embodiments, leveling the land includes adjusting the slope of the land with a slope to ensure that plants can grow normally on the land. The irrigation is to ensure that the soil has a certain amount of moisture.

[0039] In some preferred embodiments, the thickness of the artificial soil covering is 10 - 150 cm. In some more preferred embodiments, the thickness of the artificial soil covering is about 50 cm.

[0040] In some preferred embodiments, the rototilling is carried out on the surface layer of the field covered with the artificial soil by using a rototiller.

[0041] Another application of the multi-purpose artificial soil according to an embodiment of the present invention: After heating and drying the artificial soil, it is used as a subgrade material for field road engineering.

[0042] In some preferred embodiments, the temperature of the heating and drying is 60 - 130 °C. In some more preferred embodiments, the temperature of the heating and drying is 100 °C.

[0043] In this application, by selecting appropriate bottom mud raw materials, adding bulk solid wastes, pore-forming agents, plasticizers, water-reducing agents and water, and controlling the different particle sizes of different raw materials, the prepared artificial soil can further adjust the physical and chemical properties and nutrient elements of the bottom mud. At the same time, appropriate treatment of the artificial soil can further change the physical and chemical properties of the artificial soil so as to be used for the construction of farmland roads.

[0044] Example 1

[0045] A multi-purpose artificial soil, comprising 50 parts of bottom mud, 10 parts of bulk solid waste (coal gangue), 10 parts of pore-forming agent (starch), 5 parts of plasticizer (bentonite), 0.5 part of water-reducing agent (lignosulfonates) and 15 parts of water.

[0046] The preparation method is as follows: (1) Collect the sediment between 4 - 20 cm below the surface layer at the bottom of rivers and lakes as the bottom mud, and successively carry out natural drying, artificial crushing, and uniform grinding to make the particle size between 0.1 - 0.5 mm. (2) Take 50 parts of the ground bottom mud, 10 parts of bulk solid waste (coal gangue), 10 parts of pore-forming agent (starch), 5 parts of plasticizer (bentonite), 0.5 parts of water-reducing agent (lignosulfonates), and 15 parts of water, and mix them evenly. Among them, the particle size of the bulk solid waste is 1 - 2 mm, and the particle sizes of the pore-forming agent, plasticizer, and water-reducing agent are all 0.1 - 1 mm. (3) Pour the obtained mixture into a granulator, spray water while granulating at a rotation speed of 30 m / s, control the particle size to be 1 - 2 mm, and naturally dry the granulated particles to obtain the artificial soil.

[0047] Use the obtained artificial soil for the soil improvement of high-standard farmland: Level the land to be improved, cover the land with the artificial soil, cover it with a thickness of 110 cm, then carry out irrigation to ensure that the soil has a certain amount of moisture, and use a rotary tiller to till the soil covering the surface layer of the field. Plant corn in the improved soil.

[0048] Example 2

[0049] A multi-purpose artificial soil includes 40 parts of bottom mud, 15 parts of bulk solid waste (fly ash), 8 parts of pore-forming agent (rice husk powder), 6 parts of plasticizer (calcined kaolin), 1.0 part of water-reducing agent (naphthalene-based superplasticizer), and 20 parts of water.

[0050] The preparation method is as follows: (1) Collect the sediment between 4 - 20 cm below the surface layer at the bottom of rivers and lakes as the bottom mud, and successively carry out natural drying, artificial crushing, and uniform grinding to make the particle size between 0.1 - 0.5 mm. (2) Take 40 parts of the ground bottom mud, 15 parts of bulk solid waste (fly ash), 8 parts of pore-forming agent (rice husk powder), 6 parts of plasticizer (calcined kaolin), 1.0 part of water-reducing agent (naphthalene-based superplasticizer), and 20 parts of water, and mix them evenly. Among them, the particle size of the bulk solid waste is 1 - 2 mm, and the particle sizes of the pore-forming agent, plasticizer, and water-reducing agent are all 0.1 - 1 mm. (3) Pour the obtained mixture into a granulator, spray water while granulating at a rotation speed of 35 m / s, control the particle size to be 1 - 2 mm, and naturally dry the granulated particles to obtain the artificial soil.

