Organic fertilizer prepared from modified coal gangue and production method thereof

Abstract

The invention discloses an organic fertilizer prepared from modified coal gangue and a production method thereof, and belongs to the technical field of fertilizer preparation. Treating the animal carcass homogenate in an environment of 150 DEG C and 1MPa for 5 hours to obtain pretreated homogenate; mixing the pretreated homogenate and biological enzyme according to a weight ratio of (90-95): 1, hydrolyzing, carrying out inactivation treatment at 95 DEG C for 15 minutes, and carrying out centrifugal separation to obtain supernate; the supernate and the pretreated coal gangue are mixed and stirred according to the weight part ratio of 1: (18-26) to form modified coal gangue, and the modified coal gangue and the mixed strain seed solution are mixed, composted, fermented and dried according to the weight part ratio of 1: (0.05-0.06) to obtain the organic fertilizer. The supernate prepared by enzymolysis and the pretreated coal gangue obtained by gasification flotation are mixed, adsorbed and impregnated, and then the mixed strain seed solution is inoculated for composting fermentation, so that the organic fertilizer with good fertilizer efficiency is obtained, and resource utilization of the coal gangue is realized.

Description

Technical Field

[0001] This invention belongs to the field of fertilizer preparation technology, specifically relating to an organic fertilizer prepared by modifying coal gangue and its production method. Background Technology

[0002] In agricultural production, fertilizer is a fundamental production material used extensively to supply the nutrients needed for crop growth and development and to improve soil nutrient status. Chemical fertilizers dominate fertilizer use, primarily due to their rapid dissolution and nutrient release, which can significantly increase yields in a short period. While chemical fertilizers offer the advantage of quick-acting action, the rapid development of modern agriculture has led to an increasing demand for fertilizers in farmland, resulting in significant harms such as soil nutrient imbalances, soil depletion, and eutrophication of water bodies. In today's world, where environmental protection, sustainable agriculture, and pollution-free agriculture are increasingly emphasized, chemical fertilizers clearly cannot meet the requirements of environmentally friendly and sustainable development. Therefore, technological innovation and product development to produce environmentally friendly and efficient modern fertilizers are of great importance. Coal is my country's primary energy source and an important chemical raw material, forming the cornerstone of my country's energy security and industrial and supply chain security. However, the entire process of coal development and utilization inevitably generates a large amount of coal-based solid waste. Coal-based solid waste refers to various solid wastes generated during coal mining, processing, combustion, and conversion. These mainly include coal gangue, fly ash, desulfurization gypsum, coal gasification ash, and coal liquefaction residue. These wastes have significant pollution impacts on soil, water, and air. Although coal-based solid waste poses a significant pollution problem, its composition contains minerals and nutrients necessary for plant growth. If treated and applied to fertilizer applications, it would be of great significance for the resource utilization of coal-based solid waste and ultimately for addressing its environmental pollution issues.

[0003] Coal gangue has been increasing year by year along with coal production, becoming one of the industrial solid wastes with large emissions and stockpiles. Currently, the resource utilization of coal gangue mainly involves combustion for power generation, building material production, roadbed paving, and backfilling. However, these methods have revealed problems such as low added value, insufficient utilization, and secondary pollution in practical applications. Coal gangue is rich in nutrients needed for plant growth and has good prospects in fertilizer preparation. However, the nutrients in coal gangue usually exist in a form that plants cannot directly absorb and utilize, with a high degree of solidification, requiring further conversion.

[0004] Patent CN111908970A discloses a method for producing microbial fertilizer from coal gangue. This invention uses a newly developed strain of *Bacillus fusiforme* to ferment coal gangue to prepare fertilizer, realizing the resource utilization of coal gangue. However, due to the structural characteristics of coal gangue, the direct fermentation of coal gangue by conventional strains results in incomplete fermentation and difficulty in converting it into nutrients that can be absorbed by plants.

