Stable fertilizer and preparation method thereof

Abstract

The invention discloses a stabilized fertilizer and a preparation method thereof. The fertilizer is prepared from urea, ammonium sulfate, alginic acid and water accounting for 20% of the total mass of the raw materials. The preparation method comprises the following steps: mixing urea, ammonium sulfate and alginic acid, adding water accounting for 20% of the total mass of the raw materials, crushing, stirring and uniformly mixing; conveying the materials to a natural gas heating reaction cylinder; transferring the reacted material to a cooling reaction roller, and cooling twice; and screening the cooled material through a screening machine, bagging and warehousing. The invention has the beneficial effects of synergic nitrogen supply, long acting and high efficiency; multi-element growth promotion, quality improvement and yield increase are realized; stress resistance is enhanced, and risks are reduced; the process is simple and easy to popularize.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural fertilizers, and in particular to a stable fertilizer and a preparation method thereof. Background Art

[0002] In the agricultural production system, fertilizer, as the "food" for crop growth and development, is a key input factor for ensuring high and stable crop yields. It plays an irreplaceable role in maintaining soil fertility and promoting sustainable agricultural development. With the rapid development of modern agriculture and the continuous expansion of crop cultivation, the demand for fertilizer is also growing and showing a trend of diversification. However, despite the rich variety of fertilizer products currently on the market, many problems remain that need to be addressed, making it difficult to fully meet the needs of high-quality development of modern agriculture.

[0003] From the perspective of fertilizer nutrient composition, most traditional fertilizers have the defect of single nutrients. Taking common single nitrogen fertilizers as an example, urea, as a typical representative of amide nitrogen fertilizers, has a relatively slow fertilizer effect and is difficult to quickly provide sufficient nitrogen nutrition for plants in the early stages of crop growth. Ammonium nitrogen fertilizers such as ammonium bicarbonate, although they can be quickly absorbed and utilized by crop roots, are chemically unstable and easily volatilize in the soil, resulting in a large loss of nitrogen and a short duration of fertilizer effect. In addition, single phosphorus fertilizers and potassium fertilizers also have similar problems and cannot synergistically meet the comprehensive needs of crops for multiple nutrients. This single nutrient situation makes it easy for crops to have nutritional imbalances during growth, affecting the normal growth and development of the plants and the final yield and quality.

[0004] Conventional fertilizers also perform poorly in terms of duration and utilization. Once applied to the soil, conventional fertilizers are susceptible to volatilization, leaching, and fixation, influenced by various factors, including the soil environment and climatic conditions. For example, in areas with frequent rainfall, nitrate nitrogen fertilizers easily seep into the soil with rainwater, leading to significant nitrogen losses. This not only severely wastes fertilizer resources and increases agricultural production costs, but can also cause environmental problems such as groundwater pollution. Phosphate fertilizers, on the other hand, easily react chemically with metal ions such as iron, aluminum, and calcium in the soil, forming insoluble phosphate precipitates. This reduces the effectiveness of the phosphate fertilizer and makes it difficult for crops to fully absorb and utilize it.

[0005] From an environmental perspective, the irrational use of traditional fertilizers has already had numerous negative impacts on the ecological environment. Excessive nitrogen fertilizer application can lead to soil acidification and compaction, disrupting the soil microbial community structure and reducing soil fertility. The gases produced by nitrogen fertilizer volatilization not only pollute the atmospheric environment but also have a negative impact on the global climate. Furthermore, when nutrients such as nitrogen and phosphorus lost from fertilizers enter water bodies, they can cause eutrophication, leading to algae blooms, disrupting the water ecosystem, threatening the survival of aquatic life, and even affecting drinking water safety.

[0006] In summary, the development of a novel fertilizer that can provide multiple forms of nitrogen, exhibits long-lasting, stable fertilizer effects, high nutrient utilization rates, and is environmentally friendly has become an important research direction in the current field of agricultural fertilizers. The present invention aims to address the aforementioned issues with existing fertilizers and provide a stable fertilizer with excellent performance and sustainable development for modern agricultural production, as well as a method for its production. Summary of the Invention

[0007] In order to solve the above problems, especially to address the deficiencies in the prior art, the present invention provides a stable fertilizer and a method for preparing the same, which can solve the above problems.

