Water-soluble polypeptide compound fertilizer and preparation method thereof

Abstract

The invention discloses a water-soluble polypeptide compound fertilizer and a preparation method thereof. The water-soluble polypeptide compound fertilizer comprises the following raw materials in percentage by weight: 35%-45% of urea, 20%-30% of monoammonium phosphate, 1%-5% of potassium chloride, 25%-30% of potassium sulfate, 0.6%-1% of cowhide polypeptide and 0.1%-0.5% of medium trace element raw materials. The cowhide polypeptide is creatively adopted in the formula of the water-soluble polypeptide compound fertilizer, and the cowhide polypeptide has good water solubility and can be matched with medium trace element raw materials to play a synergistic effect, so that the compound fertilizer has good water solubility while the fertilizer efficiency is remarkably improved, and the loss of the fertilizer efficiency is avoided. The urea and the potassium chloride are heated and melted, and the monoammonium phosphate is added in batches in the material mixing process, so that the flowability and the mixing uniformity in the material mixing process can be improved, the granulation effect can be conveniently improved, and the obtained water-soluble polypeptide compound fertilizer is smooth and round in appearance and high in yield.

Description

Technical Field

[0001] The invention relates to the technical field of compound fertilizers, and in particular to a water-soluble polypeptide compound fertilizer and a preparation method thereof. Background Art

[0002] Water-soluble polypeptide compound fertilizer combines the biological activity of polypeptides with the convenience of water-soluble fertilizers. Polypeptides are compounds composed of amino acid chains. They play an important role in plant physiological processes, such as promoting root development, enhancing plant stress resistance, and improving photosynthesis efficiency. Polypeptides can also help plants better absorb and utilize other nutrients, such as nitrogen, phosphorus, and potassium. Water-soluble polypeptide compound fertilizers can quickly dissolve in water, making them easy to apply through modern irrigation systems such as drip irrigation and sprinkler irrigation, reducing waste and improving fertilization efficiency. The water-soluble property also makes the nutrients in the fertilizer easier to be absorbed by the plant roots, so that they can quickly take effect, reducing fertilizer loss and environmental pollution.

[0003] At present, the production process of water-soluble polypeptide compound fertilizers often has problems such as poor water solubility, rough product particles, and uneven particles. Compared with ordinary water-soluble compound fertilizers, the production of water-soluble polypeptide compound fertilizers not only requires the integration of traditional fertilizer manufacturing technology, but also takes into account the special properties of polypeptides and the requirements of water solubility. At the same time, the chemical compatibility of polypeptides with other fertilizer components is also a big problem, and it is necessary to avoid the interaction between components that leads to precipitation or inactivation.

[0004] Therefore, there is an urgent need to improve the existing production process of water-soluble polypeptide compound fertilizers, improve the appearance of product particles, increase water solubility, and ultimately improve the quality and yield of compound fertilizers. Summary of the invention

[0005] The purpose of the present invention is to overcome the above technical deficiencies, provide a water-soluble polypeptide compound fertilizer and a preparation method thereof, and solve the technical problems of poor water solubility, coarse product particles and uneven particles of the water-soluble polypeptide compound fertilizer in the prior art.

[0006] In a first aspect, the present invention provides a water-soluble polypeptide compound fertilizer, whose raw materials include, by weight percentage: 35%-45% urea, 20%-30% monoammonium phosphate, 1%-5% potassium chloride, 25%-30% potassium sulfate, 0.6%-1% cowhide polypeptide and 0.1%-0.5% medium and trace element raw materials.

[0007] In a second aspect, the present invention provides a method for preparing a water-soluble polypeptide compound fertilizer, comprising the following steps: Evenly mixing the cowhide polypeptide and the medium and trace element raw materials to obtain a first mixture; Heat and melt urea and potassium chloride to obtain a molten liquid; The melt, part of the monoammonium phosphate, potassium sulfate and the first mixture are uniformly mixed in a primary mixing tank to obtain a second mixture; uniformly mixing the second mixture and the remaining monoammonium phosphate in a secondary mixing tank to obtain a third mixture; granulating the third mixture in a high tower granulator to obtain a granulated material; The granulated material is cooled, screened and subjected to anti-caking treatment to obtain the polypeptide compound fertilizer.

