Water-soluble fertilizer capable of being quickly dissolved as well as preparation method and application of water-soluble fertilizer

Abstract

The invention provides a water-soluble fertilizer capable of being quickly dissolved as well as a preparation method and application of the water-soluble fertilizer. The water-soluble fertilizer is composed of a nitrogen source, a phosphorus source, a potassium source and chelated trace elements, the total content of the three main nutrients N, P and K reaches 50% or above, and balanced supply of the nutrients is ensured through scientific proportioning. The preparation method comprises the steps of raw material mixing, high-speed mixing, spray granulation, particle surface coating treatment and low-temperature drying, and the prepared fertilizer particles are uniform in particle size, high in dissolution speed, high in particle stability and good in anti-caking performance. Through surface coating and addition of the anti-blocking agent, the storage performance of the fertilizer is remarkably improved, and the problem of moisture absorption and blocking in the long-term storage process is avoided. In addition, trace elements (such as chelated iron, chelated zinc and borate) are reasonably added into the fertilizer, so that high-efficiency nutrient absorption of crops is ensured, and the growth rate and quality of the crops are comprehensively improved.

Description

Technical Field

[0001] The invention relates to the field of preparation of water-soluble fertilizers, and more particularly to a rapidly soluble water-soluble fertilizer, a preparation method and application thereof. Background Art

[0002] As a new type of fertilizer, water-soluble fertilizer has been widely used in recent years due to its fast dissolution, high nutrient utilization rate, and convenient irrigation system fertilization. Especially in modern agriculture, the popularization of precision agricultural technologies such as drip irrigation and sprinkler irrigation has put forward higher requirements on the performance of water-soluble fertilizers. The rapid dissolution performance of water-soluble fertilizers directly affects the fertilization efficiency and user experience. Therefore, it is of great practical significance to develop a water-soluble fertilizer that is efficient in dissolution, stable, and environmentally friendly.

[0003] However, existing water-soluble fertilizer products have the following problems in application:

[0004] ① Slow dissolution speed, easy agglomeration of particles: Some traditional water-soluble fertilizers need to be stirred for a long time during use, especially in hard water or low temperature conditions, and the dissolution efficiency is significantly reduced. The particles are highly hygroscopic or the surface coating of the particles is uneven during the preparation process, which can easily lead to agglomeration, thereby reducing the application efficiency.

[0005] ② Uneven nutrient release: After some water-soluble fertilizers are dissolved, the release rate of nutrients is inconsistent, which may lead to reduced nutrient absorption efficiency and even produce a stress effect on crop roots.

[0006] Based on the above problems, there is an urgent need for a water-soluble fertilizer product that can dissolve quickly, release nutrients in a balanced manner, and is environmentally friendly and efficient. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a rapidly dissolving water-soluble fertilizer, a preparation method and an application thereof. The specific scheme is as follows:

[0008] A rapidly soluble water-soluble fertilizer is prepared from the following raw materials in percentage by weight: nitrogen source: 30%-40%; phosphorus source: 15%-25%; potassium source: 25%-35%; trace elements: 0.5%-2%; additives: 0.1%-1%; the remainder is water and impurities; the total content of nitrogen, phosphorus and potassium in the water-soluble fertilizer is ≥50%; the nitrogen source is a combination of one or two of urea and ammonium nitrate; the phosphorus source is a combination of one or two of monoammonium phosphate and diammonium phosphate; the potassium source is a combination of one or more of potassium sulfate, potassium chloride and potassium nitrate.

[0009] Furthermore, the trace element is one or a combination of EDTA-chelated iron, zinc or borate.

[0010] Furthermore, the additives include dispersants and anti-caking agents.

[0011] Furthermore, the dispersant is polyethylene glycol or polyvinyl alcohol, or a combination of both.

[0012] Furthermore, the anti-caking agent is one or a combination of magnesium carbonate, silica gel powder or talcum powder.