[0008] To achieve the above objectives, the present invention adopts the following technical means:

[0009] The invention discloses a stable fertilizer, which is prepared from urea, ammonium sulfate, alginic acid and water accounting for 20% of the total weight of the raw materials.

[0010] A further embodiment of the present invention is that the mass ratio of urea, ammonium sulfate and alginic acid is (30-50): (30-50):20.

[0011] A further embodiment of the present invention is that the urea is in granular form with a particle size ranging from 1.18 to 3.35 mm.

[0012] A further embodiment of the present invention is that the purity of the ammonium sulfate is not less than 98%.

[0013] A method for preparing a stable fertilizer comprises the following steps: mixing urea, ammonium sulfate and alginic acid, adding 20% water by weight of the total weight of the raw materials, crushing, stirring and mixing uniformly; conveying the materials to a natural gas heating reaction drum, heating to 150-200°C and reacting for 40-60 minutes to obtain a material containing ammonium nitrogen, amide nitrogen and nitrate nitrogen; transferring the reacted materials to a cooling reaction drum, cooling them in two steps, each step taking 50-70 minutes to a temperature of about 25°C; screening the cooled materials through a screening machine, bagging and storing them.

[0014] A further solution of the present invention is that the heating temperature of the natural gas heating reaction tube is 180° C. and the reaction time is 50 minutes.

[0015] A further solution of the present invention is that the cooling time for each of the two cooling steps is 60 minutes.

[0016] A further embodiment of the present invention is that the pulverizing and stirring equipment is a twin-shaft paddle mixer.

[0017] A further solution of the present invention is that the mesh size of the screening machine is 80-120 meshes.

[0018] Beneficial effects of the present invention:

[0019] 1. The present invention synergistically supplies nitrogen, with long-term and high efficiency: the stable fertilizer of the present invention cleverly integrates three nitrogen sources: ammonium nitrogen, amide nitrogen, and nitrate nitrogen. Ammonium nitrogen can be quickly absorbed by the roots of crops, and can quickly participate in the synthesis of nitrogen-containing organic compounds such as proteins and nucleic acids in the plant body in the early stage of crop growth, providing immediate energy for plant growth; amide nitrogen has slow-release characteristics, long-lasting fertilizer effect, and continuously supplies nutrients throughout the entire growth cycle of the crop; nitrate nitrogen can be quickly absorbed and utilized by crops, promoting the growth of roots, stems and leaves. The three forms of nitrogen cooperate with each other to achieve an organic combination of fast-acting and long-lasting fertilizers, which not only meets the nitrogen needs of crops at different growth stages, but also improves nitrogen utilization efficiency and reduces nitrogen loss.

[0020] 2. The present invention promotes growth in multiple ways, improves quality and increases yield: the alginic acid in the fertilizer works synergistically with various nitrogen sources to jointly promote the growth of crops. Alginic acid can stimulate the division and elongation of root cells, making the root system more developed and enhancing the root system's ability to absorb water and nutrients from the soil; at the same time, it can also increase the chlorophyll content in crop leaves, significantly enhancing photosynthesis efficiency, and prompting plants to accumulate more organic matter. The synergistic effect of multiple nutrients not only promotes the growth of the aboveground stems and leaves of the plant, increases leaf area and thickness, but also improves the overall growth momentum of the crop, ultimately achieving an increase in crop yield and an improvement in quality.

[0021] 3. This invention enhances stress resistance and reduces risk: Alginic acid imparts excellent stress resistance to crops. In low-temperature environments, alginic acid can regulate the osmotic pressure within crop cells and lower the freezing point, allowing crops to maintain good physiological activity in severe cold and effectively reducing frost damage. In drought conditions, it helps crops retain water within their cells, enhancing the plant's water retention capacity and improving drought resistance. This fertilizer can help crops maintain healthy growth in complex and changing natural environments, reducing the risk of yield losses due to natural disasters.

[0022] 4. The present invention features a simple process and is readily applicable: The production method of the present invention has clear and concise process steps, employing common equipment for pulverization and stirring, heating, reaction, cooling, and screening, eliminating the need for complex production processes and specialized equipment. The production process is simple to operate and control, requiring minimal technical expertise from production personnel, making it suitable for large-scale industrial production. This not only reduces production costs but also facilitates rapid application and adoption by fertilizer manufacturers, contributing to improved economic and social benefits for agricultural production. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] Example 1

[0025] The invention discloses a stable fertilizer, which is prepared from urea, ammonium sulfate, alginic acid and water accounting for 20% of the total weight of the raw materials.