[0008] Compared with the prior art, the beneficial effects of the present invention include: The water-soluble polypeptide compound fertilizer formula of the present invention creatively adopts cowhide polypeptide, which has good water solubility and can cooperate with medium and trace element raw materials to play a synergistic effect, while significantly improving the fertilizer efficiency, making the compound fertilizer have good water solubility and avoiding fertilizer efficiency loss. The present invention heats and melts urea and potassium chloride, and adds monoammonium phosphate in batches during the material mixing process, which can improve the fluidity and mixing uniformity during the material mixing process, facilitates the improvement of the granulation effect, and makes the obtained water-soluble polypeptide compound fertilizer smooth and round in appearance and has a high yield rate. DETAILED DESCRIPTION

[0009] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0010] In a first aspect, the present invention provides a water-soluble polypeptide compound fertilizer, whose raw materials include, by weight percentage: 35%-45% urea, 20%-30% monoammonium phosphate, 1%-5% potassium chloride, 25%-30% potassium sulfate, 0.6%-1% cowhide polypeptide and 0.1%-0.5% medium and trace element raw materials.

[0011] In the water-soluble polypeptide compound fertilizer formula of the present invention, cowhide polypeptide is creatively used, which has good water solubility and can cooperate with medium and trace element raw materials to play a synergistic effect, while significantly improving the fertilizer efficiency, making the compound fertilizer have good water solubility and avoiding fertilizer efficiency loss. If the amount of cowhide polypeptide added is too high, due to the high viscosity and hygroscopicity of the cowhide polypeptide, the slurry viscosity will be too high, which will have an adverse effect on the granulation process; if the amount of cowhide polypeptide added is too low, it will lead to insufficient improvement of the fertilizer efficiency and will also affect the granulation process.

[0012] In this embodiment, the medium and trace element raw material includes at least one of zinc sulfate, boric acid and manganese sulfate. In the present invention, it should be noted that the above-mentioned medium and trace element raw material also includes its hydrate form.

[0013] In this embodiment, the raw materials of the polypeptide compound fertilizer also include: an anti-caking agent.

[0014] Preferably, the anti-caking agent accounts for 0.1%-1% of the water-soluble polypeptide compound fertilizer.

[0015] Preferably, the anti-caking agent comprises at least one of an organic anti-caking agent or an inorganic anti-caking agent. The present invention does not limit the types of organic anti-caking agent and inorganic anti-caking agent, and those skilled in the art can select according to actual conditions. For example, the organic anti-caking agent can be fatty acids, etc., and the inorganic anti-caking agent can be calcium carbonate, bentonite, talcum powder, etc.

[0016] In a second aspect, the present invention provides a method for preparing a water-soluble polypeptide compound fertilizer, comprising the following steps: S1. Evenly mix the cowhide polypeptide and the medium and trace element raw materials to obtain a first mixture; S2, heating and melting urea and potassium chloride to obtain a molten liquid; S3, mixing the melt, part of the monoammonium phosphate, potassium sulfate and the first mixture in a primary mixing tank to obtain a second mixture; S4, mixing the second mixture and the remaining monoammonium phosphate in a secondary mixing tank to obtain a third mixture; S5, granulating the third mixture in a high tower granulator to obtain a granulated material; S6. Cooling, screening and anti-caking treatment are performed on the granulated material to obtain polypeptide compound fertilizer.

[0017] The invention heats and melts urea and potassium chloride, so that potassium chloride can be preheated and partially dissolved in the molten urea, thereby improving the mixing and granulation process.

[0018] The present invention adds part of the monoammonium phosphate into a primary mixing tank to mix the materials uniformly, and then adds the remaining monoammonium phosphate into a secondary mixing tank, thereby improving the fluidity and mixing uniformity of the materials during the mixing process, and ultimately improving the granulation effect.

[0019] In this embodiment, the heating and melting temperature is 100-135°C, preferably 120-135°C.

[0020] In this embodiment, the temperature of the primary mixing tank is 100-120° C., and the residence time of the material in the primary mixing tank is 5-20 min.