[0005] Therefore, how to utilize conventional fermentation strains to ferment coal gangue to prepare organic fertilizer has a significant impact on improving the resource utilization of coal gangue. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention mixes and impregnates the supernatant obtained from enzymatic hydrolysis with pretreated coal gangue obtained from gasification flotation, followed by inoculation with a mixed bacterial strain seed liquid for composting and fermentation, thereby obtaining an organic fertilizer with good fertilizing effect and solving the technical problems mentioned in the background art. Specifically, the technical solution of this invention includes the following: A method for producing organic fertilizer from modified coal gangue, the method comprising the following steps: Animal carcass homogenate was treated at 150℃ and 1MPa for 5 hours to obtain pretreated homogenate; The pretreated homogenate and biological enzyme were mixed and hydrolyzed at a weight ratio of 90-95:1, then inactivated at 95℃ for 15 min and centrifuged to obtain the supernatant. The supernatant and pretreated coal gangue are mixed and stirred at a weight ratio of 1:18~26 to form modified coal gangue. The modified coal gangue and mixed bacterial seed liquid are mixed at a weight ratio of 1:0.05~0.06, composted and fermented, and then dried to obtain the organic fertilizer.

[0007] Furthermore, the animal carcass homogenate is obtained by mixing and mincing pig and water in a weight ratio of 1:10. The animal carcass homogenate can also be obtained by mixing and mincing other animal carcasses and water.

[0008] Furthermore, the bio-enzyme is composed of lipase, keratinase and collagenase in a weight ratio of 0.5~0.6:2.5~3:1~1.2.

[0009] Furthermore, the specific activity of the lipase is 100 U / mg, the specific activity of the keratinase is 200 U / mg, and the specific activity of the collagenase is 125 U / mg.

[0010] Furthermore, the conditions for the mixed hydrolysis include a pH of 7.0 to 8.0, a temperature of 40°C to 45°C, and a time of 10 to 12 hours.

[0011] Furthermore, the centrifugation conditions include a rotation speed of 7000 r / min to 8000 r / min and a time of 10 min to 15 min.

[0012] Furthermore, the method for preparing the pretreated coal gangue includes the following steps: Coal gangue is crushed and sieved to obtain coal gangue particles; Coal gangue particles, water, and grinding balls are mixed in a weight ratio of 1:10 to 15:5 and ground at a speed of 400 r / min to 500 r / min for 6 to 10 hours to obtain a slurry. The slurry, collector, and flotation agent are mixed in a weight ratio of 1:0.06~0.08:0.04 and stirred at a rotation speed of 1000r / min~1500r / min at a speed of 0.2m. 3 / (m 2 ·min)~0.3m 3 / (m 2 After stirring with an aeration rate of ·min for 150s~180s, the pretreated coal gangue was obtained by filtration and drying.

[0013] Furthermore, the collector is obtained by mixing 4-dodecylphenol and kerosene in a ratio of 1~2:1~3.

[0014] Furthermore, the flotation agent includes 1,3-dimethylbutanol.

[0015] Furthermore, the mixed strain seed liquid is derived from OD 600 The seed culture of Bacillus cereus with a concentration of 0.6-0.7 and an OD value of 0.6-0.7 were obtained. 600 The mixture consists of 0.6-0.7% Bacillus amyloliquefaciens seed culture at a weight ratio of 1:2-3.

[0016] Furthermore, the conditions for mixing and stirring the supernatant and pretreated coal gangue include a stirring speed of 200 r / min to 300 r / min and a stirring time of 5 h to 6 h.

[0017] Furthermore, the conditions for the mixed composting fermentation include a stack size of 1m long × 1m wide × 0.6m high, a temperature of 30℃~35℃, a time of 3 to 7 days, and turning the material once every 24 hours.

[0018] Furthermore, the drying conditions include a temperature of 45°C and a time of 4 hours.

[0019] One of the objectives of this invention is to provide an organic fertilizer prepared by modifying coal gangue.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes gasification flotation to remove heavy metals and other harmful substances trapped in coal gangue, thereby reducing heavy metal ion pollution and producing pretreated coal gangue. However, gasification flotation inevitably removes nutrients such as iron and aluminum from the surface of the coal gangue, resulting in lower fertilizer efficiency. Therefore, an enzymatic hydrolysis of animal carcass homogenate, rich in protein and fat, is used to obtain a supernatant rich in nutrients. This supernatant is then mixed with and impregnated with the copper supernatant from the pretreated coal gangue to increase the nutrient content. Finally, a mixed bacterial culture of Bacillus mucilaginosus and Bacillus amyloliquefaciens seed culture is inoculated for composting fermentation. Bacillus mucilaginosus converts ineffective phosphorus and potassium in the coal gangue into available phosphorus and potassium that can be absorbed and utilized by plants, while Bacillus amyloliquefaciens utilizes the minerals and other nutrients on the coal gangue to promote decomposition and transformation, forming nutrients that are easily absorbed and utilized by plants, thus improving the fertilizer efficiency of the organic fertilizer after composting fermentation. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0023] Preparation Example 1 The preparation method of pretreated coal gangue is as follows: Coal gangue was crushed in a crusher and then passed through a 100-mesh sieve to obtain coal gangue particles. One part by weight of coal gangue particles, ten parts by weight of water, and five parts by weight of zirconium oxide grinding balls were weighed and mixed in a ball mill. The mill was set to a speed of 400 r / min and ground for 6 hours to obtain a slurry. A collector (obtained by mixing 4-dodecylphenol and kerosene in a 1:1 ratio) and 1,3-dimethylbutanol were added to the slurry. The collector was added at a rate of 0.06 parts by weight per part by weight of slurry, and the 1,3-dimethylbutanol was added at a rate of 0.04 parts by weight per part by weight of slurry. After mixing, the mixture was placed in a flotation cell, and the speed was adjusted to 1000 r / min with an aeration rate of 0.2 m³ / min. 3 / (m 2 After stirring for 150 seconds, the surface bubbles were scraped off, and the solid particles were collected by filtration and then placed in a drying oven at 80°C to dry and remove water to obtain pretreated coal gangue.