[0013] A method for preparing a rapidly dissolvable water-soluble fertilizer, the method comprising the following steps:

[0014] S1. Raw material screening and pretreatment: The nitrogen source raw material is screened through a sieve of 80-100 mesh to ensure uniform raw material particles; trace elements are chelated raw materials;

[0015] S2, mixing and granulation: according to the raw material ratio, nitrogen, phosphorus, potassium source and trace elements are added to the high-speed mixer in sequence, and mixed evenly at a speed of 1000-1500 rpm for 8-10 minutes; anti-caking agent and dispersant are added, and stirring is continued for 3-5 minutes; using a spray granulation device, the mixture is heated to 80-100° C., and the particle size is controlled to 0.3-0.8 mm by spraying, and cooled to room temperature after granulation is completed;

[0016] S3, surface treatment: using coating equipment to modify the surface of the granulated particles, using 0.05% to 0.2% by weight of water-soluble wax or hydrophobic material for surface spraying; the spraying process temperature is controlled at 60 to 80°C, and the spraying time is 3 to 5 minutes;

[0017] S4, drying and screening: placing the treated particles in a dryer, controlling the temperature at 60-70°C, drying for 20-30 minutes, ensuring that the moisture content of the particles is ≤ 0.3%; using a 60-80 mesh screen to screen the particles;

[0018] S5. Packaging and storage: The final product should be sealed and packaged, and a moisture-proof agent should be added to the packaging bag to prevent moisture absorption and agglomeration due to long-term storage; the storage temperature should be 10-25°C, and the humidity should be ≤60%.

[0019] Furthermore, the hydrophobic material for surface treatment of S3 is a fatty acid ester material or polyethylene wax, and the amount used is 0.05% to 0.1% of the particle weight.

[0020] Furthermore, the anti-caking agent in the S1 additive needs to be dried and the water content is controlled at ≤0.5%.

[0021] The invention discloses an application of a fast-dissolving water-soluble fertilizer, which is suitable for modern agricultural systems such as drip irrigation and sprinkler irrigation, and the pH value is controlled at 6.0-7.5 after being dissolved.

[0022] Beneficial effects:

[0023] The present invention provides a rapidly dissolving water-soluble fertilizer and a preparation method and application thereof, which have the following significant beneficial effects compared with the prior art:

[0024] (1) The water-soluble fertilizer of the present invention adopts nitrogen, phosphorus and potassium sources in scientific proportions, and the total content of the three nutrients is as high as more than 50%, and trace elements are reasonably added to ensure that crops can absorb comprehensive and balanced nutrients during the growth process, significantly improving the growth rate and quality of crops. The present invention greatly improves the moisture resistance and storage stability of the particles by adding anti-caking agents and dispersants and performing surface coating treatment on the particles, effectively avoiding the moisture absorption and caking phenomenon caused by long-term storage.

[0025] (2) Advanced preparation technology The present invention adopts a number of optimized processes such as high-speed mixing, spray granulation, surface modification and low-temperature drying: the surface coating treatment effectively reduces the direct contact between the particles and the air, improving the applicability of the fertilizer in a humid environment; the low-temperature drying process reduces nutrient loss and ensures that the moisture content of the particles is ≤0.3%, further improving product quality.

[0026] (3) The water-soluble fertilizer of the present invention has good solubility and a controllable pH value of 6.0 to 7.5, is suitable for various types of modern agricultural systems, such as drip irrigation, sprinkler irrigation and hydroponic agriculture, and has good adaptability to efficient absorption by various crops, and can significantly increase crop yield and economic benefits. DETAILED DESCRIPTION

[0027] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0028] Embodiment 1:

[0029] Raw material ratio

[0030] Nitrogen source: urea 35%

[0031] Phosphorus source: monoammonium phosphate 20%

[0032] Potassium source: Potassium sulfate 30%

[0033] Trace elements: EDTA chelated iron 0.8%

[0034] additive:

[0035] Dispersant (polyethylene glycol) 0.3%

[0036] Anti-caking agent (magnesium carbonate) 0.5%

[0037] Others: moisture and impurities account for the balance

[0038] Preparation steps

[0039] (1) Raw material screening and pretreatment:

[0040] Urea, monoammonium phosphate and potassium sulfate were sieved through a 100-mesh sieve to ensure uniform particles.

[0041] Trace elements are chelated with iron in EDTA form to avoid ion antagonism.

[0042] The anti-caking agent magnesium carbonate is dried in advance, and the water content is controlled at ≤0.5%.

[0043] (2) Mixing and granulation:

[0044] Urea, monoammonium phosphate, potassium sulfate and trace elements were added into the high-speed mixer in order according to the proportions, the mixing speed was set to 1200 rpm, and the stirring time was 8 minutes.

[0045] The dispersant polyethylene glycol and the anti-caking agent magnesium carbonate were added and stirring was continued for 3 minutes.

[0046] The mixture was heated to 90°C by a spray granulation device, the particle size was controlled at 0.5 mm during the spraying process, and cooled to room temperature after granulation.