[0051] Use the obtained artificial soil for the soil improvement of high-standard farmland: Level the land to be improved, cover the land with the artificial soil, cover it with a thickness of 60 cm, then carry out irrigation to ensure that the soil has a certain amount of moisture, and use a rotary tiller to till the soil covering the surface layer of the field. Plant corn in the improved soil.

[0052] Example 3

[0053] A multi-purpose artificial soil, comprising 45 parts of bottom mud, 10 parts of bulk solid waste (magnesium slag), 7 parts of pore-forming agent (organic fiber), 4 parts of plasticizer (black mud), 0.5 part of water-reducing agent (melamine-based high-efficiency water-reducing agent type) and 15 parts of water.

[0054] The preparation method thereof is as follows: (1) Collect the sediment between 4 - 20 cm below the surface layer at the bottom of rivers and lakes as the bottom mud, and successively carry out natural drying, manual crushing and uniform grinding to make the particle size between 0.1 - 0.5 mm. (2) Take 45 parts of the ground bottom mud, 10 parts of bulk solid waste (magnesium slag), 7 parts of pore-forming agent (organic fiber), 4 parts of plasticizer (black mud), 0.5 part of water-reducing agent (melamine-based high-efficiency water-reducing agent type) and 15 parts of water and mix them evenly. Among them, the particle size of the bulk solid waste is 1 - 2 mm, and the particle sizes of the pore-forming agent, plasticizer and water-reducing agent are all 0.1 - 1 mm. (3) Pour the obtained mixture into a granulator, spray water and granulate while rotating at a speed of 28 m / s, control the particle size at 1 - 2 mm, and naturally dry the granulated particles to obtain the artificial soil.

[0055] Use the obtained artificial soil for the improvement of high-standard farmland soil: Level the land to be improved, cover the land with the artificial soil, cover it by 80 cm, and then irrigate to ensure that the soil has a certain amount of moisture, and use a rotary tiller to rotary till the soil covering the surface layer of the field. Plant corn in the improved soil.

[0056] Example 4

[0057] A multi-purpose artificial soil, comprising 50 parts of bottom mud, 12 parts of bulk solid waste (mica slag), 10 parts of pore-forming agent (rice husk powder), 7 parts of plasticizer (calcined kaolin), 0.8 part of water-reducing agent (amino sulfonate-based high-efficiency water-reducing agent type) and 18 parts of water.

[0058] The preparation method thereof is as follows: (1) Collect the sediment between 4 - 20 cm below the surface layer at the bottom of rivers and lakes as the bottom mud, and successively carry out natural drying, manual crushing and uniform grinding to make the particle size between 0.1 - 0.5 mm. (2) Take 50 parts of the ground bottom mud, 12 parts of bulk solid waste (mica slag), 10 parts of pore-forming agent (rice husk powder), 7 parts of plasticizer (calcined kaolin), 0.8 part of water-reducing agent (amino sulfonate-based high-efficiency water-reducing agent type) and 18 parts of water and mix them evenly. Among them, the particle size of the bulk solid waste is 1 - 2 mm, and the particle sizes of the pore-forming agent, plasticizer and water-reducing agent are all 0.1 - 1 mm. (3) Pour the obtained mixture into a granulator, spray water and granulate while rotating at a speed of 30 m / s, control the particle size at 1 - 2 mm, and naturally dry the granulated particles to obtain the artificial soil.

[0059] The obtained artificial soil is used for improving the soil of high-standard farmland: The land to be improved is leveled, covered with the artificial soil to a depth of 90 cm, then irrigated to ensure that the soil has a certain moisture content, and a rotary tiller is used to till the soil covering the surface layer of the field. Corn is planted in the improved soil.

[0060] Example 5

[0061] A multi-purpose artificial soil includes 35 parts of bottom mud, 20 parts of bulk solid waste (fly ash), 12 parts of pore-forming agent (starch), 9 parts of plasticizer (calcined kaolin), 1.2 parts of water-reducing agent (naphthalene-based high-efficiency water-reducing agent type), and 22 parts of water.