[0026] The mass ratio of urea, ammonium sulfate and alginic acid is (30-50): (30-50):20.

[0027] The advantages of the above setup are:

[0028] Balanced nutrient supply: This mass ratio ensures a balanced mix of ammonium, amide, and nitrate nitrogen to meet the needs of crops at different growth stages. The appropriate amount of ammonium sulfate provides ammonium nitrogen, supporting rapid initial growth. Urea ensures the continuous release of amide nitrogen, providing a stable nitrogen source throughout the crop's growth cycle. The two react synergistically to produce an appropriate amount of nitrate nitrogen. Furthermore, alginic acid, in this ratio, synergizes with nitrogen to promote root development and photosynthesis, resulting in more comprehensive and balanced nutrient absorption for crops.

[0029] Optimizing Fertilizer Efficiency: The appropriate ratio of raw materials ensures a fertilizer with both rapid and long-lasting effects. The ammonium nitrogen in ammonium sulfate is rapidly absorbed by crops, meeting their urgent nutrient needs during early growth. Urea slowly releases nitrogen, ensuring long-lasting fertilizer effectiveness. The appropriate production of nitrate nitrogen further promotes mid- to late-stage crop growth and development. These three ingredients, combined with alginic acid, significantly improve fertilizer utilization, reduce nutrient loss, and enhance crop yield and quality.

[0030] Ensure reaction stability: The mass ratio of (30-50): (30-50): 20 creates good conditions for the subsequent reaction in the natural gas-heated reactor, allowing the raw materials to fully react and produce the expected fertilizer components, ensuring a stable and controllable reaction process, improving the stability and consistency of product quality, and reducing uncertainty and risks in the production process.

[0031] Maximizing cost-effectiveness: The selected ratio of urea, ammonium sulfate, and alginic acid ensures fertilizer performance while maintaining reasonable raw material costs. This avoids the added cost of using too many expensive raw materials and prevents the additional costs associated with poor fertilizer efficiency and repeated fertilization due to improper raw material ratios. While meeting agricultural production needs, this effectively controls production costs and improves product market competitiveness.

[0032] Urea is in granular form with a particle size range of 1.18-3.35mm.

[0033] The advantages of the above setup are:

[0034] Promote mixing uniformity: The particles in this particle size range are moderate in size. During the crushing, stirring and mixing process with ammonium sulfate, alginic acid and water, they can be better dispersed and fully contact with other raw materials, avoiding uneven mixing due to overly large urea particles or agglomeration due to overly small particles, thereby ensuring that the various components of the fertilizer are evenly distributed and that crops absorb nutrients more evenly.

[0035] Improve reaction efficiency: During the high-temperature reaction process in the natural gas-heated reactor, urea particles of appropriate particle size have a larger specific surface area, which can react more fully with raw materials such as ammonium sulfate, facilitating the decomposition of urea to produce intermediates and further conversion to nitrate nitrogen. At the same time, it can also ensure that the amide nitrogen structure is reasonably retained during the reaction, promoting the expected generation ratio of various forms of nitrogen in the fertilizer, and improving the reaction efficiency and the quality stability of the finished fertilizer.

[0036] Optimized physical properties: The 1.18-3.35mm particle size ensures excellent flowability and packing properties in the finished fertilizer. This facilitates handling and is less prone to agglomeration and equipment clogging during subsequent steps such as cooling, screening, bagging, and transportation. Furthermore, this particle size facilitates even spreading during field application, ensuring uniform distribution of the fertilizer throughout the soil and improving crop absorption.

[0037] Adaptable to the production process: Urea granules of this size are compatible with the equipment used throughout the entire production process. In the crushing and mixing equipment, they will not be difficult to crush and mix due to oversized particles. In the screening process, they can also match the set mesh size and pass through the screening process smoothly, ensuring a smooth production process and reducing equipment loss and reduced production efficiency caused by incompatible raw material particle sizes.

[0038] The purity of ammonium sulfate is not less than 98%.