[0021] In this embodiment, the temperature of the secondary mixing tank is 100-120° C., and the residence time of the material in the secondary mixing tank is 5-20 min.

[0022] In this embodiment, part of the monoammonium phosphate accounts for 30%-60% of the total amount of the monoammonium phosphate.

[0023] In this embodiment, the granulation temperature is 90-120° C., and the granulation time is 5-20 min.

[0024] In this embodiment, the moisture content of the granulated material is ≤1%.

[0025] In this embodiment, the process of cooling, screening and treating the granulated material with an anti-caking agent comprises: The granulated material is subjected to primary cooling, screening, secondary cooling and anti-caking treatment in sequence.

[0026] Preferably, the temperature of the granulated material during the primary cooling is 40-70°C.

[0027] Preferably, the granulated material is screened to a particle size of 2-4.2 mm.

[0028] Preferably, the secondary cooling is performed to a temperature of the granulated material of 20-35°C.

[0029] In this embodiment, the material with a particle size of >4.2 mm obtained by screening is returned to the high tower granulator for re-granulation after being crushed, and the material with a particle size of ≤2 mm obtained by screening is directly returned to the high tower granulator for re-granulation.

[0030] Example 1 (1) 0.8 kg of cowhide polypeptide, 0.07 kg of zinc sulfate monohydrate, 0.1 kg of manganese sulfate monohydrate, and 0.13 kg of boric acid were mixed to obtain a first mixture; (2) heating 41 kg of urea and 3.5 kg of potassium chloride to 130-135° C. to melt and obtain a molten liquid; (3) 44.5 kg of the melt, 13.35 kg of monoammonium phosphate, 27.1 kg of potassium sulfate and 1.1 kg of the first mixture were mixed uniformly in a primary mixing tank at a temperature of 105-110° C. and a residence time of 10 min to obtain a second mixture; (4) The second mixture and 13.35 kg of monoammonium phosphate were mixed uniformly in a secondary mixing tank at a temperature of 105-110° C. and a residence time of 10 min to obtain a third mixture; (5) granulating the third mixture in a high tower granulator at a granulation temperature of 90-110° C. for 10 min to obtain a granulated material; (6) The granulated material is cooled to 60-70°C for the first time, and then sieved to control the particle size to 2-4.2 mm, and then cooled to 20-35°C for the second time, and finally subjected to anti-caking treatment to obtain a water-soluble polypeptide compound fertilizer.

[0031] Example 2 (1) 1 kg of cowhide polypeptide, 0.02 kg of zinc sulfate monohydrate, 0.03 kg of manganese sulfate monohydrate, and 0.05 kg of boric acid were mixed evenly to obtain a first mixture; (2) heating 35 kg of urea and 5 kg of potassium chloride to 130-135° C. to melt and obtain a molten liquid; (3) 40 kg of the melt, 16.1 kg of monoammonium phosphate, 29.2 kg of potassium sulfate and 1.1 kg of the first mixture were mixed uniformly in a primary mixing tank at a temperature of 110-115° C. and a residence time of 20 min to obtain a second mixture; (4) The second mixture and 13 kg of monoammonium phosphate were mixed uniformly in a secondary mixing tank at a temperature of 110-115° C. and a residence time of 5 min to obtain a third mixture; (5) granulating the third mixture in a high tower granulator at a granulation temperature of 100-115° C. for 10 min to obtain a granulated material; (6) The granulated material is cooled to 60-70°C for the first time, and then sieved to control the particle size to 2-4.2 mm, and then cooled to 20-35°C for the second time, and finally subjected to anti-caking treatment to obtain a water-soluble polypeptide compound fertilizer.

