Method for preparing artificial soil from open pit coal mine stripping fluid through fluidization

Abstract

The invention discloses a method for preparing artificial soil from open pit coal mine stripping fluid through fluidization, and belongs to the technical field of land reclamation. Comprising the following steps: selecting stripped substances of an open pit coal mine, preparing a dissolving solution, carrying out total amount control on the stripped substances and the dissolving solution according to a ratio of 1.5: 1, firstly putting the prepared stripped substances of a mine rock stratum into the dissolving solution, standing for 30 minutes to 1 hour, then putting the residual stripped substances on the surface layer of the mine, and fully stirring to form the basic fluidized artificial soil. The invention further provides an artificial soil improvement and solid-liquid separation method. The method has the advantages that rock soil is disintegrated in a hydrolysis mode, and dust pollution is less; the requirement on the humidity of the material is not very high; based on establishment of a fixed place, artificial soil is prepared by adopting a wet method, and the requirement on crushing and screening machinery is low; the fluidized artificial soil can be transported based on a pipeline, so that the transportation efficiency is higher, the cost is lower, and the transportation frequency is less.

Description

Technical Field

[0001] The invention belongs to the technical field of land reclamation, and particularly relates to a method for integrally preparing artificial soil from the overburden of an open-pit coal mine. Background Art

[0002] Due to open-pit mining, all the topsoil and various rock layers above the coal seam need to be stripped, which not only has a destructive impact on the original vegetation and soil in the mining area, but also the waste dump will occupy a large amount of intact land, resulting in a series of problems such as a decline in soil quality, a reduction in biodiversity, and ecological environment degradation. Therefore, the damage to the ecological environment caused by open-pit coal mine development has become one of the important problems currently faced in China. The open-pit coal mine mining seriously damages the soil layer. Although topsoil stripping has been advocated, the slope and platform area of the waste dump formed by mining are much larger than the original surface area, and the lack of topsoil has always been a difficult point in open-pit mine reclamation. At present, the soil used for mine reclamation mainly comes from the stripped topsoil generated during mining advancement and the topsoil within the original expropriated land range. Many mines lack sufficient topsoil for vegetation restoration during the stage of mining stoppage or pit closure. At the same time, the formation process of topsoil is relatively long and the resource reserves are limited. If sufficient topsoil is to be obtained for reclamation, it is necessary to supplement it by damaging the topsoil in other areas, causing secondary damage to the ecological environment. The long-term storage of topsoil will lead to a decline in soil fertility, resulting in a low survival rate of vegetation and poor reclamation effects, and the secondary transportation cost of imported soil is relatively high. Therefore, how to use the stripped materials to prepare topsoil substitute materials has become the key to solving this problem.

[0003] In terms of controlling the properties of artificial soil, the current existing technologies mainly adopt the method of physical crushing and screening. This method has problems such as relatively serious dust pollution, a large influence of physical crushing by working conditions (material humidity, climatic conditions), relatively high mechanical costs, large losses, and the need for multiple transportation and shaping after crushing and screening.

[0004] At present, there is a lack of systematic solid waste utilization methods, and there is a lack of economical utilization methods for the solid waste of open-pit coal mines. The basic process for utilization is "crushing - transportation - screening - transportation - stirring - covering soil". The whole process requires multiple transportation. If the effect cannot be achieved by one-time crushing, multiple crushing is still required. Most artificial soil needs to go through a screening process. The screening sites are mostly open-air, affected by meteorological factors such as rainfall, resulting in an increase in the humidity of the stripped materials and making it difficult to screen. There are many scene limitations in the preparation of artificial soil. Mixing the stripped materials in water can remove the influence of humidity factors; the application scenarios of artificial soil are also relatively single. It is mainly crushed by physical measures and modifiers are added to make the artificial soil approach the state of natural soil. However, after fluidization, the artificial soil is more diversified. It can be sprayed, granulated, filter-pressed into blocks, or artificial soil can be formed by drying and vibrating, and the utilization direction is wider. Summary of the Invention

[0005] Aiming at the deficiencies existing in the prior art, the purpose of the present invention is to provide a method for integrally preparing artificial soil from the stripping materials of open-pit coal mines, so as to solve the problems of insufficient topsoil in previous coal mining areas and the occupation of land resources by stripping materials.

