CN111825502A - Double-layer coated precise controllable slow-release fertilizer and preparation method thereof - Google Patents
Double-layer coated precise controllable slow-release fertilizer and preparation method thereof Download PDFInfo
- Publication number
- CN111825502A CN111825502A CN202010585687.5A CN202010585687A CN111825502A CN 111825502 A CN111825502 A CN 111825502A CN 202010585687 A CN202010585687 A CN 202010585687A CN 111825502 A CN111825502 A CN 111825502A
- Authority
- CN
- China
- Prior art keywords
- fertilizer
- double
- water
- coated
- absorbent resin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05B—PHOSPHATIC FERTILISERS
- C05B7/00—Fertilisers based essentially on alkali or ammonium orthophosphates
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
- C05G3/00—Mixtures of one or more fertilisers with additives not having a specially fertilising activity
- C05G3/40—Mixtures of one or more fertilisers with additives not having a specially fertilising activity for affecting fertiliser dosage or release rate; for affecting solubility
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
- C05G5/00—Fertilisers characterised by their form
- C05G5/30—Layered or coated, e.g. dust-preventing coatings
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
- C05G5/00—Fertilisers characterised by their form
- C05G5/30—Layered or coated, e.g. dust-preventing coatings
- C05G5/37—Layered or coated, e.g. dust-preventing coatings layered or coated with a polymer
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Pest Control & Pesticides (AREA)
- Fertilizers (AREA)
Abstract
The invention belongs to the technical field of slow release fertilizers, and particularly relates to a double-layer coated precise controllable slow release fertilizer and a preparation method thereof. The preparation method of the double-layer coated precise controllable slow-release fertilizer comprises the following steps: loading the fertilizer particles into fluidized bed coating equipment, spraying water-absorbent resin emulsion on the surface of the fertilizer, and drying to obtain a water-absorbent resin coated fertilizer; spraying the hydrophobic resin coating liquid on the surface of the fertilizer, and coating the surface of the fertilizer with the water-absorbent resin to obtain a double-layer film coated fertilizer; the preparation method of the hydrophobic resin coating liquid comprises the following steps: dissolving the recycled polystyrene foam and toluene in a mass ratio of 1:5 to form a binding solution, and then adding silica sol, calcium bentonite and monoglyceride, stirring at a high speed and emulsifying to obtain a hydrophobic resin coating solution; the invention can effectively control the sustained and controlled release period of the fertilizer, and reduce the dependence of the sustained and controlled release fertilizer on the uniformity of the film layer. Simple process, low requirement on production equipment and high product qualification rate.
Description
Technical Field
The invention belongs to the technical field of slow release fertilizers, and particularly relates to a double-layer coated precise controllable slow release fertilizer and a preparation method thereof.
Background
Most of slow release fertilizers used in agriculture at present only have conceptual properties, the effect described in the actual fertilization process is difficult to achieve, or the effect of a coating material is poor, the fertilizer is released immediately to achieve the effect of not slow release, or the coating material is too thick, so that the fertilizer can not be released in the whole season, and the growth of crops is further influenced. The slow release fertilizer with good production quality needs complete coating without defects, can achieve controllable effect to improve the fertilizer cost, and is difficult to realize large-scale popularization and application.
The fertilizer has the advantages that the accurate controllable slow-release effect of the fertilizer is realized, the utilization rate of crops to the fertilizer is improved, the fertilizing times are reduced, the labor cost of multiple times of fertilization is reduced, and the influence of the accumulated fertilizer on the soil environment is reduced. The fertilizer coated by the semipermeable membrane can slowly release nutrients, the release period can be accurately controlled, the release of the nutrients can be released according to a crop growth curve, the nutrients are synchronous with the growth period of crops, the release speed of the nutrients is maximally close to the requirement of the crops on the nutrients, and thus the yield increase of the crops is maximally achieved. However, the production process of the material capable of accurately releasing is complex, the coating requirement is high, and the coating material also has certain requirements, so that the production cost of the fertilizer is increased, and the large-scale application of the fertilizer in agricultural production is influenced.