[0047] (3) Surface treatment:

[0048] The particles are placed in a coating device and sprayed with a fatty acid ester hydrophobic material at 0.1% of the particle weight.

[0049] The spraying temperature was controlled at 70°C and the spraying time was 4 minutes to form a uniform coating.

[0050] (4) Drying and screening:

[0051] The treated particles were placed in a dryer at a drying temperature of 65°C for 25 minutes to ensure that the moisture content of the particles was ≤ 0.3%.

[0052] Use an 80-mesh screen to remove oversized or undersized particles.

[0053] (5) Packaging and storage:

[0054] The qualified particles are sealed and packed, and moisture-proof agent is added into the packing bag.

[0055] Storage conditions: Temperature controlled at 20℃, humidity ≤50%.

[0056] Performance Testing

[0057] Dissolution time: 90% solubility is achieved within 30 seconds.

[0058] Solution pH: 6.8.

[0059] Application system: Drip and sprinkler irrigation tests performed excellently without scaling.

[0060] Embodiment 2:

[0061] Raw material ratio

[0062] Nitrogen source: ammonium nitrate 30%

[0063] Phosphorus source: diammonium phosphate 25%

[0064] Potassium source: Potassium nitrate 35%

[0065] Trace elements: Chelated zinc 1%

[0066] additive:

[0067] Dispersant (polyvinyl alcohol) 0.2%

[0068] Anti-caking agent (silica gel powder) 0.8%

[0069] Others: moisture and impurities account for the balance

[0070] Preparation steps

[0071] (1) Raw material screening and pretreatment:

[0072] Ammonium nitrate, diammonium phosphate and potassium nitrate are sieved through 80-mesh sieves respectively to ensure that the raw material particles are free of impurities.

[0073] The trace element adopts chelated zinc, which is crushed into 200 mesh particles before adding.

[0074] The anti-caking agent silica gel powder is pre-dried and the moisture content is ≤0.5%.

[0075] (2) Mixing and granulation:

[0076] Add ammonium nitrate, diammonium phosphate, potassium nitrate and trace elements into a high-speed mixer in order according to the proportion, rotate at 1500 rpm and stir for 10 minutes.

[0077] Add polyvinyl alcohol and silica gel powder and mix at low speed for 4 minutes.

[0078] Use spray granulation equipment to heat to 95°C, control the particle size at 0.3-0.6mm, and cool to room temperature after granulation.

[0079] (3) Surface treatment:

[0080] The granulated particles are sprayed with polyethylene wax in an amount of 0.05% of the particle weight.

[0081] The spraying temperature is 65°C and the spraying time is 3 minutes to form a hydrophobic protective layer.

[0082] (4) Drying and screening:

[0083] Dry in a dryer at 70°C for 30 minutes.

[0084] Use a 60-mesh sieve to screen and remove unqualified particles.

[0085] (5) Packaging and storage:

[0086] Packaged in moisture-proof bags with built-in desiccant.

[0087] Storage conditions: Temperature controlled at 15°C, humidity ≤ 60%.

[0088] Performance Testing

[0089] Dissolution time: 95% solubility is achieved within 20 seconds.

[0090] Solution pH: 6.5.

[0091] Application system: Excellent performance in sprinkler irrigation tests to avoid nozzle clogging.

[0092] Embodiment 3:

[0093] Raw material ratio

[0094] Nitrogen source: urea 38%

[0095] Phosphorus source: monoammonium phosphate 15%

[0096] Potassium source: Potassium chloride 33%

[0097] Trace elements: Boric acid 0.5%

[0098] additive:

[0099] Dispersant (combination of polyethylene glycol and polyvinyl alcohol) 0.5%

[0100] Anti-caking agent (talc) 0.5%

[0101] Others: moisture and impurities account for the balance

[0102] Preparation steps

[0103] (1) Raw material screening and pretreatment:

[0104] Urea, monoammonium phosphate and potassium chloride were sieved through a 90-mesh sieve respectively.

[0105] Boric acid is used as trace elements and is crushed into 150 mesh for later use.

[0106] Talc is dried to a moisture content of ≤0.4%.

[0107] (2) Mixing and granulation:

[0108] Urea, monoammonium phosphate, potassium chloride and boric acid were added into the high-speed mixer in sequence at a speed of 1000 rpm for 9 minutes.

[0109] Add the mixed dispersant of polyethylene glycol and polyvinyl alcohol and talc, and continue stirring for 3 minutes.