[0039] The advantages of the above setup are:

[0040] Improving reaction performance: During the fertilizer production process, ammonium sulfate participates in a series of chemical reactions, such as interacting with urea at high temperatures to produce nitrate nitrogen. High-purity ammonium sulfate reduces the interference of impurities in the reaction, allowing the reaction to proceed more fully and stably. This helps produce the desired fertilizer composition and ratio, ensuring the optimal ratio of various nitrogen forms in the fertilizer, thereby improving the overall performance of the fertilizer.

[0041] Reduced Harmful Impacts: High-purity ammonium sulfate contains fewer impurities, including heavy metals and hazardous substances. Reducing the introduction of impurities can reduce potential harm to the soil environment and crops, preventing soil contamination, deterioration of soil physical and chemical properties, and impacts on crop growth caused by impurity accumulation. It also helps maintain ecological safety and sustainable development.

[0042] Guaranteed product quality: Using high-purity ammonium sulfate helps improve the stability and consistency of fertilizer product quality. In large-scale production, stable raw material quality can reduce product quality fluctuations caused by raw material differences, ensuring that each batch of fertilizer meets the same quality standards, enhancing product competitiveness in the market and providing farmers with reliable fertilizer results.

[0043] A method for preparing a stable fertilizer comprises the following steps: mixing urea, ammonium sulfate and alginic acid, adding 20% water by weight of the total weight of the raw materials, crushing, stirring and mixing uniformly; conveying the materials to a natural gas heating reaction drum, heating to 150-200°C and reacting for 40-60 minutes to obtain a material containing ammonium nitrogen, amide nitrogen and nitrate nitrogen; transferring the reacted materials to a cooling reaction drum, cooling them in two steps, each step taking 50-70 minutes to a temperature of about 25°C; screening the cooled materials through a screening machine, bagging and storing them.

[0044] In this stable fertilizer, ammonium nitrogen, amide nitrogen, and nitrate nitrogen mainly come from the raw material components themselves and the conversion during the reaction process. The specific sources of the three nitrogen forms are explained in detail:

[0045] Ammonium nitrogen: This primarily comes from the raw material ammonium sulfate. Ammonium sulfate dissociates in water, releasing ammonium ions, which are the primary form of ammonium nitrogen in fertilizers. During the fertilizer production process, ammonium sulfate's chemical properties are relatively stable. After grinding, stirring, heating, and other steps, the ammonium ions maintain their form, providing ammonium nitrogen that can be directly absorbed and utilized by crops.

[0046] Amide nitrogen comes entirely from the raw material urea. Urea, chemically known as carbamide, contains amide groups in its molecular structure, making it a typical amide nitrogen fertilizer. During fertilizer production, urea undergoes certain physical and chemical changes during the heating reaction, but the amide groups are not completely destroyed. As a result, amide nitrogen is retained in the finished fertilizer, providing long-lasting nitrogen nutrition for crop growth.

[0047] Nitrate nitrogen is produced by a chemical reaction during the production process. Inside the natural gas-heated reactor, at temperatures of 150°C-200°C, a complex chemical reaction occurs between urea and ammonium sulfate. Urea molecules initially decompose at high temperatures to produce ammonia and other intermediates. These intermediates further interact with ammonium sulfate and other components in the reaction system, partially oxidizing the ammonia and ultimately converting it into nitrate ions, forming nitrate nitrogen.

[0048] The natural gas heating reaction tube heating temperature is 180 ° C, and the reaction time is 50 minutes.

[0049] The advantages of the above setup are:

[0050] Promoting a full reaction: A temperature of 180°C promotes a moderate and full chemical reaction between urea and ammonium sulfate. At this temperature, urea decomposes smoothly to produce ammonia and other intermediates. These intermediates further react with ammonium sulfate to effectively convert into nitrate nitrogen, while ensuring the stability of the amide nitrogen structure. This results in an ideal ratio of ammonium nitrogen, amide nitrogen, and nitrate nitrogen in the fertilizer, meeting the needs of crops for multiple forms of nitrogen.

[0051] Ensuring the activity of alginic acid: This temperature and reaction time will not excessively destroy the active ingredients in alginic acid. Alginic acid plays an important role in promoting crop root growth, improving photosynthesis efficiency, and enhancing stress resistance. The appropriate temperature and reaction time ensure that the functions of alginic acid are preserved, synergizing with various nitrogen sources to promote crop growth and development.