[0032] Example 3 (1) 0.6 kg of cowhide polypeptide, 0.2 kg of zinc sulfate monohydrate, 0.1 kg of manganese sulfate monohydrate, and 0.2 kg of boric acid were mixed evenly to obtain a first mixture; (2) heating 42 kg of urea and 4 kg of potassium chloride to 120-125° C. to melt and obtain a molten liquid; (3) 46 kg of the melt, 10.2 kg of monoammonium phosphate, 26.7 kg of potassium sulfate and 1.1 kg of the first mixture were mixed uniformly in a primary mixing tank at a temperature of 100-105° C. and a residence time of 5 min to obtain a second mixture; (4) The second mixture and 15.4 kg of monoammonium phosphate were mixed uniformly in a secondary mixing tank at a temperature of 100-105° C. and a residence time of 20 min to obtain a third mixture; (5) granulating the third mixture in a high tower granulator at a granulation temperature of 95-105° C. for 10 min to obtain a granulated material; (6) The granulated material is cooled to 60-70°C for the first time, and then sieved to control the particle size to 2-4.2 mm, and then cooled to 20-35°C for the second time, and finally subjected to anti-caking treatment to obtain a water-soluble polypeptide compound fertilizer.

[0033] Comparative Example 1 Compared with Example 1, the only difference is that the amount of cowhide polypeptide added is 0.1 kg.

[0034] Comparative Example 2 Compared with Example 1, the only difference is that the amount of cowhide polypeptide added is 1.5 kg.

[0035] Comparative Example 3 (1) 0.8 kg of cowhide polypeptide, 0.07 kg of zinc sulfate monohydrate, 0.1 kg of manganese sulfate monohydrate, and 0.13 kg of boric acid were mixed to obtain a first mixture; (2) heating 41 kg of urea to 130-135° C. to melt and obtain a molten liquid; (3) 41 kg of the melt, 3.5 kg of potassium chloride, 13.35 kg of monoammonium phosphate, 27.1 kg of potassium sulfate and 1.1 kg of the first mixture were mixed uniformly in a primary mixing tank at a temperature of 105-110° C. and a residence time of 10 min to obtain a second mixture; (4) The second mixture and 13.35 kg of monoammonium phosphate were mixed uniformly in a secondary mixing tank at a temperature of 105-110° C. and a residence time of 10 min to obtain a third mixture; (5) granulating the third mixture in a high tower granulator at a granulation temperature of 90-110° C. for 10 min to obtain a granulated material; (6) The granulated material is cooled to 60-70°C for the first time, and then sieved to control the particle size to 2-4.2 mm, and then cooled to 20-35°C for the second time, and finally subjected to anti-caking treatment to obtain a water-soluble polypeptide compound fertilizer.

[0036] Comparative Example 4 (1) 0.8 kg of cowhide polypeptide, 0.07 kg of zinc sulfate monohydrate, 0.1 kg of manganese sulfate monohydrate, and 0.13 kg of boric acid were mixed to obtain a first mixture; (2) heating 41 kg of urea and 3.5 kg of potassium chloride to 130-135° C. to melt and obtain a molten liquid; (3) 44.5 kg of the melt, 26.7 kg of monoammonium phosphate, 27.1 kg of potassium sulfate and 1.1 kg of the first mixture were mixed uniformly in a primary mixing tank at a temperature of 105-110° C. and a residence time of 20 min to obtain a second mixture; (4) granulating the second mixture in a high tower granulator at a granulation temperature of 90-110° C. for 10 min to obtain a granulated material; (5) The granulated material is cooled to 60-70°C for the first time, and then sieved to control the particle size to 2-4.2 mm, and then cooled to 20-35°C for the second time, and finally subjected to anti-caking treatment to obtain a water-soluble polypeptide compound fertilizer.

[0037] Performance Testing The performance test of the polypeptide compound fertilizer obtained in the above examples and comparative examples specifically includes: 1. Appearance: visual inspection.

[0038] 2. Water-insoluble matter content: Tested in accordance with NY / T 1973-2021.

[0039] 3. Yield rate: the proportion of 2-4.2mm particles.

[0040] The test results are shown in Table 1.

[0041] Table 1 Appearance Water insoluble matter content (%) Yield rate (%) Example 1 Smooth and round 0.17 98 Example 2 Smooth and round 0.19 95 Example 3 Smooth and round 0.20 97 Comparative Example 1 Rough 0.16 78 Comparative Example 2 Rough 0.22 87 Comparative Example 3 Rough 0.19 82 Comparative Example 4 Rough 0.18 85 It can be seen from Table 1 that the water-soluble polypeptide compound fertilizer prepared by the present invention has a smooth and round appearance, a high yield rate, and good water solubility.