[0006] The technical solution adopted by the invention is: a method for integrally preparing artificial soil from the stripping materials of open-pit coal mines, and its technical key points include the following steps: Select the stripping materials of open-pit coal mines, including the stripping materials from the surface layer of the mine and the stripping materials from the mine rock stratum; control the total amount of the stripping materials and the dissolving liquid at a ratio of 1.5:1. First, put the prepared stripping materials from the mine rock stratum into the dissolving liquid, and after standing, then put the remaining stripping materials from the surface layer of the mine. After sufficient stirring, a basic fluidized artificial soil is formed. The main components of the dissolving liquid include water, citric acid, diammonium hydrogen phosphate, concentrated potassium fulvate solution, Bacillus mucilaginosus, and Bacillus subtilis. Among them, water is the main component, accounting for 95%, and the proportion of the remaining components is 5%. The remaining components mainly consist of 20 - 30 parts of citric acid, 10 - 20 parts of diammonium hydrogen phosphate, 30 - 40 parts of concentrated potassium fulvate solution, 5 - 10 parts of Bacillus mucilaginosus, and 5 - 10 parts of Bacillus subtilis.

[0007] In the above solution, the preparation method of the dissolving liquid is: inject water into a swirlable water tank, control the water temperature at 30℃ ± 2℃, add Bacillus mucilaginosus and Bacillus subtilis. After the bacterial flora is completely dissolved in water, add citric acid, diammonium hydrogen phosphate, and concentrated potassium fulvate solution, and stir them evenly to form a dissolving liquid.

[0008] In the above solution, the standing time is 30 min - 1 h.

[0009] In the above solution, the stripping materials from the surface layer of the mine mainly include loam, silt clay, clay, and sandy soil with a particle size less than 10 cm; In the above solution, the stripping materials from the mine rock stratum mainly include sedimentary mudstone with a particle size less than 5 cm, coal mine sedimentary carbonaceous mudstone, and other soluble rocks such as limestone and dolomite.

[0010] An improved method for integrally preparing artificial soil from the stripping materials of open-pit coal mines, and its technical key points are to cool the basic fluidized artificial soil described in claim 1 to room temperature 23℃ ± 2℃, and mix 60 - 80 parts of fluid artificial soil, 3 - 5 parts of peat, 5 - 10 parts of organic fertilizer, 5 - 10 parts of corn cob, 3 - 5 parts of distiller's grains, 3 - 5 parts of coconut shell or coconut coir, 1 - 2 parts of superabsorbent resin, 1 - 2 parts of soil binder, and 12 - 15 parts of grass seeds in a quantitative proportion evenly.

[0011] A solid-liquid separation method for integrally preparing artificial soil from the stripping materials of an open-pit coal mine. The technical key points are as follows: keeping the temperature of the basic fluidized artificial soil described in claim 1 unchanged, mixing 80 - 85 parts of fluid artificial soil, 5 - 10 parts of organic fertilizer, 5 - 10 parts of mine plant litter, 3 - 5 parts of coconut shell or coconut coir, and 5 - 10 parts of corncob evenly, and after maintaining for 2 hours, adopting a solid-liquid separation method based on a filter press to obtain a solid component and a liquid component.

[0012] In the above solution, the solid component is used as the artificial soil base material for mine land reclamation, and the liquid is used as the nutrient solution for topdressing arbors and shrubs. The beneficial effects of the present invention are as follows: This method for integrally preparing artificial soil from the stripping materials of an open-pit coal mine uses hydrolysis to disintegrate rock and soil, with less dust pollution; has not very high requirements for the humidity of materials; based on the establishment of a fixed site, adopts a wet method to prepare artificial soil, and does not require many crushing and screening machines; the fluidized artificial soil can be transported through pipelines, with higher transportation efficiency, lower cost, and fewer transfer times. The fluidized artificial soil has the conditions for multi-scenario applications of solids and liquids and can be utilized separately based on solid-liquid separation. Description of the Drawings

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only 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.

[0014] Figure 1 It is a block diagram of the method for integrally preparing artificial soil from the stripping materials of an open-pit coal mine in the embodiment of the present invention. Detailed Embodiments

[0015] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will further describe the present invention in detail with reference to the Figure 1 accompanying drawings and specific embodiments. Embodiment 1:

[0016] The method for integrally preparing artificial soil from the stripping materials of an open-pit coal mine in this embodiment includes the following steps: Select the stripping materials of the open-pit coal mine. The surface stripping materials of the open-pit mine include loam, silt clay, clay with a particle size of 8 cm, and sandy soil with a particle size of 2 cm. The rock stripping materials mainly include sedimentary mudstone with a particle size of 5 cm and coal mine sedimentary carbonaceous mudstone (TOC > 10%) according to the lithology. The composition of the stripping materials in this embodiment is as follows: by weight, it consists of the following components: 15 parts of loam, 15 parts of silt clay, 10 parts of clay, 5 parts of sandy soil, 20 parts of mudstone, and 10 parts of carbonaceous mudstone.