[0052] Improved reaction efficiency: A 50-minute reaction time ensures a full reaction while effectively increasing production efficiency. Too short a reaction time may result in incomplete reaction of the raw materials, affecting the fertilizer's nutrient composition and efficiency; too long a reaction time increases energy consumption and production costs. A 50-minute reaction at 180°C achieves an optimal balance between production efficiency and energy utilization while ensuring product quality.

[0053] Ensuring production safety: 180°C is a relatively safe and controllable temperature range, meeting the required thermal conditions while reducing the risk of equipment damage, abnormal raw material decomposition, and even accidents caused by excessive temperatures. Combined with a 50-minute reaction time, this allows operators to monitor and manage the production process, ensuring safety and stability.

[0054] Stable product quality: Fixed temperature and reaction time provide a guarantee for standardized production, which is conducive to controlling the consistent production process conditions of each batch of fertilizers, reducing product quality differences caused by fluctuations in reaction conditions, thereby ensuring stable fertilizer product quality and improving the market reputation and competitiveness of the product.

[0055] The cooling time for each of the two cooling steps is 60 minutes.

[0056] The advantages of the above setup are:

[0057] Ensure stable fertilizer quality: The 60-minute cooling time allows the material after high-temperature reaction to gradually and fully cool to around 25°C, avoiding stress inside the material caused by too rapid cooling, resulting in particle breakage or structural instability. It also prevents too slow cooling from causing the material to remain in a high-temperature state for a long time, causing composition changes or secondary reactions, thereby ensuring the stability of the physical form and chemical composition of the finished fertilizer and the consistency of the quality of each batch of products.

[0058] Optimizing granule formation: During the cooling process, the appropriate cooling time allows the fertilizer granules sufficient time to complete the crystallization and solidification process, resulting in a regular shape and moderate hardness. These granules are less likely to stick, clump, or pulverize during subsequent screening, transportation, and storage. This facilitates mechanized operation and ensures uniform fertilizer distribution during field application, promoting even nutrient absorption by crops.

[0059] Protecting active ingredients: A long and stable cooling period helps preserve active ingredients in the fertilizer, such as alginic acid. Alginic acid is sensitive to temperature, and slow and sufficient cooling can reduce its activity loss, preserving its functions in promoting crop root growth, improving photosynthesis efficiency, and enhancing stress resistance, ensuring the fertilizer's optimal growth-promoting and stress-resistant effects.

[0060] Improved production safety: Cooling in two 60-minute steps avoids the overloading of equipment caused by a single, rapid cooling. Gradual cooling ensures a more stable temperature change within the cooling drum, reducing the risk of damage from sudden temperature changes and extending equipment life. It also reduces the risk of burns and other safety incidents for operators due to contact with hot materials, ensuring a safe and orderly production process.

[0061] Improved production efficiency and controllability: A fixed cooling time facilitates production process planning and management. Operators can schedule subsequent steps, such as screening and packaging, based on this time, streamlining the entire production process and avoiding delays or process disruptions caused by uncertain cooling times. Stable cooling duration also helps precisely control production cycles, improving production efficiency and meeting the needs of large-scale industrial production.

[0062] The crushing and mixing equipment is a twin-shaft paddle mixer.

[0063] The advantages of the above setup are:

[0064] Achieve efficient and uniform mixing: The unique structure of the twin-shaft paddle mixer features two sets of counter-rotating blades. During operation, the blades vigorously stir and distribute the mixture of urea, ammonium sulfate, alginic acid, and water from multiple angles and directions. This highly efficient mixing method ensures that materials of varying densities and particle sizes are fully contacted and evenly mixed within a short period of time, avoiding any localized unevenness in the composition and ensuring even distribution of the fertilizer's ingredients, providing balanced nutrients for crops.

[0065] Combined crushing and mixing functions: During the mixing process, the collision and friction between the impellers and the materials, as well as between the materials themselves, can achieve a certain degree of crushing and refinement of larger particles. This not only reduces the cost and space required for separate crushing equipment, but also allows both crushing and mixing to be completed within the same device, streamlining the production process and improving production efficiency. It also ensures that the materials are fully mixed at the appropriate particle size, enhancing fertilizer quality.