[0062] Its preparation method is as follows: (1) Sediments between 4 - 20 cm below the surface layer of the river or lake bottom are collected as bottom mud, and are naturally air-dried, manually crushed, and ground evenly in sequence, so that the particle size is between 0.1 - 0.5 mm. (2) 35 parts of the ground bottom mud, 20 parts of bulk solid waste (fly ash), 12 parts of pore-forming agent (starch), 9 parts of plasticizer (calcined kaolin), 1.2 parts of water-reducing agent (naphthalene-based high-efficiency water-reducing agent type), and 22 parts of water are mixed evenly. Among them, the particle size of the bulk solid waste is 1 - 2 mm, and the particle sizes of the pore-forming agent, plasticizer, and water-reducing agent are all 0.1 - 1 mm. (3) The obtained mixture is poured into a granulator, and granulated while spraying water at a rotation speed of 32 m / s, with the particle size controlled at 1 - 2 mm. The granulated particles are naturally air-dried to obtain the artificial soil.

[0063] The obtained artificial soil is used for improving the soil of high-standard farmland: The land to be improved is leveled, covered with the artificial soil to a depth of 100 cm, then irrigated to ensure that the soil has a certain moisture content, and a rotary tiller is used to till the soil covering the surface layer of the field. Corn is planted in the improved soil.

[0064] Example 6

[0065] The multi-purpose artificial soil and its preparation method are the same as those in Example 5.

[0066] The obtained artificial soil is used for filling the roadbed of farmland: The artificial soil is heated and dried at 100 °C and then filled.

[0067] Example 7

[0068] A multi-purpose artificial soil includes 30 parts of bottom mud, 25 parts of bulk solid waste (coal gangue), 10 parts of pore-forming agent (organic fiber), 8 parts of plasticizer (black mud), 0.8 parts of water-reducing agent (lignosulfonate type), and 20 parts of water.

[0069] The preparation method is as follows: (1) Collect the sediment between 4 - 20 cm below the surface layer at the bottom of rivers and lakes as the bottom mud, and successively carry out natural drying, artificial crushing, and uniform grinding to make the particle size between 0.1 - 0.5 mm. (2) Take 30 parts of the ground bottom mud, 25 parts of bulk solid waste (coal gangue), 10 parts of pore-forming agent (organic fiber), 8 parts of plasticizer (black mud), 0.8 parts of water-reducing agent (lignosulfonates), and 20 parts of water, and mix them evenly. Among them, the particle size of the bulk solid waste is 1 - 2 mm, and the particle sizes of the pore-forming agent, plasticizer, and water-reducing agent are all 0.1 - 1 mm. (3) Pour the obtained mixture into a granulator, spray water and granulate while rotating at a speed of 28 m / s, control the particle size at 1 - 2 mm, and naturally dry the granulated particles to obtain the artificial soil.

[0070] Use the obtained artificial soil for filling the farmland roadbed: Heat and dry the artificial soil at 90 °C and then carry out the filling.

[0071] Example 8

[0072] A multi-purpose artificial soil, comprising 40 parts of bottom mud, 15 parts of bulk solid waste (magnesium slag), 8 parts of pore-forming agent (rice husk powder), 6 parts of plasticizer (calcined kaolin), 1.0 part of water-reducing agent (naphthalene-based high-performance water-reducing agent), and 18 parts of water.

[0073] The preparation method is as follows: (1) Collect the sediment between 4 - 20 cm below the surface layer at the bottom of rivers and lakes as the bottom mud, and successively carry out natural drying, artificial crushing, and uniform grinding to make the particle size between 0.1 - 0.5 mm. (2) Take 40 parts of the ground bottom mud, 15 parts of bulk solid waste (magnesium slag), 8 parts of pore-forming agent (rice husk powder), 6 parts of plasticizer (calcined kaolin), 1.0 part of water-reducing agent (naphthalene-based high-performance water-reducing agent), and 18 parts of water, and mix them evenly. Among them, the particle size of the bulk solid waste is 1 - 2 mm, and the particle sizes of the pore-forming agent, plasticizer, and water-reducing agent are all 0.1 - 1 mm. (3) Pour the obtained mixture into a granulator, spray water and granulate while rotating at a speed of 30 m / s, control the particle size at 1 - 2 mm, and naturally dry the granulated particles to obtain the artificial soil.

