CN111454107A - Coated urea containing humic acid and preparation method and application thereof - Google Patents
Coated urea containing humic acid and preparation method and application thereof Download PDFInfo
- Publication number
- CN111454107A CN111454107A CN202010136627.5A CN202010136627A CN111454107A CN 111454107 A CN111454107 A CN 111454107A CN 202010136627 A CN202010136627 A CN 202010136627A CN 111454107 A CN111454107 A CN 111454107A
- Authority
- CN
- China
- Prior art keywords
- urea
- humic acid
- humate
- coating layer
- coated
- 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.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05B—PHOSPHATIC FERTILISERS
- C05B9/00—Fertilisers based essentially on phosphates or double phosphates of magnesium
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05C—NITROGENOUS FERTILISERS
- C05C9/00—Fertilisers containing urea or urea compounds
- C05C9/005—Post-treatment
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Pest Control & Pesticides (AREA)
- Fertilizers (AREA)
Abstract
The invention discloses humic acid-containing coated urea and a preparation method thereof, wherein the humic acid-containing coated urea comprises urea particles, a first coating layer and a second coating layer, wherein the first coating layer is formed on the surface of the urea particles and contains urea-formaldehyde resin, the second coating layer is formed on the surface of the first coating layer and contains humate. Therefore, the humic acid-containing coated urea has higher fertilizer efficiency and slow release effect, thereby improving the crop yield.
Description
Technical Field
The invention belongs to the field of fertilizers, and particularly relates to coated urea containing humic acid as well as a preparation method and application thereof.
Background
Chemical fertilizers occupy an important position in agricultural production, but the fertilizer products in China fall behind and are inappropriately applied, the utilization rate of the fertilizer is low, a large amount of fertilizer enters water, and serious water pollution such as water eutrophication and the like is caused. How to effectively and safely improve the utilization rate of the fertilizer, and the weight-reducing and efficiency-improving effects are the challenges which must be faced by people. The utilization rate of the fertilizer can be greatly improved by a sustained and controlled release technology, wherein the coated fertilizer is one of the main fertilizer types of the current sustained and controlled release fertilizer, and the coated fertilizer is commonly a non-organic matter coated fertilizer, an organic polymer coated fertilizer, a thermoplastic resin coated fertilizer and the like. The non-organic coated fertilizer mainly comprises sulfur coated urea, calcium magnesium phosphate fertilizer coated urea, divalent metal ammonium phosphate potassium salt coated urea, humic acid coated urea and the like, and the coating material is mostly plant nutrient elements and also becomes fertilizer coated fertilizer.
The method for preparing the humic acid-containing double-membrane slow release fertilizer reported in the prior art adopts a twice-coating process, each coating is preheated and ventilated and dried, the process is complex and high in energy consumption, and a rotary drum coating machine is used, so that the equipment investment is large; meanwhile, in the method for preparing the coated humic acid urea suitable for the slow-release fertilizer reported in the prior art, the solution is water which can easily melt the urea, and low-order coal powder which is not activated is used, so that the method has high energy consumption, poor humic acid activity and poor fertilizer efficiency; in addition, in the method for preparing the ammonium magnesium phosphate coated fertilizer reported in the prior art, the surface of the material particles sprayed with the ammonium magnesium phosphate powder is dried and then sprayed with paraffin for sealing, the method needs to dry the sprayed fertilizer with high energy consumption, and a rotary drum coating machine is used, so that the coating is uneven and the equipment investment is large.
Therefore, the existing coated fertilizers are yet to be researched.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, one object of the present invention is to provide a humic acid-containing coated urea and a preparation method thereof, wherein the humic acid-containing coated urea has high fertilizer efficiency and slow release effect, thereby increasing crop yield.
In one aspect of the invention, the invention provides a humic acid-containing coated urea. According to an embodiment of the present invention, the humic acid-containing coated urea comprises:
urea granules;
a first coating layer formed on a surface of the urea granule, the first coating layer containing urea-formaldehyde resin;
a second coating layer which is formed on a surface of the first coating layer and contains a humate.
According to the urea coated urea containing humic acid provided by the embodiment of the invention, the first coating layer containing urea-formaldehyde resin is formed on the surface of urea particles, the first coating layer is water-insoluble, so that the release period of the coated urea is prolonged, the urea-formaldehyde resin can improve the strength of the urea particles, the cost is low, the second coating layer containing humate is formed on the first coating layer, the second coating layer is not fully water-soluble, the contained humate provides trace elements necessary for plant growth, and the contained activated humic acid can improve the utilization rate of N in the fertilizer. Therefore, the humic acid-containing coated urea has higher fertilizer efficiency and slow release effect, thereby improving the crop yield.
In addition, the humic acid-containing coated urea according to the above embodiment of the present invention may further have the following additional technical features:
in some embodiments of the invention, the urea granules have a particle size of 2.0mm to 4.75mm, preferably 3.0mm to 4.65mm, more preferably 3.5mm to 4.5 mm.
In some embodiments of the invention, the humate is at least one of potassium fulvate, potassium humate, sodium humate, ammonium humate, nitro humic acid and biochemical humic acid.
