CN109988048B

CN109988048B - Special fertilizer for seawater rice and preparation method thereof

Info

Publication number: CN109988048B
Application number: CN201910357377.5A
Authority: CN
Inventors: 商照聪; 章明洪; 陈明良; 张小沁
Original assignee: Shanghai Chemical Industry Testing Co ltd; Shanghai Research Institute of Chemical Industry SRICI
Current assignee: Shanghai Chemical Industry Testing Co ltd; Shanghai Research Institute of Chemical Industry SRICI
Priority date: 2019-04-29
Filing date: 2019-04-29
Publication date: 2021-11-12
Anticipated expiration: 2039-04-29
Also published as: CN109988048A

Abstract

The invention relates to a special fertilizer for seawater rice and a manufacturing method thereof. Compared with the prior art, the invention has low manufacturing cost, is particularly suitable for saline-alkali soil due to the acidic characteristic, has slow release effect to greatly improve the fertilizer efficiency utilization rate, and has obvious yield increase effect on seawater rice after being applied.

Description

Special fertilizer for seawater rice and preparation method thereof

Technical Field

The invention relates to the technical field of fertilizer production, in particular to a special fertilizer for seawater rice and a preparation method thereof.

Background

The sea rice is the visualization name of the saline-alkali tolerant rice, and the sea rice is not grown in the sea, but is planted in coastal beach areas or inland saline-alkali areas. In recent years, through rice breeding research, the sea rice in the test area can grow normally and the average yield per mu can reach 200-300 kg/mu. It is reported that 9.5 hundred million hectares of saline-alkali soil are reported all over the world, wherein 1 hundred million hectares (15 hundred million acres) can be developed and utilized in China, 2.8 hundred million acres, and if the sea rice can be popularized and planted, the yield of the grain can be increased considerably.

As is known, the fertilizer cannot be separated in grain planting, but the special requirements on the applied fertilizer are met due to the particularity of saline-alkali soil, and the common fertilizer is not suitable for being applied to the sea rice. The patent (application number: 201510534303.6) applied by Nanjing soil institute of Chinese academy of sciences combines soil improvement and fertilizer efficiency functions, a preparation method and application thereof, combines soil cultivation, root system activation, nutrient crop cultivation and fertilizer efficiency improvement, is suitable for coastal beach areas, and has quite wide applicability in rice planting in North China and inland northwest saline-alkali soil, and the patent comprises the following raw materials in parts by mass: 35-40 parts of humic acid, 15-20 parts of fulvic acid, 20-25 parts of compound fertilizer, 15-20 parts of calcium silicon fertilizer, 1-1.5 parts of urease inhibitor and 1-1.5 parts of nitrification inhibitor. Aiming at the particularity of saline-alkali soil, the special fertilizer specially adds a urease inhibitor and a nitrification inhibitor for improving the utilization rate and the fertilizer efficiency of the fertilizer, but also greatly improves the production cost of the fertilizer. Therefore, the research and development of the special fertilizer for the seawater rice, which has high fertilizer efficiency utilization rate and low production cost, has practical significance.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide the special fertilizer for the seawater rice, which has high fertilizer efficiency utilization rate and low production cost, and the preparation method thereof.

The purpose of the invention can be realized by the following technical scheme: the fertilizer special for the seawater rice comprises urea particles in the center, and an ardealite powder layer and a sylvite powder layer which are sequentially wrapped outside the urea particles, wherein the mass ratio of the urea particles to the ardealite powder layer to the sylvite powder layer is (4-6): (1-1.5): (3-6).

According to the special fertilizer for seawater rice, the phosphogypsum powder layer is coated on the outer layer of the urea particles, so that the contact time of ammonium nitrogen generated by decomposing urea by urease and alkaline soil is prolonged, the ammonia volatilization loss caused by the process is reduced, and the probability of converting the ammonium nitrogen into nitrate nitrogen by nitrobacteria is increased, so that the utilization rate of the fertilizer is improved; in addition, the phosphogypsum contains certain phosphorus and sulfur, and provides comprehensive nutrient elements for crops. Secondly, the potassium salt is coated outside the urea particles, so that on one hand, potassium nutrient can be provided for crops, and on the other hand, the water permeability of a coating layer can be increased due to the dissolution of the potassium salt, so that the urea in the particle cores has a certain release speed.