[0024] Preparation Example 2 The preparation method of pretreated coal gangue is as follows: Coal gangue was crushed in a crusher and then passed through a 100-mesh sieve to obtain coal gangue particles. One part by weight of coal gangue particles, 12 parts by weight of water, and 5 parts by weight of zirconium oxide grinding balls were weighed and mixed in a ball mill. The mill was set to a speed of 400 r / min and ground for 7 hours to obtain a slurry. A collector (obtained by mixing 4-dodecylphenol and kerosene in a 1:2 ratio) and 1,3-dimethylbutanol were added to the slurry. The collector was added at a rate of 0.06 parts by weight per part by weight of slurry, and the 1,3-dimethylbutanol was added at a rate of 0.04 parts by weight per part by weight of slurry. After mixing, the mixture was placed in a flotation cell, and the speed was adjusted to 1000 r / min with an aeration rate of 0.2 m³ / min. 3 / (m 2 After stirring for 150 seconds, the surface bubbles were scraped off, and the solid particles were collected by filtration and then placed in a drying oven at 80°C to dry and remove water to obtain pretreated coal gangue.

[0025] Preparation Example 3 The preparation method of pretreated coal gangue is as follows: Coal gangue was crushed in a crusher and then passed through a 100-mesh sieve to obtain coal gangue particles. One part by weight of coal gangue particles, 14 parts by weight of water, and 5 parts by weight of zirconium oxide grinding balls were weighed and mixed in a ball mill. The mill was set to a speed of 450 r / min and ground for 8 hours to obtain a slurry. A collector (obtained by mixing 4-dodecylphenol and kerosene in a 1:3 ratio) and 1,3-dimethylbutanol were added to the slurry. The collector was added at a rate of 0.07 parts by weight per part by weight of slurry, and the 1,3-dimethylbutanol was added at a rate of 0.04 parts by weight per part by weight of slurry. After mixing, the mixture was placed in a flotation cell, and the speed was adjusted to 1200 r / min with an aeration rate of 0.25 m³ / min. 3 / (m 2 After stirring for 160 seconds, the surface bubbles were scraped off, and the solid particles were collected by filtration and then placed in a drying oven at 80°C to dry and remove water to obtain pretreated coal gangue.

[0026] Preparation Example 4 The preparation method of pretreated coal gangue is as follows: Coal gangue was crushed in a crusher and then passed through a 100-mesh sieve to obtain coal gangue particles. One part by weight of coal gangue particles, 15 parts by weight of water, and 5 parts by weight of zirconium oxide grinding balls were weighed and mixed in a ball mill. The mill speed was set to 450 r / min, and the grinding process was carried out for 9 hours to obtain a slurry. A collector (obtained by mixing 4-dodecylphenol and kerosene in a 2:1 ratio) and 1,3-dimethylbutanol were added to the slurry. The amount of collector added was 0.07 parts by weight per part by weight of slurry, and the amount of 1,3-dimethylbutanol added was 0.04 parts by weight per part by weight of slurry. After mixing, the mixture was placed in a flotation cell, and the speed was adjusted to 1400 r / min with an aeration rate of 0.25 m³ / min. 3 / (m 2 After stirring for 170 seconds, the surface bubbles were scraped off, and the solid particles were collected by filtration and then placed in a drying oven at 80°C to dry and remove water to obtain pretreated coal gangue.