In some embodiments of the present invention, the humic acid-containing coated urea further comprises: a protective layer formed on a surface of the second cladding film layer, and containing magnesium phosphate.
In some embodiments of the present invention, the mass ratio of the urea particles, the urea-formaldehyde resin, the humate, and the magnesium phosphate is (93-96): 1: (1-3): (1-4).
In a further aspect of the invention, the invention provides a method for preparing the humic acid-containing coated urea. According to an embodiment of the invention, the method comprises:
(1) adding urea particles into an intensive mixer, stirring and heating, then adding a urea-formaldehyde solution, and spraying phosphoric acid at the same time so as to form a first coating layer containing urea-formaldehyde resin on the surfaces of the urea particles;
(2) mixing the urea granules obtained in the step (1) with a binder, and then spraying humate powder so as to form a second coating layer containing humate on the surface of the first coating layer.
According to the method for preparing the coated urea containing the humic acid, the urea particles are added into a strong mixer for heating and stirring, the high shear force in the strong mixer enables the urea particles to form good fluidity, then the urea-formaldehyde solution is added, meanwhile, the phosphoric acid is sprayed, and the phosphoric acid and the urea-formaldehyde solution react and polymerize to form the urea-formaldehyde resin, namely, the urea particles are uniformly coated with the first coating layer containing the urea-formaldehyde resin, the first coating layer is water-insoluble, so that the release period of the coated urea is prolonged, meanwhile, the urea-formaldehyde resin can improve the strength of the urea particles, and the cost is low. And then mixing the obtained urea particles coated with the primary coating layer with an adhesive, spraying humate powder, and forming a second coating layer containing humate on the surface of the first coating layer, wherein the second coating layer is not only water-insoluble, but also contains the humate which provides trace elements necessary for plant growth, and the contained activated humic acid can improve the utilization rate of N in the fertilizer. Therefore, the humic acid-containing coated urea with higher fertilizer efficiency and sustained release effect can be prepared by adopting the method.
In addition, the method for preparing the urea containing the humic acid coated film according to the above embodiment of the present invention may further have the following additional technical features:
in some embodiments of the present invention, in step (1), the urea-formaldehyde solution is prepared by reacting urea with formaldehyde under base catalysis, and the concentration of the urea-formaldehyde solution is 0.7-0.9 mol/L, preferably 0.75-0.85 mol/L, and more preferably 0.8-0.85 mol/L.
In some embodiments of the present invention, in the step (1), the temperature of the reaction between the urea-formaldehyde solution and the phosphoric acid is 50 to 85 ℃, preferably 55 to 80 ℃, more preferably 60 to 75 ℃, and the mixing time is 1 to 3min, preferably 1 to 2 min.
In some embodiments of the present invention, in step (1), the main shaft rotation speed of the intensive mixer is 100 to 400r/min, preferably 150 to 350r/min, and more preferably 200 to 300r/min, the auxiliary shaft rotation speed is 50 to 200r/min, preferably 80 to 180r/min, and more preferably 100 to 150r/min, and the barrel rotation speed is 5 to 10r/min, preferably 6 to 9r/min, and more preferably 7 to 8 r/min.
In some embodiments of the invention, in step (2), the binder is at least one of tung oil, castor oil, linseed oil and soybean oil.
In some embodiments of the present invention, in the step (2), the mixing temperature of the urea particles obtained in the step (1) and the binder is 50-85 ℃, preferably 55-80 ℃, and more preferably 60-75 ℃, and the mixing time is 1-10 min, preferably 2-8 min, and more preferably 3-6 min.
In some embodiments of the present invention, in the step (2), the particle size of the humate powder is 60 to 100 meshes, preferably 65 to 90 meshes, and more preferably 70 to 80 meshes.
In some embodiments of the invention, the method further comprises: (3) and (3) spraying phosphoric acid and magnesium oxide on the surfaces of the fertilizer particles obtained in the step (2), and forming a protective layer containing magnesium phosphate on the surface of the second coating layer.
In some embodiments of the present invention, in the step (3), the magnesium oxide has a particle size of 200 to 600 mesh, preferably 250 to 550 mesh, and more preferably 300 to 400 mesh.
In some embodiments of the present invention, in the step (3), the magnesium oxide and the phosphoric acid are reacted for 5 to 10min, preferably 6 to 9min, and more preferably 7 to 8min, and the reaction temperature is 50 to 85 ℃, preferably 55 to 80 ℃, and more preferably 60 to 75 ℃.
In some embodiments of the invention, the mass ratio of the urea particles, the urea-formaldehyde solution, the phosphoric acid, the binder, the humate and the magnesium oxide is (93-96): 1: (1-3): 1: (1-4): 1, preferably (93-95): 1: (1-2): 1: (2-4): 1, more preferably (93 to 94): 1: (1-1.5): 1: (2.5-3.5): 1.
additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a nutrient release curve of urea containing humic acid coated in example 1;
FIG. 2 is a nutrient release curve of humic acid-containing coated urea obtained in example 2;
FIG. 3 is a nutrient release curve of humic acid-containing coated urea obtained in example 3;
FIG. 4 is the nutrient release profile of urea containing humic acid coated in example 4.