Chinese patent publication No. CN110357720A discloses a sulfur-modified oil-based coated slow-release fertilizer, which comprises a fertilizer core and a coating material, wherein the fertilizer core is urea granules or other urea-based compound fertilizers or nitro-compound fertilizer granules; the coating material is a sulfur modified oil-based material, and the preparation method comprises the following steps: firstly, heating and melting sulfur, slowly adding castor oil into the mixture for a vulcanization reaction, mixing the obtained product with a polyisocyanate curing agent, heating the mixture, coating the fertilizer particles with the obtained coating liquid, and curing the coated fertilizer particles to obtain the slow release fertilizer. The slow release fertilizer disclosed by the invention not only can realize the effect of controlling the release of urea, but also can realize the effect of slowly supplementing the s element to the soil along with the degradation of the membrane material. The single-layer controllable coating has higher requirement on the coating layer, and the due slow release effect can be achieved only by intact coating, so that the requirement on coating equipment is high, otherwise, the slow release effect is inconsistent due to uneven coating.
Chinese patent publication No. CN105037057A discloses a biodegradable double-layer coated slow-release fertilizer, which consists of a fertilizer core and a coating outside the fertilizer core. The coating layer comprises: the inner layer is a modified starch film with adjustable slow release property, which is obtained by grafting corn starch with long-chain alkyl acyl chloride; the outer layer is a water-retaining layer, and is a product obtained by crosslinking polyvinylpyrrolidone and casein under the condition of taking formaldehyde as a crosslinking agent. The invention obtains the slow-release adjustable coating material by grafting modification of starch and long-chain alkyl acyl chloride; the polyvinylpyrrolidone and the casein are good water-retaining materials, and the high polymer material with good water-retaining function is obtained under the condition of formaldehyde crosslinking. The starch modified film with adjustable slow release property and the double-coating layer formed by the film material with the water retention function obtained by crosslinking polyvinylpyrrolidone and casein have the slow release and controlled release properties and the water retention function, and the film material is degradable, so that the slow release and controlled release coated fertilizer is novel and environment-friendly.
Chinese patent publication No. CN102424640A discloses a double-layer coated water-retaining slow-release fertilizer and a preparation method thereof. The fertilizer comprises fertilizer particles and a double-layer coating wrapped on the surface of the fertilizer particles, wherein the material for forming the inner membrane controlled release layer is carrageenin and soluble potassium salt or soluble ammonium salt; the material of the outer film water-retaining layer is high water-absorbent resin. The invention provides a plurality of required nutrient elements for plants and improves the slow release performance of the nutrient elements of the fertilizer; meanwhile, the fertilizer and the water-absorbent resin are combined to have multiple functions of water absorption and retention, slow release, soil conditioning and the like.
Chinese patent publication No. CN106831118A discloses a preparation method of a double-layer coated slow-release compound fertilizer and a preparation method thereof. The compound fertilizer is prepared by taking a granular compound fertilizer as an inner core, taking gel formed by collagen extracted from pigskin as an inner-layer coating material and taking adsorptive mineral bentonite as an outer-layer coating. The invention relates to a double-layer coated slow-release compound fertilizer, which solves the problems of the optimization condition of preparing a fertilizer-preserving coating agent by collagen gel, the preparation process and parameters of a slow-release fertilizer and the evaluation of the slow-release effect of the coated slow-release fertilizer. The coated fertilizer is simple in preparation process, the raw materials of the coated agent are from organisms, can be completely biodegraded, is green and environment-friendly, has no secondary pollution, and reduces and relieves the pollution of agricultural production to the environment while improving the fertilizer efficiency utilization rate.
Chinese patent publication No. CN107382489A discloses a urea-formaldehyde resin-starch double-layer coated slow-release compound fertilizer, which is characterized in that a pre-polymerized urea-formaldehyde solution is prepared, and the urea-formaldehyde resin slow-release particles loaded with matrine are obtained by adopting an oil-in-water emulsion method and in-situ polymerization; then mixing the slow release particles with major elements and trace elements required by plants, and granulating to obtain fertilizer particles; and finally, preparing a starch coating solution, uniformly spraying the starch coating solution on the surfaces of the fertilizer particles, and drying by air blowing to obtain the urea resin-starch double-layer coated slow-release compound fertilizer. The slow-release compound fertilizer has quick-release and slow-release double-layer envelopes, can further prolong the release time of pesticide ingredients in the compound fertilizer, does not influence the release of nutrient ingredients, and has the advantages of comprehensive nutrition, safety, low degree, high efficiency and stability.