[0027] Preparation Example 5 The preparation method of pretreated coal gangue is as follows: The coal gangue is crushed in a crusher and then passed through a 100-mesh sieve to obtain coal gangue particles. Weigh 1 part by weight of coal gangue particles, 15 parts by weight of water, and 5 parts by weight of zirconium oxide grinding balls and mix them in a ball mill. Set the rotation speed to 500 r / min and grind for 10 h to obtain a slurry. Add a collector (obtained by mixing 4-dodecylphenol and kerosene in a 2:3 ratio) and 1,3-dimethylbutanol to the slurry. The amount of collector added is 0.08 parts by weight per part by weight of slurry, and the amount of 1,3-dimethylbutanol added is 0.04 parts by weight per part by weight of slurry. After mixing, place the mixture in a flotation cell, adjust the rotation speed to 1500 r / min, and the aeration rate to 0.3 m³ / min. 3 / (m 2 After stirring for 180 seconds, the surface bubbles were scraped off, and the solid particles were collected by filtration and then placed in a drying oven at 80°C to dry and remove water to obtain pretreated coal gangue.

[0028] Preparation Example 6 The preparation method of Bacillus cereus seed culture is as follows: Weigh out 5g yeast powder, 9g peptone, 6g glucose, and 10g sodium chloride and mix them. Then, add 800mL of purified water, heat and stir to dissolve. After the powder is completely dissolved, adjust the pH to neutral, and then add purified water to bring the volume to 1000mL. Sterilize the mixture at 121℃ for 20 minutes to obtain the culture medium. Use a sterilized inoculation loop to inoculate one loopful of Bacillus lentigines strain CICC 23640 into the sterilized culture medium. Then, place the medium in a 30℃ constant temperature shaking incubator and shake at 100 rpm until the OD of the bacterial solution reaches a certain level. 600 Stop culturing when the viscosity reaches 0.6 and store at 5°C until use.

[0029] Preparation Example 7 The preparation method of Bacillus cereus seed culture is as follows: Weigh out 5g yeast powder, 9g peptone, 6g glucose, and 10g sodium chloride and mix them. Then, add 800mL of purified water, heat and stir to dissolve. After the powder is completely dissolved, adjust the pH to neutral, and then add purified water to bring the volume to 1000mL. Sterilize the mixture at 121℃ for 20 minutes to obtain the culture medium. Use a sterilized inoculation loop to inoculate one loopful of Bacillus lentigines strain CICC 23640 into the sterilized culture medium. Then, place the medium in a 30℃ constant temperature shaking incubator and shake at 100 rpm until the OD of the bacterial solution reaches a certain level. 600 Stop culturing when the concentration reaches 0.65 and store at 5°C until use.

[0030] Preparation Example 8 The preparation method of Bacillus cereus seed culture is as follows: Weigh out 5g yeast powder, 9g peptone, 6g glucose, and 10g sodium chloride and mix them. Then, add 800mL of purified water, heat and stir to dissolve. After the powder is completely dissolved, adjust the pH to neutral, and then add purified water to bring the volume to 1000mL. Sterilize the mixture at 121℃ for 20 minutes to obtain the culture medium. Use a sterilized inoculation loop to inoculate one loopful of Bacillus lentigines strain CICC 23640 into the sterilized culture medium. Then, place the medium in a 30℃ constant temperature shaking incubator and shake at 100 rpm until the OD of the bacterial solution reaches a certain level. 600 Stop culturing when the pH reaches 0.7 and store at 5°C until use.

[0031] Preparation Example 9 The preparation process of Bacillus amyloliquefaciens seed culture is as follows: Weigh 16g of beef extract peptone medium powder and dissolve it in 800mL of purified water by heating and stirring. After the powder is completely dissolved, adjust the pH to neutral, and then add purified water to bring the volume to 1000mL. Sterilize the medium at 121℃ for 20min to obtain beef extract peptone medium. Using a sterilized inoculation loop, inoculate one loopful of *Bacillus amyloliquefaciens* strain CICC 10080 into the sterilized beef extract peptone medium. Then, place the medium in a 25℃ constant temperature shaking incubator and incubate with shaking at 100 rpm until the OD of the bacterial culture reaches a certain level. 600 Stop culturing when the viscosity reaches 0.6 and store at 5°C until use.