[0074] Use the obtained artificial soil for filling the farmland roadbed: Heat and dry the artificial soil at 110 °C and then carry out the filling.

[0075] Example 9

[0076] A multi-purpose artificial soil, comprising 45 parts of bottom mud, 12 parts of bulk solid waste (mica slag), 7 parts of pore-forming agent (starch), 5 parts of plasticizer (bentonite), 1.3 parts of water-reducing agent (amino sulfonate-based high-performance water-reducing agent), and 15 parts of water.

[0077] The preparation method is as follows: (1) Collect the sediment between 4 - 20 cm below the surface layer at the bottom of rivers and lakes as the bottom mud, and successively carry out natural drying, artificial crushing, and uniform grinding to make the particle size between 0.1 - 0.5 mm. (2) Take 45 parts of the ground bottom mud, 12 parts of bulk solid waste (mica slag), 7 parts of pore-forming agent (starch), 5 parts of plasticizer (bentonite), 1.3 parts of water-reducing agent (amino sulfonate-based high-efficiency water-reducing agent type), and 15 parts of water, and mix them evenly. Among them, the particle size of the bulk solid waste is 1 - 2 mm, and the particle sizes of the pore-forming agent, plasticizer, and water-reducing agent are all 0.1 - 1 mm. (3) Pour the obtained mixture into a granulator, spray water while granulating at a rotation speed of 34 m / s, control the particle size at 1 - 2 mm, and naturally dry the granulated particles to obtain the artificial soil.

[0078] Use the obtained artificial soil for filling the farmland roadbed: Heat and dry the artificial soil at 100 °C and then carry out the filling.

[0079] Example 10

[0080] A multi-purpose artificial soil includes 50 parts of bottom mud, 10 parts of bulk solid waste (coal gangue), 12 parts of pore-forming agent (starch), 7 parts of plasticizer (calcined kaolin), 1.1 parts of water-reducing agent (naphthalene-based high-efficiency water-reducing agent type), and 25 parts of water.

[0081] The preparation method is as follows: (1) Collect the sediment between 4 - 20 cm below the surface layer at the bottom of rivers and lakes as the bottom mud, and successively carry out natural drying, artificial crushing, and uniform grinding to make the particle size between 0.1 - 0.5 mm. (2) Take 50 parts of the ground bottom mud, 10 parts of bulk solid waste (coal gangue), 12 parts of pore-forming agent (starch), 7 parts of plasticizer (calcined kaolin), 1.1 parts of water-reducing agent (naphthalene-based high-efficiency water-reducing agent type), and 25 parts of water, and mix them evenly. Among them, the particle size of the bulk solid waste is 1 - 2 mm, and the particle sizes of the pore-forming agent, plasticizer, and water-reducing agent are all 0.1 - 1 mm. (3) Pour the obtained mixture into a granulator, spray water while granulating at a rotation speed of 36 m / s, control the particle size at 1 - 2 mm, and naturally dry the granulated particles to obtain the artificial soil.

[0082] Use the obtained artificial soil for filling the farmland roadbed: Heat and dry the artificial soil at 130 °C and then carry out the filling.

[0083] Comparative Example 1

[0084] Carry out corn planting on the unimproved land and measure the soil indicators.

[0085] Comparative Example 2

[0086] The difference from Example 1 is that: Collect the sediment between 0 - 30 cm below the surface layer at the bottom of rivers and lakes as the bottom mud.

[0087] Comparative Example 3

[0088] It is different from Example 1 in that the particle size of the milled bottom mud is between 0.01 - 0.1 mm.

[0089] Comparative Example 4

[0090] It is different from Example 1 in that the particle size of the milled bottom mud is between 0.5 - 2.0 mm.

[0091] Comparative Example 5

[0092] Sampling was carried out on the unimproved field road.

[0093] The test results of the soil properties of Examples 1 - 5 and Comparative Examples 1 - 4 are shown in Table 1, and the test results of the performance of the artificial soil of Examples 6 - 10 and Comparative Example 5 used as a filling material for farmland roadbeds are shown in Table 2.