Chinese patent publication No. CN104609964A discloses a double-layer coated fertilizer and a preparation method thereof. The double-layer coated fertilizer consists of a core fertilizer, an inner-layer coating material and an outer-layer coating material, wherein the inner-layer coating material and the outer-layer coating material are coated on the surface of the core fertilizer; the inner layer coating material is microcrystalline wax; the outer layer coating material comprises a water-retaining agent and a coating agent; the mass ratio of the core fertilizer to the inner coating material to the outer coating material is 100: 0.5-2: 3-20; the mass ratio of the water-retaining agent to the coating agent is 100: 5 to 30. The preparation method comprises the following steps: 1) adding the core fertilizer and the inner-layer coating material into a coating machine, blowing and heating until the inner-layer coating material is molten and coats the surface of the core fertilizer to obtain a fertilizer coated with the inner-layer coating material; 2) and (3) coating the fertilizer coated with the inner-layer coating material with the outer-layer coating material for at least 1 time to obtain the double-layer coated fertilizer. The double-layer coated fertilizer has better slow release and water retention effects, the preparation method is simple, the dissolving effect of the coating agent is good, the coating is facilitated, and the double-layer coated fertilizer is suitable for batch production.
Chinese patent publication No. CN104447070A discloses a corn compound fertilizer and a preparation method thereof, in particular to a water-retaining and fertilizer-retaining slow-release corn compound fertilizer and a preparation method thereof. The corn compound fertilizer comprises super absorbent resin and an organic-inorganic compound fertilizer. The organic-inorganic compound fertilizer can effectively supplement nutrients for corn production, the super absorbent resin has the functions of water retention and fertilizer retention, and the mixing of the super absorbent resin and the organic-inorganic compound fertilizer can effectively improve the strength and the balling rate of fertilizer particles and reduce energy consumption. The corn compound fertilizer has good water and fertilizer retention effect, can reduce the irrigation times, is applied at one time, does not need additional fertilizer, saves labor and time, increases the yield and income of the corn, and is suitable for simple and economical planting modes. The preparation method of the corn compound fertilizer has the advantages of simple process, wide raw material source and low cost.
Chinese patent publication No. CN104478615A discloses a wheat compound fertilizer and a preparation method thereof, in particular to a water-retaining and fertilizer-retaining slow-release wheat compound fertilizer and a preparation method thereof. The wheat compound fertilizer comprises super absorbent resin and an organic-inorganic compound fertilizer. The organic-inorganic compound fertilizer can effectively supplement nutrients for wheat production, the super absorbent resin has the functions of water retention and fertilizer retention, and the organic-inorganic compound fertilizer can effectively improve the strength and the balling rate of fertilizer particles and reduce energy consumption when being mixed with the organic-inorganic compound fertilizer. The wheat compound fertilizer has good water and fertilizer retention effect, can reduce the irrigation times, is applied at one time, does not need additional fertilizer, saves labor and time, increases the yield and income of wheat, and is suitable for simple and economical planting. The preparation method of the wheat compound fertilizer has the advantages of simple process, wide raw material source and low cost.
Disclosure of Invention
Aiming at the problem that the slow-release and controlled-release period of the existing precise and controllable slow-release fertilizer is difficult to control, the first purpose of the invention is to disclose a preparation method of a double-layer coated precise and controllable slow-release fertilizer.
In order to achieve the aim, the preparation method of the double-layer coated precise controllable slow-release fertilizer comprises the following steps:
(1) loading the fertilizer particles into fluidized bed coating equipment, spraying water-absorbent resin emulsion on the surface of the fertilizer, and drying to obtain a water-absorbent resin coated fertilizer;
(2) continuously flowing the water-absorbent resin coated fertilizer obtained in the step (1) in coating equipment, spraying the hydrophobic resin coating liquid on the surface of the water-absorbent resin coated fertilizer, and solidifying the water-absorbent resin coated fertilizer on the surface of the water-absorbent resin coated fertilizer to obtain a double-layer film coated fertilizer;
the preparation method of the hydrophobic resin coating liquid comprises the following steps: dissolving the recycled polystyrene foam and toluene in a mass ratio of 1:5 to form a binding solution, and then adding silica sol, calcium bentonite and monoglyceride, stirring at a high speed and emulsifying to obtain a hydrophobic resin coating solution; the mass concentration of the silica sol is 15 percent, and the adding amount of the silica sol is 80 percent of that of the binding liquid; the addition amount of the calcium bentonite is 10 percent of the mass of the binding liquid, and the addition amount of the monoglyceride is 3 percent of the mass of the binding liquid.
