Method for preparing organic fertilizer through modification of coal-based solid waste and agricultural waste

Abstract

The invention provides a method for preparing an organic fertilizer through modification of coal-based solid waste and agricultural waste, and belongs to the technical field of solid waste reutilization. According to the method provided by the invention, the underground pit type animal house structure is prepared from solid wastes such as the coal gangue, the coal ash and the straws, and then livestock breeding is carried out, so that livestock can move on the surface soil layer of the animal house prepared by taking the coal gangue, the straws and the filler as raw materials in the breeding process; the urine naturally permeates into the packing layer of the animal house through the surface soil layer of the animal house to be stored and preliminarily fermented, and the excrement is gradually accumulated on the surface soil layer of the animal house and is regularly removed for storage for later use; the animal house packing layer not only can uniformly absorb and store urine and prevent local part from being too wet or too dry, but also can optimize a percolation environment, promote slow release decomposition and nitrogen fixation of feces, reduce emission of harmful gases such as ammonia gas and the like, and improve the air quality of a livestock farm.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste recycling, and in particular to a method for preparing organic fertilizer by modifying coal-based solid waste in conjunction with agricultural waste. Background Art

[0002] As an important traditional energy source, coal is consumed in high quantities annually, resulting in a significant amount of coal-based solid waste. Gangue, the primary solid waste generated during coal mining and washing, occupies significant land areas, carries a high risk of heavy metal leaching, and can spontaneously combust during weathering and oxidation, causing environmental pollution. Furthermore, the development of agricultural production and animal husbandry also generates significant amounts of organic waste, such as straw and livestock manure. The accumulation and improper handling of these organic wastes not only pollutes land resources but also contributes to greenhouse gas emissions.

[0003] Currently, coal gangue is generally processed separately and cannot be combined with straw, livestock manure, etc., and there are many problems. For example, the invention patent with publication number CN110999753A discloses an artificial ecological matrix based on coal gangue and its preparation method. The raw materials are coal gangue and plant-derived organic matter, and microbial agents are added for composting to produce an environmentally friendly, safe, nutrient-rich, and suitable ecological matrix for plant growth. However, the utilization rate of coal gangue in this method is low, and there are environmental problems such as odor and gas emissions. The invention patent with publication number CN118020599A discloses a coal gangue-based artificial soil and its preparation method and application. After the coal gangue is crushed and screened, it is mixed and cultured with microbial strains and a solvent to obtain activated coal gangue. This is then mixed and cultured with activated fly ash to finally produce the coal gangue-based artificial soil. Patent publication number CN117281010A discloses a method for preparing artificial soil primarily using coal gangue. The method involves screening the coal gangue and diatomaceous earth, crushing and mixing them, then heating and dehydrating them at 450-550°C. The mixture is then sprayed with water for rapid cooling to maintain moisture, followed by storage for 15-30 days for natural maturation. Most of these methods simply add coal gangue to the soil as a soil conditioner, failing to achieve soil reconstitution. They are associated with high costs, complex operations, complicated production processes, and environmental concerns.

[0004] Therefore, achieving the coordinated resource utilization of coal-based solid waste and agricultural and forestry waste is of great significance to improving the ecological environment, enhancing soil quality and promoting the circular economy. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing organic fertilizer by modifying coal-based solid waste in conjunction with agricultural waste. The method provided by the present invention utilizes solid wastes such as coal gangue, fly ash and straw to prepare an underground pit-type livestock house structure and then carries out livestock breeding. Not only can these solid wastes and livestock manure be used to produce a large amount of organic fertilizer, but in this process, no large amount of waste gas is generated, groundwater will not be polluted, and the energy consumed in livestock breeding is saved, saving costs.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing organic fertilizer by modifying coal-based solid waste in conjunction with agricultural waste, wherein the organic fertilizer is obtained by breeding livestock in an underground pit-type livestock house structure;

[0008] The underground pit-type livestock house structure comprises an anti-seepage layer, a livestock house filling layer and a livestock house topsoil layer;

[0009] The filler layer for laying the barn is on the upper surface of the anti-seepage layer, and the topsoil layer for laying the barn is on the upper surface of the filler layer for laying the barn;

[0010] The livestock house filler layer comprises, by mass percentage, 60-70% coarse-grained coal gangue, 15-20% long straw, and 10-30% fly ash; the particle size of the coarse-grained coal gangue is 2-10 mm; the length of the long straw is ≤5 cm;

[0011] Calculated by mass percentage, the topsoil layer of the barn includes 60-70% fine-grained coal gangue, 15-20% short straw and 15-20% filler; the particle size of the fine-grained coal gangue is less than 2mm; the length of the short straw is ≤1cm.

[0012] Preferably, the method for preparing the organic fertilizer is to carry out livestock breeding in an underground pit-type livestock house structure, and clean and store the feces produced during the livestock breeding process. After the livestock breeding is completed, the topsoil layer and the filler layer of the livestock house are dug out, and then mixed with the previously stored feces and composted to obtain organic fertilizer.

[0013] Preferably, the raw materials for preparing the anti-seepage layer include fly ash, carbide slag, desulfurization gypsum and water.