[0110] The granules are granulated by spray granulation equipment and heated to 80°C, and the particle size is 0.4-0.7mm.

[0111] (3) Surface treatment:

[0112] Use water-soluble wax to spray the surface at a temperature of 60°C and a spraying time of 5 minutes to form a smooth surface layer.

[0113] (4) Drying and screening:

[0114] Treat in a dryer at 65°C for 20 minutes.

[0115] Sieve using a 70 mesh screen.

[0116] (5) Packaging and storage:

[0117] Sealed packaging, adding high-efficiency moisture-proof agent.

[0118] Storage conditions: Temperature controlled at 18°C, humidity ≤ 55%.

[0119] Performance Testing

[0120] Dissolution time: 98% dissolution in 15 seconds.

[0121] Solution pH: 7.0.

[0122] Application system: Applicable to drip irrigation and sprinkler irrigation, stable release of fertilizer effect.

[0123] As a further improvement, the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rapidly soluble water-soluble fertilizer, characterized in that: The water-soluble fertilizer is made of the following raw materials in weight percentage: nitrogen source: 30% to 40%; phosphorus source: 15% to 25%; potassium source: 25% to 35%; trace elements: 0.5% to 2%; additives: 0.1% to 1%; the remainder is water and impurities; the total content of the three major nutrients of nitrogen, phosphorus and potassium in the water-soluble fertilizer is ≥50%; the nitrogen source is a combination of one or two of urea and ammonium nitrate; the phosphorus source is a combination of one or two of monoammonium phosphate and diammonium phosphate; the potassium source is a combination of one or more of potassium sulfate, potassium chloride and potassium nitrate.

2. A rapidly soluble water-soluble fertilizer according to claim 1, characterized in that: The trace element is one or a combination of EDTA-chelated iron, zinc or borate.

3. A rapidly soluble water-soluble fertilizer according to claim 1, characterized in that: The additives include dispersants and anti-caking agents.

4. A rapidly soluble water-soluble fertilizer according to claim 3, characterized in that: The dispersant is polyethylene glycol or polyvinyl alcohol or a combination of the two.

5. A rapidly soluble water-soluble fertilizer according to claim 3, characterized in that: The anti-caking agent is one or a combination of magnesium carbonate, silica gel powder or talcum powder.

6. A method for preparing a rapidly soluble water-soluble fertilizer, characterized in that: The preparation method comprises the following steps: S1. Raw material screening and pretreatment: The nitrogen source raw material is screened through a sieve of 80-100 mesh to ensure uniform raw material particles; trace elements are chelated raw materials; S2, mixing and granulation: according to the raw material ratio, nitrogen, phosphorus, potassium source and trace elements are added to the high-speed mixer in sequence, and mixed evenly at a speed of 1000-1500 rpm for 8-10 minutes; anti-caking agent and dispersant are added, and stirring is continued for 3-5 minutes; using a spray granulation device, the mixture is heated to 80-100° C., and the particle size is controlled to 0.3-0.8 mm by spraying, and cooled to room temperature after granulation is completed; S3, surface treatment: using coating equipment to modify the surface of the granulated particles, using 0.05% to 0.2% by weight of water-soluble wax or hydrophobic material for surface spraying; the spraying process temperature is controlled at 60 to 80°C, and the spraying time is 3 to 5 minutes; S4, drying and screening: placing the treated particles in a dryer, controlling the temperature at 60-70°C, drying for 20-30 minutes, ensuring that the moisture content of the particles is ≤ 0.3%; using a 60-80 mesh screen to screen the particles; S5. Packaging and storage: The final product should be sealed and packaged, and a moisture-proof agent should be added to the packaging bag to prevent moisture absorption and agglomeration due to long-term storage; the storage temperature should be 10-25°C, and the humidity should be ≤60%.

7. The method for preparing a rapidly soluble water-soluble fertilizer according to claim 6, characterized in that: The hydrophobic material for surface treatment of S3 is fatty acid ester material or polyethylene wax, and the usage amount is 0.05% to 0.1% of the particle weight.

8. The method for preparing a rapidly soluble water-soluble fertilizer according to claim 6, characterized in that: The anti-caking agent in the S1 additive needs to be dried and the water content is controlled at ≤0.5%.

9. An application of a rapidly dissolving water-soluble fertilizer, characterized in that: This water-soluble fertilizer is suitable for drip irrigation and sprinkler irrigation, and the pH value after dissolution is controlled at 6.0-7.5.