[0094] Table 1 Test Results of Soil Properties of Examples 1 - 5 and Comparative Examples 1 - 4

[0095]

[0096] Table 2 Test Results of Farmland Roadbed Performance of Examples 6 - 10 and Comparative Example 5

[0097]

[0098]

[0099] As can be seen from Table 1, the artificial soil prepared by the present invention has rich nutrient chemical elements. After the application of the artificial soil, the contents of available nitrogen, available phosphorus, and organic matter have all increased significantly. At the same time, when corn is planted in the improved soil, it can grow to a higher plant height in the same time. Therefore, the artificial soil prepared by the present invention can be used as an artificial soil for improving the soil fertility of high-standard farmland. At the same time, this artificial soil has the ability to sequester carbon. After the application of the artificial soil, the carbonate concentration in the soil has increased significantly, indicating that the artificial soil can effectively fix carbon dioxide.

[0100] It can be seen from the comparison between Comparative Example 2 and Example 1 that, compared with selecting the sediment between 4 - 20 cm as the bottom mud, collecting the sediment between 0 - 30 cm below the surface layer of the river and lake bottom as the bottom mud shows a significant reduction in nutrient chemical elements. It can be seen from the comparison between Comparative Example 3 and Example 1 that the particle size of the crushed bottom mud less than 0.1 mm has a greater impact on the carbon sequestration performance. It can be seen from the comparison between Comparative Example 4 and Example 1 that although the contents of available nitrogen, available phosphorus, and organic matter do not decrease much, their nutrient components fail to play a role, and the plant height of the planted corn is not much different from that of ordinary soil in the same time.

[0101] As can be seen from Table 2, using the artificial soil of the present invention as a subgrade material can effectively meet the various indicators for a field road subgrade material, and at the same time, this artificial soil also has the ability to fix carbon dioxide.

[0102] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification. The above embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A preparation method of a multi-purpose artificial soil, characterized in that, It includes the following steps: S1: Collect the sediment between 4 - 20 cm below the surface layer of the river or lake bottom as the bottom mud, dry, crush and grind the bottom mud to a particle size of 0.1 - 0.5 mm; S2: By weight, take 1 - 60 parts of the bottom mud obtained in step S1, 1 - 20 parts of bulk solid waste, 1 - 15 parts of pore-forming agent, 1 - 10 parts of plasticizer, 0.2 - 1.3 parts of water-reducing agent and 10 - 25 parts of water, and mix them evenly; S3: Spray water while granulating the mixture in step S2 in a granulator at a rotational speed of 20 - 60 m / s, and obtain the product after drying; The bulk solid waste includes coal gangue with a particle size of 1 - 2 mm; The pore-forming agent includes one or more of graphite, coal powder, PMMA microspheres, starch, organic fibers or rice husk powder with a particle size of 0.1 - 1 mm; The plasticizer includes one or more of calcined kaolin, bentonite or black mud with a particle size of 0.1 - 1 mm; The water-reducing agent includes one or more of lignosulfonate-based, naphthalene-based high-performance water-reducing agent-based, melamine-based high-performance water-reducing agent-based or amino sulfonate-based high-performance water-reducing agent-based with a particle size of 0.1 - 1 mm; In step S3, the particle size of the granulated product is 1 - 2 mm.

2. Application of the multi-purpose artificial soil prepared by the preparation method of the multi-purpose artificial soil according to claim 1, characterized in that Level the surface layer of the field to be improved, cover the surface layer of the field with the artificial soil and irrigate it, and rototill the surface layer of the field covered with the artificial soil.

3. Use of the multi-purpose artificial soil according to claim 2, characterized in that, The thickness of the artificial soil coverage is 10 - 150 cm.

4. Use of a multi-purpose artificial soil prepared by the method for preparing a multi-purpose artificial soil according to claim 1, characterized in that, After heating and drying the artificial soil, it is used as a subgrade material.

5. Use of the multi-purpose artificial soil according to claim 4, characterized in that, The temperature of the heating and drying is 60 - 130 °C.

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