[0014] Preferably, the raw materials for preparing the anti-seepage layer include 60-70 parts by mass of fly ash, 20-30 parts by mass of carbide slag, 10-20 parts by mass of desulfurization gypsum and water.

[0015] Preferably, the thickness of the anti-seepage layer is 0.3 to 0.5 m.

[0016] Preferably, an exhaust pipe and a bacterial agent delivery pipe are also provided in the livestock house filler layer.

[0017] Preferably, the thickness of the livestock house filler layer is 1.5 to 2 m.

[0018] Preferably, the filler includes slag and / or loess; the particle size of the slag is ≤1 cm.

[0019] Preferably, the thickness of the topsoil layer of the livestock shed is 0.3 to 0.5 m.

[0020] Preferably, the preparation method of the underground pit type livestock house structure includes: coating an impermeable layer on the bottom and around the underground pit, then laying a livestock house filler layer on the upper surface of the impermeable layer, and finally laying a livestock house topsoil layer on the upper surface of the livestock house filler layer to obtain the underground pit type livestock house structure.

[0021] The present invention provides a method for preparing organic fertilizer by modifying coal-based solid waste in conjunction with agricultural waste. The organic fertilizer is obtained by breeding poultry and livestock in an underground pit-type livestock house structure. The underground pit-type livestock house structure comprises an anti-seepage layer, a livestock house filling layer and a livestock house topsoil layer. The livestock house filling layer is on the upper surface of the anti-seepage layer, and the livestock house topsoil layer is on the upper surface of the livestock house filling layer. In terms of mass percentage, the livestock house filling layer comprises 60-70% coarse-grained coal gangue, 15-20% long straw and 10-30% fly ash. The particle size of the coarse-grained coal gangue is 2-10 mm. The length of the long straw is ≤5 cm. In terms of mass percentage, the livestock house topsoil layer comprises 60-70% fine-grained coal gangue, 15-20% short straw and 15-20% filler. The particle size of the fine-grained coal gangue is less than 2 mm. The length of the short straw is ≤1 cm. The method provided by the present invention utilizes solid waste such as coal gangue, fly ash and straw to prepare an underground pit-type livestock house structure for livestock breeding. During the breeding process, the livestock will move on the topsoil layer of the livestock house prepared with coal gangue, straw and filler as raw materials. Their urine naturally penetrates through the topsoil layer of the livestock house to the filler layer of the livestock house for storage and preliminary fermentation, while feces gradually accumulates on the topsoil layer of the livestock house and is regularly removed and stored for use. The filler layer of the livestock house relies on the synergistic effect of porous materials such as coarse-grained coal gangue, fly ash and long straw, which can not only uniformly absorb and store urine and prevent local over-wetting or over-drying, but also optimize the infiltration environment, promote the slow-release decomposition and nitrogen fixation of feces and sewage, reduce the emission of harmful gases such as ammonia, and improve the air quality of the farm. The anti-seepage layer can prevent feces and urine generated during livestock breeding from penetrating into the soil and polluting groundwater. After the livestock breeding is completed, the filler layer and the topsoil layer of the livestock house can be centrally composted and converted into efficient and stable organic fertilizer. The results of the examples show that the method provided by the present invention can consume a large amount of solid waste such as coal gangue, fly ash and straw. When used for raising beef cattle, one beef cattle can produce about 25 tons of organic fertilizer in 7 months. At the same time, no large amount of waste gas is generated in this process, and the energy consumed in raising poultry and livestock is saved, saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flow chart of the method for preparing organic fertilizer by modifying coal-based solid waste and agricultural waste provided by the present invention. DETAILED DESCRIPTION

[0023] The present invention provides a method for preparing organic fertilizer by modifying coal-based solid waste in conjunction with agricultural waste, wherein the organic fertilizer is obtained by breeding livestock in an underground pit-type livestock house structure;

[0024] The underground pit-type livestock house structure comprises an anti-seepage layer, a livestock house filling layer and a livestock house topsoil layer;

[0025] The filler layer for laying the barn is on the upper surface of the anti-seepage layer, and the topsoil layer for laying the barn is on the upper surface of the filler layer for laying the barn;

[0026] The livestock house filler layer comprises, by mass percentage, 60-70% coarse-grained coal gangue, 15-20% long straw, and 10-30% fly ash; the particle size of the coarse-grained coal gangue is 2-10 mm; the length of the long straw is ≤5 cm;

[0027] Calculated by mass percentage, the topsoil layer of the barn includes 60-70% fine-grained coal gangue, 15-20% short straw and 15-20% filler; the particle size of the fine-grained coal gangue is less than 2mm; the length of the short straw is ≤1cm.

[0028] In the present invention, the organic fertilizer is obtained by breeding livestock in an underground pit-type livestock house structure.

[0029] In the present invention, the underground pit-type livestock house structure includes an anti-seepage layer, a livestock house filler layer and a livestock house topsoil layer.

[0030] The underground pit-type livestock house structure provided by the present invention comprises an anti-seepage layer.

[0031] In the present invention, the raw materials for preparing the anti-seepage layer preferably include fly ash, carbide slag, desulfurized gypsum and water. By using the above components as raw materials, the present invention can make the anti-seepage layer have a good anti-seepage effect, preventing urine and other substances from seeping into the ground and contaminating groundwater during the breeding process.