Preferably, the water-absorbent resin emulsion in step (1) is selected from one or more of polyacrylic acid emulsion, sodium polyacrylate grafted starch emulsion, sodium polyacrylate grafted alginic acid emulsion and polyacrylamide emulsion.
Preferably, the thickness of the coating of the water-absorbent resin-coated fertilizer in the step (1) is 50 to 500 μm.
If the coating thickness of the water-absorbent resin coated fertilizer in the step (1) is too thin, the outer coating cannot be completely broken, and the fertilizer is slowly released. If the coating thickness of the water-absorbent resin coated fertilizer is too thick, the outer coating is easy to be completely broken, and the fertilizer can be quickly released. The thickness of the coating is preferably 50 to 500 μm.
The thickness of the coating film can be controlled by controlling the amount of the water-absorbent resin emulsion.
Preferably, the step (1) is: and (2) putting the fertilizer particles into fluidized bed coating equipment, preheating for 10-15 minutes at 50-60 ℃, spraying the water-absorbent resin emulsion on the surface of the fertilizer, and drying at 70-80 ℃ in hot air to obtain the water-absorbent resin coated fertilizer.
Preferably, the thickness of the outer layer film of the double-layer film in the step (2) is 50-500 μm.
The thickness of the outer layer membrane can be controlled by the amount of hydrophobic resin coating solution.
The outer membrane is a membrane which is in contact with the external environment and is prepared from hydrophobic resin coating liquid.
If the thickness of the outer film of the double-layer film in the step (2) is too thin, the double-layer film is easy to naturally age, and the fertilizer is released too fast. If the thickness of the outer layer film of the double-layer film is too thick, the raw materials of the coating film are wasted, the outer layer film is not easy to naturally age, and the fertilizer release is slow. Experiments show that the thickness of the outer layer film of the double-layer film is 50-500 mu m.
Preferably, the coating process in the step (2) is as follows: filling water-absorbent resin coated fertilizer particles into fluidized bed coating equipment, spraying a hydrophobic resin coating liquid on the surface of the water-absorbent resin coated fertilizer, and then solidifying at 30-40 ℃ to obtain the double-layer film coated fertilizer.
The second purpose of the invention is to provide a double-layer coated precise controlled slow-release fertilizer.
In order to solve the second technical problem, the double-layer coated precise controlled slow release fertilizer is prepared by the preparation method of the double-layer coated precise controlled slow release fertilizer.
Has the advantages that:
according to the fertilizer coated by the double-layer film, the hydrophobic outer coating film is used as a main sustained and controlled release material, the water-absorbing resin inner film is used as an auxiliary control material, and the release period of the fertilizer is controlled by the two coating materials together, so that the requirement of the sustained and controlled release performance on the uniformity of the coating is reduced. The hydrophobic outer coating can control the water immersion, prevent the outer coating from breaking and influencing the slow controlled release performance of the fertilizer due to the early water absorption and swelling of the inner coating, and simultaneously, a small amount of hydrophilic material is added into the hydrophobic resin coating liquid, so that the slow release period of the fertilizer can be effectively controlled, when the hydrophilic material is naturally degraded or dissolved by swelling, the water absorption resin inner coating absorbs water and swells to form a gap, and the fertilizer starts to be slowly released; when the inner envelope continues to absorb water and swell, the outer envelope is completely broken, and the release speed of the fertilizer is mainly controlled by the inner envelope, so that the slow and controlled release period of the fertilizer can be effectively controlled by controlling the thickness of the inner envelope and the outer envelope, and the dependence of the slow and controlled release fertilizer on the uniformity of the film layer is reduced.
Meanwhile, the invention has the advantages of simple process, low requirement on production equipment, high product qualification rate, easy realization of large-scale application and the like.
Drawings
FIG. 1 is a graph showing the release ratio of nitrogen with time in comparative examples 1 and 2 and example 1.
Detailed Description
The present invention will be described in further detail with reference to specific embodiments, but it should not be construed that the scope of the present invention is limited to the following examples. Various substitutions and alterations can be made by those skilled in the art and by conventional means without departing from the spirit of the method of the invention described above.