Preferably, the particle size of the urea particles is 0.85-3.35 mm.

Preferably, the raw material of the sylvite powder layer is one of potassium sulfate and potassium chloride.

The manufacturing method of the fertilizer special for the seawater rice comprises the following steps:

(1) water is sprayed on urea particles in an ultrafine mode under the action of compressed air flow, and the surfaces of the urea particles are wetted;

(2) calcining and grinding phosphogypsum into phosphogypsum powder, coating and wrapping the urea particles with wet surfaces obtained in the step (1), and screening to remove redundant powder on the outer surfaces to obtain urea particles wrapped by a phosphogypsum powder layer;

(3) dissolving fertilizer-grade phosphoric acid in water, and performing superfine spraying on the surfaces of the urea particles coated by the phosphogypsum powder layer obtained in the step (2) under the action of compressed air flow to wet the surfaces of the urea particles coated by the phosphogypsum powder layer;

(4) coating the urea particles coated with the wet-surface phosphogypsum powder layer obtained in the step (3) with potassium salt powder, and screening to remove redundant powder on the outer surface to obtain a fertilizer crude product;

(5) and drying the fertilizer crude product, and then screening to remove redundant powder to obtain the special fertilizer for the seawater rice.

Preferably, the air pressure of the compressed air is 0.1-0.3 MPa, and the airflow velocity is 0.5-2 m/s. The wetting is performed with an ultra-fine spray so that the water or fertilizer grade phosphoric acid can uniformly wet the urea particle surface for better adhesion to the subsequent powder.

Preferably, the calcination temperature of the phosphogypsum is 800-1000 ℃, the calcination time is 15-30 min, and the particle size of the phosphogypsum powder is less than or equal to 0.074 mm.

Preferably, the mass concentration of the fertilizer grade phosphoric acid after being dissolved in water is 25-40%. The used phosphoric acid not only makes the special fertilizer for the seawater rice have acidity, partially neutralizes the pH value of the alkaline soil of the seawater field, but also provides a high-quality phosphate fertilizer for crops.

Preferably, the drying temperature is 70-100 ℃, and the drying time is 10-20 min.

Preferably, the mesh number of the screen used for screening in the step (2) is 1.00 mm;

the mesh number of the screen mesh adopted in the screening in the steps (4) and (5) is 4.75 mm.

Compared with the prior art, the beneficial effects of the invention are embodied in the following aspects:

1. the fertilizer with the acidic coating layer is applied to alkaline soil such as saline-alkali soil, the pH value of the soil is partially neutralized, the contact time of ammonium nitrogen generated by urea decomposition by urease and the alkaline soil is delayed, ammonia volatilization loss caused by the process is reduced, and the probability of converting the ammonium nitrogen into nitrate nitrogen by nitrifying bacteria is increased, so that the utilization rate of the fertilizer is improved.

2. The used phosphoric acid not only enables the special fertilizer for the seawater rice to have acidity, but also provides a high-quality phosphate fertilizer for crops.

3. The potassium salt is contained in the coating layer, on one hand, potassium nutrient can be provided for crops, and on the other hand, the water permeability of the coating layer can be increased due to the dissolution of the potassium salt, so that urea in the particle core has a certain release speed.

4. The phosphogypsum contains certain phosphorus and sulfur, and provides comprehensive nutrient elements for crops.

5. The raw materials are easy to obtain, the manufacturing cost is low, and the popularization and application values are obvious.

Drawings

FIG. 1 is a process flow diagram of a method of manufacturing the present invention.

Detailed Description

The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.

Example 1

A manufacturing method of a special fertilizer for seawater rice comprises the following steps of manufacturing, as shown in figure 1, metering granular urea with the grain diameter of phi 0.85-2.8 mm, and spraying water onto the granular urea in an ultrafine mode under the action of compressed air flow to moisten the surface of the granular urea. Grinding calcined phosphogypsum to powder passing through a 0.074mm sieve by using an ultrafine grinding technology to form ultrafine phosphogypsum powder, coating granular urea wetted by water surface, and sieving and dedusting. Mixing a certain amount of fertilizer-grade phosphoric acid with water, carrying out superfine spraying under the action of compressed air flow to wet the surface of the granular urea coated with the phosphogypsum, then coating the wet coated granular urea with powdery potassium chloride for the second time, and drying. And (4) after sieving and dedusting again, metering and packaging the granulated fertilizer, thus completing the manufacture of the special fertilizer for the seawater rice.

Example 2

A manufacturing method of a special fertilizer for seawater rice comprises the following steps of manufacturing, as shown in figure 1, metering granular urea with the grain diameter of phi 1.18-3.35 mm, and spraying water onto the granular urea in an ultrafine mode under the action of compressed air flow to moisten the surface of the granular urea. Grinding calcined phosphogypsum to powder passing through a 0.074mm sieve by using an ultrafine grinding technology to form ultrafine phosphogypsum powder, coating granular urea wetted by water surface, and sieving and dedusting. Mixing a certain amount of fertilizer-grade phosphoric acid with water, and carrying out superfine spraying again under the action of compressed air flow to wet the surface of the granular urea coated with the phosphogypsum coating. Coating the wet coated granular urea with powdered potassium sulfate, and drying. And (4) after sieving and dedusting again, metering and packaging the granulated fertilizer, thus completing the manufacture of the special fertilizer for the seawater rice.

Example 3

The same starting materials and preparation steps as in example 1 were used, except that:

(1) the air pressure of compressed air used for wetting is 0.1Mpa, and the flow velocity of air flow is 0.5 m/s;

(2) the calcination temperature of the phosphogypsum is 800 ℃, and the calcination time is 30 min;

(3) the percentage concentration of the fertilizer grade phosphoric acid mixed and dissolved with water is 25 percent;

(4) the temperature for drying is 70 ℃, and the time for drying is 20 min.

Example 4

The same starting materials and preparation steps as in example 2 were used, except that:

(1) the air pressure of compressed air used for wetting is 0.3Mpa, and the flow velocity of air flow is 2 m/s;

(2) the calcination temperature of the phosphogypsum is 1000 ℃, and the calcination time is 15 min;

(3) the percentage concentration of the fertilizer grade phosphoric acid mixed and dissolved with water is 40 percent;

(4) the temperature for drying is 100 ℃, and the time for drying is 10 min.

Claims

1. The fertilizer special for seawater rice is characterized by comprising core urea particles, and an ardealite powder layer and a sylvite powder layer which are sequentially wrapped outside the urea particles, wherein the mass ratio of the urea particles to the ardealite powder layer to the sylvite powder layer is (4-6): (1-1.5): (3-6).

2. The fertilizer special for seawater rice as claimed in claim 1, wherein the particle size of the urea particles is 0.85-3.35 mm.

3. The fertilizer special for seawater rice as claimed in claim 1, wherein the raw material of the potassium salt powder layer is one of potassium sulfate and potassium chloride.

4. A method for preparing a fertilizer special for sea rice as claimed in any one of claims 1 to 3, comprising the following steps:

5. The method for preparing fertilizer special for seawater rice as claimed in claim 4, wherein the air pressure of the compressed air is 0.1-0.3 MPa, and the air flow velocity is 0.5-2 m/s.

6. The method for manufacturing the fertilizer special for seawater rice as claimed in claim 4, wherein the calcination temperature of the phosphogypsum is 800-1000 ℃, the calcination time is 15-30 min, and the particle size of the phosphogypsum powder is less than or equal to 0.074 mm.

7. The method for manufacturing the fertilizer special for seawater rice as claimed in claim 4, wherein the mass concentration of the fertilizer-grade phosphoric acid after being dissolved in water is 25% to 40%.

8. The method for preparing fertilizer special for seawater rice as claimed in claim 4, wherein the temperature for drying is 70-100 ℃ and the time for drying is 10-20 min.

9. The method for preparing fertilizer special for seawater rice as claimed in claim 4, wherein the mesh number of the screen mesh adopted in the screening in the step (2) is 1.00 mm;