[0032] In the present invention, the raw materials for preparing the anti-seepage layer preferably include, by weight, 60-70 parts fly ash, 20-30 parts carbide slag, 10-20 parts desulfurized gypsum, and water. By controlling the amounts of fly ash, carbide slag, and desulfurized gypsum used, the anti-seepage performance of the anti-seepage layer can be further improved.

[0033] In the present invention, the amount of water used is preferably such that the solid-liquid ratio is 0.50 to 0.70. By controlling the amount of water used, the present invention can make the raw materials have good fluidity after mixing, thereby facilitating the subsequent coating into an impermeable layer.

[0034] In the present invention, the method for preparing the anti-seepage layer preferably includes: mixing fly ash, carbide slag, desulfurization gypsum, and water, and then applying the mixture to the bottom and surrounding areas of the underground pit to form the anti-seepage layer. The present invention is not particularly limited to the specific method of mixing, as long as the fly ash, carbide slag, desulfurization gypsum, and water are uniformly mixed.

[0035] In the present invention, the thickness of the anti-seepage layer is preferably 0.3 to 0.5 μm.

[0036] The underground pit-type livestock house structure provided by the present invention further comprises a livestock house filler layer.

[0037] In the present invention, the livestock house filler layer comprises, by mass percentage, 60-70% coarse-grained coal gangue, 15-20% long straw and 10-30% fly ash.

[0038] In the present invention, the particle size of the coarse-grained gangue is 2 to 10 mm. In the present invention, the coarse-grained gangue is preferably prepared by crushing and screening gangue. The present invention does not specifically limit the specific operations of the crushing and screening, as long as the particle size of the coarse-grained gangue meets the requirements. As one embodiment of the present invention, the particle size of the coarse-grained gangue can be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm.

[0039] In the present invention, the length of the long straw is ≤ 5 cm. In the present invention, the long straw is preferably obtained by cutting straw. The present invention does not particularly limit the specific cutting operation, as long as the length of the long straw meets the requirements. As an embodiment of the present invention, the length of the long straw can be 1.5 to 5 cm, and can also be 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, or 4.5 cm.

[0040] The present invention does not specifically limit the specific sources of the gangue, straw, and fly ash; gangue, straw, and fly ash well known to those skilled in the art may be used. The present invention uses gangue, straw, and fly ash as raw materials, all of which are solid wastes. This not only allows for the large-scale consumption of solid waste, thus preventing environmental pollution, but also allows for high-value resource utilization and reduced production costs.

[0041] In the present invention, the livestock shed filler layer comprises, by mass percentage, 60-70% coarse-grained coal gangue, 15-20% long straw, and 10-30% fly ash. As one embodiment of the present invention, the mass percentage of the coarse-grained coal gangue in the livestock shed filler layer can be 60%, 62%, 65%, 68%, or 70%; the mass percentage of the long straw in the livestock shed filler layer can be 15%, 16%, 17%, 18%, 19%, or 20%; and the mass percentage of the fly ash in the livestock shed filler layer can be 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, or 30%. By controlling the relationship between the three in amount, the present invention can form a livestock shed filler layer with a porosity of 15-20% after mixing. In the present invention, coal gangue and fly ash are used as the main skeleton materials. Due to their high mechanical strength and stable physical and chemical properties, they can provide a solid support structure, ensuring that the livestock house filler layer remains stable during long-term use, preventing structural damage due to self-weight settlement or external force, and avoiding pore collapse of the livestock house filler layer, thereby maintaining a good infiltration environment and air permeability; long straw enhances the infiltration capacity of the livestock house filler, and its fiber structure not only helps the uniform penetration of urine and feces, and prevents uneven decomposition caused by local accumulation, but also optimizes moisture management. By adjusting the pore moisture content, it avoids excessive drying of the system that affects microbial activity, or anaerobic corruption caused by excessive moisture, thereby ensuring a stable aerobic fermentation environment. The livestock house filler layer provided by the present invention has good cation exchange performance, wherein the surface of coal gangue and fly ash can effectively adsorb ammonium nitrogen in urine, reduce the release of ammonia and other volatile organic compounds, reduce the risk of environmental pollution, and at the same time improve the retention and recycling efficiency of nitrogen, so that it can be further fixed by microorganisms or converted into an effective nitrogen source that can be absorbed and utilized by plants; at the same time, by adjusting the air permeability, moisture content and carbon-nitrogen ratio of the livestock house filler, the metabolic activity of the microbial community can be optimized, so that organic matter can be decomposed at a preset rate, avoiding the overheating effect caused by too rapid degradation or the stench and anaerobic corruption caused by incomplete degradation.

[0042] In the present invention, the method for preparing the livestock shed filler layer preferably comprises mixing coarse-grained coal gangue, long straw, and fly ash, and then laying the mixture on the upper surface of the impermeable layer to obtain the livestock shed filler layer. The present invention does not specifically limit the specific method of mixing the coarse-grained coal gangue, long straw, and fly ash, as long as the mixture is uniform. The present invention does not specifically limit the specific operation of laying the mixture, and it can be determined according to the technical knowledge of those skilled in the art to ensure that the livestock shed filler layer has a thickness that meets the requirements and is flat.