[0042] Compared with Example 1, Comparative Example 1 uses less cowhide polypeptide, and the viscosity of the system is too low, which is not conducive to the subsequent granulation process. The obtained polypeptide compound fertilizer has a rough appearance and a low yield.

[0043] Compared with Example 1, Comparative Example 2 uses more cowhide polypeptide, and the viscosity of the system is too high, which is not conducive to the subsequent granulation process. The obtained polypeptide compound fertilizer has a rough appearance and a low yield.

[0044] Compared with Example 1, in Comparative Example 3, urea and potassium chloride were not mixed, heated and melted, the material mixing uniformity was poor, and the obtained polypeptide compound fertilizer had a rough appearance and a low yield.

[0045] Compared with Example 1, in Comparative Example 4, monoammonium phosphate was added and mixed at one time, the material mixing uniformity was poor, the obtained polypeptide compound fertilizer had a rough appearance and a low yield.

[0046] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A water-soluble polypeptide compound fertilizer, characterized in that: Calculated by weight percentage, the raw materials include: 35%-45% urea, 20%-30% monoammonium phosphate, 1%-5% potassium chloride, 25%-30% potassium sulfate, 0.6%-1% cowhide polypeptide and 0.1%-0.5% medium and trace element raw materials.

2. The water-soluble polypeptide compound fertilizer according to claim 1, characterized in that: The medium and trace element raw materials include at least one of zinc sulfate, boric acid and manganese sulfate.

3. The water-soluble polypeptide compound fertilizer according to claim 1, characterized in that: The raw materials of the polypeptide compound fertilizer also include: anti-caking agent; wherein, The anti-caking agent accounts for 0.1%-1% of the water-soluble polypeptide compound fertilizer.

4. A method for preparing the water-soluble polypeptide compound fertilizer according to any one of claims 1 to 3, characterized in that: The following steps are involved: Evenly mixing the cowhide polypeptide and the medium and trace element raw materials to obtain a first mixture; Heat and melt urea and potassium chloride to obtain a molten liquid; uniformly mixing the molten liquid, part of the monoammonium phosphate, potassium sulfate and the first mixture in a primary mixing tank to obtain a second mixture; uniformly mixing the second mixture and the remaining monoammonium phosphate in a secondary mixing tank to obtain a third mixture; granulating the third mixture in a high tower granulator to obtain a granulated material; The granulated material is cooled, screened and subjected to anti-caking treatment to obtain a polypeptide compound fertilizer.

5. The method for preparing the water-soluble polypeptide compound fertilizer according to claim 4, characterized in that: The heating and melting temperature is 100-135°C.

6. The method for preparing the water-soluble polypeptide compound fertilizer according to claim 4, characterized in that: The temperature of the primary mixing tank is 100-120°C, and the residence time of the material in the primary mixing tank is 5-20min; the temperature of the secondary mixing tank is 100-120°C, and the residence time of the material in the secondary mixing tank is 5-20min.

7. The method for preparing the water-soluble polypeptide compound fertilizer according to claim 4, characterized in that: The partial monoammonium phosphate accounts for 30%-60% of the total amount of the monoammonium phosphate.

8. The method for preparing the water-soluble polypeptide compound fertilizer according to claim 4, characterized in that: The granulation temperature is 90-120° C., and the granulation time is 5-20 min.

9. The method for preparing the water-soluble polypeptide compound fertilizer according to claim 4, characterized in that: The moisture content of the granulated material is ≤1%.

10. The method for preparing the water-soluble polypeptide compound fertilizer according to claim 4, characterized in that: The process of cooling, screening and treating the granulated material with an anti-caking agent comprises: sequentially cooling, screening, secondary cooling and treating the granulated material with an anti-caking agent; wherein: The primary cooling is performed until the temperature of the granulated material is 40-70°C; The sieving process is performed to obtain a particle size of the granulated material of 2-4.2 mm; The secondary cooling is performed to reduce the temperature of the granulated material to 20-35°C.