Detailed Description
The following detailed description of the embodiments of the present invention is intended to be illustrative, and not to be construed as limiting the invention.
In one aspect of the invention, the invention provides a humic acid-containing coated urea. According to an embodiment of the present invention, the humic acid-containing coated urea comprises: urea granule, first envelope layer and second envelope layer, wherein, first envelope layer is formed on the urea granule surface to first envelope layer contains urea-formaldehyde resin, and the second envelope layer is formed on first envelope layer surface, and the second envelope layer contains humate. The inventor finds that the urea-formaldehyde resin can improve the strength of the urea granules and has lower cost by forming a first coating layer containing the urea-formaldehyde resin on the surface of the urea granules, wherein the first coating layer is water-insoluble, so that the release period of the coated urea is prolonged. And a second coating layer containing humate is formed on the first coating layer, the second coating layer is not only water-insoluble, but also contains humate which provides trace elements necessary for plant growth, and the contained activated humic acid can improve the utilization rate of N in the fertilizer. Therefore, the humic acid-containing coated urea has higher fertilizer efficiency and slow release effect, thereby improving the crop yield.
Further, in the humic acid-containing coated urea, the particle size of urea particles is 2.0mm to 4.75mm, preferably 3.0mm to 4.65mm, more preferably 3.5mm to 4.5mm, and the humate is at least one of potassium fulvate, potassium humate, sodium humate, ammonium humate, nitro humic acid and biochemical humic acid, preferably potassium fulvate, wherein K in potassium fulvate is2The content of O is more than or equal to 8wt percent. The inventor finds that the potassium fulvate can provide K for crops2And the potassium fulvate has good water solubility, small molecular weight and high activity, can be quickly absorbed by crops, and has obvious synergistic effect.
Further, the humic acid-containing coated urea further comprises a protective layer, wherein the protective layer is formed on the surface of the second coating layer and contains magnesium phosphate. The inventors found that by forming a protective layer containing magnesium phosphate on the second coating layer, the strength and wear resistance of the coated urea can be improved, thereby reducing dusting of the coated urea.
Preferably, the mass ratio of the urea particles, the urea-formaldehyde resin, the humate and the magnesium phosphate is (93-96): 1: (1-3): (1-4). The inventor finds that too much urea can affect the slow release performance of the urea, and too little urea can affect the diffusion of the urea in soil, so that the crop is malnourished; too much urea-formaldehyde resin can cause the coating to be too thick, so that the fertilizer efficiency of urea is influenced, and too little urea-formaldehyde resin can influence the slow release performance of urea; the cost is increased due to excessive humate, the powder is easy to remove, the coating of the magnesium phosphate layer is not facilitated, and the synergistic effect of humic acid on urea is influenced due to too little humic acid; too much magnesium phosphate can affect the diffusion of urea in soil, causing crop fertilizer loss, and too little magnesium phosphate can affect the strength and wear resistance of fertilizer granules. Therefore, the coated urea adopting the composition has higher fertilizer efficiency and slow release effect.
In a further aspect of the invention, the invention provides a method for preparing the humic acid-containing coated urea. According to an embodiment of the invention, the method comprises:
s100: adding urea granules into an intensive mixer, stirring and heating, then adding urea formaldehyde solution, and spraying phosphoric acid
In the step, urea particles are added into a powerful mixer for heating and stirring, high shearing force in the powerful mixer enables the urea particles to form good fluidity, then urea-formaldehyde solution is added, phosphoric acid is sprayed, and the phosphoric acid and the urea-formaldehyde solution react and polymerize to form urea-formaldehyde resin, namely, a first coating layer containing urea-formaldehyde resin is uniformly coated on the surfaces of the urea particles, and the first coating layer is water-insoluble, so that the release period of the coated urea is prolonged, and the urea-formaldehyde resin can improve the strength of the urea particles and is low in cost.
The urea-formaldehyde solution is prepared by reacting urea and formaldehyde under the catalysis of alkali, and the concentration of the urea-formaldehyde solution is 0.7-0.9 mol/L. the inventor finds that if the concentration is too low, the water content in the urea-formaldehyde solution is increased, and the water content is too much, so that the surface of urea particles is dissolved, and the coating effect is influenced, and if the concentration of the urea-formaldehyde is too high, a high-concentration formaldehyde solution or formaldehyde gas is required, so that the synthesis is difficult to realize and the cost is high, the concentration is preferably 0.75-0.85 mol/L, more preferably 0.8-0.85 mol/L, and the reaction temperature of the urea-formaldehyde solution and phosphoric acid is 50-85 ℃.
Furthermore, the rotating speed of the main shaft of the intensive mixer is 100-400 r/min, preferably 150-350 r/min, more preferably 200-300 r/min, the rotating speed of the auxiliary shaft is 50-200 r/min, preferably 80-180 r/min, more preferably 100-150 r/min, and the rotating speed of the cylinder is 5-10 r/min, preferably 6-9 r/min, more preferably 7-8 r/min. The inventor finds that the linear speed of urea particles is too high due to the fact that the shaft rotating speed, the auxiliary shaft rotating speed and the cylinder rotating speed are too high, the impact force among the urea particles is too large, the breakage rate of the urea particles is too high, and the coating yield is affected, and the coating of the urea particles is not uniform due to the fact that the shaft rotating speed, the auxiliary shaft rotating speed and the cylinder rotating speed are too low. Therefore, the urea granules can be uniformly coated by adopting the conditions.