[0043] In the present invention, the livestock shed packing layer is preferably further provided with an exhaust pipe and a microbial inoculant delivery pipe. The present invention does not specifically limit the arrangement of the exhaust pipe and microbial inoculant delivery pipe; these arrangements can be determined based on the technical expertise of those skilled in the art. In the present invention, the exhaust pipe is preferably an inside-out exhaust pipe; the microbial inoculant delivery pipe is preferably an outside-in microbial inoculant delivery pipe. The exhaust pipe facilitates the collection and discharge of fermentation gases; the microbial inoculant delivery pipe is provided to regulate the fermentation process and deliver microbial inoculants, thereby improving fermentation efficiency within the livestock shed packing layer.

[0044] In the present invention, the thickness of the livestock house filler layer is preferably 1.5 to 2 m; the porosity of the livestock house filler layer is preferably 15 to 20%. In the present invention, the livestock house filler layer has a porous structure and plays multiple roles in the livestock breeding process, such as storing urine, promoting fermentation, supporting filler, regulating percolation, cation exchange, and controlled decomposition.

[0045] The underground pit-type livestock house structure provided by the present invention further comprises a livestock house topsoil layer.

[0046] In the present invention, the surface soil layer of the livestock shed comprises, by mass percentage, 60-70% of fine-grained coal gangue, 15-20% of short straw and 15-20% of filler.

[0047] In the present invention, the particle size of the fine-grained gangue is less than 2 mm. In the present invention, the fine-grained gangue is preferably prepared by crushing and screening gangue. The present invention does not specifically limit the specific operations of the crushing and screening, as long as the particle size of the fine-grained gangue meets the requirements. As an embodiment of the present invention, the particle size of the fine-grained gangue can be 0.1 to 1.8 mm, and can also be 0.2 mm, 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, or 1.5 mm.

[0048] In the present invention, the length of the short straw is ≤1 cm. In the present invention, the short straw is preferably obtained by cutting straw. The present invention does not particularly limit the specific cutting operation, as long as the length of the short straw meets the requirements. As an embodiment of the present invention, the length of the short straw can be 0.1 to 1 cm, and can also be 0.2 cm, 0.3 cm, 0.5 cm, 0.6 cm, or 0.8 cm.

[0049] In the present invention, the filler preferably includes slag and / or loess. In the present invention, the slag particle size is preferably ≤1 cm. In the present invention, when the slag particle size does not meet the above requirements, the slag is preferably crushed and screened. The specific operations of the crushing and screening are not particularly limited, as long as the slag particle size meets the requirements.

[0050] In the present invention, the topsoil layer of the livestock shed includes, by mass percentage, 60-70% fine-grained coal gangue, 15-20% short straw, and 15-20% filler. As one embodiment of the present invention, the mass percentage of the fine-grained coal gangue in the topsoil layer of the livestock shed can be 60%, 62%, 65%, 68%, or 70%; the mass percentage of the short straw in the topsoil layer of the livestock shed can be 15%, 16%, 17%, 18%, 19%, or 20%; and the mass percentage of the filler in the topsoil layer of the livestock shed can be 15%, 16%, 17%, 18%, 19%, or 20%. In the present invention, the poultry and livestock move above the topsoil layer of the livestock shed, and the urine they produce will naturally seep through the topsoil layer of the livestock shed to the filler layer of the livestock shed for storage, while undergoing preliminary fermentation; the feces will accumulate in the topsoil layer of the livestock shed. When the feces accumulate to a certain level, they will be cleaned by a scraper and temporarily stored for further composting treatment.

[0051] In the present invention, the method for preparing the barn topsoil layer preferably comprises mixing fine-grained coal gangue, short straw, and filler, and then laying the mixture on the upper surface of the barn filler layer to obtain the barn topsoil layer. The present invention does not particularly limit the specific method of mixing the fine-grained coal gangue, short straw, and filler, as long as the mixture is uniform. The present invention does not particularly limit the specific operation of laying the barn topsoil layer, and it can be determined according to the technical knowledge of those skilled in the art to ensure that the barn topsoil layer has a thickness that meets the requirements and is flat.

[0052] In the present invention, the thickness of the topsoil layer of the livestock shed is preferably 0.3 to 0.5 m. The present invention facilitates livestock breeding by controlling the thickness of the topsoil layer of the livestock shed.

[0053] The present invention uses coal gangue, straw and fly ash as raw materials to prepare the livestock house filling layer, and uses coal gangue, straw and filler as raw materials to prepare the livestock house topsoil layer. During the breeding process, livestock and poultry will move on the livestock house topsoil layer, and their urine will naturally penetrate through the livestock house topsoil layer to the livestock house filling layer for storage and preliminary fermentation, while feces will gradually accumulate on the livestock house topsoil layer and be regularly removed and stored for use; the livestock house filling layer relies on the synergistic effect of porous materials such as coarse-grained coal gangue, fly ash and long straw, which can not only evenly absorb and store urine to prevent local over-wetting or over-drying, but also optimize the infiltration environment, promote the slow-release decomposition and nitrogen fixation of feces, reduce the emission of harmful gases such as ammonia, and improve the air quality of the farm; the anti-seepage layer can prevent feces and urine generated during livestock and poultry breeding from penetrating into the soil and polluting groundwater; after the livestock and poultry breeding is completed, the livestock house filling layer and the livestock house topsoil layer can be centrally composted and converted into efficient and stable organic fertilizer.