Example 1
(1) Mixing potassium chloride, urea and calcium phosphate fertilizer according to the weight ratio of 1: 1: 1, uniformly mixing and prefabricating into particles with the particle size of about 3 mm; putting the fertilizer into a fluidized bed coating device, preheating for 12 minutes at 55 ℃, spraying polyacrylic emulsion water-absorbent resin emulsion on the surface of the fertilizer, drying, and controlling the amount of the polyacrylic emulsion water-absorbent resin emulsion to obtain a water-absorbent resin coated fertilizer with the thickness of 95-150 mu m;
(2) dissolving the recycled polystyrene foam and toluene in a mass ratio of 1:5 to form a binding solution, and then adding silica sol, calcium bentonite and monoglyceride, stirring at a high speed and emulsifying to obtain a hydrophobic resin coating solution; the mass concentration of the silica sol is 15 percent, and the adding amount of the silica sol is 80 percent of that of the binding liquid; the addition amount of the calcium bentonite is 10 percent of the mass of the binding liquid, and the addition amount of the monoglyceride is 3 percent of the mass of the binding liquid. And (2) continuously flowing the water-absorbent resin coated fertilizer obtained in the step (1) in coating equipment, spraying the hydrophobic resin coating liquid on the surface of the fertilizer, drying the fertilizer by hot air at 80 ℃, and solidifying the fertilizer on the surface of the water-absorbent resin coated fertilizer at 30 ℃ to obtain the double-layer film coated fertilizer, wherein the thickness of an outer layer film is 100-200 mu m.
Example 2
(1) Mixing potassium chloride, urea and calcium phosphate fertilizer according to the weight ratio of 1: 1: 1, uniformly mixing and prefabricating into particles with the particle size of about 3 mm; putting the fertilizer into a fluidized bed coating device, preheating for 12 minutes at 55 ℃, spraying polyacrylic emulsion water-absorbent resin emulsion on the surface of the fertilizer, drying, and controlling the amount of the polyacrylic emulsion water-absorbent resin emulsion to obtain a water-absorbent resin coated fertilizer with the thickness of 300-400 mu m;
(2) dissolving the recycled polystyrene foam and toluene in a mass ratio of 1:5 to form a binding solution, and then adding silica sol, calcium bentonite and monoglyceride, stirring at a high speed and emulsifying to obtain a hydrophobic resin coating solution; the mass concentration of the silica sol is 15 percent, and the adding amount of the silica sol is 80 percent of that of the binding liquid; the addition amount of the calcium bentonite is 10 percent of the mass of the binding liquid, and the addition amount of the monoglyceride is 3 percent of the mass of the binding liquid. And (2) continuously flowing the water-absorbent resin coated fertilizer obtained in the step (1) in coating equipment, spraying the hydrophobic resin coating liquid on the surface of the fertilizer, drying at 75 ℃ by hot air, cooling at 30 ℃ and solidifying on the surface of the water-absorbent resin coated fertilizer to obtain the double-layer film coated fertilizer, wherein the thickness of an outer layer film is 200-300 mu m.
Example 3
(1) Mixing potassium chloride, urea and calcium phosphate fertilizer according to the weight ratio of 1: 1: 1, uniformly mixing and prefabricating into particles with the particle size of about 3 mm; putting the fertilizer into a fluidized bed coating device, preheating for 12 minutes at 55 ℃, spraying polyacrylic emulsion water-absorbent resin emulsion on the surface of the fertilizer, drying, and controlling the amount of the polyacrylic emulsion water-absorbent resin emulsion to obtain a water-absorbent resin coated fertilizer with the thickness of 200-300 mu m;
(2) dissolving the recycled polystyrene foam and toluene in a mass ratio of 1:5 to form a binding solution, and then adding silica sol, calcium bentonite and monoglyceride, stirring at a high speed and emulsifying to obtain a hydrophobic resin coating solution; the mass concentration of the silica sol is 15 percent, and the adding amount of the silica sol is 80 percent of that of the binding liquid; the addition amount of the calcium bentonite is 10 percent of the mass of the binding liquid, and the addition amount of the monoglyceride is 3 percent of the mass of the binding liquid. And (2) continuously flowing the water-absorbent resin coated fertilizer obtained in the step (1) in coating equipment, spraying the hydrophobic resin coating liquid on the surface of the fertilizer, drying the fertilizer at the temperature of 70 ℃ by hot air, cooling the fertilizer at the temperature of 30 ℃, and solidifying the fertilizer on the surface of the water-absorbent resin coated fertilizer to obtain a double-layer film coated fertilizer, wherein the thickness of an outer layer film is 50-150 microns.
