A preparation method of a new organic fertilizer based on attapulgite

Abstract

This invention relates to the field of agricultural fertilizer technology and discloses a novel organic fertilizer preparation method based on attapulgite, comprising the following steps: S1, attapulgite ore is sequentially subjected to thermal activation, compound acid activation, and compound organic activation treatment to obtain composite modified attapulgite powder; S2, livestock and poultry manure, crop straw powder, composite modified attapulgite powder, microbial compound fermentation agent, and urea are mixed in proportion, added to a mixing tank and mixed evenly, and the moisture content is adjusted to 55%–60%; S3, the mixture is subjected to three-stage temperature-controlled aerobic fermentation: medium-temperature fermentation, high-temperature fermentation, and cooling composting; through a stepped treatment process of "thermal activation, dilute sulfuric acid pre-activation, phosphoric acid deep activation, and organic multi-component grafting", the specific surface area of ​​the composite modified attapulgite powder can reach 450 m². 2 With a cation exchange capacity of over / g, the cation exchange capacity is increased by 2.5 to 3.5 times compared to the original ore. At the same time, phosphorus nutrients and various active functional groups such as carboxyl, hydroxyl, and amino groups are introduced, which greatly enhances the adsorption and slow release performance.

Description

Technical Field

[0001] This invention relates to the field of agricultural fertilizer technology, specifically to a novel method for preparing organic fertilizer based on attapulgite. Background Technology

[0002] my country is a major agricultural country, generating billions of tons of organic waste such as crop straw, livestock and poultry manure, and kitchen waste every year. How to efficiently convert these wastes into high-quality organic fertilizers and achieve the dual goals of agricultural circular economy and improved arable land quality has become an important issue for the sustainable development of agriculture. Attapulgite clay, due to its unique chain-layered crystal structure and abundant nanopores, naturally has good adsorption, colloidal and carrier functions, and is widely used as a slow-release fertilizer additive or soil conditioner.

[0003] The existing attapulgite ore contains impurities such as carbonates and quartz, as well as interlayer bound water, which occupy a large amount of effective space. The microporous structure is not fully opened. When used directly as an organic fertilizer additive, its adsorption and fixation capacity for nutrient ions such as ammonium and phosphate is limited, the slow release effect is not ideal, and it cannot effectively reduce nutrient leaching. At the same time, the surface of natural attapulgite is mainly composed of silanol groups and lacks diverse active functional groups such as carboxyl and amine groups that can form chemical bonds with organic matter, microorganisms and plant roots. It is difficult to achieve chelation and synergistic effect of micronutrients, and it cannot form a "mineral-organic" complex with humic acid in organic fertilizer. Thus, it limits its potential to improve soil aggregate structure and increase cation exchange capacity. Therefore, a new method for preparing organic fertilizer based on attapulgite is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a novel organic fertilizer preparation method based on attapulgite, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a novel organic fertilizer preparation method based on attapulgite, comprising the following steps: S1. Attapulgite ore is subjected to thermal activation, compound acid activation and compound organic activation treatment in sequence to obtain composite modified attapulgite powder. S2. Mix livestock and poultry manure, crop straw powder, compound modified attapulgite powder, microbial compound fermentation agent and urea in a certain proportion, add to the mixing tank and mix evenly, and adjust the moisture to 55% to 60%; S3. The mixture is subjected to three stages of temperature-controlled aerobic fermentation: medium-temperature fermentation, high-temperature fermentation, and cooling composting. S4. After fermentation, the material is aged, dried, and crushed. Then, composite modified attapulgite powder and biosurfactant are added to granulate the material. After granulation, the material is coated with a film and dried to obtain the finished organic fertilizer.

[0006] Preferably, in S1, the composite acid activation is performed by first treating with 0.5–1.0 mol / L dilute sulfuric acid at 55–65°C for 1–2 hours, and then treating with 0.8–1.2 mol / L phosphoric acid at 60–70°C for 1–2 hours, with a solid-liquid ratio of 1:3–1:5.

[0007] Preferably, the composite organic activation is as follows: a 6%–9% suspension of composite acid-activated attapulgite powder is prepared, and 3%–5% of potassium humate, 2%–4% of sodium humate and 1%–2% of glutamic acid by weight of the attapulgite powder are added, and the mixture is reacted at 70–80°C for 1.5–2.5 hours.