[0054] In the present invention, the method for preparing the organic fertilizer is preferably to carry out livestock breeding in an underground pit-type livestock house structure, and clean and store the feces produced during the livestock breeding process. After the livestock breeding is completed, the topsoil layer and the filler layer of the livestock house are dug out, and then mixed with the previously stored feces and composted to obtain organic fertilizer.

[0055] The present invention does not specifically limit the types of livestock in the livestock farming, and the livestock to be farmed can be determined according to the technical common sense of those skilled in the art. As an embodiment of the present invention, the livestock in the livestock farming can be pigs, cattle, sheep, chickens, ducks or geese.

[0056] In the present invention, the livestock breeding period is preferably from September of each year to April of the following year. By breeding livestock during this period, the present invention can not only prevent livestock from dying due to low outdoor temperatures, but also generate heat through fermentation of urine and other substances stored in the filler layer of the livestock shed during breeding, thereby reducing the energy consumption required to keep the livestock warm.

[0057] The present invention does not specifically limit the specific method of cleaning and storing the feces generated during the livestock farming process, and can be determined based on the technical knowledge of those skilled in the art. As one embodiment of the present invention, the cleaning method is preferably scraper cleaning. The present invention does not specifically limit the time interval for cleaning, and can be determined based on the technical knowledge of those skilled in the art to avoid the negative impact of feces accumulation on livestock. The present invention does not specifically limit the storage method, and can be stored based on the technical knowledge of those skilled in the art.

[0058] In the present invention, the moisture content of the raw materials during composting is preferably 45-65%; the composting time is preferably 20-30 days; the composting temperature is 50-65°C; the composting temperature is preferably ≥55°C for ≥5 days; the composting frequency is preferably: turning once a day when the composting time is ≤12 days, turning once every 2-3 days for the remaining composting time, and turning 2-4 times every 2 days when the composting temperature is ≥60°C. The present invention can improve the quality of organic fertilizer by controlling the composting process; and by regularly turning the compost to promote oxygen supply and uniform temperature distribution, thereby improving composting efficiency.

[0059] The present invention preferably further comprises adding bacterial liquid and additives during composting.

[0060] In the present invention, the bacterial solution is preferably a commercially available EM bacterial solution; the amount of the bacterial solution used is preferably 0.05-0.2%, more preferably 0.1%, of the total mass of the raw materials used in composting. In the present invention, the EM bacterial solution is primarily composed of more than 80 microorganisms from 10 genera, including photosynthetic bacteria, lactic acid bacteria, yeasts, and actinomycetes, thereby improving composting efficiency.

[0061] In the present invention, the additive is preferably a chemical additive and / or a physical additive; the chemical additive preferably includes at least one of magnesium hydroxide, potassium dihydrogen phosphate, and magnesium chloride; the amount of the chemical additive is preferably 0.5-2% of the total mass of the raw materials during composting, more preferably 1-1.5%; the physical additive preferably includes biochar and / or bentonite; the amount of the physical additive is preferably 2.5-10% of the total mass of the raw materials during composting, more preferably 3-8%, and even more preferably 4-6%. The present invention can further improve the efficiency of composting and the fertility of organic fertilizers by adding additives.

[0062] In the present invention, the coal-based solid waste and agricultural waste modified organic fertilizer are preferably used for farmland production and sale, mining area reclamation or desertification control. The present invention does not specifically limit the specific method of use, which can be determined according to the technical common sense of those skilled in the art.

[0063] The method proposed in the present invention combines coal-based solid waste with agricultural and forestry waste to form an innovative aquaculture waste treatment solution, so that the coal-based solid waste has higher porosity and nutrient slow-release capacity. At the same time, combined with the high organic matter characteristics of agricultural waste, it forms an efficient and environmentally friendly organic fertilizer, which can effectively solve the problems of resource waste, pollution risks and high technical costs existing in traditional processes, and provide new solutions for ecological restoration and agricultural sustainable development in coal resource-based areas.

[0064] The present invention uses coal gangue, fly ash and straw in a scientific ratio for livestock bedding, achieving the triple goals of "solid waste resource utilization - harmless treatment of manure and sewage - fertilizer value-added", which can reduce environmental pollution and convert waste into organic fertilizer to create additional economic benefits; the underground pit-type livestock house structure provided by the present invention is environmentally friendly, reduces the direct discharge of breeding waste, and can better control odor and solve the problem of groundwater seepage.

[0065] This invention uses coal-based solid waste and agricultural and forestry waste as primary raw materials to create filler for livestock barn construction. The leaked manure and retained feces from the livestock farming process become nutrient-rich fertilizer over time, providing a practical solution for regions where coal-based and livestock farming are key industries. The underground pit-type barn structure provided by this invention is suitable for areas primarily centered around mining and animal husbandry, and is particularly well-suited for small-scale, free-range livestock operations and those with distinct seasonality.