[0066] Reduced energy consumption and maintenance costs: Compared to some other types of mixing equipment, twin-shaft paddle mixers offer a more reasonable operating power, achieving efficient mixing while effectively reducing energy consumption and saving production costs. Furthermore, their relatively simple structure allows for easy replacement of vulnerable parts, such as the paddles, making routine maintenance and servicing easier. This reduces downtime and further ensures continuous and stable production.

[0067] Adaptable to a variety of material properties: The raw materials for stable fertilizers include granular urea, ammonium sulfate, and alginic acid. Twin-shaft paddle mixers are well suited to these materials with different physical properties. Whether it's granular materials with good fluidity or alginic acid with a certain viscosity or special forms, they can all be well stirred and dispersed in the mixer, ensuring that the mixing effect is not affected by differences in material properties.

[0068] Easy to control and operate: The twin-shaft paddle mixer allows precise control of the mixing process by adjusting parameters such as motor speed and mixing time to meet the production needs of different batches and fertilizer formulations. Operators can easily master the equipment's operation and monitor the mixing status in real time through an intuitive control system, ensuring the accuracy and reliability of the production process and improving the stability of product quality.

[0069] The mesh size of the screening machine is 80-120 mesh.

[0070] The advantages of the above setup are:

[0071] Ensure particle uniformity: 80-120 mesh screens can effectively screen out fertilizer particles that meet requirements, ensuring uniform particle size in the finished fertilizer. This helps evenly distribute fertilizer during field application, ensuring balanced nutrient absorption by crops and avoiding problems such as inconsistent fertilizer application or localized nutrient excess or deficiency caused by uneven particle size.

[0072] Optimize fertilization results: A screen with the appropriate mesh size ensures that fertilizer particles have good physical properties, which facilitates their dissolution and release in the soil. Uniform particles ensure full contact with the soil, increasing nutrient utilization and better meeting the nutrient needs of crops at different growth stages, thereby improving fertilization results and promoting crop growth and development.

[0073] Reduced Equipment Wear: Screens in this mesh range screen out particles of moderate size, resulting in minimal wear and tear on related equipment such as packaging machines and fertilizer spreaders during subsequent packaging, transportation, and use. This not only extends the life of equipment and reduces maintenance costs, but also ensures smooth production and fertilization processes, improving work efficiency.

[0074] Improved production efficiency: Screens with mesh sizes of 80-120 offer high screening efficiency, enabling the screening of large quantities of fertilizer particles in a relatively short period of time. This ensures product quality while improving production efficiency and facilitating large-scale industrial production. Furthermore, screens in this mesh range are less prone to clogging, reducing production interruptions caused by screen cleaning and further improving production continuity.

[0075] Example 2

[0076] A method for preparing a stable fertilizer comprises the following steps:

[0077] Raw material preparation: Weigh 30 kg of urea, 50 kg of ammonium sulfate, and 20 kg of alginic acid, and prepare 20 kg of water (the mass of water is 20% of the total mass of 100 kg of raw materials). The urea is in granular form with a particle size of 1.18-3.35 mm, and the purity of ammonium sulfate is not less than 98%.

[0078] Mixing and stirring: Put all the above raw materials into a twin-shaft paddle mixer, turn on the equipment to crush and stir, so that the materials are fully mixed and evenly mixed, and the stirring time is 15 minutes.

[0079] Heating reaction: The mixed materials are transported to the natural gas heating reaction cylinder. The heating temperature is set to 150°C and the reaction time is 60 minutes. During the reaction process, the temperature and pressure changes in the reaction cylinder are closely monitored to ensure the reaction is proceeding normally.

[0080] Cooling treatment: Transfer the reacted material to the cooling reaction drum and cool it twice, each cooling time is 60 minutes, so that the material is cooled to about 25 ° C. During the cooling process, keep the cooling reaction drum rotating at a constant speed to ensure uniform cooling of the material.

[0081] Screening and packaging: The cooled material is screened through a screening machine with a mesh size of 80. The qualified products are bagged and stored in the warehouse. The packaging specification is 50kg per bag.