[0032] Preparation Example 10 The preparation process of Bacillus amyloliquefaciens seed culture is as follows: Weigh 16g of beef extract peptone medium powder and dissolve it in 800mL of purified water by heating and stirring. After the powder is completely dissolved, adjust the pH to neutral, and then add purified water to bring the volume to 1000mL. Sterilize the medium at 121℃ for 20min to obtain beef extract peptone medium. Using a sterilized inoculation loop, inoculate one loopful of *Bacillus amyloliquefaciens* strain CICC 10080 into the sterilized beef extract peptone medium. Then, place the medium in a 25℃ constant temperature shaking incubator and incubate with shaking at 100 rpm until the OD of the bacterial culture reaches a certain level. 600 Stop culturing when the concentration reaches 0.65 and store at 5°C until use.

[0033] Preparation Example 11 The preparation process of Bacillus amyloliquefaciens seed culture is as follows: Weigh 16g of beef extract peptone medium powder and dissolve it in 800mL of purified water by heating and stirring. After the powder is completely dissolved, adjust the pH to neutral, and then add purified water to bring the volume to 1000mL. Sterilize the medium at 121℃ for 20min to obtain beef extract peptone medium. Using a sterilized inoculation loop, inoculate one loopful of *Bacillus amyloliquefaciens* strain CICC 10080 into the sterilized beef extract peptone medium. Then, place the medium in a 25℃ constant temperature shaking incubator and incubate with shaking at 100 rpm until the OD of the bacterial culture reaches a certain level. 600 Stop culturing when the pH reaches 0.7 and store at 5°C until use.

[0034] Example 1 A method for producing organic fertilizer from modified coal gangue specifically includes the following steps: Pigs and purified water were mixed in a weight ratio of 1:5, and then minced to remove solid residues such as bones, forming an animal carcass homogenate. The animal carcass homogenate was heated to 150°C and subjected to high-temperature and high-pressure inactivation at 1 MPa for 5 hours, followed by natural cooling to room temperature to obtain a pretreated homogenate. One part by weight of a biological enzyme (composed of lipase with a specific activity of 100 U / mg, keratinase with a specific activity of 200 U / mg, and collagenase with a specific activity of 125 U / mg, mixed in a weight ratio of 0.5:2.5:1) was weighed and mixed with 90 parts by weight of the pretreated homogenate. The mixture was stirred continuously at 100 r / min, then the pH was adjusted to 7.0, and the temperature was adjusted to 40°C. The mixture was stirred and hydrolyzed for 10 hours. After hydrolysis, the mixture was heated to 95℃ for 15 minutes to inactivate the bacteria, and then centrifuged at 7000 rpm for 15 minutes to obtain the supernatant. 18 parts by weight of the pretreated coal gangue obtained in Preparation Example 1 were weighed and mixed with 1 part by weight of the supernatant. The mixture was stirred at 200 rpm for 5 hours and then dried in an oven at 50℃ for 1 hour to obtain modified coal gangue. 0.05 parts by weight of a mixed bacterial seed solution (composed of 1 part by weight of Bacillus colloidis seed solution obtained in Preparation Example 6 and 2 parts by weight of Bacillus amyloliquefaciens seed solution obtained in Preparation Example 9) was evenly sprayed onto the surface of 1 part by weight of the modified coal gangue. The mixture was then piled up with dimensions of 1m long × 1m wide × 0.6m high. The temperature was then controlled at 30℃, and fermentation was timed for 3 days, with the material turned over every 24 hours during composting. After composting, the mixture was dried at 45℃ for 4 hours to complete the preparation of organic fertilizer.