S200: mixing the urea granules obtained in step S100 with a binder, and then spraying humate powder
In the step, the urea particles containing the first coating layer obtained in the step are mixed with an adhesive, and then humate powder is sprayed, so that a second coating layer containing humate is formed on the surface of the first coating layer, wherein the second coating layer is not only water-insoluble, but also contains humate which provides trace elements necessary for plant growth, and simultaneously contains activated humic acid which can improve the utilization rate of N in the fertilizer.
Further, in the step, the mixing temperature of the urea granules containing the first coating layer and the adhesive is 50-85 ℃. The inventor finds that if the temperature is too low, the flowability of the adhesive is poor, and the uniformity of the coating is affected, and if the temperature is too high, the energy consumption is increased, and the production cost is increased. The optimal selection is 55-80 ℃, the optimal selection is 60-75 ℃, the mixing time is 1-10 min, the optimal selection is 2-8 min, the optimal selection is 3-6 min, and meanwhile, the particle size of the humate powder is 60-100 meshes, the optimal selection is 65-90 meshes, and the optimal selection is 70-80 meshes. The inventor finds that if the particle size of the humate powder is too large, the humate coating is not uniform, and if the particle size of the humate powder is too small, the dust emission phenomenon is caused, the pollution to the working environment is caused, and the waste of the humate raw material is caused.
According to the method for preparing the coated urea containing the humic acid, the urea particles are added into a strong mixer for heating and stirring, the high shear force in the strong mixer enables the urea particles to form good fluidity, then the urea-formaldehyde solution is added, meanwhile, the phosphoric acid is sprayed, and the phosphoric acid and the urea-formaldehyde solution react and polymerize to form the urea-formaldehyde resin, namely, the urea particles are uniformly coated with the first coating layer containing the urea-formaldehyde resin, the first coating layer is water-insoluble, so that the release period of the coated urea is prolonged, meanwhile, the urea-formaldehyde resin can improve the strength of the urea particles, and the cost is low. And then mixing the obtained urea particles coated with the primary coating layer with an adhesive, spraying humate powder, and forming a second coating layer containing humate on the surface of the first coating layer, wherein the second coating layer is not only water-insoluble, but also contains the humate which provides trace elements necessary for plant growth, and the contained activated humic acid can improve the utilization rate of N in the fertilizer. Therefore, the humic acid-containing coated urea with higher fertilizer efficiency and sustained release effect can be prepared by adopting the method.
Further, the method further comprises:
s300: spraying phosphoric acid and magnesium oxide on the surface of the fertilizer granules obtained in the step S200
In this step, phosphoric acid and magnesium oxide are sprayed onto the surface of the fertilizer granule obtained in step S200, so that a protective layer containing magnesium phosphate is formed on the surface of the second coating layer. Specifically, the surface of the fertilizer granule obtained in step S200 of spraying the phosphoric acid solution is first uniformly mixed and then sprayed with MgO powder, and after the reaction and solidification, phosphoric acid and MgO powder are sprayed again (since the reaction speed of phosphoric acid and magnesium oxide powder is slow, the two coatings are performed to fully mix and contact phosphoric acid and magnesium oxide, and the reaction effect is increased), so that a protective layer containing magnesium phosphate is formed on the surface of the second coating layer, and the urea containing the humic acid coating is obtained. The inventor finds that by spraying phosphoric acid and magnesium oxide on the surface of fertilizer granules containing the second coating layer to form a protective layer containing magnesium phosphate on the second coating layer, the strength and wear resistance of the coated urea can be improved, and the powder removal of the coated urea can be reduced.
Further, in the step, the particle size of the magnesium oxide is 200-600 meshes, preferably 250-550 meshes, and more preferably 300-400 meshes, the reaction time of the magnesium oxide and the phosphoric acid is 5-10 min, preferably 6-9 min, and more preferably 7-8 min, and the reaction temperature is 50-85 ℃, preferably 55-80 ℃, and more preferably 60-75 ℃. It should be noted that the limited reaction time of the magnesium oxide and the phosphoric acid is the total time of the two-step reaction of the phosphoric acid and the magnesium oxide powder.
