CN1666972A - A kind of effect control urea and preparation method thereof - Google Patents

Abstract

The invention relates to an effect-controlling fertilizer, in particular to an effect-controlling urea and a preparation method thereof. The effect-controlling urea is composed of a coating layer and a large-grain urea fertilizer core. The coating layer is a high-molecular polymer material added with urease inhibitors and/or nitrification inhibitors. The high-molecular polymer material used for the coating layer is acrylic resin or acrylic acid Resin - ethyl cellulose blend. The coating process adopts fluidized bed spray coating technology, specifically: dissolving high molecular polymer materials, urease inhibitors and/or nitrification inhibitors in ethanol solvent, adding inorganic membrane conditioners, plasticizers, etc. After miscibility, spray coating on the outer surface of fluidized large particle urea to form a smooth, continuous and uniform coating. The process of the invention is easy to realize, can fully control the release and conversion process of urea in soil, and greatly improves the utilization rate of urea nitrogen.

Description

A kind of effect control urea and preparation method thereof

technical field

The invention relates to an effect-controlling fertilizer, in particular to an effect-controlling urea combined with a coating and an inhibitor and a preparation method thereof.

Background technique

The utilization rate of traditional chemical fertilizers, especially nitrogen fertilizers, has been low due to losses such as volatilization, leaching and runoff, and the utilization rate of nitrogen fertilizers in the current season is only 30% to 40%. The low utilization rate of nitrogen fertilizer not only has poor effect on increasing crop yield and quality, but also has low economic benefits, and can also cause serious ecological and environmental problems such as atmospheric N ₂ O and NO _x pollution, groundwater nitrate accumulation, and water eutrophication.

In order to improve the utilization rate of nitrogen fertilizer, the production of slow-release high-efficiency nitrogen fertilizer has become an important direction for the development of the international fertilizer industry. At present, in view of the shortcoming that nitrogen fertilizer dissolves and releases too quickly in soil, sulfur-coated urea, polymer material-coated urea, natural organic matter-coated urea and slow-release phosphate fertilizer-coated urea have been developed. The nutrient release rate of coated urea was mainly determined by the characteristics of the coated wall material, and was relatively less affected by the soil environmental conditions. Its nutrient release rate is relatively uniform and slow, can significantly reduce NO ₃ ^- -N leaching loss and ammonia volatilization loss, and can be applied at the same time as seeds, and a large amount of application will not cause seedling burning. However, coated urea cannot control the soil transformation behavior after urea dissolution.

Urea combined with urease inhibitor can inhibit the enzymatic hydrolysis of urea, reduce the damage to seedlings, and reduce the loss of ammonia volatilization. Urea combined with nitrification inhibitors can inhibit the conversion process of NH ₄ ⁺ -N from urea hydrolysis to NO ₃ ^- -N and NO ₂ ^- -N, so that more nitrogen in the soil can be converted into NH ₄ ⁺ - The existence of N forms can reduce the release of N ₂ O and NO _x gases, reduce the accumulation of NO ₃ ^- -N and NO ₂ ^- -N in the soil and the possibility of leaching, thereby improving the utilization rate of nitrogen fertilizer. However, urease inhibitors and nitrification inhibitors are easy to degrade or fix in the soil, reducing or losing the inhibitory effects of urea hydrolysis and nitrification, and the application effects of urease inhibitors and nitrification inhibitors often change with the variation of soil environmental conditions.

Contents of the invention

The purpose of the present invention is to provide a novel controlled-efficiency urea capable of controlling the dissolution of urea and the transformation of the dissolved urea in soil and a preparation method thereof.

In order to achieve the above object, the technical solution of the present invention is: the control effect urea is to add urease inhibitor and/or nitrification inhibitor in the coating layer of coated urea, and the coating layer is a cheap high-molecular polymer material; The dosage of the polymeric material is 8-15% of the weight of the urea fertilizer core, the urease inhibitor contained therein is 1-5% of the weight of the high-molecular polymeric material, and the contained nitrification inhibitor is 2-5% of the weight of the high-molecular polymeric material ; The fat core urea is a large granular urea with a particle size of 2.5 to 4.0 mm; the urease inhibitor is hydroquinone (HQ) or N-butylthiophosphoric triamide (NBPT); the nitrification inhibitor It is dicyandiamide (DCD) or 3,4-dimethylpyrazole phosphate (DMPP); the polymeric material used for coating is: acrylic resin RS100 or acrylic resin RS100-ethyl cellulose blend .

The preparation method of controlled-efficiency urea is as follows: adopt fluidized bed spraying and coating technology, add 100 parts of high molecular polymer material whose dosage is 8% to 15% of the weight of the fertilizer core, 1 to 5 parts of urease inhibitor and/or 2 to 5 parts Nitrification inhibitor, dissolved in 1000-1500 parts of ethanol solvent, adding 5-10 parts of inorganic membrane conditioner to the solvent, and then adding 3-5 parts of plasticizer, after miscible, it will be mixed with large-grained urea in fluidized state The surface is sprayed and coated to form a smooth, continuous and uniform coating.

The operating parameters of the fluidized bed coating machine are: air inlet temperature: 50-75°C; compressed air pressure: 0.3-0.6Pa; nozzle atomization pressure: 0.05-0.2Pa;

The organic solvent is ethanol; the inorganic membrane conditioner is talcum powder, zeolite powder or diatomaceous earth; the plasticizer is polyethylene glycol or dimethyl phthalate.

Principle of the present invention is:

The physical coating of urea can effectively prevent the rapid increase of NH ₄ ⁺ -N in the soil near the fertilization point caused by the rapid hydrolysis of urea in the soil, as well as the resulting sharp increase of local soil pH, ammonia volatilization loss and Ammonia poisoning of crops, so that it can be applied at the same time as the seeds, without burning seedlings. The slow dissolution of the urease inhibitor in the coating layer can further control the hydrolysis of urea and reduce the possibility of ammonia volatilization loss. The slow dissolution of nitrification inhibitors in the coating layer can make more nitrogen fertilizers remain in the soil in the form of NH ₄ ⁺ -N, reduce the release of N ₂ O and NO _x gases, and reduce NO ₃ ^- -N and NO ₂ ^- - The leaching of N improves the utilization efficiency of nitrogen fertilizer. Comprehensive utilization of the above two control methods, the present invention can not only control the dissolution process of urea, but also control the transformation process of dissolved urea in the soil, control the supply ratio of NH ₄ ⁺ -N and NO ₃ ^- -N in the soil, and make it It is basically consistent with the fertilizer demand characteristics of most crops in one season, and realizes effective control of nitrogen fertilizer supply.

Adding inorganic membrane conditioner to the polymer coating wall material can effectively overcome the adhesion phenomenon in the coating process; adding plasticizer can increase the plasticity and toughness of the membrane, making the coating more uniform and complete.

Compared with prior art, advantage and positive effect of the present invention are as follows:

The comprehensive control of urea soil release and conversion process is realized, and the utilization rate of urea nitrogen is greatly improved, and the utilization rate can be as high as 50% to 70%.

In addition, the process of the present invention is easy to realize, without any modification to the existing high molecular polymer coated urea production equipment, only need to add urease inhibitor and nitrification inhibitor to the organic solution of the coating material.

Description of drawings

Fig. 1 is a schematic diagram of the fluidized bed coating process of the present invention.

Detailed ways

The present invention is described in detail below by way of examples and accompanying drawings.

Example 1 Coating and urease inhibitor combined type control effect urea (the fat core urea is the large granular urea with a particle size of 2.5 to 4.0 mm)

Adopt fluidized bed spray coating method, dissolve 100 parts of acrylic resin RS100 used for coating in 1500 parts of ethanol solvent, wherein the amount of acrylic resin RS100 is 8% of the weight of the fertilizer core; then add 5 parts of urease to this solution to inhibit Agent hydroquinone, 10 parts of inorganic membrane conditioning agent talcum powder, then add 5 parts of plasticizer dimethyl phthalate of total weight of the solution, pour into fluidized bed liquid tank after miscibility, spray on fluidized large On the surface of granular urea, the operating parameters of the fluidized bed coating machine are: air inlet temperature 65°C, compressed air pressure 0.4Pa, nozzle atomization pressure 0.1Pa, after about 1 hour, milky white, smooth , Continuous and uniform coating.

Its result is: coating wall material is 7.1% of fertilizer weight, and fertilizer N content is 42.9%, and after spring basal fertilization, the time that fertilizer core urea dissolves 80% from coating shell is 15～20 days completely, can be mixed with seed Simultaneously applied at the same position, the effective period of the fertilizer is 90-120 days, and the utilization rate of urea nitrogen is increased by 5-12% compared with ordinary urea with the same amount of nitrogen.

As shown in Figure 1, the fluidized bed coating process of this embodiment is as follows: 1 represents a spray tower, and the tower body is equipped with a fertilizer feed port 2 and a waste gas discharge port 3. The air is sent from the blower 9 to the spray tower 1 through the orifice flowmeter 8 and the heat exchanger 7, and then through the air inlet channel 6; the flow rate is controlled by the orifice flowmeter 8, the temperature is controlled by the heat exchanger 7, and the exhaust gas passes through the exhaust port 3 put it outside the spray tower 1. The fertilizer particles undergoing encapsulation treatment are sent in through the fertilizer inlet 2, and a certain amount of hot air is sent in at the same time to form a jet; the temperature of the hot air is detected by the air inlet thermometer _T1 , and the particle temperature is determined by the fluidized material during encapsulation. The temperature of the exhaust gas is detected by the thermometer _T2 , and the exhaust gas temperature is detected by the exhaust air thermometer _T3 ; when the temperature of the fluidized material thermometer _T2 reaches a certain value, the encapsulating liquid is sprayed out through the atomizing nozzle 4, and the encapsulating liquid is sprayed in the liquid tank 10 When using powder, the powder is evenly dispersed here. Such liquid or liquid and powder are sent out from the liquid tank by the metering pump 5 and lead to the atomizing nozzle 4 to spray on the fluidized material.

SL in the figure indicates the direction of heat exchange.

Example 2 Coating and Nitrification Inhibitor Combination Type Controlled Effect Urea (Fat core urea is large granular urea with a particle size of 2.5-4.0mm)

Adopt fluidized bed spray coating method, 50 parts of acrylic resin RS100 and 50 parts of ethyl cellulose for coating are miscible in 1000 parts of ethanol solvent, wherein the sum of the miscible amount of acrylic resin RS100 and ethyl cellulose is fertilizer 10% of the core weight; then add 4 parts of nitrification inhibitor dicyandiamide to this solution, 5 parts of inorganic membrane conditioner zeolite powder, and then add 4 parts of plasticizer polyethylene glycol of the total weight of the solution, after miscible Pour it into a fluidized bed liquid tank and spray it on the surface of fluidized large particle urea. The operating parameters of the fluidized bed coating machine are: inlet air temperature 75°C, compressed air pressure 0.3Pa, nozzle atomization pressure 0.15Pa, approximately After 1 hour, a milky white, smooth, continuous and uniform coating is formed on the outer surface of the fertilizer core.

Its result is: coating wall material is 8.5% of fertilizer weight, and fertilizer N content is 42.2%, and after spring basal fertilization, the time that fertilizer core urea dissolves 80% from coating shell completely is 15～25 days, can be mixed with seed Simultaneous application at the same position, the effective period of the fertilizer is 120-140 days, and the nitrogen utilization rate of the urea is increased by 8-20% compared with ordinary urea with the same amount of nitrogen.

Example 3 Coating, urease inhibitor, and nitrification inhibitor combined effect-controlling urea (the fat core urea is large granular urea with a particle size of 2.5 to 4.0 mm)

Adopt fluidized bed spray coating method, 65 parts of acrylic resin RS100 and 35 parts of ethyl cellulose for coating are miscible in 1300 parts of ethanol solvent, wherein the total miscible amount of acrylic resin RS100 and ethyl cellulose is fertilizer 12% of core weight; add 1 part urease inhibitor N-butylthiophosphoric triamide, 3 parts nitrification inhibitor 3,4-dimethylpyrazole phosphate, 8 parts inorganic membrane conditioner to this solution Diatomaceous earth, then add plasticizer polyethylene glycol of 3 parts of total solution weights, pour into the fluidized bed liquid tank after miscible, spray on the surface of fluidized large particle urea, wherein the fluidized bed coating machine The operating parameters are: air inlet temperature 55°C, compressed air pressure 0.5Pa, nozzle atomization pressure 0.05Pa, after about 1 hour, a milky white, smooth, continuous and uniform coating will be formed on the outer surface of the fertilizer core.

Its result is: coating wall material is 10.1% of fertilizer weight, and fertilizer N content is 41.5%, and after spring basal fertilization, the time that fertilizer core urea dissolves 80% from coating shell is 18～30 days completely, can be mixed with seed Simultaneous application at the same position, the effective period of the fertilizer is 120-140 days, and the nitrogen utilization rate of the urea is increased by 12-25% compared with ordinary urea with the same amount of nitrogen.

Example 4 Coating, urease inhibitor, and nitrification inhibitor combined type control effect urea (the fat core urea is large granular urea with a particle size of 2.5 to 4.0 mm)

Adopt fluidized bed spray coating method, 75 parts of acrylic resin RS100 and 25 parts of ethyl cellulose for coating are miscible in 1400 parts of ethanol solvent, wherein the total miscible amount of acrylic resin RS100 and ethyl cellulose is fertilizer 15% of the weight of the core; add 3 parts of urease inhibitor hydroquinone, 3 parts of nitrification inhibitor dicyandiamide, 7 parts of inorganic membrane conditioner talcum powder to this solution, and then add 4 parts of plasticizer by total weight of the solution Dimethyl phthalate, after being miscible, pour it into a fluidized bed liquid tank, and spray it on the surface of fluidized large particle urea. The operating parameters of the fluidized bed coating machine are: inlet air temperature 60°C, compressed air pressure 0.6Pa, nozzle atomization pressure 0.2Pa, after about 1 hour, a milky white, smooth, continuous and uniform coating will be formed on the outer surface of the fertilizer core.

Its result is: coating wall material is 12.6% of fertilizer weight, and fertilizer N content is 40.3%, and after spring basal fertilization, the time that fertilizer core urea dissolves 80% from coating shell is 25～40 days completely, can be mixed with seed Simultaneous application at the same position, the effective period of the fertilizer is 130-160 days, and compared with ordinary urea with the same amount of nitrogen, the utilization rate of urea nitrogen is increased by 15-30%.

Claims (9)

1. urea is imitated in a control, it is characterized in that: be made up of coating layer and urea fertilizer core, coating layer is for adding the macromolecule polymeric material of urease inhibitor and/or nitrification inhibitor.

2. imitate urea by the described control of claim 1, it is characterized in that: described macromolecule polymeric material consumption is 8～15% of a urea fertilizer core weight, wherein contained urease inhibitor is 1～5% of a macromolecule polymeric material weight, and contained nitrification inhibitor is 2～5% of a macromolecule polymeric material weight.

3. imitate urea by claim 1 or 2 described controls, it is characterized in that: described urea is granular urea, and particle diameter is 2.5～4.0mm.

4. imitate urea by claim 1 or 2 described controls, it is characterized in that: described urease inhibitor is quinhydrones or N-NBPT, and nitrification inhibitor is Dyhard RU 100 or 3,4-dimethyl phosphoric acid pyrazoles.

5. imitate urea by claim 1 or 2 described controls, it is characterized in that: the described macromolecule polymeric material that is used for coating is: acrylic resin or acrylic resin-ethyl cellulose blend.

6. preparation method of urea is imitated in a control, it is characterized in that: adopt the fluidized-bed spraying film-coating technique, with 100 parts of consumptions macromolecule polymeric material that is fertile core weight 8%～15%, 1～5 part of urease inhibitor and/or 2～5 portions of nitrification inhibitors, be dissolved in 1000～1500 parts of alcohol solvents, in described solution, add 5～10 portions of mineral membrane amendments, add 3～5 parts of softening agent again, miscible back sprays the bag quilt at fluidized granular urea outside surface, forms coating smooth, continuous, homogeneous.

7. imitate preparation method of urea by the described control of claim 6, it is characterized in that: described mineral membrane amendment is talcum powder, zeolite powder or diatomite.

8. imitate preparation method of urea by the described control of claim 6, it is characterized in that: described softening agent is polyoxyethylene glycol or dimethyl phthalate.

9. imitate preparation method of urea by the described control of claim 6, it is characterized in that: the operating parameter of described fluidized-bed coating machine is: inlet temperature: 50～75 ℃; Pressurized air pressure: 0.3～0.6Pa; The shower nozzle atomizing is pressed: 0.05～0.2Pa.

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