[0035] Example 2 A method for producing organic fertilizer from modified coal gangue specifically includes the following steps: Pig carcass and purified water were mixed in a weight ratio of 1:5, and then minced to remove solid residues such as bones, forming an animal carcass homogenate. The animal carcass homogenate was heated to 150°C and subjected to high-temperature and high-pressure inactivation at a pressure of 1 MPa for 5 hours, followed by natural cooling to room temperature to obtain a pretreated homogenate. One part by weight of a biological enzyme (composed of lipase with a specific activity of 100 U / mg, keratinase with a specific activity of 200 U / mg, and collagenase with a specific activity of 125 U / mg, mixed in a weight ratio of 0.5:2.7:1) was weighed and mixed with 92 parts by weight of the pretreated homogenate. The mixture was stirred continuously at 100 r / min, then the pH was adjusted to 7.0, and the temperature was adjusted to 40°C. The mixture was stirred and hydrolyzed for 11 hours. After hydrolysis, the mixture was heated to 95℃ for 15 minutes to inactivate the bacteria, and then centrifuged at 7000 rpm for 15 minutes to obtain the supernatant. 20 parts by weight of the pretreated coal gangue obtained in Preparation Example 2 were weighed and mixed with 1 part by weight of the supernatant. The mixture was stirred at 200 rpm for 5 hours and then dried in an oven at 50℃ for 1 hour to obtain modified coal gangue. 0.05 parts by weight of a mixed bacterial seed solution (composed of 1 part by weight of Bacillus colloidis seed solution obtained in Preparation Example 6 and 2.5 parts by weight of Bacillus amyloliquefaciens seed solution obtained in Preparation Example 9) was evenly sprayed onto the surface of 1 part by weight of the modified coal gangue. The mixture was then piled up with dimensions of 1m long × 1m wide × 0.6m high. The temperature was controlled at 30℃, and fermentation was timed for 4 days, with the material turned over every 24 hours during composting. After composting, the mixture was dried at 45℃ for 4 hours to complete the preparation of organic fertilizer.

[0036] Example 3 A method for producing organic fertilizer from modified coal gangue specifically includes the following steps: Pig carcass and purified water were mixed in a weight ratio of 1:5, and then minced to remove solid residues such as bones, forming an animal carcass homogenate. The animal carcass homogenate was heated to 150°C and subjected to high-temperature and high-pressure inactivation at 1 MPa for 5 hours, followed by natural cooling to room temperature to obtain a pretreated homogenate. One part by weight of a biological enzyme (composed of lipase with a specific activity of 100 U / mg, keratinase with a specific activity of 200 U / mg, and collagenase with a specific activity of 125 U / mg, mixed in a weight ratio of 0.55:2.7:1.1) was weighed and mixed with 94 parts by weight of the pretreated homogenate. The mixture was stirred continuously at 100 r / min, then the pH was adjusted to 7.5, and the temperature was adjusted to 45°C. The mixture was stirred and hydrolyzed for 11 hours. After hydrolysis, the mixture was heated to 95℃ for 15 minutes to inactivate the bacteria, and then centrifuged at 7500 rpm for 13 minutes to obtain the supernatant. 22 parts by weight of the pretreated coal gangue obtained in Preparation Example 3 were weighed and mixed with 1 part by weight of the supernatant. The mixture was stirred at 250 rpm for 5.5 hours and then dried in an oven at 50℃ for 1 hour to obtain modified coal gangue. 0.06 parts by weight of a mixed bacterial seed solution (composed of 1 part by weight of Bacillus colloidis seed solution obtained in Preparation Example 7 and 2.5 parts by weight of Bacillus amyloliquefaciens seed solution obtained in Preparation Example 10) was evenly sprayed onto the surface of 1 part by weight of the modified coal gangue. The mixture was then piled up with dimensions of 1m long × 1m wide × 0.6m high. The temperature was controlled at 30℃, and fermentation was timed for 5 days, with the material turned over every 24 hours during composting. After composting, the mixture was dried at 45℃ for 4 hours to complete the preparation of organic fertilizer.

[0037] Example 4 A method for producing organic fertilizer from modified coal gangue specifically includes the following steps: Pig carcass and purified water were mixed in a weight ratio of 1:5, then minced to remove solid residues such as bones, forming an animal carcass homogenate. The homogenate was heated to 150°C and subjected to high-temperature, high-pressure inactivation at 1 MPa for 5 hours, followed by natural cooling to room temperature to obtain a pretreated homogenate. One part by weight of a biological enzyme (composed of lipase with a specific activity of 100 U / mg, keratinase with a specific activity of 200 U / mg, and collagenase with a specific activity of 125 U / mg, mixed in a weight ratio of 0.55:3:1.2) was weighed and mixed with 95 parts by weight of the pretreated homogenate. The mixture was stirred continuously at 100 rpm, then the pH was adjusted to 8.0, and the temperature was adjusted to 45°C. The mixture was stirred and hydrolyzed for 12 hours. After hydrolysis, the mixture was heated to 95℃ for 15 minutes to inactivate the bacteria, and then centrifuged at 7500 rpm for 12 minutes to obtain the supernatant. 24 parts by weight of the pretreated coal gangue obtained in Preparation Example 4 were weighed and mixed with 1 part by weight of the supernatant. The mixture was stirred at 250 rpm for 5.5 hours and then dried in an oven at 50℃ for 1 hour to obtain modified coal gangue. 0.06 parts by weight of a mixed bacterial seed solution (composed of 1 part by weight of Bacillus colloidis seed solution obtained in Preparation Example 8 and 2.5 parts by weight of Bacillus amyloliquefaciens seed solution obtained in Preparation Example 11) was evenly sprayed onto the surface of 1 part by weight of the modified coal gangue. The mixture was then piled up with dimensions of 1m long × 1m wide × 0.6m high. The temperature was controlled at 35℃, and fermentation was timed for 6 days, with the material turned over every 24 hours during composting. After composting, the mixture was dried at 45℃ for 4 hours to complete the preparation of organic fertilizer.