Example 4
(1) Mixing potassium chloride, urea and calcium phosphate fertilizer according to the weight ratio of 1: 1: 1, uniformly mixing and prefabricating into particles with the particle size of about 3 mm; putting the fertilizer into a fluidized bed coating device, preheating for 12 minutes at 55 ℃, spraying polyacrylic emulsion water-absorbent resin emulsion on the surface of the fertilizer, drying, and controlling the amount of the polyacrylic emulsion water-absorbent resin emulsion to obtain a water-absorbent resin coated fertilizer with the thickness of 200-350 mu m;
(2) dissolving the recycled polystyrene foam and toluene in a mass ratio of 1:5 to form a binding solution, and then adding silica sol, calcium bentonite and monoglyceride, stirring at a high speed and emulsifying to obtain a hydrophobic resin coating solution; the mass concentration of the silica sol is 15 percent, and the adding amount of the silica sol is 80 percent of that of the binding liquid; the addition amount of the calcium bentonite is 10 percent of the mass of the binding liquid, and the addition amount of the monoglyceride is 3 percent of the mass of the binding liquid. And (2) continuously flowing the water-absorbent resin coated fertilizer obtained in the step (1) in coating equipment, spraying the hydrophobic resin coating liquid on the surface of the fertilizer, drying the fertilizer by hot air at 80 ℃, cooling the fertilizer at 30 ℃ and solidifying the fertilizer on the surface of the water-absorbent resin coated fertilizer to obtain the double-layer film coated fertilizer, wherein the thickness of an outer layer film is 100-200 mu m.
Comparative example 1
A single-layer film-coated fertilizer prepared using only the hydrophobic resin coating solution was the same as in example 1.
Comparative example 2
Compared with the embodiment 1, the coating of the outer layer hydrophobic resin coating liquid is not carried out, and only one layer of the water-absorbent resin coating is coated.
And (3) detecting the controlled release performance:
and (4) testing standard: the fertilizers of examples 1-4 and comparative examples 1-2 were tested for sustained release performance by referring to the method and requirements of the national standard for sustained release fertilizers (GB/T23348-2009).
The test method comprises the following steps: (1) 10g of the fertilizer obtained in the examples and the comparative examples is put into a small bag made of a nylon gauze of 100 meshes, the small bag is sealed, the small bag is respectively put into a 250ml glass bottle, 200 ml of water is added, the cover is sealed, the small bag is cultured in a constant temperature incubator at 25 ℃, the sampling time is 1d, 3d, 5d, 7d, 10d, 14d, 28d and 42d, the upper part and the lower part are reversed for three times during sampling, 200 ml of distilled water is added into the original glass bottle again after the nitrogen content is measured by each sampling, the small bag is put into a biochemical incubator after the cover is sealed, the nitrogen content is measured by using a boric acid solution and a sulfuric acid standard titration solution, and the nitrogen release amount is calculated. The results are detailed in table 1, and the nitrogen content release amount versus time for example 1 and comparative examples 1 and 2 is shown in fig. 1.
TABLE 1 test results of examples 1 to 4 and comparative examples 1 and 2
| 1d | 3d | 5d | 7d | 10d | 14d | 28d | 42d | |
| Example 1 | 0% | 0% | 0% | 11.2% | 15.5% | 26.2% | 50.7% | 83.2% |
| Example 2 | 0% | 0% | 0% | 9.8% | 13.3% | 27.4% | 53.3% | 84.7% |
| Example 3 | 0% | 0% | 0% | 10.5% | 14.7% | 25.7% | 51.8% | 84.1% |
| Example 4 | 0% | 0% | 0% | 9.2% | 12.9% | 26.8% | 52.4% | 85.3% |
| Comparative example 1 | 0% | 0% | 0% | 0.2% | 0.9% | 1.6% | 4.2% | 10.1% |
| Comparative example 2 | 1.1% | 2.3% | 5.1% | 15.6% | 51.8% | 98.1% | 99.2% | 99.5% |
As can be seen from Table 1 and FIG. 1, in comparative example 1, since the degradation is difficult only by using the resin, the nitrogen release amount is only about 10% in 42 days, and the fertilizer does not achieve the sustained and controlled release effect; as can be seen from the comparative example 2, the early fertilizer has a slow release effect, but when the hydrophilic material on the membrane is degraded, the internal fertilizer is quickly released, so that the slow and controlled release effect of the material is poor; in example 1, almost no fertilizer is released in the first 5 days, and at the beginning of the 7 th day, the fertilizer starts to slowly release the nitrogen fertilizer due to the slow release effect of the internal water-absorbent resin, and the nitrogen release amount is 50.7% in the first 28 days of the experiment, which meets the national standard that the release amount is less than 80% in the first 28 days of slow-release fertilizer; therefore, the double-layer film coated fertilizer has good sustained and controlled release performance, and the fertilizer prepared by the method can be better absorbed and utilized by crops, improve the utilization rate of the fertilizer and reduce the loss of nutrients.
Claims (8)
1. A preparation method of a double-layer coated precise controllable slow-release fertilizer is characterized by comprising the following steps:
(1) loading the fertilizer particles into fluidized bed coating equipment, spraying water-absorbent resin emulsion on the surface of the fertilizer, and drying to obtain a water-absorbent resin coated fertilizer;
(2) continuously flowing the water-absorbent resin coated fertilizer obtained in the step (1) in coating equipment, spraying the hydrophobic resin coating liquid on the surface of the water-absorbent resin coated fertilizer, and obtaining a double-layer film coated fertilizer on the surface of the water-absorbent resin coated fertilizer;
the preparation method of the hydrophobic resin coating liquid comprises the following steps: dissolving the recycled polystyrene foam and toluene in a mass ratio of 1:5 to form a binding solution, and then adding silica sol, calcium bentonite and monoglyceride, stirring at a high speed and emulsifying to obtain a hydrophobic resin coating solution; the mass concentration of the silica sol is 15 percent, and the adding amount of the silica sol is 80 percent of that of the binding liquid; the addition amount of the calcium bentonite is 10 percent of the mass of the binding liquid, and the addition amount of the monoglyceride is 3 percent of the mass of the binding liquid.
2. The method for preparing the double-layer coated precise controlled and slow release fertilizer according to claim 1, wherein the fertilizer in the step (1) is one or more of a nitrogenous fertilizer, a potash fertilizer and a phosphate fertilizer; the nitrogen fertilizer is selected from one or more of urea, ammonium sulfate and ammonium nitrate, the potassium fertilizer is selected from one or two of potassium chloride and potassium sulfate, and the phosphate fertilizer is selected from one or two of calcium superphosphate and calcium magnesium phosphate; the particle size of the fertilizer particles is 2-4 mm.
3. The method for preparing the double-layer coated precise and controllable slow-release fertilizer according to claim 1, wherein the water-absorbing resin emulsion in the step (1) is one or more selected from polyacrylic acid emulsion, sodium polyacrylate grafted starch emulsion, sodium polyacrylate grafted alginic acid emulsion and polyacrylamide emulsion.
4. The method for preparing the double-layer coated precise and controllable slow-release fertilizer according to claim 1, wherein the coating thickness of the water-absorbent resin coated fertilizer in the step (1) is 50-500 μm.
5. The preparation method of the double-layer coated precise controlled-release fertilizer according to claim 1, characterized in that the step (1) is as follows: and (2) putting the fertilizer particles into fluidized bed coating equipment, preheating for 10-15 minutes at 50-60 ℃, spraying the water-absorbent resin emulsion on the surface of the fertilizer, and drying at 70-80 ℃ in hot air to obtain the water-absorbent resin coated fertilizer.
6. The preparation method of the double-layer coated precision controlled-release fertilizer as claimed in claim 1, wherein the thickness of the outer layer film of the double-layer film in the step (2) is 50-500 μm.
7. The preparation method of the double-layer coated precise controlled-release fertilizer as claimed in claim 1, wherein the coating process in the step (2) is as follows: filling water-absorbent resin coated fertilizer particles into fluidized bed coating equipment, spraying a hydrophobic resin coating liquid on the surface of the water-absorbent resin coated fertilizer, and solidifying at 30-40 ℃ to obtain the double-layer film coated fertilizer.