[0066] Compared with the prior art, the present invention has the following advantages:

[0067] Compared with the current conventional technologies such as slatted floors, urine storage tanks, scraper manure removers and water-saving drinking fountains, the underground pit-type livestock house structure provided by the present invention has significant advantages in the synergistic fertilizer production of livestock and poultry manure and coal-based solid waste, and is particularly suitable for small-scale free-range households and breeding models with distinct seasonality. Although traditional slatted floors and urine storage tanks can store manure, they are prone to water accumulation and the treatment process is cumbersome, making it difficult to ensure environmental hygiene; although scraper manure removers can remove manure, the equipment cost is high and it is not suitable for smaller-scale farms; although water-saving drinking fountains help reduce water waste, they do not solve the problem of efficient treatment and resource utilization of manure; the method provided by the present invention not only improves the insulation effect in winter and reduces water accumulation in manure and urine, but also effectively promotes the fermentation and resource utilization of manure, converts waste into high-fertility organic fertilizer, and reduces environmental pollution. Especially for the enclosure grazing model with distinct seasons, this technology can adapt to the needs of different seasons, achieve efficient waste treatment and resource recycling, and has strong economic and ecological benefits.

[0068] The underground pit-type livestock house structure preparation method provided by the present invention is simple and low-cost and can process a large amount of livestock manure and coal-based solid waste to synergistically produce fertilizer, thereby achieving an ecological restoration effect of resource recycling according to local conditions.

[0069] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0070] Example 1

[0071] A method for preparing organic fertilizer by modifying coal-based solid waste in conjunction with agricultural waste, wherein the organic fertilizer is obtained by raising livestock in an underground pit-type livestock house structure;

[0072] The underground pit-type livestock house structure is composed of an anti-seepage layer, a livestock house filling layer, and a livestock house topsoil layer;

[0073] The filler layer for paving the barn is on the upper surface of the anti-seepage layer, and the topsoil layer for paving the barn is on the upper surface of the filler layer for paving the barn; the thickness of the anti-seepage layer is 0.5m, the thickness of the filler layer for paving the barn is 2m, and the thickness of the topsoil layer for paving the barn is 0.5m;

[0074] The anti-seepage layer is prepared by mixing 65 parts of fly ash, 25 parts of carbide slag and 10 parts of desulfurized gypsum by weight, then adding water to adjust the solid-liquid ratio to 0.65, stirring evenly and applying the mixture to the bottom and surrounding areas of the underground pit to form an anti-seepage layer with a thickness of 0.5m;

[0075] The composition of the livestock house filler layer is, by mass percentage, 65% coarse-grained coal gangue, 15% long straw, and 20% fly ash; the particle size of the coarse-grained coal gangue is 2 to 10 mm; the length of the long straw is 1.5 to 5 cm; the livestock house filler layer is also provided with an exhaust pipe and a microbial agent delivery pipe;

[0076] The composition of the topsoil layer of the barn is, by mass percentage, 60% fine-grained coal gangue, 20% short straw, and 20% slag; the particle size of the fine-grained coal gangue is less than 2 mm; the length of the short straw is ≤ 1 cm; and the particle size of the slag is ≤ 1 cm.

[0077] The preparation method of the underground pit-type livestock house structure is as follows: an anti-seepage layer is applied to the bottom and surrounding areas of the underground pit, and then coarse-grained coal gangue, long straw and fly ash are mixed and laid on the upper surface of the anti-seepage layer to form a livestock house filling layer, and an exhaust pipe and a microbial agent delivery pipe are simultaneously provided in the livestock house filling layer. Finally, fine-grained coal gangue, short straw and slag are mixed and laid on the upper surface of the livestock house filling layer to form a livestock house topsoil layer, thereby obtaining the underground pit-type livestock house structure.

[0078] Application Example 1

[0079] The method and underground pit-type livestock house structure provided in Example 1 are used for Shanxi beef cattle breeding, and the breeding period is from September to April of the following year. The feces generated during the Shanxi beef cattle breeding process are cleaned and stored with a scraper. After the Shanxi beef cattle breeding is completed, the topsoil layer and the filler layer of the livestock house are dug out, and then mixed with the previously stored feces for composting. The moisture content of the raw materials during the composting is 50-60%; the composting time is 30 days; the composting temperature is 50-65°C; the composting temperature is ≥55°C for 6 days; the compost turning frequency is preferably: turning the compost once a day during the first 10 days of composting, turning the compost once every two days during the remaining composting time, and turning the compost four times in two days when the compost temperature is ≥60°C to obtain organic fertilizer.

[0080] For example 1, the amount of urine and feces discharged by Shanxi beef cattle during the breeding process, as well as the amount of organic fertilizer produced, were calculated. The results are as follows:

[0081] During the breeding period from September to April, a Shanxi beef cattle produces about 30L of manure per day (20L of feces + 10L of urine). During the 7-month livestock house breeding period, about 6300L of manure is produced, namely 4200L of feces and 2100L of urine. The activity area of ​​a Shanxi beef cattle is about 6m 2 The thickness of the filler layer is 2m, and the volume of the filler layer is 12m 3 The porosity of the filler layer of the livestock house is about 20%, that is, the filler layer of the livestock house has 2.4m 3 The pore structure can meet the needs of storing urine;

[0082] The activity area of ​​a Shanxi beef cattle is about 6m 2 The thickness of the filler layer in the livestock house is 2m, and the density is about 1.2t / m 3 After calculation, the weight of the filler layer of the barn is about 14.4t; the thickness of the topsoil layer of the barn is 0.5m, and the density is about 1.5t / m 3 , after calculation, the weight is about: 4.5t; a Shanxi beef cattle produces about 6300L of manure in the 7 months of breeding in the barn. The density of the mixture of cow manure and cow urine is 1.0t / m 3 A rough calculation shows that the total weight of manure is approximately 6.3 tons. In total, the manure produced by one head of Shanxi beef cattle during breeding, after primary fermentation in the packing bed and further composting and fermentation, can produce approximately 25 tons of organic fertilizer.

[0083] The obtained coal-based solid waste and agricultural waste modified organic fertilizer was analyzed and found to meet the requirements of the "Organic Fertilizer Standard" (NY / T 525-2021), effectively realizing the comprehensive utilization of solid waste.

[0084] Example 2

[0085] A method for preparing organic fertilizer by modifying coal-based solid waste in conjunction with agricultural waste, wherein the organic fertilizer is obtained by raising livestock in an underground pit-type livestock house structure;

[0086] The underground pit-type livestock house structure is composed of an anti-seepage layer, a livestock house filling layer, and a livestock house topsoil layer;

[0087] The filler layer for paving the barn is on the upper surface of the anti-seepage layer, and the topsoil layer for paving the barn is on the upper surface of the filler layer for paving the barn; the thickness of the anti-seepage layer is 0.5m, the thickness of the filler layer for paving the barn is 2m, and the thickness of the topsoil layer for paving the barn is 0.5m;

[0088] The method for preparing the anti-seepage layer is as follows: 60 parts by mass of fly ash, 20 parts by mass of carbide slag and 20 parts by mass of desulfurized gypsum are mixed, and then water is added to adjust the solid-liquid ratio to 0.6, and the mixture is evenly stirred and applied to the bottom and surrounding areas of the underground pit to form an anti-seepage layer with a thickness of 0.5 m;

[0089] The composition of the livestock house filler layer is 68% coarse-grained coal gangue, 16% long straw, and 16% fly ash by mass percentage; the particle size of the coarse-grained coal gangue is 2 to 10 mm; the length of the long straw is 1.5 to 5 cm; the livestock house filler layer is also provided with an exhaust pipe and a microbial agent delivery pipe;

[0090] The composition of the topsoil layer of the barn is, by mass percentage, 62% fine-grained coal gangue, 19% short straw, and 19% slag; the particle size of the fine-grained coal gangue is less than 2 mm; the length of the short straw is ≤ 1 cm; and the particle size of the slag is ≤ 1 cm;

[0091] The preparation method of the underground pit-type livestock house structure is as follows: an anti-seepage layer is applied to the bottom and surrounding areas of the underground pit, and then coarse-grained coal gangue, long straw and fly ash are mixed and laid on the upper surface of the anti-seepage layer to form a livestock house filling layer, and an exhaust pipe and a microbial agent delivery pipe are simultaneously provided in the livestock house filling layer. Finally, fine-grained coal gangue, short straw and slag are mixed and laid on the upper surface of the livestock house filling layer to form a livestock house topsoil layer, thereby obtaining the underground pit-type livestock house structure.

[0092] Example 3

[0093] A method for preparing organic fertilizer by modifying coal-based solid waste in conjunction with agricultural waste, wherein the organic fertilizer is obtained by breeding livestock in an underground pit-type livestock house structure;

[0094] The underground pit-type livestock house structure is composed of an anti-seepage layer, a livestock house filling layer, and a livestock house topsoil layer;

[0095] The filler layer for paving the barn is on the upper surface of the anti-seepage layer, and the topsoil layer for paving the barn is on the upper surface of the filler layer for paving the barn; the thickness of the anti-seepage layer is 0.5m, the thickness of the filler layer for paving the barn is 2m, and the thickness of the topsoil layer for paving the barn is 0.5m;

[0096] The method for preparing the anti-seepage layer is as follows: 70 parts by mass of fly ash, 20 parts by mass of carbide slag and 10 parts by mass of desulfurized gypsum are mixed, and then water is added to adjust the solid-liquid ratio to 0.7, and the mixture is evenly stirred and applied to the bottom and sides of the underground pit to form an anti-seepage layer with a thickness of 0.5 m.

[0097] The livestock house filler layer is composed of 70% coarse-grained coal gangue, 15% long straw, and 15% fly ash by mass percentage; the particle size of the coarse-grained coal gangue is 2 to 10 mm; the length of the long straw is 1.5 to 5 cm; and an exhaust pipe and a microbial agent delivery pipe are also provided in the livestock house filler layer.