[0038] Example 5 A method for producing organic fertilizer from modified coal gangue specifically includes the following steps: Pig carcass and purified water were mixed in a weight ratio of 1:5, then minced to remove solid residues such as bones, forming an animal carcass homogenate. The homogenate was heated to 150°C and subjected to high-temperature, high-pressure inactivation at 1 MPa for 5 hours, followed by natural cooling to room temperature to obtain a pretreated homogenate. One part by weight of a biological enzyme (composed of lipase with a specific activity of 100 U / mg, keratinase with a specific activity of 200 U / mg, and collagenase with a specific activity of 125 U / mg, mixed in a weight ratio of 0.6:3:1.2) was weighed and mixed with 95 parts by weight of the pretreated homogenate. The mixture was stirred continuously at 100 rpm, then the pH was adjusted to 8.0, and the temperature was adjusted to 45°C. The mixture was stirred and hydrolyzed for 12 hours. After hydrolysis, the mixture was heated to 95℃ for 15 minutes to inactivate the bacteria, and then centrifuged at 8000 rpm for 10 minutes to obtain the supernatant. 26 parts by weight of the pretreated coal gangue obtained in Preparation Example 5 were weighed and mixed with 1 part by weight of the supernatant. The mixture was stirred at 300 rpm for 6 hours and then dried in an oven at 50℃ for 1 hour to obtain modified coal gangue. 0.06 parts by weight of a mixed bacterial seed solution (composed of 1 part by weight of Bacillus colloidis seed solution obtained in Preparation Example 8 and 3 parts by weight of Bacillus amyloliquefaciens seed solution obtained in Preparation Example 11) was evenly sprayed onto the surface of 1 part by weight of modified coal gangue. The mixture was then piled up with dimensions of 1m long × 1m wide × 0.6m high. The temperature was controlled at 35℃, and fermentation was timed for 7 days, with the material turned over every 24 hours during composting. After composting, the mixture was dried at 45℃ for 4 hours to complete the preparation of organic fertilizer.

[0039] Comparative Example 1 A method for producing organic fertilizer from modified coal gangue specifically includes the following steps: 0.06 parts by weight of a mixed bacterial seed solution (composed of 1 part by weight of the Bacillus mucilaginosus seed solution obtained in Preparation Example 8 and 3 parts by weight of the Bacillus amyloliquefaciens seed solution obtained in Preparation Example 11) was evenly sprayed onto the surface of 1 part by weight of pretreated coal gangue, and then piled up with dimensions of 1m long × 1m wide × 0.6m high. The temperature was then controlled at 35°C, and fermentation was carried out for 7 days, with the material turned over every 24 hours during the composting fermentation. After the composting fermentation was completed, the material was dried at 45°C for 4 hours to complete the preparation of organic fertilizer.

[0040] Comparative Example 2 A method for producing organic fertilizer from modified coal gangue specifically includes the following steps: The amount of mixed strain seed liquid in Example 4 was increased to 0.1 parts by weight, and the rest of the preparation process remained the same as in Example 4.

[0041] Comparative Example 3 A method for producing organic fertilizer from modified coal gangue specifically includes the following steps: The composting fermentation temperature in Example 4 was increased to 40°C and the fermentation time was extended to 8 days, while the rest of the preparation process remained the same as in Example 4.

[0042] Fertilizer efficacy verification: 1 kg of organic fertilizer obtained from Examples 1-5 and Comparative Examples 1-3 was mixed with 30 kg of soil and then the cultivated cabbage seedlings were transplanted into the soil with organic fertilizer. A total of 8 rows were transplanted, with 10 seedlings in each row. The soil moisture content was kept within the range of 70±2%. Finally, the average fresh weight and average root length were measured on the 30th day. The results are shown in Table 1 below.