8. A double-layer coated precise controllable slow-release fertilizer, which is characterized by being prepared by the preparation method of the double-layer coated precise controllable slow-release fertilizer according to any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010585687.5A CN111825502A (en) | 2020-06-24 | 2020-06-24 | Double-layer coated precise controllable slow-release fertilizer and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010585687.5A CN111825502A (en) | 2020-06-24 | 2020-06-24 | Double-layer coated precise controllable slow-release fertilizer and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111825502A true CN111825502A (en) | 2020-10-27 |
Family
ID=72897908
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010585687.5A Withdrawn CN111825502A (en) | 2020-06-24 | 2020-06-24 | Double-layer coated precise controllable slow-release fertilizer and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111825502A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112266302A (en) * | 2020-10-30 | 2021-01-26 | 安徽省农业科学院土壤肥料研究所 | Controlled release fertilizer and application thereof in rice cultivation |
| CN114031458A (en) * | 2021-11-16 | 2022-02-11 | 淮安大华生物科技有限公司 | Fluid zinc-boron fertilizer and preparation method thereof |
| CN115448794A (en) * | 2022-09-20 | 2022-12-09 | 安徽司尔特化肥科技有限公司 | Preparation and coating method of controlled-release fertilizer coating material |
-
2020
- 2020-06-24 CN CN202010585687.5A patent/CN111825502A/en not_active Withdrawn
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112266302A (en) * | 2020-10-30 | 2021-01-26 | 安徽省农业科学院土壤肥料研究所 | Controlled release fertilizer and application thereof in rice cultivation |
| CN114031458A (en) * | 2021-11-16 | 2022-02-11 | 淮安大华生物科技有限公司 | Fluid zinc-boron fertilizer and preparation method thereof |
| CN115448794A (en) * | 2022-09-20 | 2022-12-09 | 安徽司尔特化肥科技有限公司 | Preparation and coating method of controlled-release fertilizer coating material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111825502A (en) | Double-layer coated precise controllable slow-release fertilizer and preparation method thereof | |
| CN104311253B (en) | A kind of chitosan sustained-release fertilizer microballoon and preparation method thereof | |
| CN104447027B (en) | Preparation method of in-situ reaction film-forming and hole-forming type controlled-release fertilizers | |
| CN101857490B (en) | Slow/controlled-release compound fertilizer suitable for field crops | |
| US20210380502A1 (en) | Multi-layered fertilizer and preparation method thereof | |
| CN101225009A (en) | Process for synthesizing gel-based water-holding slow-release carbamide fertilizer and production method | |
| CN102807445B (en) | Preparation method for controlled-release fertilizer special for mechanically applied rice | |
| CN110041136A (en) | Compound coating slow-release or control-release fertilizer of water retaining function type bio-based polyurethane and preparation method thereof | |
| MXPA02009946A (en) | Permeable composition, controlled release product and methods for the production thereof. | |
| US6358295B1 (en) | Method for producing granular coated fertilizer | |
| CN111018626A (en) | Stable fertilizer containing nitrification inhibitor and preparation method thereof | |
| IE53838B1 (en) | Plant-promoting preparations with controlled start plant-promoting agent release | |
| CN112521224A (en) | Soil improvement preparation and preparation method thereof | |
| CN112062637A (en) | Large-particle long-acting fertilizer and granulation method thereof | |
| CN115594551B (en) | Accurate controlled release membrane material filled with thermosensitive polymer nanoparticles and application thereof | |
| CN106748068A (en) | A kind of corn durable composite fertilizer | |
| CN106608768A (en) | Water-retention slow-release fertilizer | |
| CN209584033U (en) | Biological powdered carbon multilayer coating film vegetables Special slow release fertilizer | |
| CN114380650A (en) | Phosphorus potassium nitrate composite microbial fertilizer and preparation method thereof | |
| CN112521226A (en) | Water-retention and fertilizer loss-control additive and continuous production process thereof | |
| CN112358351A (en) | Ceramic hollow microsphere coated fish protein amino acid water-soluble slow-release fertilizer and preparation method thereof | |
| CN111362752A (en) | Prepolymerization liquid for preparing water-retaining coated urea and method for preparing water-retaining coated urea by using prepolymerization liquid | |
| CN105294303A (en) | Nonmetallic mineral-based urea coated slow-release fertilizer particle and preparation method thereof | |
| CN108623391A (en) | A kind of soybean oil modified alkyd film-coated controlled release fertilizer | |
| CN116621645A (en) | Water-retaining slow-release fertilizer and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20201027 |