Preferably, in the above step, the mass ratio of the urea particles, the urea-formaldehyde solution, the phosphoric acid, the binder, the humate, and the magnesium oxide is (93-96): 1: (1-3): 1: (1-4): 1. the inventor finds that too much urea can affect the slow release performance of the urea, and too little urea can affect the diffusion of the urea in soil, so that the crop is malnourished; too much urea-formaldehyde resin can cause the coating to be too thick, so that the fertilizer efficiency of urea is influenced, and too little urea-formaldehyde resin can influence the slow release performance of urea; the cost is increased due to excessive humate, the powder is easy to remove, the coating of the magnesium phosphate layer is not facilitated, and the synergistic effect of humic acid on urea is influenced due to too little humic acid; too much magnesium phosphate can affect the diffusion of urea in soil, causing crop fertilizer loss, and too little magnesium phosphate can affect the strength and wear resistance of fertilizer granules. Therefore, the coated urea adopting the composition has higher fertilizer efficiency and slow release effect. Preferably (93-95): 1: (1-2): 1: (2-4): 1, more preferably (93 to 94): 1: (1-1.5): 1: (2.5-3.5): 1.
as described above, the method for preparing humic acid-containing coated urea according to an embodiment of the present invention may have at least one of the following advantages selected from:
1) according to the invention, the high shearing force of the intensive mixer is adopted to enable the urea to form good fluidity, and the uniformity of coating is better;
2) the urea coating is carried out by utilizing the intensive mixer, the existing compound fertilizer granulation device is fully utilized, and the independent investment of coating equipment is reduced;
3) the humic acid coated urea adopts urea resin, phosphoric acid and magnesium oxide as coating materials, so that the release period of the fertilizer can be prolonged, magnesium also contains trace elements necessary for plant growth, and activated humic acid is contained, so that the utilization rate of N in the fertilizer can be improved;
4) the humic acid-containing coated urea prepared by the invention adopts a multilayer coating process, can meet the standard of slow release fertilizers, has an initial nutrient release rate of less than or equal to 15 percent, a 28-day accumulated nutrient release rate of less than or equal to 80 percent and has a good slow release effect.
It should be noted that the features and advantages described above for the urea containing humic acid and the preparation method thereof are also applicable to the method for preparing urea containing humic acid and are not described herein again.
The following embodiments of the present invention are described in detail, and it should be noted that the following embodiments are exemplary only, and are not to be construed as limiting the present invention. In addition, all reagents used in the following examples are commercially available or can be synthesized according to methods herein or known, and are readily available to those skilled in the art for reaction conditions not listed, if not explicitly stated.
Example 1
(1) 930 kilograms of large-particle urea with the particle size of 2.0-4.75 mm is added into a powerful mixer, the rotating speed of a main shaft of the powerful mixer is adjusted to be 200r/min, the rotating speed of an auxiliary shaft is 100r/min, the rotating speed of a cylinder body is 8r/min, the urea is heated to 65 ℃, 15 kilograms of urea-formaldehyde solution (the urea-formaldehyde solution is prepared by reacting urea and formaldehyde under the catalysis of alkali, the concentration of the urea-formaldehyde solution is 0.8 mol/L) is added, 0.5 kilogram of phosphoric acid is sprayed after uniform coating, and the mixture is mixed for 1-3 min, so that a first coating layer containing urea-formaldehyde resin is formed on the surface of urea particles;
(2) after the reaction and solidification in the step (1), adding 5 kg of castor oil into the intensive mixer, stirring for 5min at the mixing temperature of 55-60 ℃, and then adding 10 kg of potassium humate powder for wrapping for 3min so as to form a second wrapping film layer containing humate on the surface of the first wrapping film layer;
(3) and adding 10 kg of phosphoric acid solution into the intensive mixer, then quickly adding 10 kg of MgO powder, reacting for 8min at 65 ℃, then adding 10 kg of phosphoric acid solution and 10 kg of MgO powder, reacting, solidifying, and cooling to obtain the humic acid-containing coated urea.
Example 2
(1) 940 kg of large-particle urea with the particle size of 2.0-4.75 mm is added into a powerful mixer, the rotating speed of a main shaft of the powerful mixer is adjusted to be 250r/min, the rotating speed of an auxiliary shaft is 150r/min, the rotating speed of a cylinder body is 9r/min, the urea is heated to 70 ℃, 5 kg of urea-formaldehyde solution (the urea-formaldehyde solution is prepared by reacting urea and formaldehyde under the catalysis of alkali, the concentration of the urea-formaldehyde solution is 0.8 mol/L) is added, 0.5 kg of phosphoric acid is sprayed after uniform coating, and mixing is carried out for 1-3 min, so that a first coating layer containing urea-formaldehyde resin is formed on the surface of urea particles;
(2) after the reaction and solidification in the step (1), adding 5 kg of castor oil into the intensive mixer, stirring for 5min at the mixing temperature of 55-60 ℃, and then adding 30 kg of potassium humate powder for wrapping for 3min so as to form a second wrapping film layer containing humate on the surface of the first wrapping film layer;
(3) adding 1 kg of phosphoric acid solution into the intensive mixer, then quickly adding 1 kg of MgO powder, reacting for 8min at 65 ℃, then adding 1 kg of phosphoric acid solution and 1 kg of MgO powder, reacting and solidifying, and cooling to obtain the humic acid-containing coated urea.