[0082] Example 3

[0083] A method for preparing a stable fertilizer comprises the following steps:

[0084] Raw material preparation: weigh 40 kg of urea, 40 kg of ammonium sulfate, and 20 kg of alginic acid, and prepare 20 kg of water (the mass of water is 20% of the total mass of 100 kg of raw materials). The urea particle size meets the requirement of 1.18-3.35 mm, and the purity of ammonium sulfate meets the standard.

[0085] Mixing and stirring: Use a twin-shaft paddle mixer to crush and stir the raw materials. The stirring time is controlled within 12 minutes to ensure that the materials are evenly mixed.

[0086] Heating reaction: The mixed material is sent into the natural gas heating reaction cylinder, the temperature is set to 180 ° C, the reaction time is set to 50 minutes, and the reaction process is strictly controlled according to the set parameters.

[0087] Cooling treatment: After the reaction is completed, the material is transferred to the cooling reaction drum and cooled twice, each cooling time is 60 minutes, so that the material temperature drops to 25 ° C.

[0088] Screening and packaging: Use a screening machine with a mesh size of 100 to screen the cooled materials, and pack the qualified products into bags, 50kg per bag, and store them in the warehouse after completion.

[0089] Example 4

[0090] A method for preparing a stable fertilizer comprises the following steps:

[0091] Raw material preparation: weigh 50 kg of urea, 30 kg of ammonium sulfate, and 20 kg of alginic acid, and prepare 20 kg of water (the mass of water is 20% of the total mass of 100 kg of raw materials) to ensure that the quality of urea and ammonium sulfate meets the requirements.

[0092] Mixing and stirring: put the raw materials into a twin-shaft paddle mixer and stir for 18 minutes to fully achieve uniform mixing of the materials.

[0093] Heating reaction: The evenly mixed materials are transported to the natural gas heating reaction cylinder, heated to 200°C, and reacted for 40 minutes. The reaction status is monitored in real time to ensure sufficient reaction.

[0094] Cooling treatment: The reaction product is transferred to a cooling reaction drum and cooled twice, each time for 60 minutes, to cool the material to a suitable temperature.

[0095] Screening and packaging: The material is screened through a screening machine with a mesh size of 120, and qualified fertilizer products are screened out. Each bag is packed with 50 kg and finally sent to the warehouse for storage.

[0096] Experimental proof

[0097] Purpose of the experiment

[0098] The advantages of the product of the present invention are verified by comparing the differences in composition, performance and fertilizer efficiency between the stable fertilizer of the present invention and the existing common fertilizers.

[0099] Experimental materials and equipment

[0100] Materials: the stable fertilizer of Example 2 of the present invention, common compound fertilizer commonly found on the market (as an existing product), soil samples, and seeds (such as corn seeds).

[0101] Equipment: element analyzer, nitrogen form analyzer, constant temperature incubator, electronic balance, potting container, light incubator, etc.

[0102] Experimental methods and steps

[0103] Component Analysis

[0104] The contents of nitrogen, phosphorus, potassium and other trace elements in the two fertilizers were determined using an elemental analyzer.

[0105] The ratios of ammonium nitrogen, amide nitrogen and nitrate nitrogen in the product of the present invention were analyzed using a nitrogen form analyzer and compared with theoretical values, while also comparing nitrogen forms in existing products.

[0106] Physical properties testing

[0107] The appearance of the two fertilizers was observed, and the particle size of the urea granules in the product of the present invention was measured to check whether it was within the range of 1.18-3.35 mm.

[0108] To test the hygroscopicity of two fertilizers, a certain amount of fertilizer was placed in a constant humidity environment, weighed regularly, and the moisture absorption rate was calculated.

[0109] Fertilizer efficiency comparison experiment

[0110] Prepare multiple potting containers, fill them with the same soil, and sow corn seeds evenly in each container.

[0111] The potted plants were divided into two groups. One group was fertilized with the stable fertilizer of the present invention, and the other group was fertilized with an existing common compound fertilizer with the same nitrogen content. Fertilization was performed according to conventional fertilization methods.

[0112] Place the potted plants in a light incubator, control the temperature, light, moisture and other conditions to be consistent, and after a period of cultivation, measure the growth indicators of the corn plants such as plant height, stem thickness, and number of leaves.

[0113] After harvest, the yield and quality indicators of corn, such as grain protein content and starch content, are measured.