[0017] Prepare a dissolution solution by the following method: Inject water into a swirlable pool, control the water temperature at 30°C ± 2°C, add Bacillus mucilaginosus and Bacillus subtilis. After the bacterial community is completely dissolved in water, add citric acid, diammonium hydrogen phosphate, and potassium fulvate concentrate, and stir evenly to form a dissolution solution.

[0018] Control the total amount of the stripping material and the dissolution solution at a ratio of 1.5:1. First, put the prepared stripping material of the mine rock formation into the dissolution solution, let it stand for 30 minutes, and then put the remaining stripping material of the mine surface layer. After sufficient stirring, a basic fluidized artificial soil is formed.

[0019] In this example, the main components of the dissolution solution include water, citric acid, diammonium hydrogen phosphate, potassium fulvate concentrate, Bacillus mucilaginosus, and Bacillus subtilis. Among them, water is the main component, accounting for 95%, and the proportion of the remaining components is 5%. The remaining components mainly consist of 20 parts of citric acid, 10 parts of diammonium hydrogen phosphate, 30 parts of potassium fulvate concentrate, 5 parts of Bacillus mucilaginosus, and 5 parts of Bacillus subtilis. Example 2:

[0020] The difference between this example and Example 1 is that the stripping loam of the selected target open-pit coal mine has less soil and is severely desertified. The stripping material on the surface layer of the open-pit mine includes clay loam with a particle size of 10 cm, clay, and sandy soil with a particle size of 2 cm. The stripping material of the rock formation mainly includes sedimentary mudstone with a particle size of 5 cm and coal mine sedimentary carbonaceous mudstone (TOC > 10%) according to the lithology. The composition of the stripping material in this example is: by weight, it consists of the following components: 10 parts of loam, 20 parts of clay loam, 15 parts of clay, 10 parts of sandy soil, 30 parts of mudstone, and 15 parts of carbonaceous mudstone.

[0021] In this example, the main components of the dissolution solution include water, citric acid, diammonium hydrogen phosphate, potassium fulvate concentrate, Bacillus mucilaginosus, and Bacillus subtilis. Among them, water is the main component, accounting for 95%, and the proportion of the remaining components is 5%. The remaining components mainly consist of 30 parts of citric acid, 20 parts of diammonium hydrogen phosphate, 40 parts of potassium fulvate concentrate, 10 parts of Bacillus mucilaginosus, and 10 parts of Bacillus subtilis.

[0022] Control the total amount of the stripping material and the dissolution solution at a ratio of 1.5:1. First, put the prepared stripping material of the mine rock formation into the dissolution solution, let it stand for 1 hour, and then put the remaining stripping material of the mine surface layer. After sufficient stirring, a basic fluidized artificial soil is formed. Example 3:

[0023] This embodiment provides an improved method for fluidized artificial soil suitable for spraying substrates. The specific method is as follows: Using the prepared basic fluidized artificial soil, cool the basic fluidized artificial soil to room temperature of 21°C. Take 60 parts of fluid artificial soil, 3 parts of peat, 5 parts of organic fertilizer, 5 parts of corn cobs, 3 parts of distiller's grains, 3 parts of coconut husk or coconut coir, 1 part of superabsorbent resin, 1 part of soil binder, and the grass seeds account for 12 parts in a fixed ratio. After mixing evenly, pump it through a slurry pump and use it for spraying in mine land reclamation. Example 4:

[0024] This embodiment provides an improved method for fluidized artificial soil suitable for spraying substrates. The specific method is as follows: Using the prepared basic fluidized artificial soil, cool the basic fluidized artificial soil to room temperature of 25°C. Take 80 parts of fluid artificial soil, 5 parts of peat, 10 parts of organic fertilizer, 10 parts of corn cobs, 5 parts of distiller's grains, 5 parts of coconut husk or coconut coir, 2 parts of superabsorbent resin, 2 parts of soil binder, and the grass seeds account for 15 parts in a fixed ratio. After mixing evenly, pump it through a slurry pump and use it for spraying in mine land reclamation. Example 5:

[0025] This embodiment provides a method for solid-liquid separation of fluidized artificial soil. The specific method is as follows: Using the prepared basic fluidized artificial soil, keep the temperature of the basic fluidized artificial soil unchanged. Take 80 parts of fluid artificial soil, 5 parts of organic fertilizer, 5 parts of mine plant litter, 3 parts of coconut husk or coconut coir, 5 parts of corn cobs, and mix evenly. After maintaining for 2 hours, based on a filter press, adopt a solid-liquid separation method to obtain a solid component and a liquid component. The solid component is the artificial soil substrate and can be used for mine land reclamation, and the liquid can be used as a nutrient solution for topdressing of trees and shrubs. Example 6:

[0026] This embodiment provides a method for solid-liquid separation of fluidized artificial soil. The specific method is as follows: Using the prepared basic fluidized artificial soil, keep the temperature of the basic fluidized artificial soil unchanged. Take 85 parts of fluid artificial soil, 10 parts of organic fertilizer, 10 parts of mine plant litter, 5 parts of coconut husk or coconut coir, 10 parts of corn cobs, and mix evenly. After maintaining for 2 hours, based on a filter press, adopt a solid-liquid separation method to obtain a solid component and a liquid component. The solid component is the artificial soil substrate and can be used for mine land reclamation, and the liquid can be used as a nutrient solution for topdressing of trees and shrubs.

[0027] As mentioned above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A method for preparing artificial soil by fluidization of open-pit coal mine stripping, characterized in that: The following steps are involved: Select the strippings from the open-pit coal mine, including the strippings from the mine surface and the strippings from the mine rock layer; the total amount of the strippings and the dissolving liquid is controlled at a ratio of 1.5:1, the prepared strippings from the mine rock layer are first put into the dissolving liquid, and after standing, the remaining strippings from the mine surface are put into the dissolving liquid, and after being fully stirred, the basic fluidized artificial soil is formed; The main components of the dissolving solution include water, citric acid, diammonium hydrogen phosphate, potassium humate concentrate, jelly-like Bacillus, and Bacillus subtilis, wherein water is the main component, accounting for 95%, and the remaining components account for 5%. The remaining components are mainly composed of 20-30 parts of citric acid, 10-20 parts of diammonium hydrogen phosphate, 30-40 parts of potassium humate concentrate, 5-10 parts of jelly-like Bacillus, and 5-10 parts of Bacillus subtilis.

2. The method for preparing artificial soil by fluidization of open-pit coal mine stripping according to claim 1, characterized in that: The preparation method of the dissolving solution is as follows: inject water into a swirling water pool, control the water temperature to be 30°C±2°C, add jelly-like bacillus and bacillus subtilis, and after the bacterial flora is completely dissolved in the water, add citric acid, diammonium hydrogen phosphate, and potassium humate concentrate, stir evenly, and form a dissolving solution.

3. The method for preparing artificial soil by fluidization of open-pit coal mine stripping according to claim 1, characterized in that: The standing time is 30min-1h.

4. The method for solid-liquid separation of open-pit coal mine stripping fluidization to prepare artificial soil according to claim 1, characterized in that: The stripping materials on the surface of the mine mainly include loam, sub-clay, clay and sand with a particle size less than 10 cm.

5. The solid-liquid separation method for preparing artificial soil by fluidizing open-pit coal mine stripping according to claim 1, characterized in that: The stripping materials of the mine rock strata mainly include sedimentary mudstone with a particle size less than 5 cm, coal mine sedimentary carbonaceous mudstone and other soluble rocks such as limestone and dolomite.

6. An improved method for preparing artificial soil by fluidization of open-pit coal mine stripping, characterized in that: The basic fluidized artificial soil of claim 1 is cooled to room temperature of 23°C±2°C, and 60-80 parts of fluidized artificial soil, 3-5 parts of peat, 5-10 parts of organic fertilizer, 5-10 parts of corn cobs, 3-5 parts of wine lees, 3-5 parts of coconut shells or coconut bran, 1-2 parts of highly absorbent resin, 1-2 parts of soil adhesive, and 12-15 parts of grass seeds are mixed evenly.

7. A solid-liquid separation method for preparing artificial soil by fluidizing stripping fluids in open-pit coal mines, characterized in that: Keeping the temperature of the basic fluidized artificial soil described in claim 1 unchanged, 80-85 parts of fluidized artificial soil, 5-10 parts of organic fertilizer, 5-10 parts of mine plant litter, 3-5 parts of coconut shells or coconut husks, and 5-10 parts of corn cobs are uniformly mixed and maintained for 2 hours, and then solid-liquid separation is performed using a filter press to obtain a solid component and a liquid component.

8. The solid-liquid separation method for preparing artificial soil by fluidizing open-pit coal mine stripping according to claim 7, characterized in that: The solid component is used as an artificial soil base material for mine land reclamation, and the liquid is used as a nutrient solution for topdressing trees and shrubs.

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