[0008] As a preferred option, in S2, by mass parts: 55-70 parts of livestock and poultry manure, 20-28 parts of crop straw powder, 15-22 parts of compound modified attapulgite powder, 2-3 parts of microbial compound fermentation agent, and 2-4 parts of urea.

[0009] Preferably, the microbial compound fermentation agent contains Bacillus subtilis, Bacillus licheniformis, Aspergillus oryzae, and EM compound bacteria, with a total effective viable count ≥3.0×10⁻⁶. 8 CFU / g.

[0010] Preferably, in S3, the mesophilic fermentation temperature is 30-40°C, lasting for 48-72 hours, with ventilation and turning every 8-12 hours; The high-temperature fermentation temperature is 55-62℃, lasting for 7-10 days, with the mixture being turned over 1-2 times per day; The cooling and composting temperature is 35-40℃, lasting for 4-6 days, and the compost is turned over every 24-36 hours until the temperature difference between the compost and the environment is less than 5℃.

[0011] As a preferred option, in S4, the mixture is aged for 25 to 30 days, dried to a moisture content of 20% to 25%, and then pulverized through a 60 to 80 mesh sieve.

[0012] Preferably, the added composite modified attapulgite powder accounts for 5% to 8% of the total mass of the material, and the biosurfactant is rhamnolipin or trehalose, with an addition amount of 1.5% to 2.5% and a granulation particle size of 2.5 to 5 mm.

[0013] Preferably, a first support frame and a second support frame are provided on both sides of the mixing tank, and a connecting shaft is rotatably connected to one side of the first support frame and the second support frame via a bearing. The connecting shaft is fixed at the center of the two sides of the mixing tank. A stirring component is provided on one side of the mixing tank, and a water spraying component is provided on one side of the stirring component; The stirring assembly includes a first motor, a first pulley is fixed to the output shaft end of the first motor, and a second pulley is fixed to the end of the connecting shaft away from the stirring tank. The first pulley and the second pulley are connected by a belt. The mixing tank is rotatably connected to a mixing shaft via bearings on its inner side, and several mixing rods are fixed to the outer side of the mixing shaft.

[0014] Preferably, the water spray assembly includes a housing, the inner side of which is provided with a water storage chamber, and a connecting pipe is fixed to one end of the stirring shaft, with a water inlet hole opened on the inner side of the connecting pipe; The stirring shaft has several water spray holes on its outer side, and a filter screen is fixed at the opening of each water spray hole. The water storage chamber, the water inlet, and the water spray holes are connected. The outer side of the connecting pipe is rotatably connected to the housing and the connecting shaft respectively through sealed bearings. A water pump is provided on the outer side of the second support frame. The water pump outlet is connected to the inner side of the water storage chamber through a water pipe. A fourth pulley is fixedly sleeved on the outside of the connecting pipe, a second motor is fixed at the bottom of the inner wall of the second support frame, a third pulley is fixed at the output shaft end of the second motor, and the third pulley is connected to the fourth pulley via a belt; The first motor is fixed to the bottom of the inner wall of the first support frame, the outside of the mixing tank is connected to a material pipe, a cover plate is detachably fixed on the material pipe, and the box body is fixed to the top of the inner wall of the second support frame.

[0015] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects: First, the mixing tank is rotated by the first motor, while the second motor drives the mixing shaft and mixing rod to rotate in the opposite direction. The two motors create relative motion, which generates strong convection and shearing forces on the raw materials inside the tank. Compared with the single rotation method, the mixing uniformity is significantly improved. The water pump sends water into the water storage chamber and sprays it at multiple points along the mixing shaft through the water inlet, water delivery tank and multiple spray holes. Humidification is carried out simultaneously during the mixing process to avoid local over-wetting or dry material residue, and to meet the strict humidity requirements of subsequent processes.

[0016] II. Through a tiered processing technique involving thermal activation, dilute sulfuric acid pre-activation, phosphoric acid deep activation, and organic multi-component grafting, the specific surface area of ​​the composite-modified attapulgite powder can reach 450 m². 2 With a cation exchange capacity of over / g, the cation exchange capacity is increased by 2.5 to 3.5 times compared to the original ore. At the same time, phosphorus nutrients and various active functional groups such as carboxyl, hydroxyl, and amine groups are introduced, which greatly enhances the adsorption and slow release performance.