[0098] The composition of the topsoil layer of the barn is, by mass percentage, 65% fine-grained coal gangue, 20% short straw, and 15% slag; the particle size of the fine-grained coal gangue is less than 2 mm; the length of the short straw is ≤ 1 cm; and the particle size of the slag is ≤ 1 cm;

[0099] The preparation method of the underground pit-type livestock house structure is as follows: an anti-seepage layer is applied to the bottom and surrounding areas of the underground pit, and then coarse-grained coal gangue, long straw and fly ash are mixed and laid on the upper surface of the anti-seepage layer to form a livestock house filling layer, and an exhaust pipe and a microbial agent delivery pipe are simultaneously provided in the livestock house filling layer. Finally, fine-grained coal gangue, short straw and slag are mixed and laid on the upper surface of the livestock house filling layer to form a livestock house topsoil layer, thereby obtaining the underground pit-type livestock house structure.

[0100] Comparative Example 1 (A method for preparing a solid waste-based soil conditioner using microbial mineralization of coal gangue)

[0101] Step 1: Select nine 7cm*7cm*7cm square molds and add 18-50 mesh coal gangue to a height of 4cm in the molds.

[0102] Step 2: Prepare the bacterial solution. Adjust the pH value of the prepared LB medium to 8.5, sterilize it under high pressure steam at 120°C for 10 minutes, and after cooling to room temperature, add carbonate mineralizing bacteria powder to a concentration of 0.2% in the medium. Then, place it in a constant volume flask and adjust the volume to 300 ml. Place the prepared bacterial solution in a constant temperature shaking incubator and culture it at 25°C and 200 r / min;

[0103] Step 3: Prepare the binder solution by taking 5.55g of anhydrous calcium chloride and 45g of urea, adding distilled water to make up to 500ml;

[0104] Step 4: Mix 60 parts of gangue particles, 25 parts of sheep manure, 15 parts of straw, and high-efficiency solid compost fermentation agent (0.2 kg per ton of material) thoroughly with a shaking car, spray water on the material while mixing, and add high-efficiency solid compost fermentation agent (silicate bacteria, commercially available EM fermentation bacteria, special bacteria for gangue activation). The compost size is 6 meters wide, 6 meters long, and 3 meters high. Cover the surface of the substrate with black plastic film. During the composting period, it needs to be stirred for 15 minutes every other day to ensure air circulation and control the temperature between 55 and 65°C. Stack it for about 35 days. When the pile temperature drops to 45°C again, the composting is completed to obtain sludge compost raw material with gangue as the matrix.

[0105] By comparing Examples 1 to 3 with Comparative Example 1, it can be seen that when coal gangue is used as the preparation of organic fertilizer, the present invention uses coal-based solid waste and agricultural and forestry waste, which has lower cost, simpler operation, greater environmental friendliness and greater benefits.

[0106] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing organic fertilizer by modifying coal-based solid waste and agricultural waste, characterized in that: The organic fertilizer is obtained by breeding livestock through underground pit-type livestock houses; The underground pit-type livestock house structure comprises an anti-seepage layer, a livestock house filling layer and a livestock house topsoil layer; The filler layer for laying the barn is on the upper surface of the anti-seepage layer, and the topsoil layer for laying the barn is on the upper surface of the filler layer for laying the barn; The livestock house filler layer comprises, by mass percentage, 60-70% coarse-grained coal gangue, 15-20% long straw, and 10-30% fly ash; the particle size of the coarse-grained coal gangue is 2-10 mm; the length of the long straw is ≤5 cm; Calculated by mass percentage, the topsoil layer of the barn includes 60-70% fine-grained coal gangue, 15-20% short straw and 15-20% filler; the particle size of the fine-grained coal gangue is less than 2mm; the length of the short straw is ≤1cm.

2. The method according to claim 1, characterized in that The method for preparing the organic fertilizer comprises the following steps: carrying out livestock breeding in an underground pit-type livestock house structure, cleaning and storing the excrement produced during the livestock breeding process, and after the livestock breeding is completed, digging out the topsoil layer and the filler layer of the livestock house, and then mixing them with the previously stored excrement and composting them to obtain the organic fertilizer.

3. The method according to claim 1, characterized in that The raw materials for preparing the anti-seepage layer include fly ash, carbide slag, desulfurized gypsum and water.

4. The method according to claim 3, characterized in that Calculated by mass, the raw materials for preparing the anti-seepage layer include 60-70 parts of fly ash, 20-30 parts of carbide slag, 10-20 parts of desulfurization gypsum and water.

5. The method according to claim 1, wherein The thickness of the anti-seepage layer is 0.3 to 0.5 m.

6. The method according to claim 1, wherein An exhaust pipe and a bacterial agent delivery pipe are also provided in the filler layer of the livestock house.

7. The method according to claim 1, characterized in that The thickness of the filler layer of the livestock house is 1.5 to 2 meters.

8. The method according to claim 1, characterized in that The filler includes slag and / or loess; the particle size of the slag is ≤1 cm.

9. The method according to claim 1, characterized in that The thickness of the topsoil layer of the livestock house is 0.3 to 0.5 m.

10. The method according to claim 1, characterized in that The preparation method of the underground pit type livestock house structure includes: coating an anti-seepage layer on the bottom and surrounding of the underground pit, then laying a livestock house filling layer on the upper surface of the anti-seepage layer, and finally laying a livestock house topsoil layer on the upper surface of the livestock house filling layer to obtain the underground pit type livestock house structure.

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