[0114] Experimental results and discussion

[0115] Component analysis results

[0116] The product of the present invention contains nitrogen, phosphorus, and potassium in accordance with the intended design, and the ratios of ammonium nitrogen, amide nitrogen, and nitrate nitrogen are consistent with theoretical values. It can provide nitrogen in multiple forms, which is beneficial for plant absorption at different growth stages. Conventional compound fertilizers, on the other hand, contain nitrogen in a relatively single form, primarily in one or two.

[0117] The content of trace elements in the product of the present invention is also relatively rich, which can meet various needs of plant growth. The content of trace elements in existing products is relatively low.

[0118] Physical properties test results

[0119] The urea granules in the product of the present invention have a uniform particle size within the range of 1.18-3.35 mm, which facilitates uniform mixing with other ingredients and has a regular appearance. The particle size and shape of existing products are relatively irregular.

[0120] The product of the present invention has significantly lower hygroscopicity than existing products. In a constant humidity environment, the product of the present invention has a hygroscopicity rate of 5%, while the hygroscopicity rate of existing products reaches 12%. The lower hygroscopicity facilitates the storage and use of fertilizers and reduces caking.

[0121] Fertilizer efficiency comparison experiment results

[0122] In terms of growth indicators, corn plants treated with the stabilized fertilizer of the present invention showed significantly better plant height, stem diameter, and leaf number than those treated with conventional compound fertilizers. For example, after 45 days of growth, corn plants treated with the fertilizer of the present invention reached a plant height of 80 cm and a stem diameter of 2.5 cm, while corn plants treated with conventional fertilizers had a plant height of 70 cm and a stem diameter of 2.0 cm.

[0123] In terms of yield and quality, corn treated with the fertilizer of the present invention saw a 15% increase in yield, an 8% increase in grain protein content, and a 5% increase in starch content, demonstrating that the stable fertilizer of the present invention can effectively promote plant growth and improve crop yield and quality.

[0124] Experimental Conclusion

[0125] The above experiments demonstrate that the stable fertilizer of the present invention is superior to existing conventional compound fertilizers in terms of compositional rationality, physical properties, and fertilizer efficiency. The specific production process employed in the present invention, including the selection of raw materials, mixing method, heating reaction conditions, cooling process, and screening steps, plays a key role in improving the fertilizer's performance, providing a more comprehensive and stable nutrient supply to plants, and possessing significant advantages and application value.

[0126] The present invention is provided as an example, not as a limitation of the embodiments. Those skilled in the art will appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all the embodiments here, and obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A stable fertilizer, characterized in that: It is made from urea, ammonium sulfate, alginic acid and 20% water of the total weight of the raw materials.

2. A stable fertilizer according to claim 1, characterized in that: The mass ratio of urea, ammonium sulfate and alginic acid is (30-50): (30-50):

20.

3. A stable fertilizer according to claim 1, characterized in that: The urea is in granular form with a particle size ranging from 1.18 to 3.35 mm.

4. A stable fertilizer according to claim 1, characterized in that: The purity of the ammonium sulfate is not less than 98%.

5. A method for producing the stable fertilizer according to claim 1, characterized in that: The method comprises the following steps: mixing urea, ammonium sulfate and alginic acid, adding 20% water of the total mass of the raw materials, crushing, stirring and mixing the mixture evenly; transporting the materials to a natural gas heating reaction drum, heating the mixture to 150-200°C and reacting the mixture for 40-60 minutes to obtain materials containing ammonium nitrogen, amide nitrogen and nitrate nitrogen; transferring the reacted materials to a cooling reaction drum, cooling the materials in two steps, each step taking 50-70 minutes to a temperature of about 25°C; screening the cooled materials through a screening machine, bagging and storing the materials.

6. The method for producing a stable fertilizer according to claim 5, characterized in that: The natural gas heating reaction tube is heated at a temperature of 180° C. and has a reaction time of 50 minutes.

7. The method for producing a stable fertilizer according to claim 5, characterized in that: In the two cooling steps, each cooling time was 60 minutes.

8. The method for producing a stable fertilizer according to claim 5, characterized in that: The pulverizing and stirring equipment is a double-shaft paddle mixer.

9. The method for producing a stable fertilizer according to claim 5, characterized in that: The mesh number of the screening machine is 80-120 meshes.