Example 3
(1) Adding 935 kilograms of large-particle urea with the particle size of 2.0-4.75 mm into a powerful mixer, adjusting the rotating speed of a main shaft of the powerful mixer to 250r/min, the rotating speed of an auxiliary shaft to 150r/min and the rotating speed of a cylinder to 10r/min, heating the urea to 70 ℃, adding 20 kilograms of urea-formaldehyde solution (the urea-formaldehyde solution is prepared by reacting urea and formaldehyde under the catalysis of alkali, and the concentration of the urea-formaldehyde solution is 0.8 mol/L), uniformly coating, spraying 0.5 kilograms of phosphoric acid, and mixing for 1-3 min so as to form a first coating layer containing urea-formaldehyde resin on the surface of urea particles;
(2) after the reaction and solidification in the step (1), adding 10 kg of castor oil into the intensive mixer, stirring for 5min at the mixing temperature of 55-60 ℃, and then adding 15 kg of potassium humate powder for wrapping for 3min so as to form a second wrapping film layer containing humate on the surface of the first wrapping film layer;
(3) and adding 5 kg of phosphoric acid solution into the intensive mixer, then quickly adding 5 kg of MgO powder, reacting for 8min at 65 ℃, then adding 5 kg of phosphoric acid solution and 5 kg of MgO powder, reacting, solidifying, and cooling to obtain the humic acid-containing coated urea.
Example 4
(1) 960 kilograms of large-particle urea with the particle size of 2.0-4.75 mm is added into a powerful mixer, the rotating speed of a main shaft of the powerful mixer is adjusted to be 250r/min, the rotating speed of an auxiliary shaft is 150r/min, the rotating speed of a cylinder body is 7r/min, the urea is heated to 70 ℃, 5 kilograms of urea-formaldehyde solution (the urea-formaldehyde solution is prepared by reacting urea and formaldehyde under the catalysis of alkali, the concentration of the urea-formaldehyde solution is 0.8 mol/L) is added, 0.5 kilogram of phosphoric acid is sprayed after uniform coating, and the mixture is mixed for 1-3 min, so that a first coating layer containing urea-formaldehyde resin is formed on the surface of urea particles;
(2) after the reaction and solidification in the step (1), adding 5 kg of castor oil into the intensive mixer, stirring for 5min at the mixing temperature of 55-60 ℃, and then adding 10 kg of potassium humate powder for wrapping for 3min so as to form a second wrapping film layer containing humate on the surface of the first wrapping film layer;
(3) and adding 5 kg of phosphoric acid solution into the intensive mixer, then quickly adding 5 kg of MgO powder, reacting for 8min at 65 ℃, then adding 5 kg of phosphoric acid solution and 5 kg of MgO powder, reacting, solidifying, and cooling to obtain the humic acid-containing coated urea.
Evaluation:
1. the nutrient release rates of the urea containing humic acid coated films obtained in the examples 1 to 4 are respectively measured;
2. the test method comprises the following steps:
and (3) determining the nutrient release rate: (GB/T23348-2009): weighing 10g of the un-crushed humic acid-containing coated urea fertilizer into a small bag made of a nylon gauze with 100 meshes, sealing, putting the small bag into a 250ml glass or plastic bottle, adding 200ml of water, and covering and sealing. Placing in a biochemical constant temperature incubator at 25 ℃, sampling for 14h, 3d, 5d, 7d, 10d, 14d, 28d and 56d, and sampling for 28d later until the dissolution rate of the accumulated nutrients reaches more than 80%. And (3) turning the sample bottle upside down for three times during sampling to enable the liquid concentration in the bottle to be consistent, transferring the bottle into a 250ml volumetric flask, cooling the bottle to room temperature, fixing the volume to the scale, and measuring the total nitrogen release amount.
And (4) conclusion: the urea containing humic acid coated obtained in the embodiments 1 to 4 has a three-layer structure, that is, the urea containing humic acid coated in the present application contains a first coating layer, a second coating layer and a protective layer; the nutrient release curves of the urea containing the humic acid coated membrane obtained in the examples 1 to 4 are shown in fig. 1 to 4, and it can be seen that the initial nutrient release rate of the urea containing the humic acid coated membrane obtained in the example 1 is 6.38%, the 28-day cumulative nutrient release rate is 49.68%, and the national standard of sustained and controlled release is met; the initial nutrient release rate of the urea containing the humic acid coated in the example 2 is 7.16%, the 28-day accumulated nutrient release rate is 51.29%, and the national sustained and controlled release standard is met; the initial nutrient release rate of the urea coated with the humic acid obtained in the example 3 is 8.31 percent, the cumulative nutrient release rate in 28 days is 54.68 percent, and the national sustained and controlled release standard is met; the initial nutrient release rate of the urea containing the humic acid coated by the embodiment 4 is 9.46%, the cumulative nutrient release rate in 28 days is 67.23%, and the national sustained and controlled release standard is met, which shows that the urea containing the humic acid coated by the method has higher sustained release effect.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (16)
1. The humic acid-containing coated urea is characterized by comprising the following components:
urea granules;
a first coating layer formed on a surface of the urea granule, the first coating layer containing urea-formaldehyde resin;
a second coating layer which is formed on a surface of the first coating layer and contains a humate.
2. The humic acid-containing coated urea according to claim 1, wherein the particle size of the urea particles is 2.0mm to 4.75mm, preferably 3.0mm to 4.65mm, and more preferably 3.5mm to 4.5 mm.
3. The humic acid-containing coated urea according to claim 1, wherein the humate is at least one of potassium fulvate, potassium humate, sodium humate, ammonium humate, nitro humic acid and biochemical humic acid.