[0017] Third, through three stages of temperature-controlled aerobic fermentation—medium-temperature, high-temperature, and cooling composting—combined with the synergistic effects of Bacillus subtilis, Bacillus licheniformis, Aspergillus oryzae, and EM compound bacteria, the humic acid content is increased by more than 25% compared to conventional compost, and the final product has an organic matter content of ≥52%. This effectively enhances the soil's organic carbon pool. The organic fertilizer is rich in humus and modified attapulgite colloids, which can promote the formation of soil micro-aggregates, reduce soil bulk density, increase porosity and water and fertilizer retention capacity, and is especially suitable for improving sandy soils or compacted farmland. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a schematic diagram of the overall structure of the present invention; Figure 3 This is a schematic diagram of the structure at the stirring shaft of the present invention; Figure 4 This is a schematic diagram of the front cross-sectional structure of the present invention; Figure 5 This is a schematic cross-sectional view of the housing structure of the present invention; Figure 6 This is a schematic diagram of the stirring rod structure of the present invention.

[0020] Explanation of reference numerals in the attached drawings: 1. Mixing tank; 11. Material pipe; 12. First motor; 13. First pulley; 14. Second pulley; 15. Mixing rod; 16. Mixing shaft; 2. First support frame; 3. Second support frame; 5. Water spray assembly; 51. Water pump; 52. Second motor; 53. Third pulley; 54. Box body; 55. Fourth pulley; 56. Water spray hole; 57. Water supply tank; 58. Water storage chamber; 59. Connecting pipe; 510. Water inlet; 6. Connecting shaft. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0023] Example Please see Figure 1 This invention provides a technical solution: a novel organic fertilizer preparation method based on attapulgite, comprising the following steps: S1. The raw attapulgite ore is subjected to thermal activation, compound acid activation and compound organic activation in sequence to obtain composite modified attapulgite powder. The thermal activation is as follows: the raw attapulgite ore is crushed to a particle size of less than 3 mm, calcined at 350-400℃ for 2-3 hours, naturally cooled, and pulverized through a 150-200 mesh sieve to obtain thermally activated attapulgite powder. The composite acid activation method is as follows: first, treat with 0.5-1.0 mol / L dilute sulfuric acid at 55-65℃ for 1-2 hours, then treat with 0.8-1.2 mol / L phosphoric acid at 60-70℃ for 1-2 hours, with a solid-liquid ratio of 1:3-1:5. Thermally activated attapulgite powder is mixed with dilute sulfuric acid (0.5–1.0 mol / L) at a solid-liquid ratio of 1:3–1:4, and stirred at 55–65°C for 1–2 hours. After filtration and washing with water until neutral, pre-acid activated powder is obtained. The pre-acid activated powder is then mixed with phosphoric acid solution (0.8–1.2 mol / L) at a solid-liquid ratio of 1:3–1:5, and stirred at 60–70°C for 1–2 hours. After filtration and washing with water until neutral, the powder is dried to obtain composite acid activated attapulgite powder. The sulfuric acid first opens the pores and increases the specific surface area, while the phosphoric acid further dissolves metal cations and introduces phosphorus nutrients. The two work synergistically to achieve more complete activation.

[0024] The composite organic activation process is as follows: A 6%–9% suspension of composite acid-activated attapulgite powder is prepared, and 3%–5% (by weight) of potassium humate, 2%–4% (by weight) of sodium humate, and 1%–2% (by weight) of attapulgite powder are added. The mixture is reacted at 70–80℃ for 1.5–2.5 hours. The composite acid-activated attapulgite powder is then dispersed in deionized water to prepare a 6%–9% suspension. 3%–5% (by weight) of potassium humate, 2%–4% (by weight) of sodium humate, and 1%–2% (by weight) of attapulgite powder are added, and the mixture is stirred at 70–80℃ for 1.5–2.5 hours. The mixture is then centrifuged, washed, dried at 80–100℃, and pulverized through a 200-mesh sieve to obtain the composite modified attapulgite powder. Potassium / sodium humate provides a large number of carboxyl and hydroxyl groups, while glutamic acid introduces amino groups, forming a multifunctional group synergistic grafting effect, significantly enhancing the complexation and adsorption of ammonium and potassium ions.

[0025] S2. Mix livestock and poultry manure, crop straw powder, compound modified attapulgite powder, microbial compound fermentation agent and urea in proportion, add to mixing tank 1 and mix evenly, adjust the moisture to 55% to 60%; By weight: 55-70 parts of livestock and poultry manure, 20-28 parts of crop straw powder, 15-22 parts of compound modified attapulgite powder, 2-3 parts of microbial compound fermentation agent, and 2-4 parts of urea. The livestock and poultry manure is a mixture of two or more types of cow manure, chicken manure, and sheep manure. The crop straw powder is one or more types of corn stalks, sorghum stalks, and rapeseed stalks, and is crushed through a 10-20 mesh sieve.

[0026] The microbial compound fermentation agent contains Bacillus subtilis, Bacillus licheniformis, Aspergillus oryzae, and EM compound bacteria, with a total effective viable count ≥3.0×10⁻⁶. 8 CFU / g.

[0027] S3. The mixture is subjected to three stages of temperature-controlled aerobic fermentation: medium-temperature fermentation, high-temperature fermentation, and cooling composting. Mesophilic fermentation is carried out at a temperature of 30–40℃ for 48–72 hours, with ventilation and turning every 8–12 hours; this promotes the rapid degradation of soluble sugars and proteins by mesophilic microorganisms. High-temperature fermentation is carried out at 55-62℃ for 7-10 days, with the mixture turned over 1-2 times a day. The fermentation time is no less than 5 days at temperatures above 55℃. This process aims to kill pathogens and weed seeds and efficiently degrade cellulose.

[0028] The cooling and composting temperature is 35-40℃, lasting for 4-6 days, and the compost is turned over every 24-36 hours until the temperature difference between the compost and the environment is less than 5℃.

[0029] S4. After fermentation, the material is aged, dried, and crushed. Then, composite modified attapulgite powder and biosurfactant are added to granulate the material. After granulation, the material is coated with a film and dried to obtain the finished organic fertilizer.

[0030] After aging for 25–30 days, the material is dried to a moisture content of 20%–25%, then pulverized through a 60–80 mesh sieve. After fermentation, the material is piled into windrows 1.2–1.8 m high and aged for another 25–30 days, turning the pile every 5 days to promote humus stabilization. After aging, the material is dried at 55–65℃ to a moisture content of 20%–25%, then pulverized through a 60–80 mesh sieve. 5%–8% of the total mass of the composite modified attapulgite powder obtained in step one and 1.5%–2.5% of the total mass of the biosurfactant are added to the pulverized material. After mixing evenly, the mixture is fed into a disc granulator or a flat die granulator for granulation, with the particle size controlled at 2.5–5 mm.

[0031] The added composite modified attapulgite powder is 5% to 8% of the total mass of the material, and the biosurfactant is rhamnolipin or trehalose, with an addition amount of 1.5% to 2.5%. The granulation particle size is 2.5 to 5 mm, and the spraying amount is 3% to 5% of the particle mass. After coating, it is dried to a moisture content of ≤18%, and then fluidized and dried at 45 to 60℃ to a moisture content of ≤18% to obtain the finished organic fertilizer.

[0032] Example 2 Please see Figure 2-6 The difference between this embodiment and Embodiment 1 is that: The mixing tank 1 is provided with a first support frame 2 and a second support frame 3 on both sides respectively. The first support frame 2 and the second support frame 3 are rotatably connected to a connecting shaft 6 on one side via a bearing. The connecting shaft 6 is fixed at the center of the two sides of the mixing tank 1. The mixing tank 1 is provided with a mixing component on one side and a water spraying component 5 on the other side of the mixing component. The stirring assembly includes a first motor 12, with a first pulley 13 fixed to the output shaft end of the first motor 12, and a second pulley 14 fixed to the end of the connecting shaft 6 away from the stirring tank 1. The first pulley 13 and the second pulley 14 are connected by a belt. The output shaft end of the first motor 12 drives the first pulley 13 to rotate, and the first pulley 13 transmits power to the second pulley 14 through the belt. The second pulley 14 drives the connecting shaft 6 to rotate. Since the connecting shaft 6 is rotatably connected to the first support frame 2 and the second support frame 3 through bearings, and the connecting shaft 6 is fixed at the axis on both sides of the stirring tank 1, the connecting shaft 6 drives the stirring tank 1 to rotate around its axis.