[0043] Table 1 Fertilizer Efficiency Test

[0044] The following conclusions can be drawn from Table 1 above: (1) As can be seen from Examples 1 to 5, the organic fertilizer prepared by the method of the present invention has good fertilizer effect and realizes the resource utilization of coal gangue.

[0045] (2) Comparative Example 1 shows that the prepared organic fertilizer has poor fertilizer effect. This may be because although flotation can reduce heavy metal ions in coal gangue, it also inevitably causes the loss of other nutrients. Direct inoculation of bacterial strains for fermentation is not conducive to improving fertilizer effect.

[0046] (3) Comparative Example 2 shows that the prepared organic fertilizer has poor fertilizer effect. This may be due to the excessive number of strains, which leads to an overly intense microbial fermentation process, affecting the symbiotic relationship, causing an imbalance in the microbial population structure, and affecting the fermentation, decomposition, and release of organic matter.

[0047] (4) Comparative Example 3 shows that the prepared organic fertilizer has poor fertilizer effect. This may be due to the high fermentation temperature and long fermentation time, which may reduce the activity of the strain and lead to poor fertilizer effect after fermentation.

[0048] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for producing organic fertilizer from modified coal gangue, characterized in that, The production method includes the following steps: Animal carcass homogenate was treated at 150℃ and 1MPa for 5 hours to obtain pretreated homogenate; The pretreated homogenate and biological enzyme were mixed and hydrolyzed at a weight ratio of 90-95:1, then inactivated at 95℃ for 15 min and centrifuged to obtain the supernatant. The supernatant and pretreated coal gangue are mixed and stirred at a weight ratio of 1:18~26 to form modified coal gangue. The modified coal gangue and mixed bacterial seed liquid are mixed at a weight ratio of 1:0.05~0.06, composted and fermented, and then dried to obtain the organic fertilizer.

2. The method for producing organic fertilizer from modified coal gangue according to claim 1, characterized in that, The animal carcass homogenate was obtained by mixing and grinding pig and water in a weight ratio of 1:

10.

3. The method for producing organic fertilizer from modified coal gangue according to claim 1, characterized in that, The bio-enzyme is composed of lipase, keratinase and collagenase in a weight ratio of 0.5~0.6:2.5~3:1~1.

2.

4. The method for producing organic fertilizer from modified coal gangue according to claim 1, characterized in that, The conditions for the mixed hydrolysis include a pH of 7.0 to 8.0, a temperature of 40°C to 45°C, and a time of 10 to 12 hours.

5. The method for producing organic fertilizer from modified coal gangue according to claim 1, characterized in that, The method for preparing the pretreated coal gangue includes the following steps: Coal gangue is crushed and sieved to obtain coal gangue particles; Coal gangue particles, water, and grinding balls are mixed in a weight ratio of 1:10 to 15:5 and ground at a speed of 400 r / min to 500 r / min for 6 to 10 hours to obtain a slurry. The slurry, collector, and flotation agent are mixed in a weight ratio of 1:0.06~0.08:0.04 and stirred at a rotation speed of 1000r / min~1500r / min at a speed of 0.2m. 3 / (m 2 ·min)~0.3m 3 / (m 2 After stirring with an aeration rate of ·min for 150s~180s, the pretreated coal gangue was obtained by filtration and drying.

6. The method for producing organic fertilizer from modified coal gangue according to claim 5, characterized in that, The collector is obtained by mixing 4-dodecylphenol and kerosene in a ratio of 1~2:1~3.

7. The method for producing organic fertilizer from modified coal gangue according to claim 5, characterized in that, The flotation agent includes 1,3-dimethylbutanol.

8. The method for producing organic fertilizer from modified coal gangue according to claim 1, characterized in that, The mixed strain seed liquid is derived from OD 600 The seed culture of Bacillus cereus with a concentration of 0.6-0.7 and an OD value of 0.6-0.7 were obtained. 600 The mixture consists of 0.6-0.7% Bacillus amyloliquefaciens seed culture at a weight ratio of 1:2-3.

9. The method for producing organic fertilizer from modified coal gangue according to claim 1, characterized in that, The conditions for the mixed composting fermentation include a stack size of 1m long × 1m wide × 0.6m high, a temperature of 30℃~35℃, a time of 3 to 7 days, and turning the material once every 24 hours.

10. An organic fertilizer prepared by modifying coal gangue, characterized in that, The organic fertilizer is produced by the production method of organic fertilizer prepared from modified coal gangue as described in any one of claims 1 to 9.

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