4. The humic acid-containing coated urea according to any one of claims 1 to 3, further comprising:
a protective layer formed on a surface of the second cladding film layer, and containing magnesium phosphate.
5. The humic acid-containing coated urea as claimed in claim 4, wherein the mass ratio of the urea particles, the urea-formaldehyde resin, the humate and the magnesium phosphate is (93-96): 1: (1-3): (1-4).
6. A method for preparing the humic acid-containing coated urea of any one of claims 1 to 5, which comprises:
(1) adding urea particles into an intensive mixer, stirring and heating, then adding a urea-formaldehyde solution, and spraying phosphoric acid at the same time so as to form a first coating layer containing urea-formaldehyde resin on the surfaces of the urea particles;
(2) mixing the urea granules obtained in the step (1) with a binder, and then spraying humate powder so as to form a second coating layer containing humate on the surface of the first coating layer.
7. The method according to claim 6, wherein in step (1), the urea-formaldehyde solution is prepared by reacting urea with formaldehyde under base catalysis, and the concentration of the urea-formaldehyde solution is 0.7-0.9 mol/L, preferably 0.75-0.85 mol/L, and more preferably 0.8-0.85 mol/L.
8. The method according to claim 6 or 7, wherein in step (1), the temperature for the reaction of the urea-formaldehyde solution and the phosphoric acid is 50-85 ℃, preferably 55-80 ℃, more preferably 60-75 ℃, and the mixing time is 1-3 min, preferably 1-2 min.
9. The method according to claim 6, wherein in the step (1), the main shaft speed of the intensive mixer is 100-400 r/min, preferably 150-350 r/min, more preferably 200-300 r/min, the auxiliary shaft speed is 50-200 r/min, preferably 80-180 r/min, more preferably 100-150 r/min, and the barrel speed is 5-10 r/min, preferably 6-9 r/min, more preferably 7-8 r/min.
10. The method of claim 6, wherein in step (2), the binder is at least one of tung oil, castor oil, linseed oil and soybean oil.
11. The method according to claim 6 or 10, wherein in the step (2), the urea particles obtained in the step (1) are mixed with the binder at a temperature of 50-85 ℃, preferably 55-80 ℃, more preferably 60-75 ℃, and for a mixing time of 1-10 min, preferably 2-8 min, more preferably 3-6 min.
12. The method according to claim 6, wherein in step (2), the particle size of the humate powder is 60-100 mesh, preferably 65-90 mesh, and more preferably 70-80 mesh.
13. The method of claim 6, further comprising: (3) and (3) spraying phosphoric acid and magnesium oxide on the surfaces of the fertilizer particles obtained in the step (2), and forming a protective layer containing magnesium phosphate on the surface of the second coating layer.
14. The method according to claim 13, wherein in the step (3), the particle size of the magnesium oxide is 200 to 600 mesh, preferably 250 to 550 mesh, and more preferably 300 to 400 mesh.
15. The method according to claim 13 or 14, wherein in the step (3), the magnesium oxide and the phosphoric acid are reacted for 5-10 min, preferably 6-9 min, more preferably 7-8 min, and the reaction temperature is 50-85 ℃, preferably 55-80 ℃, more preferably 60-75 ℃.
16. The method according to claim 13, wherein the mass ratio of the urea particles, the urea-formaldehyde solution, the phosphoric acid, the binder, the humate and the magnesium oxide is (93-96): 1: (1-3): 1: (1-4): 1, preferably (93-95): 1: (1-2): 1: (2-4): 1, more preferably (93 to 94): 1: (1-1.5): 1: (2.5-3.5): 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010136627.5A CN111454107B (en) | 2020-03-02 | 2020-03-02 | Coated urea containing humic acid and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010136627.5A CN111454107B (en) | 2020-03-02 | 2020-03-02 | Coated urea containing humic acid and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111454107A true CN111454107A (en) | 2020-07-28 |
| CN111454107B CN111454107B (en) | 2022-04-26 |
Family
ID=71675293
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010136627.5A Active CN111454107B (en) | 2020-03-02 | 2020-03-02 | Coated urea containing humic acid and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111454107B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1491924A (en) * | 2002-10-25 | 2004-04-28 | 中国科学院沈阳应用生态研究所 | Humic acid long-acting compound fertilizer and its preparing method |
| CN1569769A (en) * | 2003-07-21 | 2005-01-26 | 南京大学 | Coated slow-release urea and its preparation method |
| CN102181126A (en) * | 2011-01-27 | 2011-09-14 | 武汉材料保护研究所 | Low surface energy polymer microcapsules and preparation method thereof |
| CN102211963A (en) * | 2011-02-11 | 2011-10-12 | 北京雷力农用化学有限公司 | Algae sustained-release granular fertilizer, preparation method and application thereof |
| CN104058898A (en) * | 2014-06-18 | 2014-09-24 | 燕山大学 | Humic acid coated urea and production method thereof |