[0033] A stirring shaft 16 is rotatably connected to the inside of the mixing tank 1 via a bearing. Several stirring rods 15 are fixed to the outside of the stirring shaft 16. The stirring tank 1 and the stirring shaft 16 rotate in opposite directions, and the stirring rods 15 rotate in the opposite direction to the stirring tank 1, thereby generating a strong shearing and tumbling effect on the raw materials inside the mixing tank 1, achieving efficient and uniform mixing.

[0034] The water spray assembly 5 includes a housing 54, with a water storage chamber 58 inside the housing 54. A connecting pipe 59 is fixed to one end of the stirring shaft 16, and a water inlet 510 is opened inside the connecting pipe 59. Several water spray holes 56 are opened on the outside of the stirring shaft 16, and a filter screen is fixed at the opening of the water spray hole 56. The water storage chamber 58, the water inlet 510, and the water spray holes 56 are connected. The outside of the connecting pipe 59 is rotatably connected to the housing 54 and the connecting shaft 6 through sealed bearings. A water pump 51 is provided on the outside of the second support frame 3, and the water outlet of the water pump 51 is connected to the housing 54 and the connecting shaft 6 through sealed bearings. The water pipe is connected to the inside of the water storage chamber 58; the water pump 51 is started, and the water pump 51 delivers water through the water pipe to the water storage chamber 58 inside the box 54. The water in the water storage chamber 58 enters the water delivery tank 57 through the water inlet 510 opened on the inside of the connecting pipe 59, and then sprays out through several water spray holes 56 opened on the outside of the stirring shaft 16, spraying it on the surface of the raw materials inside the stirring tank 1 to humidify the raw materials. The filter screen fixed at the opening of the water spray hole 56 can effectively prevent raw material particles from clogging the water spray hole 56 and ensure the uniformity of water spraying.

[0035] A fourth pulley 55 is fixedly sleeved on the outside of the connecting pipe 59. A second motor 52 is fixed at the bottom of the inner wall of the second support frame 3. A third pulley 53 is fixed at the output shaft end of the second motor 52. The third pulley 53 is connected to the fourth pulley 55 through a belt. The output shaft end of the second motor 52 drives the third pulley 53 to rotate. The third pulley 53 transmits power to the fourth pulley 55 through the belt. The fourth pulley 55 drives the connecting pipe 59 to rotate. Since the outside of the connecting pipe 59 is rotatably connected to the box 54 and the connecting shaft 6 through sealed bearings, and the connecting pipe 59 is fixedly connected to the stirring shaft 16, the connecting pipe 59 drives the stirring shaft 16 to rotate. Several stirring rods 15 fixed on the outside of the stirring shaft 16 rotate accordingly.

[0036] The first motor 12 is fixed to the bottom of the inner wall of the first support frame 2. The outside of the mixing tank 1 is connected to the material pipe 11. A cover plate is detachably fixed on the material pipe 11. The raw material is put into the inside of the mixing tank 1 through the material pipe 11. Then the cover plate is fixed on the material pipe 11 to seal it and prevent the raw material from overflowing. The box body 54 is fixed to the top of the inner wall of the second support frame 3.

[0037] Working principle or structural principle: The raw material to be processed is added into the mixing tank 1 through the feed pipe 11, and then the cover plate is closed and fixed. The first motor 12 is started, and its output shaft drives the first pulley 13 to rotate, which drives the second pulley 14 through belt transmission, so that the connecting shaft 6 drives the entire mixing tank 1 to rotate; At the same time, the second motor 52 is started, and its output shaft drives the third pulley 53 to rotate. The fourth pulley 55 is driven by the belt, which causes the connecting pipe 59 to drive the stirring shaft 16 to rotate. The multiple stirring rods 15 fixed on the stirring shaft 16 rotate accordingly. The stirring shaft 16 rotates in the opposite direction to the stirring tank 1, thereby achieving full stirring of the raw materials in the stirring tank 1. During the mixing process, the water pump 51 is started to deliver water to the water storage chamber 58 inside the housing 54. The water in the water storage chamber 58 enters the water delivery tank 57 through the water inlet 510, and is then evenly sprayed onto the surface of the raw materials through multiple water spray holes 56 on the stirring shaft 16 to humidify the raw materials and adjust their moisture content to the target range of 55% to 60%.

[0038] Example 3 The difference between this embodiment and Embodiments 1 and 2 is that: S1. Attapulgite ore is subjected to thermal activation, compound acid activation and compound organic activation treatment in sequence to obtain composite modified attapulgite powder. Take 500 kg of attapulgite ore, crush it to <3 mm, calcine it at 380℃ for 2.5 h, cool it, and then pulverize it through a 180 mesh sieve to obtain thermally activated powder. Take 400 kg of thermally activated powder, add 1200 L of 0.8 mol / L dilute sulfuric acid (solid-liquid ratio 1:3), stir at 60℃ for 1.5 h, filter and wash with water until neutral; add 1600 L of 1.0 mol / L phosphoric acid (solid-liquid ratio 1:4) to the wet filter cake, stir at 65℃ for 1.5 h, filter and wash with water until neutral, and dry at 90℃ to obtain composite acid activated powder; Take 350 kg of composite acid-activated powder, disperse it in 5000 L of water, add 14 kg of potassium humate, 10.5 kg of sodium humate and 5.25 kg of glutamic acid (accounting for 4%, 3% and 1.5% of the powder weight, respectively), stir at 75℃ for 2 h, centrifuge, wash, dry at 90℃, and pulverize through 200 mesh to obtain composite modified attapulgite powder. S2. Mix livestock and poultry manure, crop straw powder, compound modified attapulgite powder, microbial compound fermentation agent and urea in proportion, add to mixing tank 1 and mix evenly, adjust the moisture to 55% to 60%; Take 650 kg of a mixture of chicken and cow manure (1:1, 70% moisture content), 250 kg of corn stalk powder (passed through 15 mesh), 180 kg of compound modified attapulgite powder, and a compound microbial agent (Bacillus subtilis, Bacillus licheniformis, Aspergillus oryzae, EM bacteria, total viable count 3.2 × 10⁻⁶). 8 25 kg of CFU / g, 30 kg of urea, add water to adjust the moisture content to 58%, and mix well; S3. The mixture is subjected to three stages of temperature-controlled aerobic fermentation: medium-temperature fermentation, high-temperature fermentation, and cooling composting. Medium temperature period: 35-38℃, 60h, turning and ventilating every 10h; High temperature period: temperature rises to 58-62℃, lasts for 8 days, turning twice a day, with 7 days above 55℃; Maturation period: temperature naturally drops to 34-37℃, lasts for 6 days, turning once every 30h, final pile temperature 30℃, ambient temperature 27℃, temperature difference 3℃; S4. After fermentation, the material is aged, dried, and crushed. Then, composite modified attapulgite powder and biosurfactant are added to granulate the material. After granulation, the material is coated with a surface coating and dried to obtain the finished organic fertilizer. The material is piled up to a height of 1.5m and aged for 28 days, turning over every 5 days. After aging, it is dried at 60℃ to a moisture content of 22%, crushed and passed through an 80-mesh sieve, and 7% of the material mass of composite modified attapulgite powder is added. The mixture is granulated to obtain 3-4mm particles, with a spraying amount of 4.5%, and fluidized at 50℃ to a moisture content of 16% to obtain the finished product.

[0039] Product performance: Organic matter 53.1%, humic acid 20.2%, total nutrients 6.4%, pH 7.0, effective viable bacteria count 0.7×10⁻⁶ 8 CFU / g, particle crushing resistance 30N, 24h static water integrity 81%, soil maximum water holding capacity increased by 32%.

[0040] Example 4 The difference between this embodiment and Embodiments 1, 2, and 3 is that: S1. Attapulgite ore is subjected to thermal activation, compound acid activation, and compound organic activation in sequence to obtain composite modified attapulgite powder; thermal activation is 350℃ / 3h; sulfuric acid concentration is 0.5 mol / L, phosphoric acid concentration is 1.2 mol / L; organic activation contains 3% potassium humate, 2% sodium humate, and 1% glutamic acid. S2. Mix livestock and poultry manure, crop straw powder, compound modified attapulgite powder, microbial compound fermentation agent and urea in proportion, add to mixing tank 1 and mix evenly, adjust the moisture to 55% to 60%; the livestock and poultry manure is pig manure + sheep manure, and the straw powder is sorghum straw powder. S3. The mixture is subjected to three stages of temperature-controlled aerobic fermentation: mesophilic fermentation, high-temperature fermentation, and cooling composting; the high-temperature stage is 56-60℃, lasting 9 days. S4. After fermentation, the material is aged, dried, and pulverized. Then, composite modified attapulgite powder and biosurfactant are added to granulate the material. After granulation, a surface coating treatment is performed, and the material is dried to obtain the finished organic fertilizer. The fertilizer is aged for 25 days with a coating solution concentration of 1.5%. The product contains 51.8% organic matter and 19.1% humic acid, and its other properties are comparable to those in Example 1.

[0041] In summary, the first motor 12 drives the mixing tank 1 to rotate as a whole, while the second motor 52 drives the mixing shaft 16 and the mixing rod 15 to rotate in the opposite direction. The two motors form a relative motion, which causes strong convection and shearing action in the raw materials inside the tank. Compared with the single rotation method, the mixing uniformity is significantly improved. The water pump 51 sends water into the water storage chamber 58, and sprays it at multiple points along the mixing shaft 16 through the water inlet 510, the water delivery tank 57 and multiple water spray holes 56. Humidification is carried out simultaneously during the mixing process to avoid local over-wetting or dry material residue, and to meet the strict humidity requirements of subsequent processes.

[0042] Through a tiered processing technique involving thermal activation, dilute sulfuric acid pre-activation, phosphoric acid deep activation, and organic multi-component grafting, the specific surface area of ​​the composite-modified attapulgite powder can reach 450 m². 2 With a cation exchange capacity of over / g, the cation exchange capacity is increased by 2.5 to 3.5 times compared to the original ore. At the same time, phosphorus nutrients and various active functional groups such as carboxyl, hydroxyl, and amine groups are introduced, which greatly enhances the adsorption and slow release performance.

[0043] Through three stages of temperature-controlled aerobic fermentation—medium-temperature, high-temperature, and cooling composting—combined with the synergistic effects of Bacillus subtilis, Bacillus licheniformis, Aspergillus oryzae, and EM compound bacteria, the humic acid content is increased by more than 25% compared to conventional compost, and the final product has an organic matter content of ≥52%. This effectively enhances the soil's organic carbon pool. The organic fertilizer is rich in humus and modified attapulgite colloids, which can promote the formation of soil micro-aggregates, reduce soil bulk density, increase porosity and water and fertilizer retention capacity, and is especially suitable for improving sandy soils or compacted farmland.

[0044] Those skilled in the art will understand that the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

Claims

1. A novel method for preparing organic fertilizer based on attapulgite, characterized in that, Includes the following steps: S1. Attapulgite ore is subjected to thermal activation, compound acid activation and compound organic activation treatment in sequence to obtain composite modified attapulgite powder. S2. Mix livestock and poultry manure, crop straw powder, compound modified attapulgite powder, microbial compound fermentation agent and urea in proportion, add to the mixing tank (1) and mix evenly, adjust the moisture to 55% to 60%; S3. The mixture is subjected to three stages of temperature-controlled aerobic fermentation: mesophilic fermentation, high-temperature fermentation, and cooling composting. S4. After fermentation, the material is aged, dried, and crushed. Then, composite modified attapulgite powder and biosurfactant are added to granulate the material. After granulation, the material is coated with a film and dried to obtain the finished organic fertilizer.

2. The method for preparing a novel organic fertilizer based on attapulgite according to claim 1, characterized in that, In S1, the composite acid activation is performed by first treating with 0.5–1.0 mol / L dilute sulfuric acid at 55–65°C for 1–2 hours, and then treating with 0.8–1.2 mol / L phosphoric acid at 60–70°C for 1–2 hours, with a solid-liquid ratio of 1:3–1:

5.

3. The method for preparing a novel organic fertilizer based on attapulgite according to claim 2, characterized in that, The composite organic activation is as follows: a 6%–9% suspension of composite acid-activated attapulgite powder is prepared, and 3%–5% of potassium humate, 2%–4% of sodium humate and 1%–2% of glutamic acid by weight of attapulgite powder are added. The mixture is then reacted at 70–80°C for 1.5–2.5 hours.

4. The method for preparing a novel organic fertilizer based on attapulgite according to claim 1, characterized in that, In S2, by mass parts: 55-70 parts of livestock and poultry manure, 20-28 parts of crop straw powder, 15-22 parts of compound modified attapulgite powder, 2-3 parts of microbial compound fermentation agent, and 2-4 parts of urea.

5. A novel organic fertilizer preparation method based on attapulgite according to claim 4, characterized in that, The microbial compound fermentation agent contains Bacillus subtilis, Bacillus licheniformis, Aspergillus oryzae, and EM compound bacteria, with a total effective viable count ≥3.0×10⁻⁶. 8 CFU / g.

6. The method for preparing a novel organic fertilizer based on attapulgite according to claim 1, characterized in that, In S3, the mesophilic fermentation temperature is 30-40°C, lasting for 48-72 hours, with ventilation and turning every 8-12 hours; The high-temperature fermentation temperature is 55-62℃, lasting for 7-10 days, with the mixture being turned over 1-2 times per day; The cooling and composting temperature is 35-40℃, lasting for 4-6 days, and the compost is turned over every 24-36 hours until the temperature difference between the compost and the environment is less than 5℃.

7. The method for preparing a novel organic fertilizer based on attapulgite according to claim 1, characterized in that, In S4, it is aged for 25 to 30 days, dried to a moisture content of 20% to 25%, and then pulverized through a 60 to 80 mesh sieve.

8. A novel organic fertilizer preparation method based on attapulgite according to claim 7, characterized in that, The added composite modified attapulgite powder accounts for 5% to 8% of the total mass of the material, and the biosurfactant is rhamnolipin or trehalose, with an addition amount of 1.5% to 2.5% and a granulation particle size of 2.5 to 5 mm.

9. The method for preparing a novel organic fertilizer based on attapulgite according to claim 1, characterized in that, The mixing tank (1) is provided with a first support frame (2) and a second support frame (3) on both sides respectively. The first support frame (2) and the second support frame (3) are rotatably connected to a connecting shaft (6) on one side by a bearing. The connecting shaft (6) is fixed at the center of the two sides of the mixing tank (1). The mixing tank (1) is provided with a mixing component on one side, and a water spraying component (5) is provided on one side of the mixing component. The stirring assembly includes a first motor (12), a first pulley (13) is fixed to the output shaft end of the first motor (12), and a second pulley (14) is fixed to the end of the connecting shaft (6) away from the stirring tank (1). The first pulley (13) and the second pulley (14) are connected by a belt. The mixing tank (1) is rotatably connected to a mixing shaft (16) via a bearing on its inner side, and several mixing rods (15) are fixed on the outer side of the mixing shaft (16).

10. A novel organic fertilizer preparation method based on attapulgite according to claim 9, characterized in that, The water spray assembly (5) includes a housing (54), a water storage chamber (58) is provided inside the housing (54), and a connecting pipe (59) is fixed at one end of the stirring shaft (16), with a water inlet (510) opened inside the connecting pipe (59). The stirring shaft (16) has several water spray holes (56) on its outer side. A filter screen is fixed at the opening of the water spray hole (56). The water storage chamber (58), the water inlet (510) and the water spray hole (56) are connected. The outer side of the connecting pipe (59) is rotatably connected to the box (54) and the connecting shaft (6) respectively through sealed bearings. A water pump (51) is provided on the outer side of the second support frame (3). The water outlet of the water pump (51) is connected to the inner side of the water storage chamber (58) through a water pipe. The fourth pulley (55) is fixedly sleeved on the outside of the connecting pipe (59), the second motor (52) is fixed at the bottom of the inner wall of the second support frame (3), the third pulley (53) is fixed at the output shaft end of the second motor (52), and the third pulley (53) is connected to the fourth pulley (55) by a belt; The first motor (12) is fixed to the bottom of the inner wall of the first support frame (2), the outside of the mixing tank (1) is connected to the material pipe (11), the material pipe (11) is detachably fixed with a cover plate, and the box body (54) is fixed to the top of the inner wall of the second support frame (3).

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