| CN104829331A (en) * | 2015-04-21 | 2015-08-12 | 湖北省农业科学院植保土肥研究所 | Round particle slow release potash fertilizer preparation method |
| CN108456121A (en) * | 2018-02-09 | 2018-08-28 | 郑州高富肥料有限公司 | A kind of nucleocapsid slow-release or control-release fertilizer and preparation method thereof |
| CN109574748A (en) * | 2018-12-14 | 2019-04-05 | 河北百禾丰化肥有限公司 | A kind of Synergistic slow release coated fertilizer and preparation method thereof |
| CN110683897A (en) * | 2019-10-29 | 2020-01-14 | 金陵科技学院 | Potassium chloride and humic acid composite slow-release fertilizer granules and preparation method thereof |
-
2020
- 2020-03-02 CN CN202010136627.5A patent/CN111454107B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1491924A (en) * | 2002-10-25 | 2004-04-28 | 中国科学院沈阳应用生态研究所 | Humic acid long-acting compound fertilizer and its preparing method |
| CN1569769A (en) * | 2003-07-21 | 2005-01-26 | 南京大学 | Coated slow-release urea and its preparation method |
| CN102181126A (en) * | 2011-01-27 | 2011-09-14 | 武汉材料保护研究所 | Low surface energy polymer microcapsules and preparation method thereof |
| CN102211963A (en) * | 2011-02-11 | 2011-10-12 | 北京雷力农用化学有限公司 | Algae sustained-release granular fertilizer, preparation method and application thereof |
| CN104058898A (en) * | 2014-06-18 | 2014-09-24 | 燕山大学 | Humic acid coated urea and production method thereof |
| CN104829331A (en) * | 2015-04-21 | 2015-08-12 | 湖北省农业科学院植保土肥研究所 | Round particle slow release potash fertilizer preparation method |
| CN108456121A (en) * | 2018-02-09 | 2018-08-28 | 郑州高富肥料有限公司 | A kind of nucleocapsid slow-release or control-release fertilizer and preparation method thereof |
| CN109574748A (en) * | 2018-12-14 | 2019-04-05 | 河北百禾丰化肥有限公司 | A kind of Synergistic slow release coated fertilizer and preparation method thereof |
| CN110683897A (en) * | 2019-10-29 | 2020-01-14 | 金陵科技学院 | Potassium chloride and humic acid composite slow-release fertilizer granules and preparation method thereof |
Non-Patent Citations (3)
| Title |
|---|
| 常中春等: "Fe_3O_4磁性液芯微胶囊的液化制备方法研究", 《材料导报》 * |
| 朱志峰 等: "强力混合机在聚氨酯包膜尿素生产中的应用", 《磷肥与复肥》 * |
| 秦保罗，郭振铎，赵二茹，马燕，张昕: "多元营养素涂层尿素的研制", 《天津化工》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111454107B (en) | 2022-04-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103772074B (en) | A kind of long-acting dry farming special fertilizer for sweet potato and preparation method thereof | |
| CN103073356B (en) | Production method of slow-release chelated compound fertilizer containing multiple elements | |
| CN101177365B (en) | Long-acting special controlled release fertilizer for corn and preparation method thereof | |
| CN103172453B (en) | Slow-release compound fertilizer and production method thereof | |
| CN100484906C (en) | Preparation of humic urea | |
| CN107298609B (en) | Long-acting rice ecological special fertilizer suitable for basal application and preparation method thereof | |
| CN103936524B (en) | A kind of production method of urea aldehyde slow-release compound fertilizer | |
| CN103880558B (en) | A kind of anti-salt is improved the soil slow release fertilizer and preparation method thereof | |
| CN103333033B (en) | The preparation method of low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer | |
| CN102584471B (en) | Organosilicone water soluble long-acting compound fertilizer and preparation method thereof | |
| CN104761324A (en) | Production method of novel ureaformaldehyde slow-release nitrogen fertilizer and composite fertilizers of novel ureaformaldehyde slow-release nitrogen fertilizer | |
| CN103664369B (en) | A kind of synergy loss controlling fertilizer and preparation method thereof | |
| CN103910577B (en) | Slowly-soluble fertilizer and preparation method thereof | |
| CN110734337A (en) | high-water-absorption medium-trace element mixing agent and application thereof | |
| CN103435425B (en) | Hierarchical slow release multielement fertilizer and manufacturing process thereof | |
| WO2021103942A1 (en) | Secondary and trace element mixture and application thereof | |
| CN105237295A (en) | Special humic acid chelated slow-release fertilizer for wheat and preparation method thereof | |
| CN105384550B (en) | A kind of organic-inorganic complex fertilizer and preparation method thereof of long-acting slow-release P | |
| WO2021103941A1 (en) | Environmental-friendly medium trace element mixing agent and application | |
| CN103588574B (en) | Method for preparing slow/controlled release fertilizer by using urea coated with diatomite | |
| CN111454107B (en) | Coated urea containing humic acid and preparation method and application thereof | |
| CN103086803A (en) | Lumbrukinase compound fertilizer and preparation method thereof | |
| CN106396987A (en) | Potassium chloride granular fertilizer and production method thereof | |
| CN102584480B (en) | Colloidal suspension agent for nitrogen fertilizer synergism and application thereof | |
| CN106565308A (en) | Anti-caking fast-dissolving nitro-compound 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |